Dr. David Park, MD, PhD, is a neurosurgeon who graduated from medical school at the Catholic University of Korea in Seoul, South Korea. He completed his internship and residency training in the Department of Neurosurgery at Seoul St. Mary’s Hospital. He became a board-certified neurosurgeon in South Korea in 2014 and subsequently completed a 2-year fellowship at the same hospital, specializing in brain tumor surgery and skull base surgery. During his residency, he also attended graduate school while practicing neurosurgery as a trainee and successfully defended his Ph.D. thesis, titled “Combination therapy for gliomas using temozolomide and interferon-beta secreting human bone marrow-derived mesenchymal stem cells,” in 2015.

After completing his fellowship in South Korea, Dr. Park moved to Singapore in 2016 and worked as a Clinical Fellow (Clinical Associate) at the National Neuroscience Institute for one year, focusing on Neurosurgical Oncology and Skull Base Surgery.

In 2017, Dr. Park joined Dr. Christian Badr’s lab at Massachusetts General Hospital, Harvard Medical School, as a Postdoctoral Research Fellow, conducting translational research on glioblastoma and studying the role of fatty acids and lipid metabolism in glioblastoma to complement his clinical expertise.

During this time, Dr. Park also launched a startup based on his invention of an intraoperative diagnostic tool for tumor detection during glioma surgery. He collaborated with bioengineers at M.I.T. to develop a prototype and secured seed funding from the MIT Sandbox Innovation Fund Program. As an alumnus of the MIT Sandbox program, he continues to develop this project.

In 2020, Dr. Park served as a Neurosurgical Oncology and Radiosurgery Fellow (Teaching Associate) for a year at North Shore University Hospital, Zucker School of Medicine at Hofstra/Northwell, in Long Island, New York, where he worked with Dr. Michael Schulder on brain tumor surgery including advanced techniques, such as Laser Interstitial Thermal Therapy (LITT) and Stereotactic Radiosurgery (SRS).

From July 2021 to June 2022, he completed another fellowship in Neurosurgical Oncology and Radiosurgery at the Cleveland Clinic in Cleveland. He devoted his efforts to minimally invasive neurosurgical techniques such as LITT and Gamma Knife SRS, as well as awake brain tumor surgery under the guidance of Drs. Gene Barnett, Lilyana Angelov, and Ali Mohammadi.

As of July 2022, Dr. Park joined the Department of Neurosurgery at Stanford University as a Clinical Instructor, working with Dr. Steven D. Chang in the fields of Neurosurgical Oncology and CyberKnife SRS. As of July 2024, he has been promoted to Clinical Assistant Professor in the same field.

Clinical Focus

  • Neurosurgery
  • Brain tumor
  • Neurosurgical-oncology
  • Radiosurgery
  • Laser induced thermal therapy (LITT)
  • Skull base surgery
  • Fluorescence-guided surgery
  • Minimally invasive brain surgery
  • Glioblastoma
  • Glioma
  • Meningioma
  • Vestibular schwannoma
  • Pituitary adenoma
  • Brain metastasis
  • Spine metastasis
  • Arteriovenous Malformations

Academic Appointments

Honors & Awards

  • Semi-Finalist, 2018 MIT Sloan Healthcare Innovation Prize (2018)
  • Semi-Finalist, 2018 MIT $100K Entrepreneurship Competition (2018)
  • Academic Award in Brain Tumor Research & Treatment, Korean Brain Tumor Society (2016)
  • Excellence in Basic Sciences Award, Korean Brain Tumor Society (2015)
  • Namchun Academic Award, The Catholic University of Korea (2015)
  • Namchun Academic Award, The Catholic University of Korea (2014)

Boards, Advisory Committees, Professional Organizations

  • Special Faculty Permit, Medical Board of California (2022 - Present)
  • Ohio State Medical License, State Medical Board of Ohio (2021 - Present)
  • New York State Medical License, NYS Office of the Professions (Medicine) (2020 - Present)
  • U.S. Medical License, ECFMG (2019 - Present)
  • Singapore Medical License, Singapore Medical Council (2016 - Present)
  • Neurosurgery Board-certified (Korea), Korean Board of Neurological Surgery (2014 - Present)
  • Medical License (Korea), Korean Board of Medical Examiners (2009 - Present)

Professional Education

  • FCNS, Congress of Neurological Surgeons (CNS), Neurosurgery (2024)
  • Board Certification: Ministry of Health and Welfare of Korea, Neurosurgery (2014)
  • Clinical Fellowship, Cleveland Clinic Foundation, Cleveland, OH, Neurosurgical Oncology and Radiosurgery (Gamma Knife) (2022)
  • Clinical Fellowship, North Shore University Hospital, Zucker School of Medicine at Hofstra/Northwell, Manhasset, NY, Neurosurgical Oncology and Radiosurgery (2021)
  • Postdoc Research Fellowship, Massachusetts General Hospital, Harvard Medical School, Boston, MA, Neurology (Lipid metabolism and tumor microenvironment in glioma) (2018)
  • Clinical Fellowship, Department of Neurosurgery, National Neuroscience Institute, Singapore, Neurosurgical Oncology and Functional Neurosurgery (2017)
  • Clinical Fellowship, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea, Skull Base Surgery, Neurosurgical Oncology, and Radiosurgery (CyberKnife) (2016)
  • Ph.D., Graduate School of Catholic University of Korea, Seoul, Korea, Neuroscience (Neuro-oncology) (2015)
  • Visiting Scholarship, Brigham and Women's Hospital, Harvard Medical School, MA, Focused Ultrasound & Tissue Bioprinting Lab (2013)
  • Residency, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea, Neurosurgery (2014)
  • Internship, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea, Medicine / Surgery (2010)
  • M.D., Catholic University of Korea, Seoul, Korea, Medicine (2009)


  • David Park. "United States Patent 17/343,896 DEVICE AND METHOD FOR AN INTRAOPERATIVE CANCER DETECTOR", ORFACRORY, Inc., Feb 3, 2022
  • David Park. "United States Patent 63/058,637 A METHOD OF AND DEVICE FOR AN INTRAOPERATIVE CANCER DETECTOR", ORFACTORY, Inc., Jul 30, 2020

Current Research and Scholarly Interests

The goal of our Laboratory is to improve patients’ care and outcomes by analyzing clinical data from thousands of patients treated at our institution. Our current primary areas of interest are benign tumors, brain and spine metastases, and neurogenetic disorders.
Our lab is led by Dr. Steven D. Chang and Dr. David J. Park and proudly hosts talented young clinical scientists from around the world.

All Publications

  • Recurrent choroid plexus carcinoma treated with CyberKnife radiosurgery: illustrative case. Journal of neurosurgery. Case lessons Yuan, L., Park, D. J., Persad, A. R., Hori, Y. S., Tayag, A., Ustrzynski, L., Emrich, S. C., Chang, S. D. 2024; 8 (2)


    Choroid plexus carcinomas (CPCs) are rare malignant brain tumors primarily affecting children younger than 2 years old. These tumors originate from the choroid plexus epithelium and are a subtype of choroid plexus tumors, which account for 1%-4% of pediatric brain tumors. Although CPCs often show a notably high recurrence rate after surgery, the standard treatment approach remains gross-total resection (GTR) of the tumor, given the lack of clinical data supporting the effectiveness of adjunct treatment options such as radiotherapy or chemotherapy.A 16-year-old female with a history of a recurrent cranial CPC resistant to surgery and radiotherapy was treated with CyberKnife stereotactic radiosurgery (SRS), following resection. The procedures successfully maintained local disease control for 41 months; however, there was a subsequent recurrence, ultimately leading to the death of the patient.CPC treatment remains challenging. SRS can be used as a viable adjunct to surgery, which remains the gold standard, although it can also be considered for nonsurgical candidates or when GTR cannot be achieved. Nevertheless, it is crucial to conduct additional research to explore diverse approaches for radiosurgery, including its role as the primary treatment modality versus its combination with surgery, radiotherapy, or chemotherapy.

    View details for DOI 10.3171/CASE23748

    View details for PubMedID 38976919

  • The Role of CyberKnife Stereotactic Radiosurgery in Recurrent Cranial Medulloblastomas across Pediatric and Adult Populations. Journal of clinical medicine Yoo, K. H., Marianayagam, N. J., Park, D. J., Zamarud, A., Gu, X., Pollom, E., Soltys, S. G., Meola, A., Chang, S. D. 2024; 13 (12)


    Background/Objectives: Medulloblastoma is the most common malignant brain tumor in children. In recent decades, the therapeutic landscape has undergone significant changes, with stereotactic radiosurgery (SRS) emerging as a promising treatment for recurrent cases. Our study provides a comprehensive analysis of the long-term efficacy and safety of SRS in recurrent medulloblastomas across both pediatric and adult patients at a single institution. Methods: We retrospectively reviewed the clinical and radiological records of patients who underwent CyberKnife SRS for recurrent cranial medulloblastomas at our institution between 1998 and 2023. Follow-up data were available for 15 medulloblastomas in 10 patients. The cohort comprised eight pediatric patients (ages 3-18) and two adult patients (ages 19-75). The median age at the time of SRS was 13 years, the median tumor volume accounted for 1.9 cc, the median biologically equivalent dose (BED) was 126 Gy, and the single-fraction equivalent dose (SFED) was 18 Gy. The SRS was administered at 75% of the median isodose line. Results: Following a median follow-up of 39 months (range: 6-78), 53.3% of the medulloblastomas progressed, 13.3% regressed, and 33.3% remained stable. The 3-year local tumor control (LTC) rate for all medulloblastomas was 65%, with lower rates observed in the adult cohort (50%) and higher rates in pediatric patients (67%). The 3-year overall survival (OS) rate was 70%, with significantly higher rates in pediatric patients (75%) compared to adult patients (50%). The 3-year progression-free survival (PFS) rate was 58.3%, with higher rates in pediatric patients (60%) compared to adult patients (50%). Two pediatric patients developed radiation-induced edema, while two adult patients experienced radiation necrosis at the latest follow-up, with both adult patients passing away. Conclusions: Our study provides a complex perspective on the efficacy and safety of CyberKnife SRS in treating recurrent cranial medulloblastomas across pediatric and adult populations. The rarity of adverse radiation events (AREs) underscores the safety profile of SRS, reinforcing its role in enhancing treatment outcomes. The intricacies of symptomatic outcomes, intertwined with factors such as age, tumor location, and prior surgeries, emphasize the need for personalized treatment approaches. Our findings underscore the imperative for ongoing research and the development of more refined treatment strategies for recurrent medulloblastomas. Given the observed disparities in treatment outcomes, a more meticulous tailoring of treatment approaches becomes crucial.

    View details for DOI 10.3390/jcm13123592

    View details for PubMedID 38930121

  • Stereotactic radiosurgery for facial nerve hemangioma: Case report and systematic review. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Park, D. J., Hori, Y. S., Nernekli, K., Persad, A. R., Tayag, A., Ustrzynski, L., Emrich, S. C., Hancock, S. L., Chang, S. D. 2024; 126: 21-25


    Facial nerve hemangiomas (FNHs) are rare tumors that primarily occur near the geniculate ganglion in the temporal bone. Despite their rarity, they can cause significant facial nerve dysfunction. The optimal management approach for FNHs remains uncertain, with surgery being the mainstay but subject to debate regarding the extent of resection and preservation of the facial nerve.Systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We queried the PubMed/Medline (accessed on 5 March 2024) electronic database using combinations of the following search terms and words text: "geniculate ganglion hemangioma", "ganglional hemangioma", "hemangioma of the facial nerve", "facial hemangioma", and "intratemporal hemangioma".We identified a total of 30 literatures (321 patients). The most common site involved for the facial nerve hemangioma was the geniculate ganglion area followed by internal auditory canal, tympanic segment, labyrinthine segment and mastoid involvement. All patients were treated with conservative management or surgery. We report a 48-year-old female patient with HB grade 2 facial palsy and hemifacial spasm underwent SRS using Cyberknife technology. The treatment targeted the FNH in the left internal acoustic canal near the geniculate ganglion. Six months post-treatment, clinical improvement was evident, and lesion control was confirmed in a follow-up brain MRI.The rarity of FNHs contributes to the lack of consensus on optimal management. This illustrative case demonstrates the feasibility of SRS as a standalone treatment for FNHs.

    View details for DOI 10.1016/j.jocn.2024.05.023

    View details for PubMedID 38823231

  • Primary Stereotactic Body Radiotherapy for Spinal Bone Metastases From Lung Adenocarcinoma. Clinical lung cancer Chou, K. N., Park, D. J., Hori, Y. S., Persad, A. R., Chuang, C., Emrish, S. C., Ustrzynski, L., Tayag, A., Kumar, K., Usoz, M., Mendoza, M., Rahimy, E., Pollom, E., Soltys, S. G., Lai, S. W., Chang, S. D. 2024


    This study aimed to assess the results of primary stereotactic body radiotherapy (SBRT) for spinal bone metastases (SBM) originating from lung adenocarcinoma (ADC). We considered the revised Tokuhashi score (rTS), Spinal Instability Neoplastic Score (SINS), and genetic characteristics.We examined adult patients with lung ADC who underwent primary SBRT (using the CyberKnife System) for SBM between March 2012 and January 2023.We analyzed data from 99 patients, covering 152 SBM across 194 vertebrae. The overall local control (LC) rate was 77.6% for SBM from lung ADC, with a LC rate of 90.7% at 1 year. The median period for local progression (LP) occurrence was recorded at 10.0 (3-52) months. Additionally, Asian patients demonstrated higher LC rates than White patients. Utilizing the rTS and SINS as predictive tools, we revealed that a poor survival prognosis and an unstable spinal structure were associated with increased rates of LP. Furthermore, the presence of osteolytic bone destructions and pain complaints were significantly correlated with the occurrence of LP. In the cohort of this study, 108 SBM underwent analysis to determine the expression levels of programmed cell death ligand 1 (PD-L1). Additionally, within this group, 60 showed mutations in the epidermal growth factor receptor (EGFR) alongside PD-L1 expression. Nevertheless, these genetic differences did not result in statistically significant differences in the LC rate.The one-year LC rate for primary SBRT targeting SBM from lung ADC stood at 90.7%, particularly with the use of the CyberKnife System. Patients achieving LC exhibited significantly longer survival times compared to those with LP.

    View details for DOI 10.1016/j.cllc.2024.05.007

    View details for PubMedID 38897849

  • Stereotactic Radiosurgery for Ependymoma in Pediatric and Adult Patients: A Single-Institution Experience. Neurosurgery Yoo, K. H., Marianayagam, N. J., Park, D. J., Persad, A., Zamarud, A., Shaghaghian, E., Tayag, A., Ustrzynski, L., Emrich, S. C., Gu, X., Ho, Q. A., Soltys, S. G., Meola, A., Chang, S. D. 2024


    Ependymoma is commonly classified as World Health Organization grade 2 with the anaplastic variant categorized as grade 3. Incomplete resection or anaplastic features can result in unfavorable outcomes. Stereotactic radiosurgery (SRS) provides a minimally invasive approach for recurrent ependymomas. Our study investigates the efficacy and safety of SRS for grade 2 and 3 ependymomas in pediatric and adult populations.We conducted a retrospective analysis on 34 patients with 75 ependymomas after CyberKnife SRS between 1998 and 2023. Fourteen were pediatric (3-18 years), and 20 were adult (19-75 years) patients. The median age was 21 years, and the median tumor volume was 0.64 cc. The median single-fraction equivalent dose was 16.6 Gy, with SRS administered at 77% of the median isodose line.After a median follow-up of 42.7 months (range: 3.8-438.3), 22.7% of ependymomas progressed. The 5-year local tumor control rate was 78.1%, varying between 59.6% and 90.2% for children and adults, with grade 2 at 85.9% compared with 58.5% for grade 3 tumors. The 5-year overall survival rate was 73.6%, notably higher in adults (94.7%) than in children (41%), and 100% for grade 2 but decreased to 35.9% for grade 3 patients. The 5-year progression-free survival rate was 68.5%, with 78.3% and 49.2% for adults and children, respectively, and a favorable 88.8% for grade 2, contrasting with 32.6% for grade 3 patients. Symptom improvement was observed in 85.3% of patients. Adverse radiation effects occurred in 21.4% of pediatric patients.Our study supports SRS as a viable modality for pediatric and adult patients with grade 2 and 3 ependymomas. Despite lower local tumor control in pediatric and grade 3 cases, integrating SRS holds promise for improved outcomes. Emphasizing careful patient selection, personalized treatment planning, and long-term follow-up is crucial for optimal neurosurgical outcomes.

    View details for DOI 10.1227/neu.0000000000002979

    View details for PubMedID 38785440

  • CyberKnife stereotactic radiosurgery for extramedullary plasmacytoma in the external auditory canal: illustrative case. Journal of neurosurgery. Case lessons Patil, S., Shaghaghian, E., Yuan, L., Shah, A., Marianayagam, N. J., Park, D. J., Soltys, S. G., Veeravagu, A., Gibbs, I. C., Li, G., Chang, S. D. 2024; 7 (19)


    Plasmacytoma, a rare plasma cell disorder, often presents as a solitary or multiple tumors within the bone marrow or soft tissues, typically associated with multiple myeloma. Extramedullary plasmacytomas (EMPs), particularly those located in the external auditory canal (EAC), are exceedingly rare and pose significant treatment challenges given their location, anatomical complexity, and high risk of recurrence.The authors report the case of a 72-year-old male with a history of multiple myeloma, presenting with recurrent left EAC plasmacytoma. After initial conventional radiotherapy for the lesion, a recurrence was documented in 7 years. The patient subsequently underwent stereotactic radiosurgery, which proved successful, leading to complete resolution of the lesion without any long-term adverse effects or radiation-related complications over a 45-month period.This case is a unique instance of utilizing stereotactic radiosurgery for recurrent EMP in the EAC, highlighting its potential as an effective approach in managing complex plasmacytomas.

    View details for DOI 10.3171/CASE2479

    View details for PubMedID 38710109

    View details for PubMedCentralID PMC11076403

  • Automatic Segmentation of Vestibular Schwannomas: A Systematic Review. World neurosurgery Nernekli, K., Persad, A. R., Hori, Y. S., Yener, U., Celtikci, E., Sahin, M. C., Sozer, A., Sozer, B., Park, D. J., Chang, S. D. 2024


    Vestibular Schwannomas (VS) are benign tumors often monitored over time, with measurement techniques for assessing growth rates subject to significant interobserver variability. Automatic segmentation of these tumors could provide a more reliable and efficient for tracking their progression, especially given the irregular shape and growth patterns of VS.Various studies and segmentation techniques employing different Convolutional Neural Network architectures and models, such as U-Net and CATS, were analyzed. Models were evaluated based on their performance across diverse datasets, and challenges, including domain shift and data sharing, were scrutinized.Automatic segmentation methods offer a promising alternative to conventional measurement techniques, offering potential benefits in precision and efficiency. However, these methods are not without challenges, notably the "domain shift" that occurs when models trained on specific datasets underperform when applied to different datasets. Techniques such as domain adaptation, domain generalization, and data diversity were discussed as potential solutions.Accurate measurement of VS growth is a complex process, with volumetric analysis currently appearing more reliable than linear measurements. Automatic segmentation, despite its challenges, offers a promising avenue for future investigation. Robust, well-generalized models could potentially improve the efficiency of tracking tumor growth, thereby augmenting clinical decision-making. Further work needs to be done to develop more robust models, address the domain shift, and enable secure data sharing for wider applicability.

    View details for DOI 10.1016/j.wneu.2024.04.145

    View details for PubMedID 38685346

  • Percutaneous Disc Biopsy versus Bone Biopsy for the Identification of Infectious Agents in Osteomyelitis/Discitis. Journal of vascular and interventional radiology : JVIR Zamarud, A., Kesten, J., Park, D. J., Pulli, B., Telischak, N. A., Dodd, R. L., Do, H. M., Marks, M. P., Heit, J. J. 2024


    To determine whether sampling of the disc or bone is more likely to yield positive tissue culture results in patients with vertebral discitis and osteomyelitis (VDO).Retrospective review was performed of consecutive patients who underwent vertebral disc or vertebral body biopsy at a single institution between February 2019 and May 2023. Inclusion criteria were age ≥18 years, presumed VDO on spinal magnetic resonance (MR) imaging, absence of paraspinal abscess, and technically successful percutaneous biopsy with fluoroscopic guidance. The primary outcome was a positive biopsy culture result, and secondary outcomes included complications such as nerve injury and segmental artery injury.Sixty-six patients met the inclusion criteria; 36 patients (55%) underwent disc biopsy, and 30 patients (45%) underwent bone biopsy. Six patients required a repeat biopsy for an initially negative culture result. No significant demographic, laboratory, antibiotic administration, or pain medication use differences were observed between the 2 groups. Patients who underwent bone biopsy were more likely to have a history of intravenous drug use (26.7%) compared with patients who underwent disc biopsy (5.5%; P = .017). Positive tissue culture results were observed in 41% of patients who underwent disc biopsy and 15% of patients who underwent bone biopsy (P = .016). No vessel or nerve injuries were detected after procedure in either group.Percutaneous disc biopsy is more likely to yield a positive tissue culture result than vertebral body biopsy in patients with VDO.

    View details for DOI 10.1016/j.jvir.2024.02.016

    View details for PubMedID 38613536

  • Dosimetric Comparison of Dedicated Radiosurgery Platforms for the Treatment of Essential Tremor: Technical Report. Cureus Marianayagam, N. J., Paddick, I., Persad, A. R., Hori, Y. S., Maslowski, A., Thirunarayanan, I., Khanna, A. R., Park, D. J., Buch, V., Chang, S. D., Schneider, M. B., Yu, H., Weidlich, G. A., Adler, J. R. 2024; 16 (4): e57452


    Essential tremor (ET) is one of the most common adult movement disorders. As the worldwide population ages, the incidence and prevalence of ET is increasing. Although most cases can be managed conservatively, there is a subset of ET that is refractory to medical management. By virtue of being "reversible", deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) of the thalamus is one commonly accepted intervention. As an alternative to invasive and expensive DBS, there has been a renaissance in treating ET with lesion-based approaches, spearheaded most recently by high-intensity focused ultrasound (HIFU), the hallmark of which is that it is non-invasive. Meanwhile, stereotactic radiosurgical (SRS) lesioning of VIM represents another time-honored lesion-based non-invasive treatment of ET, which is especially well suited for those patients that cannot tolerate open neurosurgery and is now also getting a "second look". While multiple SRS platforms have been and continue to be used to treat ET, there is little in the way of dosimetric comparison between different technologies. In this brief technical report we compare the dosimetric profiles of three major radiosurgical platforms (Gamma Knife, CyberKnife Robotic Radiosurgery, and Zap-X Gyroscopic Radiosurgery (GRS)) for the treatment of ET. In general, the GRS and Gamma Knife were shown to have the best theoretical dosimetric profiles for VIM lesioning. Nevertheless the relevance of such superiority to clinical outcomes requires future patient studies.

    View details for DOI 10.7759/cureus.57452

    View details for PubMedID 38699125

    View details for PubMedCentralID PMC11064878

  • Therapeutic approaches for spinal synovial sarcoma: a comprehensive review of the literature. Journal of neurosurgery. Spine Zamarud, A., Shahnoor, S., Maryyum, A., Khan, A. M., Hassan, K. M., Ijaz, A., Sayed, R., Yoo, K., Park, D. J., Chang, S. D. 2024: 1-8


    Synovial sarcoma (SS) is a relatively rare type of soft-tissue sarcoma that is commonly treated with surgery, radiation, chemotherapy, and palliative care. Stereotactic radiosurgery (SRS) is an emerging approach that shows promise in treating CNS conditions, but it has not been studied for SS. The authors present a systematic review that explores the effectiveness of different treatments, with a focus on SRS, for managing spinal SS.A systematic PubMed search was conducted that covered studies from 1964 to 2022, yielding 70 relevant studies. Inclusion criteria encompassed primary and metastatic spinal SS, various treatment modalities, patient age 17 years or older, English-language studies, retrospective series, and case reports. Based on these criteria, 26 studies were included in this review and 44 were excluded.Of the included studies, 15 patients from 9 studies were treated with surgical intervention followed by both conventional radiotherapy (RT) and chemotherapy, 10 patients from 10 studies were treated with surgery followed by RT, 5 studies comprising 8 patients were exclusively treated with surgery, 5 cases in 3 studies were treated with surgery plus concomitant chemotherapy, 4 patients in 2 studies were treated with SRS, and only 1 study reported treatment without surgery and with chemotherapy and RT. The median progression-free survival and overall survival periods observed in the SRS-treated patients were 37 months and 60 months, respectively, which were higher than those of any other treatment method or combination used.The authors' study offers a thorough review of spinal SS treatments. They are hopeful that this will aid clinicians in informed decision-making for better patient outcomes.

    View details for DOI 10.3171/2024.1.SPINE231184

    View details for PubMedID 38489819

  • Treatment of Trigeminal Neuralgia Secondary to Petroclival Meningioma Using Microsurgical Resection, Microvascular Decompression, and Stereotactic Radiosurgery: 2-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Park, D. J., Kumar, K. K., Marianayagam, N. J., Yener, U., Rahimy, E., Hancock, S., Meola, A., Chang, S. D. 2024; 26 (1): 107-108

    View details for DOI 10.1227/ons.0000000000000927

    View details for PubMedID 38099694

  • Navigating alopecia: Practical guidelines for minimizing hair loss in CyberKnife stereotactic radiosurgery for calvarial or scalp tumors. Journal of Cancer Biology. Park, D. J., Chang, S. D. 2024; 5 (1): 21-22
  • The Promise of Tumor Mutation Burden and Microenvironment as Biomarkers in Glioma Treatment. Journal of Biomedical Research & Environmental Sciences. Park, D. J., Chang, S. D. 2024; 5 (6): 537-539

    View details for DOI 10.37871/jbres1923

  • Surgery and stereotactic radiosurgery for spinal leiomyosarcoma: a single-institution retrospective series and systematic review. Journal of neurosurgery. Spine Zamarud, A., Marianayagam, N. J., Sekar, V., Testa, S., Park, D. J., Yener, U., McCleary, T. L., Yoo, K. H., Emrich, S., Tayag, A., Ustrzynski, L., Pollom, E., Soltys, S., Wang, L., Charville, G., Ganjoo, K., Chang, S. D., Meola, A. 2023: 1-13


    Leiomyosarcoma (LMS) is a rare, aggressive soft-tissue sarcoma that seldom spreads to the bone. The spine can be either the site of LMS osseous metastases or the primary tumor site. The optimal treatment option for spinal LMS is still unclear. The authors present a cohort of patients with spinal LMS treated with either upfront surgery or upfront CyberKnife stereotactic radiosurgery (SRS).The authors retrospectively studied the clinical and radiological outcomes of 17 patients with spinal LMS treated at their institution between 2004 and 2020. Either surgery or SRS was used as the upfront treatment. The clinical and radiological outcomes were assessed. A systematic review of the literature was also conducted.Of the 17 patients (20 spinal lesions), 12 (70.6%) were female. The median patient age was 61 years (range 41-80 years). Ten patients had upfront surgery for their spinal lesions, and 7 had upfront CyberKnife radiosurgery. The median follow-up was 11 months (range 0.3-130 months). The median overall survival (OS) for the entire cohort was 13 months (range 0.3-97 months). In subgroup analysis, the median OS was lower for the surgical group (13 months, range 0.3-50 months), while the median OS for the SRS group was 15 months (range 5-97 months) (p = 0.5). Forty percent (n = 4) of those treated with surgery presented with local recurrence at a median of 6.7 months (range 0.3-36 months), while only 14% (n = 1) of those treated with CyberKnife radiosurgery had local recurrence after 5 months. Local tumor control (LTC) rates at the 6-, 12-, and 18-month follow-ups were 72%, 58%, and 43%, respectively, for the SRS group and 40%, 30%, and 20%, respectively, for the surgery group (p < 0.05). The literature review included 35 papers with 70 patients harboring spinal LMS; only 2 patients were treated with SRS. The literature review confirms the clinical and radiological outcomes of the surgical group, while data on SRS are anecdotal.The authors present the largest series in the literature of spinal LMS and the first on SRS for spinal LMS. This study shows that LTC is statistically significantly better in patients receiving upfront SRS instead of surgery. The OS does not appear different between the two groups.

    View details for DOI 10.3171/2023.10.SPINE23666

    View details for PubMedID 38157539

  • CyberKnife Radiosurgery for Extracranial Metastases of Oligodendroglioma: A Clinical Case Report. Cureus Shaghaghian, E., Park, D. J., Yoo, K. H., Meola, A., Chang, S. D. 2023; 15 (12): e51035


    Oligodendroglioma is an uncommon glial tumor known for its extremely rare tendency to metastasize to extracranial areas, particularly to the spinal region. We present a rare case of oligodendroglioma that metastasizes to the spinal cord 14 years after resection of the initial tumor. Furthermore, a systematic review of the relevant literature is conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, encompassing oligodendroglioma cases with extracranial metastases. Our PRISMA-guided systematic review fills a critical knowledge gap in neurosurgery by consolidating scattered data on oligodendroglioma metastases, offering pivotal insights for clinical practice and future research. A 50-year-old male patient exhibited severe headaches and dizziness, with MRI findings revealing a significant brain mass suggestive of oligodendroglioma. Consequently, the patient underwent a craniotomy procedure. After 14 years, the patient presented with weakness in both lower extremities and bladder as well as bowel dysfunction. A lumbosacral MRI of the patient revealed two intradural enhancing masses in the lumbosacral spine. Surgical resection was performed, and the characteristics were identical to those of the primary tumor. The systemic review encompassed 52 articles, covering 67 cases of extracranial metastases from oligodendroglioma. Only three cases in the literature review fulfilled the inclusion criteria, demonstrating the required molecular genetic profiles of isocitrate dehydrogenase​​​ (IDH)-mutation and chromosome 1p/19q-codeletion. The inclusion criteria encompassed cases of oligodendroglioma with confirmed extracranial metastases, focusing on those with documented molecular genetic profiles indicating IDH-mutation and 1p/19q-codeletion. Our emphasis was on identifying cases with this specific genetic profile to ensure consistency and relevance in the literature review. Interestingly, our case was the first to exhibit intradural spinal metastases, while the other cases involved metastasis to the spinal bone marrow. Our case and literature review demonstrate that oligodendrogliomas, although exceptionally rare, can metastasize not only to the extracranial area but also to the spinal cord. To improve survival in oligodendroglioma cases, it is recommended to implement regular radiological screening and monitoring to enable early detection and treatment of extracranial metastases.

    View details for DOI 10.7759/cureus.51035

    View details for PubMedID 38264380

    View details for PubMedCentralID PMC10805176

  • Spinal metastases of pineal region glioblastoma with primitive neuroectodermal features highlighting the importance of molecular diagnoses: illustrative case. Journal of neurosurgery. Case lessons Shah, A., Marianayagam, N. J., Zamarud, A., Park, D. J., Persad, A. R., Soltys, S. G., Chang, S. D., Veeravagu, A. 2023; 6 (20)


    Glioblastoma (GBM) is the most common primary brain tumor with poor patient prognosis. Spinal leptomeningeal metastasis has been rarely reported, with long intervals between the initial discovery of the primary tumor in the brain and eventual spine metastasis.Here, the authors present the case of a 51-year-old male presenting with 7 days of severe headache, nausea, and vomiting. Magnetic resonance imaging of the brain and spine demonstrated a contrast-enhancing mass in the pineal region, along with spinal metastases to T8, T12, and L5. Initial frozen-section diagnosis led to the treatment strategy for medulloblastoma, but further molecular analysis revealed characteristics of isocitrate dehydrogenase-wild type, grade 4 GBM.Glioblastoma has the potential to show metastatic spread at the time of diagnosis. Spinal imaging should be considered in patients with clinical suspicion of leptomeningeal spread. Furthermore, molecular analysis should be confirmed following pathological diagnosis to fine-tune treatment strategies.

    View details for DOI 10.3171/CASE23536

    View details for PubMedID 37956418

  • The outcome of central nervous system hemangioblastomas in Von Hippel-Lindau (VHL) disease treated with belzutifan: a single-institution retrospective experience. Journal of neuro-oncology Zamarud, A., Marianayagam, N. J., Park, D. J., Yener, U., Yoo, K. H., Meola, A., Chang, S. D. 2023


    Belzutifan is a Hypoxia Inducible Factor 2-alpha inhibitor approved in 2021 by the FDA for the treatment of renal cell carcinoma (RCC) in patients with Von-Hippel Landau (VHL) disease. These patients can also present with central nervous system (CNS) hemangioblastomas (HBs). We aim to study the effectiveness and adverse effects of belzutifan for CNS HBs, by reporting our preliminary institutional experience.We present a series of VHL patients with CNS HBs undergoing treatment with belzutifan for RCC. All the included patients met the RECIST inclusion criteria. The clinical and radiological outcome measures included: Objective response rate (ORR), time-to-response (TTR), adverse events (AE), and patient response. Patient response was classified as partial response (PR), complete response (CR), progressive disease (PD), or stable disease (SD).Seven patients with 25 HBs were included in our study. A belzutifan dose of 120 mg/day PO was administered for a median of 13 months (range 10-17). Median follow up time was 15 months (range 10-24). An ORR of 71% was observed. The median TTR was 5 months (range: 1-10). None of the patients showed CR, while 5 patients (71.4%) showed PR and 2 (28.5%) showed SD. Among patients with SD the maximum tumor response was 20% [increase/decrease] of the lesion diameter. All the patients experienced decreased hemoglobin concentration, fatigue, and dizziness. None of the patients experienced severe anemia (grade 3-4 CTCAE).Belzutifan appears to be an effective and safe treatment for CNS hemangioblastoma in VHL patients. Further clinical trials to assess the long-term effectiveness of the medication are required.

    View details for DOI 10.1007/s11060-023-04496-z

    View details for PubMedID 37955759

    View details for PubMedCentralID 5573741

  • Stereotactic Radiosurgery for Cranial and Spinal Hemangioblastomas: A Single-Institution Retrospective Series. Neurosurgery Yoo, K. H., Park, D. J., Marianayagam, N. J., Gu, X., Pollom, E. L., Soltys, S. G., Chang, S. D., Meola, A. 2023


    Stereotactic radiosurgery (SRS) has been an attractive treatment modality for both cranial and spinal hemangioblastomas, especially for multiple lesions commonly associated with von Hippel-Lindau (VHL) disease. This study aims to provide the largest long-term analysis of treatment efficacy and adverse effects of SRS for cranial and spinal hemangioblastomas at a single institution.We evaluated the clinical and radiological outcomes of patients with hemangioblastomas treated with CyberKnife SRS at our institute from 1998 to 2022. The follow-up data were available for 135 hemangioblastomas in 35 patients. Twenty-eight patients had 123 hemangioblastomas associated with VHL, and 7 had 12 sporadic hemangioblastomas. The median age was 36 years, and the median tumor volume accounted for 0.4 cc. The SRS was administered with the median single-fraction equivalent dose of 18 Gy to the 77% median isodose line.At a median follow-up of 57 months (range: 3-260), only 20 (16.2%) of the VHL-associated and 1 (8.3%) sporadic hemangioblastomas progressed. The 5-year local tumor control rate was 91.3% for all hemangioblastomas, 91.7% among the sporadic lesions, and 92.9% in patients with VHL. SRS improved tumor-associated symptoms of 98 (74.8%) of 131 symptomatic hemangioblastomas, including headache, neck pain, dizziness, visual disturbances, dysesthesia, ataxia, motor impairment, seizures, and dysphagia. Two patients developed radiation necrosis (5.7%), and 1 of them required surgical resection.SRS is a safe and effective treatment option for patients with hemangioblastomas in critical locations, such as the brainstem, cervicomedullary junction, and spinal cord, and in patients with multiple hemangioblastomas associated with VHL disease.

    View details for DOI 10.1227/neu.0000000000002728

    View details for PubMedID 37967154

  • Overall Survival Prediction in Stereotactic Radiosurgery Patients with Glioblastoma Via a Deep-Learning Approach. International journal of radiation oncology, biology, physics Yang, Z., Zamarud, A., Marianayagam, N., Park, D., Yener, U., Soltys, S. G., Chang, S. D., Meola, A., Lu, W., Gu, X. 2023; 117 (2S): e159


    PURPOSE/OBJECTIVE(S): Accurate and automated early survival prediction is critical for glioblastoma (GBM) patients as their poor prognosis requires timely treatment decision-making. We have developed a deep learning (DL)-based GBM overall survival (OS) prediction model based on a multi-institutional public dataset using only pre-operative basic structural multi-parametric magnetic resonance images (MRIs). The purpose of this study is to evaluate this DL-based OS prediction model with an institutional stereotactic radiosurgery (SRS) clinical trial dataset.MATERIALS/METHODS: The task of this study is to classify GBM patients into 3 OS classes: long-survivors (>15 months), mid-survivors (between 10 and 15 months) and short-survivors (< 10 months). The proposed OS prediction model is an ensemble of a ResNet-based classifier and a K-NN classifier. The ResNet-based classifier is trained in a Siamese fashion to explore inter-class differences. During testing, training sample features are implemented with a K-NN classifier to ensemble with the ResNet-based classifier. A public dataset from Medical Image Computing and Computer Assisted Intervention (MICCAI) Brain Tumor Segmentation (BraTS) challenge 2020 (235 patients) were used for model establishing and initial validation. Then the validated model was evaluated on 19 GBM patients from an institutional SRS clinical trial. Each data entry consists of pre-operative basic structural multi-parametric MRIs and survival days, as well as patient ages for BraTS data and basic clinical characteristics for institutional data. GBM sub-regions, including contrast-enhancing tumor, peri-tumoral edema, and necrotic/non-enhancing tumor core, were segmented in the multi-parametric MRIs by an in-house DL model for both datasets. The OS prediction model was trained on 90% of the segmented BraTS data and validated on the rest 10%, then further evaluated on the institutional data. The model performance was assessed by prediction accuracy (ACC) and the area under the curve (AUC).RESULTS: For this 3-class OS classification task, our DL-based prediction model achieved an ACC of 65.22% and an AUC of 0.81 on the BraTS dataset compared with the top-ranked result from the BraTS challenge 2020 (Rank 1st: ACC 61.7%), and an ACC of 52.63% and an AUC of 0.69 on the institutional dataset. Further analysis of the institutional dataset found that the predicted OS class had a statistically significant correlation with treatment volume (p = 0.012) and age (p = 0.006), which matches the analysis that the patients' ground truth OS class is statistical significantly correlated with treatment volume (p = 0.045).CONCLUSION: Our DL-based OS prediction model for GBM using basic structural multi-parametric pre-operative MRIs has demonstrated promising performance in both public and institutional dataset with minimal manual processing requirements. This OS prediction model can be potentially applied to assist timely clinical decision-making.

    View details for DOI 10.1016/j.ijrobp.2023.06.988

    View details for PubMedID 37784752

  • Practical Guideline for Prevention of Patchy Hair Loss following CyberKnife Stereotactic Radiosurgery for Calvarial or Scalp Tumors: Retrospective Analysis of a Single Institution Experience. Stereotactic and functional neurosurgery Park, D. J., Marianayagam, N. J., Yener, U., Tayag, A., Ustrzynski, L., Emrich, S. C., Pollom, E., Soltys, S., Meola, A., Chang, S. D. 2023: 1-7


    Patchy alopecia is a common adverse effect of stereotactic radiosurgery (SRS) on the calvarium and/or scalp, yet no guidelines exist for its prevention. This study aims to investigate the incidence and outcomes of patchy alopecia following SRS for patients with calvarial or scalp lesions and establish preventive guidelines.The study included 20 patients who underwent CyberKnife SRS for calvarial or scalp lesions, resulting in a total of 30 treated lesions. SRS was administered as a single fraction for 8 lesions and hypofractionated for 22 lesions. The median SRS target volume was 9.85 cc (range: 0.81-110.7 cc), and the median prescription dose was 27 Gy (range: 16-40 Gy), delivered in 1-5 fractions (median: 3). The median follow-up was 15 months.Among the 30 treated lesions, 11 led to patchy alopecia, while 19 did not. All cases of alopecia resolved within 12 months, and no patients experienced other adverse radiation effects. Lesions resulting in alopecia exhibited significantly higher biologically effective dose (BED) and single-fraction equivalent dose (SFED) on the overlying scalp compared to those without alopecia. Patients with BED and SFED exceeding 60 Gy and 20 Gy, respectively, were 9.3 times more likely to experience patchy alopecia than those with lower doses. The 1-year local tumor control rate for the treated lesions was 93.3%. Chemotherapy was administered for 26 lesions, with 11 lesions receiving radiosensitizing agents. However, no statistically significant difference was found.In summary, SRS is a safe and effective treatment for patients with calvarial/scalp masses regarding patchy alopecia near the treated area. Limiting the BED under 60 Gy and SFED under 20 Gy for the overlying scalp can help prevent patchy alopecia during SRS treatment of the calvarial/scalp mass. Clinicians can use this information to inform patients about the risk of alopecia and the contributing factors.

    View details for DOI 10.1159/000533555

    View details for PubMedID 37699370

  • Stereotactic Radiosurgery for Medically Refractory Trigeminal Neuralgia Secondary to Stroke: A Systematic Review and Clinical Case Presentation. World neurosurgery Zamarud, A., Park, D. J., Ung, T. H., McCleary, T. L., Yoo, K. H., Soltys, S. G., Lim, M., Chang, S. D., Meola, A. 2023

    View details for DOI 10.1016/j.wneu.2023.08.092

    View details for PubMedID 37640262

  • Optimizing the synergy between stereotactic radiosurgery and immunotherapy for brain metastases. Frontiers in oncology Yoo, K. H., Park, D. J., Choi, J. H., Marianayagam, N. J., Lim, M., Meola, A., Chang, S. D. 2023; 13: 1223599


    Solid tumors metastasizing to the brain are a frequent occurrence with an estimated incidence of approximately 30% of all cases. The longstanding conventional standard of care comprises surgical resection and whole-brain radiotherapy (WBRT); however, this approach is associated with limited long-term survival and local control outcomes. Consequently, stereotactic radiosurgery (SRS) has emerged as a potential alternative approach. The primary aim of SRS has been to improve long-term control rates. Nevertheless, rare observations of abscopal or out-of-field effects have sparked interest in the potential to elicit antitumor immunity via the administration of high-dose radiation. The blood-brain barrier (BBB) has traditionally posed a significant challenge to the efficacy of systemic therapy in managing intracranial metastasis. However, recent insights into the immune-brain interface and the development of immunotherapeutic agents have shown promise in preclinical and early-phase clinical trials. Researchers have investigated combining immunotherapy with SRS to enhance treatment outcomes in patients with brain metastasis. The combination approach aims to optimize long-term control and overall survival (OS) outcomes by leveraging the synergistic effects of both therapies. Initial findings have been encouraging in the management of various intracranial metastases, while further studies are required to determine the optimal order of administration, radiation doses, and fractionation regimens that have the potential for the best tumor response. Currently, several clinical trials are underway to assess the safety and efficacy of administering immunotherapeutic agents concurrently or consecutively with SRS. In this review, we conduct a comprehensive analysis of the advantages and drawbacks of integrating immunotherapy into conventional SRS protocols for the treatment of intracranial metastasis.

    View details for DOI 10.3389/fonc.2023.1223599

    View details for PubMedID 37637032

    View details for PubMedCentralID PMC10456862

  • Stereotactic Radiosurgery for Contrast-Enhancing Satellite Nodules in Recurrent Glioblastoma: A Rare Case Series From a Single Institution. Cureus Park, D. J., Persad, A. R., Yoo, K. H., Marianayagam, N. J., Yener, U., Tayag, A., Ustrzynski, L., Emrich, S. C., Chuang, C., Pollom, E., Soltys, S. G., Meola, A., Chang, S. D. 2023; 15 (8): e44455


    Introduction Glioblastoma (GBM) is the most common malignant adult brain tumor and is invariably fatal. The standard treatment for GBM involves resection where possible, followed by chemoradiation per Stupp's protocol. We frequently use stereotactic radiosurgery (SRS) as a single-fraction treatment for small (volume ≤ 1cc) nodular recurrent GBM to the contrast-enhancing target on T1 MRI scan. In this paper, we aimed to evaluate the safety and efficacy of SRS for patients with contrast-enhancing satellite nodules in recurrent GBM. Methods This retrospective study analyzed the clinical and radiological outcomes of five patients who underwent CyberKnife (Accuray Inc., Sunnyvale, California) SRS at the institute between 2013 and 2022. Results From 96 patients receiving SRS for GBM, five (four males, one female; median age 53) had nine distinct new satellite lesions on MRI, separate from their primary tumor beds. Those nine lesions were treated with a median margin dose of 20 Gy in a single fraction. The three-, six, and 12-month local tumor control rates were 77.8%, 66.7%, and 26.7%, respectively. Median progression-free survival (PFS) was seven months, median overall survival following SRS was 10 months, and median overall survival (OS) was 35 months. Interestingly, the only lesion that did not show radiological progression was separate from the T2-fluid attenuated inversion recovery (FLAIR) signal of the main tumor. Conclusion Our SRS treatment outcomes for recurrent GBM satellite lesions are consistent with existing findings. However, in a unique case, a satellite nodule distinct from the primary tumor's T2-FLAIR signal and treated with an enlarged target volume showed promising control until the patient's demise. This observation suggests potential research avenues, given the limited strategies for 'multicentric' GBM lesions.

    View details for DOI 10.7759/cureus.44455

    View details for PubMedID 37664337

    View details for PubMedCentralID PMC10470661

  • Stereotactic radiosurgery for distant brain metastases secondary to esthesioneuroblastoma: a single-institution series. Neurosurgical focus Zamarud, A., Yener, U., Yoo, K. H., Park, D. J., Marianayagam, N. J., Ho, Q. A., Pollom, E., Soltys, S., Wang, L., Chang, S. D., Meola, A. 2023; 55 (2): E6


    Esthesioneuroblastoma (ENB), also known as olfactory neuroblastoma, is a rare, malignant tumor of neuroectodermal origin that arises from the olfactory neuroepithelium. In this study the authors present the first series in the literature on distant brain metastases (BMs) secondary to ENB that were treated with stereotactic radiosurgery (SRS), to evaluate the safety and effectiveness of SRS for this indication.A retrospective analysis of clinical and radiological outcomes of patients with ENB who underwent CyberKnife (CK) SRS at a single center was conducted. The clinical and radiological outcomes of patients, including progression-free survival, overall survival, and local tumor control (LTC) were reported.Between 2003 and 2022, 32 distant BMs in 8 patients were treated with CK SRS at Stanford University. The median patient age at BM diagnosis was 62 years (range 47-75 years). Among 32 lesions, 2 (6%) had previously been treated with surgery, whereas for all other lesions (30 [94%]), CK SRS was used as their primary treatment modality. The median target volume was 1.5 cm3 (range 0.09-21.54 cm3). CK SRS was delivered by a median marginal dose of 23 Gy (range 15-30 Gy) and a median of 3 fractions (range 1-5 fractions) to a median isodose line of 77% (range 70%-88%). The median biologically effective dose was 48 Gy (range 21-99.9 Gy) and the median follow-up was 30 months (range 3-95 months). The LTC at 1-, 2-, and 3-year follow-up was 86%, 65%, and 50%, respectively. The median progression-free survival and overall survival were 29 months (range 11-79 months) and 51 months (range 15-79 months), respectively. None of the patients presented adverse radiation effects.In the authors' experience, SRS provided excellent LTC without any adverse radiation effects for BMs secondary to ENB.

    View details for DOI 10.3171/2023.5.FOCUS23216

    View details for PubMedID 37527675

  • Stereotactic radiosurgery for sarcoma metastases to the brain: a single-institution experience. Neurosurgical focus Zamarud, A., Park, D. J., Dadey, D. Y., Yoo, K. H., Marianayagam, N. J., Yener, U., Szalkowski, G. A., Pollom, E., Soltys, S., Chang, S. D., Meola, A. 2023; 55 (2): E7


    Brain metastases (BMs) secondary to sarcoma are rare, and their incidence ranges from 1% to 8% of all bone and soft tissue sarcomas. Although stereotactic radiosurgery (SRS) is widely used for BMs, only a few papers have reported on SRS for sarcoma metastasizing to the brain. The purpose of this study was to evaluate the safety and effectiveness of SRS for sarcoma BM.The authors retrospectively reviewed the clinical and radiological outcomes of patients with BM secondary to histopathologically confirmed sarcoma treated with SRS, either as primary treatment or as adjuvant therapy after surgery, at their institution between January 2005 and September 2022. They also compared the outcomes of patients with hemorrhagic lesions and of those without.Twenty-three patients (9 females) with 150 BMs secondary to sarcoma were treated with CyberKnife SRS. Median age at the time of treatment was 48.22 years (range 4-76 years). The most common primary tumor sites were the heart, lungs, uterus, upper extremities, chest wall, and head and neck. The median Karnofsky Performance Status on presentation was 73.28 (range 40-100). Eight patients underwent SRS as a primary treatment and 15 as adjuvant therapy to the resection cavity. The median tumor volume was 24.1 cm3 (range 0.1-150.3 cm3), the median marginal dose was 24 Gy (range 18-30 Gy) delivered in a median of 1 fraction (range 1-5) to a median isodose line of 76%. The median follow-up was 8 months (range 2-40 months). Median progression-free survival and overall survival were 5.3 months (range 0.4-32 months) and 8.2 months (range 0.1-40), respectively. The 3-, 6-, and 12-month local tumor control (LTC) rates for all lesions were respectively 78%, 52%, and 30%. There were no radiation-induced adverse effects. LTC at the 3-, 6-, and 12-month follow-ups was better in patients without hemorrhagic lesions (100%, 70%, and 40%, respectively) than in those with hemorrhagic lesions (68%, 38%, and 23%, respectively).SRS, both as a primary treatment and as adjuvant therapy to the resection cavity after surgery, is a safe and relatively effective treatment modality for sarcoma BMs. Nonhemorrhagic lesions show better LTC than hemorrhagic lesions. Larger studies aiming to validate these results are encouraged.

    View details for DOI 10.3171/2023.5.FOCUS23168

    View details for PubMedID 37527671

  • CyberKnife radiosurgery for treatment of residual or recurrent Grade 1 choroid plexus papilloma: A single institution experience. World neurosurgery Zhang, M., Park, D. J., Marianayagam, N. J., Yener, U., Soltys, S. G., Pollom, E., Chang, S. D., Meola, A. 2023


    Choroid plexus papillomas (CPP) are rare intraventricular brain tumors derived from the epithelium of the choroid plexus. Gross total resection has traditionally been considered curative, but residual tumor or recurrence remains possible. SRS has become particularly more important strategy for subtotally resectied and recurrent tumors. The evidence-based rationale of SRS treatment for residual or recurrent CPP in adult patients is still lacking due to its rarity.We retrospectively reviewed histopathologically confirmed cases of residual or recurrent CPP treated with SRS at our institute in the adult population between 2005 and 2022. Three patients, with five lesions, were identified with a median age of 63 years. Patients presented initially with hydrocephalus-related symptoms, although ventriculomegaly was noted only in one patient radiographically. The tumor locations were most common in 4th ventricle or along foramen of Luschka. Treatment was delivered in a single fraction in 4 lesions and in 3 fractions in 1 patient. The median follow-up was 26 months.The local tumor control rate for the lesions was 80%. One patient developed a new lesion outside the SRS field, and one lesion developed progression without need for subsequent treatment. There were no significant shrinkage of the lesions radiographically. None of the patients revealed radiation-related adverse events. No patients required surgical management after SRS treatment at our institution. Based on the literature review, our case series was the second largest retrospective series from a single institution on SRS for recurrent or residual CPP.SRS for patients with recurrent or residual CPP was a safe and effective treatment modality in this case series. Larger studies are encouraged to validate the role of SRS in the treatment of recurrent or residual CPP.

    View details for DOI 10.1016/j.wneu.2023.07.003

    View details for PubMedID 37423336

  • Cyberknife Radiosurgery for Synovial Sarcoma Metastasizing to the Spine: Illustrative Case Reports. Cureus Zamarud, A., Park, D. J., Haider, G., Chang, S. D., Meola, A. 2023; 15 (4): e37087


    Synovial sarcoma (SS) is a rare and aggressive type of soft tissue sarcoma that commonly affects young adults. Metastasis in the spine is a rare complication, and the management of these lesions is challenging. Radiosurgery is an increasingly popular treatment option for spinal metastasis due to its ability to deliver high doses of radiation to the target volume with minimal exposure to surrounding healthy tissues. In this paper, we present two cases of SS with spinal metastasis that were treated with CyberKnife radiosurgery (CKRS). The first case was a 52-year-old female with a history of multiple thoracotomies and lobectomies for lung metastases, who was diagnosed with T6-T8 and T4 spinal metastasis. The second case was a 53-year-old female with Down syndrome, who was diagnosed with T12-L1 spinal metastasis. Both patients experienced an improvement in their symptoms following CKRS treatment and showed stable or decreasing lesion sizes on follow-up imaging. The progression-free survival (PFS) in the first case was 37 months and overall survival (OS) was 79 months. In the second case, the PFS was 12 months and OS was 18 months. These cases highlight the potential benefits of CKRS as a treatment option for SS with spinal metastasis and support its use in the management of this challenging condition.

    View details for DOI 10.7759/cureus.37087

    View details for PubMedID 37168194

    View details for PubMedCentralID PMC10166278

  • Using 68Ga-DOTATATE PET for Postoperative Radiosurgery and Radiotherapy Planning in Patients With Meningioma: A Case Series. Neurosurgery Hintz, E. B., Park, D. J., Ma, D., Viswanatha, S. D., Rini, J. N., Schulder, M., Goenka, A. 2023


    For patients with either an incompletely resected meningioma or recurrence after surgery, stereotactic radiosurgery is frequently used. MRI is typically used for stereotactic radiosurgery targeting, but differentiating tumor growth from postoperative change can be challenging. 68Ga-DOTATATE, a positron emission tomography (PET) radiotracer targeting the somatostatin receptor type 2, has been shown to be a reliable meningioma biomarker.To evaluate the impact of 68Ga-DOTATATE on treatment planning in patients who had previously undergone meningioma resection.We present a consecutive case series of 12 patients with pathology-proven meningioma who received a 68Ga-DOTATATE PET between April 2019 and April 2021. Treatment planning was performed first using MRI. DOTATATE-PET images were then used to assess accurate tumor identification.Ten patients had WHO Grade 2 meningioma, and 2 patients had Grade 1 tumor. Eight patients had recurrent meningiomas, and 4 patients had newly diagnosed disease. Overall, 68Ga-DOTATATE PET scans altered previously formulated treatment plans in 5 of 12 patients. In addition, 9 of 12 patients had disease foci not appreciated on MRI.In this series, incorporating 68Ga-DOTATATE PET imaging had clinical utility for most patients in whom it was used. It proved particularly adept in demonstrating intraosseous meningiomas, differentiating recurrence from postoperative changes, and identifying subcentimeter disease foci. It is an imaging modality that our center will continue to use as a means of improving postoperative treatment plans after the surgical resection of meningiomas.

    View details for DOI 10.1227/neu.0000000000002377

    View details for PubMedID 36722951

  • Stereotactic radiosurgery for localized cranial Langerhans cell histiocytosis: A single institution experience and review of literature. World neurosurgery Park, D. J., Marianayagam, N. J., Yener, U., Wang, L., Soltys, S. G., Pollom, E., Chang, S. D., Meola, A. 2023


    Langerhans cell histiocytosis (LCH) is a rare idiopathic disease characterized by the clonal proliferation of Langerhans histiocytes in various parts of the body and capable of leading to organ damage and tumor formation. Reports of cranial LCH in the adult population are extremely rare. Although surgery remains the preferred option for localized LCH lesions, the role of stereotactic radiosurgery (SRS) is emerging as well.To retrospectively review a rare case series to determine the safety and effectiveness of SRS for patients with localized cranial LCH.We retrospectively reviewed histopathologically confirmed cases of localized cranial LCH treated with SRS at our institute in the adult population between January 2005 and September 2022. Five patients were identified with a median age of 34 years (19-54 years). The tumor location was in the pituitary stalk in three patients, the orbit in one patient, and the parietal skull in one patient. The median target volume was 2.8 cc (range: 0.37-6.11). Treatment was delivered in a single fraction in 4 patients (median margin dose of 8 Gy (range: 7-10 Gy) and in 3 fractions (22.5 Gy) in 1 patient. The median follow-up was 12 years (range: 4-17). None of the patients required craniotomy for tumor debulking before or after SRS.The local tumor control rate for the lesions was 100%. All three patients with LCH in the pituitary stalk had diabetes insipidus at the initial presentation and developed panhypopituitarism after SRS. Diabetes insipidus was not improved after SRS. The other two patients presented no adverse radiation effects. Based on the literature review, our case series was the largest retrospective series on SRS for localized cranial LCH, with the longest median follow-up.SRS for patients with localized cranial LCH was a safe and effective treatment modality in this case series. Larger studies are encouraged to validate the role of SRS in the treatment of localized cranial LCH.

    View details for DOI 10.1016/j.wneu.2023.01.053

    View details for PubMedID 36681322

  • Cyberknife Radiosurgery for Synovial Sarcoma Metastasizing to the Spine Cureus Zamarud, A., Park, D. J., Haider, G., Chang, S. D., Meola, A. 2023; 15 (4)

    View details for DOI 10.7759/cureus.37087

  • Overall Survival Prediction in Stereotactic Radiosurgery Patients with Glioblastoma Via a Deep-Learning Approach. International journal of radiation oncology, biology, physics Yang, Z., Zamarud, A., Marianayagam, N., Park, D. J., Yener, U., Soltys, S. G., Chang, S. D., Meola, A., Lu, W., Gu, X. 2023; 117 (2S)
  • Papillary craniopharyngioma in a patient following resection of nonfunctioning pituitary adenoma: illustrative case. Journal of neurosurgery. Case lessons Park, D. J., Mishra, A., Golub, D., Li, J. Y., Black, K. S., Schulder, M. 2021; 1 (2): CASE2063


    Although craniopharyngioma and pituitary adenoma are common tumors of the sellar or suprasellar region, the development of papillary craniopharyngioma in the same sellar region after resection of a nonfunctioning pituitary adenoma has not been reported.Here the authors report the first case of craniopharyngioma that developed long after resection of a pituitary adenoma. A 66-year-old male patient underwent endoscopic transsphenoidal resection for a large sellar mass, which histopathologically confirmed the diagnosis of a pituitary adenoma. He had an excellent recovery after surgery. For several years, he had no clinical or imaging evidence of tumor recurrence and then was lost to follow-up. Seven years after the initial surgery, the patient returned with a one-month history of visual field defects, and imaging confirmed a heterogeneous, cystic suprasellar mass. Endoscopic transsphenoidal resection of the tumor was performed, and histological examination showed it to be a papillary craniopharyngioma.Neurosurgeons should be aware that after pituitary adenoma resection, a recurrent mass could be a craniopharyngioma, with implications for very different management recommendations.

    View details for DOI 10.3171/CASE2063

    View details for PubMedID 35854932

    View details for PubMedCentralID PMC9241323

  • Cystic Brain Metastases Managed With Reservoir Placement and Stereotactic Radiosurgery Neurosurgery Open Park, D. J., Unadkat, P., Goenka, A., Schulder, M. 2021; 2 (4): 1-10

    View details for DOI 10.1093/neuopn/okab028

  • Stearoyl CoA Desaturase Is Essential for Regulation of Endoplasmic Reticulum Homeostasis and Tumor Growth in Glioblastoma Cancer Stem Cells STEM CELL REPORTS Pinkham, K., Park, D., Hashemiaghdam, A., Kirov, A. B., Adam, I., Rosiak, K., da Hora, C. C., Teng, J., Cheah, P., Carvalho, L., Ganguli-Indra, G., Kelly, A., Indra, A. K., Badr, C. E. 2019; 12 (4): 712-727


    Inherent plasticity and various survival cues allow glioblastoma stem-like cells (GSCs) to survive and proliferate under intrinsic and extrinsic stress conditions. Here, we report that GSCs depend on the adaptive activation of ER stress and subsequent activation of lipogenesis and particularly stearoyl CoA desaturase (SCD1), which promotes ER homeostasis, cytoprotection, and tumor initiation. Pharmacological targeting of SCD1 is particularly toxic due to the accumulation of saturated fatty acids, which exacerbates ER stress, triggers apoptosis, impairs RAD51-mediated DNA repair, and achieves a remarkable therapeutic outcome with 25%-100% cure rate in xenograft mouse models. Mechanistically, divergent cell fates under varying levels of ER stress are primarily controlled by the ER sensor IRE1, which either promotes SCD1 transcriptional activation or converts to apoptotic signaling when SCD1 activity is impaired. Taken together, the dependence of GSCs on fatty acid desaturation presents an exploitable vulnerability to target glioblastoma.

    View details for DOI 10.1016/j.stemcr.2019.02.012

    View details for Web of Science ID 000463364400007

    View details for PubMedID 30930246

    View details for PubMedCentralID PMC6450460

  • Virus vector-mediated genetic modification of brain tumor stromal cells after intravenous delivery JOURNAL OF NEURO-ONCOLOGY Volak, A., LeRoy, S. G., Natasan, J., Park, D. J., Cheah, P., Maus, A., Fitzpatrick, Z., Hudry, E., Pinkham, K., Gandhi, S., Hyman, B. T., Mu, D., Guhasarkar, D., Stemmer-Rachamimov, A. O., Sena-Esteves, M., Badr, C. E., Maguire, C. A. 2018; 139 (2): 293-305


    The malignant primary brain tumor, glioblastoma (GBM) is generally incurable. New approaches are desperately needed. Adeno-associated virus (AAV) vector-mediated delivery of anti-tumor transgenes is a promising strategy, however direct injection leads to focal transgene spread in tumor and rapid tumor division dilutes out the extra-chromosomal AAV genome, limiting duration of transgene expression. Intravenous (IV) injection gives widespread distribution of AAV in normal brain, however poor transgene expression in tumor, and high expression in non-target cells which may lead to ineffective therapy and high toxicity, respectively. Delivery of transgenes encoding secreted, anti-tumor proteins to tumor stromal cells may provide a more stable and localized reservoir of therapy as they are more differentiated than fast-dividing tumor cells. Reactive astrocytes and tumor-associated macrophage/microglia (TAMs) are stromal cells that comprise a large portion of the tumor mass and are associated with tumorigenesis. In mouse models of GBM, we used IV delivery of exosome-associated AAV vectors driving green fluorescent protein expression by specific promoters (NF-κB-responsive promoter and a truncated glial fibrillary acidic protein promoter), to obtain targeted transduction of TAMs and reactive astrocytes, respectively, while avoiding transgene expression in the periphery. We used our approach to express the potent, yet toxic anti-tumor cytokine, interferon beta, in tumor stroma of a mouse model of GBM, and achieved a modest, yet significant enhancement in survival compared to controls. Noninvasive genetic modification of tumor microenvironment represents a promising approach for therapy against cancers. Additionally, the vectors described here may facilitate basic research in the study of tumor stromal cells in situ.

    View details for DOI 10.1007/s11060-018-2889-2

    View details for Web of Science ID 000441544800007

    View details for PubMedID 29767307

    View details for PubMedCentralID PMC6454875

  • Acute Paraplegia as a Result of Hemorrhagic Spinal Ependymoma Masked by Spinal Anesthesia: Case Report and Review of Literature. Brain tumor research and treatment Lee, S. H., Park, D. J., Jeun, S. S. 2016; 4 (1): 30-4


    Ependymomas are the most common intramedullary spinal cord tumors in adults. Although a hemorrhage within spinal ependymoma on imaging studies is not uncommon, it has rarely been reported to bea cause of acute neurological deficit. In the present report, we describe a case of a 24-year-old female patient who developed acute paraplegia as a result of hemorrhagic spinal ependymoma immediately after a cesarean delivery under spinal regional anesthesia. We review the literature of hemorrhagic spinal ependymomas presenting with acute neurological deficit and discuss the most appropriate treatment for a good neurological recovery.

    View details for DOI 10.14791/btrt.2016.4.1.30

    View details for PubMedID 27195260

    View details for PubMedCentralID PMC4868815

  • Remote Postoperative Epidural Hematoma after Brain Tumor Surgery. Brain tumor research and treatment Chung, H. J., Park, J. S., Park, J. H., Jeun, S. S. 2015; 3 (2): 132-7


    A postoperative epidural hematoma (EDH) is a serious and embarrassing complication, which usually occurs at the site of operation after intracranial surgery. However, remote EDH is relatively rare. We report three cases of remote EDH after brain tumor surgery. All three cases seemed to have different causes of remote postoperative EDH; however, all patients were managed promptly and showed excellent outcomes. Although the exact mechanism of remote postoperative EDH is unknown, surgeons should be cautious of the speed of lowering intracranial pressure and implement basic procedures to prevent this hazardous complication of brain tumor surgery.

    View details for DOI 10.14791/btrt.2015.3.2.132

    View details for PubMedID 26605271

    View details for PubMedCentralID PMC4656891

  • Efficacy of Procarbazine, Lomustine, and Vincristine Chemotherapy for Recurrent Primary Central Nervous System Lymphomas. Brain tumor research and treatment Kim, Y. J., Choe, J. H., Park, J. H., Hong, Y. K. 2015; 3 (2): 75-80


    Optimal treatment for recurrent primary central nervous system lymphomas (PCNSLs) has not been defined yet and there is no general consensus about the salvage chemotherapy after high-dose methotrexate (HD-MTX)-based chemotherapy. The purpose of the present study was to evaluate the efficacy and safety of procarbazine, lomustine, and vincristine (PCV) chemotherapy for recurrent PCNSLs.We reviewed eight immunocompetent patients (five males/three females, mean age: 56 years) who received salvage PCV chemotherapy (procarbazine 60 mg/m(2), days 8 through 21: CCNU 110 mg/m(2), day 1: vincristine 2 mg, days 8 and 28) for recurrent PCNSL and two patients switched to PCV chemotherapy due to severe adverse effects of HD-MTX chemotherapy. Radiologic responses, survival, and adverse effects were analyzed.Of the eight recurrent PCNSLs, three patients (37.5%) showed radiologic complete response, one patient (12.5%) showed partial response, and four patients (50%) showed progressive disease after PCV chemotherapy. Median progression free survival (PFS) from the first administration of PCV to relapse or last follow-up was 7 months (range 5-32 months) and median overall survival was 8 months (range 2-41 months). The two patients who switched to PCV chemotherapy showed PFS of 9 and 5 months from the beginning of PCV to relapse. The common side effects were thrombocytopenia, neutropenia, and peripheral neuropathy. There were 4 grade III or IV myelo-suppression, but no fatal complications, including severe hemorrhage or infection, were observed.Salvage PCV chemotherapy has a moderate anti-lymphoma activity for recurrent PCNSLs after the HD-MTX-based chemotherapy with tolerable toxicity.

    View details for DOI 10.14791/btrt.2015.3.2.75

    View details for PubMedID 26605261

    View details for PubMedCentralID PMC4656899

  • Treatment Strategy of Intracranial Hemangiopericytoma. Brain tumor research and treatment Kim, Y. J., Park, J. H., Kim, Y. I., Jeun, S. S. 2015; 3 (2): 68-74


    Recent studies suggest aggressive management combining a grossly total resection (GTR) with adjuvant radiotherapy (RT) as a treatment of choice for intracranial hemangiopericytoma (HPC). However, in these papers, the definitions of complete or GTR are equivocal. In the present study, we reviewed the relevant cases from our experience focused on the clinical efficacy of surgical grading of resection, and analyzed the optimal treatment strategies as well.From January 1995 through December 2014, 17 patients treated for intracranial HPC were included in this study. We analyzed clinical presentation, radiologic appearance, pathologic diagnosis, extent of resection, and follow-up outcomes.A total of 26 operations were performed including 9 recurrent intracranial HPCs. Every tumor was single and had no evidence of metastasis. Most common area of tumor was parasagittal (8 patients, 47.1%), which is adjoined to superior sagittal sinus. For the initial operation, GTR was performed in 16 cases (61.5%), partial resection (PR) in 8 cases (30.8%), and an endoscopic biopsy in 2 patients (7.7%). In Simpson grading system, grade 1 was done in 2 patients (7.7%), grade 2 in 11 patients (42.3%) and grade 3 in 3 patients (11.5%). Postoperative RT was delivered in 16 patients (94.1%) regardless of the extent of resection. The median 57.57 Gy (range, 50-60 Gy) was delivered in median 33 fractions (range, 30-40). The extent of resection (conventional classification and Simpson grading system) and adjuvant RT were significantly associated with recurrence-free survival.Surgical resection of intracranial HPC, in an attempt to reach Simpson grade 1 removal, is necessary for better outcome. Adjuvant RT should be done as recommended before, to prevent recurrence, regardless of surgical resection and pathological diagnosis.

    View details for DOI 10.14791/btrt.2015.3.2.68

    View details for PubMedID 26605260

    View details for PubMedCentralID PMC4656898

  • Modified Graded Repair of Cerebrospinal Fluid Leaks in Endoscopic Endonasal Transsphenoidal Surgery. Journal of Korean Neurosurgical Society Park, J. H., Choi, J. H., Kim, Y. I., Kim, S. W., Hong, Y. K. 2015; 58 (1): 36-42


    Complete sellar floor reconstruction is critical to avoid postoperative cerebrospinal fluid (CSF) leakage during transsphenoidal surgery. Recently, the pedicled nasoseptal flap has undergone many modifications and eventually proved to be valuable and efficient. However, using these nasoseptal flaps in all patients who undergo transsphenoidal surgery, including those who had none or only minor CSF leakage, appears to be overly invasive and time-consuming.Patients undergoing endoscopic endonasal transsphenoidal tumor surgery within a 5 year-period were reviewed. Since 2009, we classified the intraoperative CSF leakage into grades from 0 to 3. Sellar floor reconstruction was tailored to each leak grade. We did not use any tissue grafts such as abdominal fat and did not include any procedures of CSF diversions such as lumbar drainage.Among 200 cases in 188 patients (147 pituitary adenoma and 41 other pathologies), intraoperative CSF leakage was observed in 27.4% of 197 cases : 14.7% Grade 1, 4.6% Grade 2a, 3.0% Grade 2b, and 5.1% Grade 3. Postoperative CSF leakage was observed in none of the cases. Septal bone buttress was used for Grade 1 to 3 leakages instead of any other foreign materials. Pedicled nasoseptal flap was used for Grades 2b and 3 leakages. Unused septal bones and nasoseptal flaps were repositioned.Modified classification of intraoperative CSF leaks and tailored repair technique in a multilayered fashion using an en-bloc harvested septal bone and vascularized nasoseptal flaps is an effective and reliable method for the prevention of postoperative CSF leaks.

    View details for DOI 10.3340/jkns.2015.58.1.36

    View details for PubMedID 26279811

    View details for PubMedCentralID PMC4534737

  • Combination Therapy for Gliomas Using Temozolomide and Interferon-Beta Secreting Human Bone Marrow Derived Mesenchymal Stem Cells. Journal of Korean Neurosurgical Society Park, J. H., Ryu, C. H., Kim, M. J., Jeun, S. S. 2015; 57 (5): 323-8


    Malignant gliomas are the most common primary tumors of the central nervous system and the prognosis of patients with gliomas is poor. The combination of interferon-bata (IFN-β) and temozolomide (TMZ) has shown significant additive antitumor effects in human glioma xenograft models. Considering that the poor survival of patients with human malignant gliomas relates partly to the inability to deliver therapeutic agents to the tumor, the tropism of human bone marrow-derived mesenchymal stem cells (MSC) for malignant gliomas can be exploited to therapeutic advantages. We investigated the combination effects of TMZ and MSCs that secrete IFN-β on gliomas.We engineered human MSCs to secret mouse IFN-β (MSC-IFN-β) via adenoviral transduction and confirmed their secretory capacity using enzyme-linked immunosorbent assays. In vitro and in vivo experiments were performed to determine the effects of the combined TMZ and MSC-IFN-β treatment.In vitro, the combination of MSC-IFN-β and TMZ showed significantly enhanced antitumor effects in GL26 mouse glioma cells. In vivo, the combined MSC-IFN-β and TMZ therapy significantly reduced the tumor size and improved the survival rates compared to each treatment alone.These results suggest that MSCs can be used as an effective delivery vehicle so that the combination of MSC-IFN-β and TMZ could be considered as a new option for the treatment of malignant gliomas.

    View details for DOI 10.3340/jkns.2015.57.5.323

    View details for PubMedID 26113958

    View details for PubMedCentralID PMC4479712

  • Thrombosed large middle cerebral artery aneurysm mimicking an intra-axial brain tumor: case report and review of literature. Brain tumor research and treatment Kim, Y. J., Jeun, S. S., Park, J. H. 2015; 3 (1): 39-43


    This case report presents a fully thrombosed large aneurysm of middle cerebral artery mimicking an intra-axial brain tumor in a 54-year-old male patient. A small mass like lesion was found incidentally in right frontal area. Brain magnetic resonance image showed dark signal intensity on T2-weighted images and peripheral high signal intensity on T1-weighted images with peripheral rim enhancement. We considered intra-axial tumors such as glioma or metastatic tumor as a differential diagnosis. The lesion was approached transcortically, and intraoperatively, the lesion was found to be a large thrombosed aneurysm originating from the lateral lenticulostriate artery of right middle cerebral artery. One vascular clip was applied at the parent artery, and the thrombosed aneurysm was totally removed. There have been many reports of other intracranial lesions wrongly diagnosed as intracranial neoplasms. And thrombosed aneurysms mimicking intracranial neoplasm have been reported in 4 cases previously. According to those case reports, there were no efficient imaging tools to differentiate between these thrombosed aneurysms and intracranial neoplasms. We reviewed those reports and considered about the efficient method to diagnosed accurately before surgery. To sum up, when a patient presents with an intracranial lesion lying on the course of major or distal cerebral arteries, the surgeon should have thrombosed aneurysm in mind as one of the differential diagnosis and be prepared when surgically treating such lesions.

    View details for DOI 10.14791/btrt.2015.3.1.39

    View details for PubMedID 25977906

    View details for PubMedCentralID PMC4426276

  • Primary malignant melanoma in the pineal region. Journal of Korean Neurosurgical Society Park, J. H., Hong, Y. K. 2014; 56 (6): 504-8


    A 59-year-old male patient had 5-month history of gait disturbance and memory impairment. His initial brain computed tomography scan showed 3.5×2.8 cm sized mass with high density in the pineal region. The tumor was hypointense on T2 weighted magnetic resonance images and hyperintense on T1 weighted magnetic resonance images with heterogenous enhancement of central portion. The tumor was totally removed via the occipital transtentorial approach. Black mass was observed in the operation field, and after surgery, histopathological examination confirmed the diagnosis of malignant melanoma. Whole spine magnetic resonance images and whole body 18-fluoro-deoxyglucose positron emission tomography could not demonstrate the primary site of this melanoma. Scrupulous physical examination of his skin and mucosa was done and dark pigmented lesion on his left leg was found, but additional studies including magnetic resonance images and skin biopsy showed negative finding. As a result, final diagnosis of primary pineal malignant melanoma was made. He underwent treatment with the whole brain radiotherapy and extended local boost irradiation without chemotherapy. His preoperative symptoms were disappeared, and no other specific neurological deficits were founded. His follow-up image studies showed no recurrence or distant metastasis until 26 weeks after surgery. Primary pineal malignant melanomas are extremely rare intracranial tumors, and only 17 cases have been reported since 1899. The most recent case report showed favorable outcome by subtotal tumor resection followed by whole brain and extended local irradiation without chemotherapy. Our case is another result to prove that total tumor resection with radiotherapy can be the current optimal treatment for primary malignant melanoma in the pineal region.

    View details for DOI 10.3340/jkns.2014.56.6.504

    View details for PubMedID 25628812

    View details for PubMedCentralID PMC4303728

  • Disseminated Hemangioblastoma of the Central Nervous System without Von Hippel-Lindau Disease. Brain tumor research and treatment Chung, S. Y., Jeun, S. S., Park, J. H. 2014; 2 (2): 96-101


    Hemangioblastoma (HB) of the central nervous system may occur sporadically or in association with von Hippel-Lindau (VHL) disease. Disseminated HB means malignant spread of the original primary HB without local recurrence at surgically resected site. It has been rarely reported previously, and rarer especially without VHL gene mutation. We report a case of disseminated HB without VHL disease. A 59-year-old man underwent a surgery for total removal of a cerebellar HB. From five years after the surgery, multiple dissemination of HB was identified intracranially and he subsequently underwent cyberknife radiosurgery. The lesions got smaller temporarily, but they soon grew larger. Nine years after the initial surgery for cerebellar HB, he showed severe back pain. His magnetic resonance image of spine revealed intradural extramedullary mass at T6-7 level. Complete surgical removal of the mass was performed and the pathological diagnosis was identical to the previous one. He had no evidence of VHL disease. And there was no recurrence of the tumor at the site of the original operation. The exact mechanism of dissemination is unknown, but the surgeon should be cautious of tumor cell spillage during surgery and prudently consider the decision to perform ventriculo-peritoneal shunt. In addition, continuous follow-up for recurrence or dissemination is necessary for patients even who underwent complete removal of cerebellar HB.

    View details for DOI 10.14791/btrt.2014.2.2.96

    View details for PubMedID 25408933

    View details for PubMedCentralID PMC4231619

  • An intracranial chondroma with intratumoral hemorrhage: a case report and review of the literature. Brain tumor research and treatment Park, J. H., Jeun, S. S. 2013; 1 (1): 42-4


    A 55-year-old female presented to the emergency room with a complaint of aphasia. Her initial brain computed tomography scan showed an intracranial hemorrhage in the left frontal area. After surgery, histopathological examination confirmed the diagnosis of a chondroma. Intradural chondroma is a rare, slow growing, benign intracranial neoplasm, but is even rarer in combination with an intratumoral hemorrhage. Chondromas are generally avascular cartilaginous lesions. Our case was thought to be caused by the rupture of abnormally weak vessels derived from the friable tumor. Intradural chondromas may be included in the differential diagnosis of intracranial tumors with acute hemorrhages.

    View details for DOI 10.14791/btrt.2013.1.1.42

    View details for PubMedID 24904889

    View details for PubMedCentralID PMC4027121

  • Pain assessment in brain tumor patients after elective craniotomy. Brain tumor research and treatment Kim, Y. D., Park, J. H., Yang, S. H., Kim, I. S., Hong, J. T., Sung, J. H., Son, B. C., Lee, S. W. 2013; 1 (1): 24-7


    This study was performed to assess the postoperative pain of brain tumor patients who underwent elective craniotomy and to evaluate the factors associated with pain intensity.From January 2010 to December 2011, 47 patients with newly diagnosed brain tumors who underwent craniotomy were enrolled. The postoperative pain status was assessed daily until discharge using the visual analogue scale (VAS).The study participants comprised of 22 males and 25 females with ages ranging from 18-76 years (median age, 50 years). Patients were divided into two groups: the painful group included patients who had a VAS score of more than 3 during their hospital stay after the craniotomy, and the tolerable group included patients who had a VAS score of 1 to 3 during their hospital stay. There were no differences between the two groups in terms of age, sex, location of surgery, history of diabetes, hypertension and smoking, body mass index, and hospital stay. Univariate analysis revealed that operating time, length of wound, head fixation, and perioperative administration of opioid were not associated with the intensity of postoperative pain. Daily assessment of VAS revealed the two peaks of pain on the operation day and the 4th postoperative day. The intensity of pain during the ambulation period was higher than that during intensive care unit (ICU) stay.Pain following elective craniotomy for brain tumor removal is insufficiently managed, especially after discharge from the ICU. More attention needs to be paid to patients' pain throughout the hospital stay.

    View details for DOI 10.14791/btrt.2013.1.1.24

    View details for PubMedID 24904885

    View details for PubMedCentralID PMC4027119

  • Critical use of balloon angioplasty after recanalization failure with retrievable stent in acute cerebral artery occlusion. Journal of Korean Neurosurgical Society Park, J. H., Park, S. K., Jang, K. S., Jang, D. K., Han, Y. M. 2013; 53 (2): 77-82


    Sudden major cerebral artery occlusion often resists recanalization with currently available techniques or can results in massive symptomatic intracranial hemorrhage (sICH) after thrombolytic therapy. The purpose of this study was to examine mechanical recanalization with a retrievable self-expanding stent and balloon in acute intracranial artery occlusions.Twenty-eight consecutive patients with acute intracranial artery occlusions were treated with a Solitaire retrievable stent. Balloon angioplasty was added if successful recanalization was not achieved after stent retrieval. The angiographic outcome was assessed by Thrombolysis in Cerebral Infarction (TICI) and the clinical outcomes were assessed by the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS).At baseline, mean age was 69.4 years and mean initial NIHSS score was 12.5. A recanalization to TICI 2 or 3 was achieved in 24 patients (85%) after stent retrieval. Successful recanalization was achieved after additional balloon angioplasty in 4 patients. At 90-day follow-up, 24 patients (85%) had a NIHSS improvement of ≥4 and 17 patients (60%) had a good outcome (mRS ≤2). Although there was sICH, there was one death associated with the procedure.Mechanical thromboembolectomy with a retrievable stent followed by additional balloon angioplasty is a safe and effective first-line therapy for acute intracranial artery occlusions especially in case of unsuccessful recanalization after stent thrombectomy.

    View details for DOI 10.3340/jkns.2013.53.2.77

    View details for PubMedID 23560170

    View details for PubMedCentralID PMC3611063