Brain radiotherapy and risk of wound healing following Ommaya reservoir placement in leptomeningeal disease (LMD).

e13579 Background: Leptomeningeal disease (LMD) is a late-stage sequelae of solid and hematologic disease progression. Development of LMD generally portends a poor prognosis. Aggressive treatment with cranial spinal radiotherapy and intrathecal therapy (IT) shows promise in extending survival; whereas delays in treatment could negatively impact survival. Ommaya reservoirs are the most common implant for IT therapy. The timing of brain radiation is often delayed following Ommaya placement due to concerns of wound infection or delayed wound healing. We seek to determine whether whole brain radiation (WBRT) negatively impacts wound healing following Ommaya reservoir placement. Methods: The authors performed a retrospective chart review on all patients who underwent Ommaya reservoir placement for LMD at an NCI-accredited comprehensive cancer center between 2007 and 2025. Patient demographics, clinical characteristics, tumor characteristics, IT regimen, radiotherapy regimen, infection status, and mortality data were collected. Results: A total of 198 patients were identified who underwent Ommaya reservoir placement and perioperative irradiation. Of those, 165 (83.3%) patients underwent WBRT, with the remainder undergoing targeted radiotherapy. 68% of the patients were female. Breast cancer was the most common histology (46%), followed by melanoma (15%) and lung cancer (14%). 43% of patients were active smokers and 13% had diabetes mellitus. 28% of patients received WBRT within 7 days after Ommaya reservoir placement, 26% received WBRT within 7 days prior to surgery, 25% received WBRT 15-30 days after surgery, and 12% received WBRT 15-30 days prior to surgery. The rate of infection among these patients was 2.4%. 50% of infections occurred 30-90 days after surgery, while the other half occurred more than 90 days after surgery. There was no correlation between infections and timing of radiation. The overall cohort 30- and 90-day mortality rates were 10.6% and 12.1%, respectively. Among patients who were infected, there were no 30-day mortalities, and there was one 90-day mortality. Conclusions: WBRT does not appear to increase the risk of wound infection before or after Ommaya reservoir placement. These findings offer opportunities for future studies examining the timing of WBRT and IT directed therapy in LMD.