Nirmeen Zagzoog

All Publications

• Clinical utility of liquid biopsy in distinguishing true progression from radiation necrosis and pseudoprogression in malignant brain tumor. Journal of neuro-oncology Izhar, M., Hori, Y. S., Lam, F. C., Kalra, N., Zagzoog, N., Tayag, A., Ustrzynski, L., Emrich, S. C., Park, D. J., Chang, S. D. 2026; 178 (1)

  Abstract

  Distinguishing true tumor progression from pseudoprogression (PsP) and radiation necrosis (RN) following radiotherapy or radiosurgery for intracranial tumors remains a significant clinical challenge. Conventional imaging modalities, including MRI and PET, often lack sufficient diagnostic accuracy, while histopathological confirmation, although definitive, is invasive and not always feasible. Liquid biopsy (LB) has emerged as a promising noninvasive diagnostic approach.A systematic review was conducted across PubMed, Embase, Scopus, and Cochrane databases. A total of 964 records were identified, including PubMed (n = 322), Embase (n = 280), Scopus (n = 297), and Cochrane (n = 65), along with three clinical trials identified from trial registers. After removal of 157 duplicates using Covidence, 807 studies were screened by title and abstract. Of these, 749 were excluded, and 58 articles underwent full-text review. Ultimately, 11 studies met the inclusion criteria and were included in the analysis.A diverse range of LB-based biomarkers has been investigated, including immune cell-based markers (e.g., HLA-DRneg/low and VNN2+ CD14+ monocytic myeloid-derived suppressor cells), immune-related proteins (e.g., CXCL11 and MUC-16), circulating tumor cells, cell-free DNA, mitochondrial DNA, B1-SINE elements, microvesicles, and RNA analytes. Plasma was the most used biofluid, with limited evaluation of urine and cerebrospinal fluid. Analytical techniques varied widely, including flow cytometry, PCR-based assays, immunostaining-FISH, and multiplex protein platforms. Several biomarkers showed statistically significant differences among RN, PsP, and tumor recurrence; however, these findings were largely derived from small, heterogeneous cohorts with inconsistent reporting of diagnostic performance metrics. Composite indices, such as the DR-VNN2 index (DVI) and the Necrosis Prediction Index (NPI), showed potential for improving diagnostic differentiation.LB-based biomarkers show promise for differentiating RN and PsP from tumor recurrence; however, current evidence is limited by small sample sizes, methodological heterogeneity, and lack of standardized diagnostic criteria. Larger prospective studies and validation of composite biomarker models are required to establish their clinical utility.Not Applicable.

  View details for DOI 10.1007/s11060-026-05618-z

  View details for PubMedID 42185659

  View details for PubMedCentralID 12860303

• Outcome of CyberKnife stereotactic radiosurgery for the brain metastases in patients with Li Fraumeni syndrome. Journal of neuro-oncology Izhar, M., Hori, Y. S., Kattaa, A. H., Harary, P. M., Lam, F. C., Kalra, N., Zagzoog, N., Tayag, A., Ustrzynski, L., Emrich, S. C., Park, D. J., Chang, S. D. 2026; 178 (1)

  Abstract

  Li-Fraumeni syndrome (LFS) is a hereditary cancer predisposition syndrome associated with germline TP53 mutations and an increased risk of radiation-induced malignancies, posing significant challenges in the management of brain metastases (BM). Data regarding the safety and efficacy of stereotactic radiosurgery (SRS) for BM in this population remain limited.We performed a retrospective analysis of patients with LFS who underwent SRS for BM at our institution. Patient-level, lesion-level, and treatment-related data were collected. Outcomes assessed included local tumor control (LTC), overall survival (OS), distant progression-free survival (DPFS), radiographic response, and treatment-related adverse events.A total of 5 patients with 16 BM lesions were treated with SRS. The median age at treatment was 49 years (range, 37-65). Lesions were typically small (median diameter 6.1 mm) and predominantly supratentorial (87.5%). Most lesions (93.7%) were treated with single-fraction SRS with a median prescribed dose of 24 Gy. LTC was 100% at 3 months, 6 months, and the last follow-up. Median OS and DPFS were 11.03 months (95% CI, 9.53-12.54) and 7.5 months (95% CI, 7.3-7.7), with all deaths attributable to systemic disease rather than neurological causes. Importantly, no cases of radiation necrosis or radiation-induced secondary malignancies were observed during a median follow-up of 45 weeks.SRS demonstrated a short-term favorable local control and safety profile for the treatment of BM in patients with LFS. Given the tendency for lesions to be small and multifocal, along with the need to minimize radiation exposure, SRS represents a rational, focal treatment approach in this high-risk population. However, longer follow-up and prospective studies are needed to better define long-term safety, particularly regarding the risk of radiation-induced malignancies.Not applicable.

  View details for DOI 10.1007/s11060-026-05610-7

  View details for PubMedID 42149268

  View details for PubMedCentralID 1858532

• The Efficacy and Safety of Rimegepant Every Other Day as Preventive Treatment for Migraine: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Current pain and headache reports Attar, A., Alqsair, A., Halabi, M., Barwais, K., Alzaid, A., Alshaikhi, R., Alamri, L., Aljadani, H., Alsharif, J., Zagzoog, N., Aladdin, Y. 2026; 30 (1)

  View details for DOI 10.1007/s11916-026-01486-4

  View details for PubMedID 42024209

  View details for PubMedCentralID 7708887

• The impact of CHEK2 status on radiosurgical outcomes in breast cancer brain metastases. Neurosurgical review Harary, P. M., Hori, Y. S., Kattaa, A. H., Tan, S. K., Lam, F. C., Kalra, N., Zagzoog, N., Tayag, A., Ustrzynski, L., Emrich, S. C., Gibbs, I. C., Li, G., Kuno, A., Park, D. J., Chang, S. D. 2026; 49 (1)

  View details for DOI 10.1007/s10143-026-04272-3

  View details for PubMedID 41963546

  View details for PubMedCentralID 3698070

• Treatment outcomes of stereotactic radiosurgery for sarcoma brain metastases-systematic review. Journal of neuro-oncology Izhar, M., Kattaa, A. H., Hori, Y. S., Lam, F. C., Kalra, N., Zagzoog, N., Tayag, A., Ustrzynski, L., Emrich, S. C., Park, D. J., Chang, S. D. 2026; 177 (2)

  View details for DOI 10.1007/s11060-026-05542-2

  View details for PubMedID 41872576

  View details for PubMedCentralID 10725339

• Treatment outcomes of cerebral arteriovenous malformations in patients with Hereditary hemorrhagic Telangiectasia: A case series from a Single-Center experience. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Izhar, M., Al Gharyani, M. F., Hori, Y. S., Kattaa, A. H., Lam, F. C., Kalra, N., Zagzoog, N., Tayag, A., Ustrzynski, L., Emrich, S. C., Park, D. J., Chang, S. D. 2025; 143: 111750

  Abstract

  Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant vascular disorder characterized by multisystemic arteriovenous malformations (AVMs), including those in the central nervous system. Cerebral AVMs (cAVM), present in up to 23% of patients with HHT, pose a risk of serious neurological complications such as hemorrhage or seizures. Despite their clinical significance, standardized treatment guidelines for cAVM in HHT remain lacking due to limited data. This study evaluates outcomes of stereotactic radiosurgery (SRS) and microsurgical resection for unruptured cAVM in patients with HHT.We retrospectively analyzed 26 patients with clinically or genetically confirmed HHT and radiologically verified unruptured cAVM treated at our institution between 1996 and 2024. Patients were selected based on treatment with either surgery or SRS and a minimum of 1-year follow-up, excluding cases with prior ruptures or previous AVM interventions. Clinical, radiographic, and treatment data were collected and reviewed, including AVM characteristics, intervention parameters, and functional outcomes. The outcomes were changes in functional status measured by the modified Rankin Scale (mRS), complication rates, AVM obliteration, and recurrence. Statistical analysis included the X2 test, Fisher's exact test, and the Mann-Whitney U test, with significance set at p < 0.05. Survival outcomes were assessed using Kaplan-Meier analysis.Among 26 patients, 4 underwent CyberKnife SRS and 22 had microsurgical resection. In the SRS group, all patients were female with a mean age of 39 years at the time of diagnosis; 80 % of lesions achieved complete obliteration at a median follow-up of 5.9 years. Most lesions were superficial, small in volume (mean: 0.16 cm3), and received an average marginal dose of 20.1 Gy. Post-radiosurgical complications occurred in 50 %, primarily headaches and visual disturbances; no hemorrhages or seizures were reported. In the surgery group, 92 % of lesions were obliterated with a median follow-up of 2.75 years. Functional status remained stable or improved in 68 % of patients, with a significant change between pre- and postoperative scores (P = 0.03). Postoperative complications occurred in 23 % of patients, and AVM recurrence was significantly associated with SM grade (P = 0.005). No mortality was observed in either group.In patients with HHT, cAVMs are typically small, multiple, and low-grade with a low risk of hemorrhage. Both surgical resection and SRS are effective treatment options, though further prospective studies are needed to better define and compare their long-term outcomes.

  View details for DOI 10.1016/j.jocn.2025.111750

  View details for PubMedID 41237734

• Stereotactic radiosurgery for hepatitis C virus-related hepatocellular carcinoma brain metastasis: A retrospective analysis and systematic review WORLD NEUROSURGERY-X Izhar, M., Hori, Y. S., Kattaa, A. H., Lam, F. C., Kalra, N., Zagzoog, N., Tayag, A., Ustrzynski, L., Emrich, S. C., Pollom, E. L., Soltys, S. G., Gephart, M., Park, D. J., Chang, S. D. 2025; 28

  View details for DOI 10.1016/j.wnsx.2025.100541

  View details for Web of Science ID 001602623500001

• Pilot Study of Optical Topographic Imaging Based Neuronavigation for Mastoidectomy WORLD NEUROSURGERY Zagzoog, N., Rastgarjazi, S., Ramjist, J., Lui, J., Hopfgartner, A., Jivraj, J., Yeretsian, T., Zadeh, G., Lin, V., Yang, V. X. D. 2022; 166: E790-E798

  Abstract

  Mastoidectomy involves drilling the temporal bone while avoiding the facial nerve, semicircular canals, sigmoid sinus, and tegmen. Optical topographic imaging (OTI) is a novel registration technique that allows rapid registration with minimal navigational error. To date, no studies have examined the use of OTI in skull-base procedures.In this cadaveric study, 8 mastoidectomies were performed in 2 groups-4 free-hand (FH) and 4 OTI-assisted mastoidectomies. Registration accuracy for OTI navigation was quantified with root mean square (RMS) and target registration error (TRE). Procedural time, percent of mastoid resected, and the proximity of the mastoidectomy cavity to critical structures were determined.The average RMS and TRE associated with OTI-based registration were 1.44 mm (±0.83 mm) and 2.17 mm (±0.89 mm), respectively. The volume removed, expressed as a percentage of the total mastoid volume, was 37.5% (±10.2%) versus 31.2% (±2.3%), P = 0.31, for FH and OTI-assisted mastoidectomy. There were no statistically significant differences between FH and OTI-assisted mastoidectomies with respect to proximity to critical structures or procedural time.This work is the first examining the application of OTI neuronavigation in lateral skull-base procedures. This pilot study revealed the RMS and TRE for OTI-based navigation in the lateral skull base are 1.44 mm (±0.83 mm) and 2.17 mm (±0.89 mm), respectively. This pilot study demonstrates that an OTI-based system is sufficiently accurate and may address barriers to widespread adoption of navigation for lateral skull-base procedures.

  View details for DOI 10.1016/j.wneu.2022.07.150

  View details for Web of Science ID 000877423400052

  View details for PubMedID 35953033