QLTI-08. SURVEY OF CANADIAN NEURO-ONCOLOGY CLINICIANS ABOUT THE TREATMENT OF ADULT MEDULLOBLASTOMA

Abstract BACKGROUND Given the rarity of medulloblastoma in adults (fewer than 50 incident cases annually across Canada), optimal chemotherapy strategy this population is unknown. The management adult medulloblastomas thought to vary from institution institution. Guidelines often omit suggestions for specific regimens, reflecting lack high quality evidence population. We sought understand Canadian practice patterns, hoping inform future metrics and guidelines. METHODS In March 2022 a 30-question survey was sent out 71 neuro-oncology clinicians on Adolescent Young Adult national rounds mailing list. Snowball sampling permitted. RESULTS There were 25 responses (up 35% response rate). Radiation oncologists (11), neuro-oncologists (8), medical (4), neurosurgeons (2) responded 6/10 provinces. They each treated average 1.6 patients per year. Most (61% respondents) said that molecular subgrouping always done at their centre. Half (50%) indicated cerebrospinal fluid testing diagnosis. most common (64%) radiation regimen 36 Gy (in 20 fractions) craniospinal irradiation + 18 10 boost. Concomitant rarely given (75% respondents included less half time). Adjuvant frequently administered (79% give it more adjuvant Cisplatin/Lomustine/Vincristine (57%), but other regimens alternating with Cyclophosphamide/Vincristine (21%), Cisplatin/Cyclophosphamide/Vincristine (14%), carboplatin-based (14%). Respondents noted challenges prescribing population: drug toxicities, limited resources, clinical uncertainty. support standard care guidelines 92% respondents. CONCLUSIONS significant variation among centres treating medulloblastoma. This can serve as an opportunity improvement research.