Hypofractionated radiotherapy to the pancreas: U.K. experience

ABSTRACT

Background: During the COVID19 pandemic, many centres in the UK, shifted towards utilising hypofractionated radiotherapy (RT) to pancreas. We aim to report the UK experience hypofractionated (3-5 fractions) RT to the pancreas from 7 centres in the UK. Rates of toxicity, progression, death and potential prognostic factors were assessed. Univariate and multivariate Cox proportional hazards analyses were performed. Results: 92 patients from 7 centres were included in the analysis (median age 71 (range 49-88). 90% had performance status of 0-1. 66% had locally advanced disease. 53% had RT delivered over 3- 5 fractions (n = 49, median 30Gy/5f, range30- 40Gy in 3-5f). The rest had 15-fraction RT with or without concurrent chemotherapy (n = 43, median 45Gy/15f, range 36-45Gy/15f). Induction chemotherapy (CT) was used in 64% (FOLFIRINIOX -42/59). Median follow-up was 13 months from first treatment (induction CT or RT). Median overall survival (OS) among all patient was 17 months, (95% CI-14.5-19.5 months). On multivariable analysis, induction CT was the only predictor of improved PFS (median survival (MS) 12 vs 5 months;hazard ratio [HR] 0.23;95% confidence interval [CI] 0.12-0.44, p < 0.001) and OS (MS 24 vs 11 months;HR 0.15;95% CI 0.07 - 0.34, p < 0.001). There were no deaths. 4 patients had grade 3+ toxicities (transaminitis, cholecystitis and gall bladder perforation, small bowel obstruction and diarrhoea) -all had concurrent CT. Conclusions: Our survival outcome appears to be comparable with published data from CT + concurrent chemoradiotherapy. Induction CT appears to improve outcome. Careful selection of patients can help maximise advantage in this patient population.