ESTRO 2022 - Abstract Book

S772

Abstract book

ESTRO 2022

Since the start of the NHS POP Programme, an agreement between NHS England and UK referring centres ensured outcomes data collection. Follow-up correspondence has been stored in patient files in a national database and curated by the Proton Clinical Outcomes Unit, established in 2018. Clinical and treatment-related data were extracted from the central patient database. The POP patient cohort was divided into CNS and extracranial diseases. Spinal and skull base (BoS) chordoma and chondrosarcoma were grouped with CNS diseases. Grade (G) ≥ 3 late toxicities (LT), as per CTCAE (Common Terminology Criteria for Adverse Events) v 4.0 definition, occurring later than 90 days since completion of treatment, were recorded. Where toxicity could not be graded accurately, individualised workbooks were sent to referring centres for clarification. The follow up time is calculated from end of PBT treatment to death or last follow up. Results Between 2008 and September 2020, 830 patients were treated within the POP for CNS malignancies. Their demographics and clinical characteristics are listed in Table 1. After a median follow up of 2.65 years (range 0.03 - 11.59) the overall survival for the whole cohort was 91.33%, and the local control was 75.42%. Of note, the local control was unknown in 12.29% of the patients, and 12.29% experienced disease progression. Toxicity analysis (Table 2) was carried out on 760 patients, with patients excluded due to short follow-up (<90 days) and/or inadequate toxicity data available. Median follow up in this population is 2.8 years (0.26 - 11.59), and median radiotherapy prescription dose 54 GyRBE (34.8-79.2).