Clinical Focus


  • Radiation Oncology

Academic Appointments


Professional Education


  • Residency: University of Arizona Radiation Oncology Residency Program (2022) AZ
  • Internship: UCSF Fresno Internal Medicine Residency (2018) CA
  • Medical Education: University of California Davis Registrar (2017) CA

All Publications


  • ASO Visual Abstract: Patterns of Recurrence after Poor Response to Neoadjuvant Chemotherapy in Gastric Cancer and the Role for Adjuvant Radiation. Annals of surgical oncology Hui, C., Ewongwo, A., Lau, B., Fisher, G., Delitto, D., Poultsides, G., Ho, Q. A., Rahimy, E., Pollom, E., Chang, D. T., Vitzthum, L. K. 2023

    View details for DOI 10.1245/s10434-023-14475-3

    View details for PubMedID 37875741

  • Patterns of Recurrence After Poor Response to Neoadjuvant Chemotherapy in Gastric Cancer and the Role for Adjuvant Radiation. Annals of surgical oncology Hui, C., Ewongwo, A., Lau, B., Fisher, G., Delitto, D., Poultsides, G., Ho, Q., Rahimy, E., Pollom, E., Chang, D. T., Vitzthum, L. K. 2023

    Abstract

    BACKGROUND: Improved treatment strategies are needed for patients with locally advanced gastric cancer with poor response to neoadjuvant chemotherapy. We aimed to describe patterns of failure for patients with no or partial response (NR, PR) to preoperative chemotherapy.PATIENTS AND METHODS: We analyzed patients with locally advanced gastric cancer treated from 2008 to 2022 with preoperative chemotherapy followed by surgery with D2 resection. We excluded patients who received radiation. Cumulative incidence of locoregional failure (LRF) and distant metastases (DM) were calculated. For patients with recurrent abdominal disease, hypothetical radiation clinical treatment volumes (CTV) were contoured on postoperative scans and compared with patterns of recurrence.RESULTS: A total of 60 patients were identified. The most used preoperative chemotherapy was FLOT (38.6%), followed by FOLFOX (30%) and ECF/ECX/EOX (23.3%). Four (6.7%), 40 (66.7%), and 9 patients (15%) had a complete pathologic response (CR), PR, and NR to neoadjuvant therapy, respectively. Among patients without a CR, 3-year overall and progression-free survival rates were 62.3% (95% CI 48-76.6%) and 51.3% (95% CI 36.9-65.7%), respectively. Three-year cumulative incidence of LRF and DM were 8.4% (95% CI 0.4-16.4%) and 41.0% (95% CI 26.3-55.4%), respectively. Absolute rates of patients having the first site of recurrence encompassed by a postoperative radiation CTV was 2.0% for patients without a CR and 0% for patients with NR.CONCLUSIONS: Patients with locally advanced gastric cancer with less than a CR to chemotherapy have poor outcomes due to high rates of DM. Adjuvant locoregional therapy such as radiation is unlikely to affect survival.

    View details for DOI 10.1245/s10434-023-14350-1

    View details for PubMedID 37755563

  • 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

    Abstract

    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