OTHER-10 EARLY CLINICAL EXPERIENCE OF SRS AND SBRT STEREOTACTIC BODY RADIOTHERAPY FOR CENTRAL NERVOUS SYSTEM (CNS) CASE SERIES AT HCG CANCER CENTRE, NAIROBI.

BACKGROUND: Stereotactic Radiosurgery (SRS), Stereotactic Radiotherapy(SRT) and Stereotactic Body Radiation Therapy (SBRT) delivers fewer high-dose fractions of radiation which may be radiobiologically favorable to conventional low-dose fractions commonly used for central nervous system. We report our early experience using SBRT in central nervous tumours (CNS). METHODS / INTRODUCTION: Sequential patients treated with SBRT from December 2022 to May 2023 at HCG Cancer Care Kenya for CNS tumours will be included in this retrospective review of early clinical data collected in the institutional database. SBRT treatments were delivered using VersaHD Linac with doses ranging from 36.25Gy to 30Gy delivered in 3 to 5 fractions. Local guidelines have been developed to guide stereotactic radiotherapy treatments in Kenya. The national health insurer is currently reimbursing for stereotactic treatments would further increases the uptake. Discussion The CNS cases that has been treated locally with SRS/SRT/SBRT with CNS case series shall be evaluated under clinical presentation, treatment planning process in recurrent Meningioma, Glomus tymphanicum and brain metastasis. The radiobiological advantage of SRS/SRT/SBRT over conventional radiotherapy is the short course treatment with minimal toxicity. SRS/SBRT is not oxygen dependent tumor DNA damage but related to endothelial cell damage from apoptosis. The treatment volume margins in CNS cancers are tight to a millimeter hence rigid immobilization with head fraxion frame is required. The turnaround time from diagnosis, planning to treatment delivery for the patients is 72 hours. RESULTS: 30 patients underwent SBRT treatment techniques varying from CNS and other sites. The case presentations in case series met the criteria and indications for SBRT treatment. The initial patient reported the treatment to be tolerable however currently we do have data on acute and long term in terms of both outcomes and toxicity. Follow up is needed to review and report on the outcomes.