Radical accelerated radiotherapy for non-small cell lung cancer (NSCLC): A 5-year retrospective review of two dose fractionation schedules.

Abstract

BACKGROUND AND PURPOSE\nNumerous fractionation regimes are used for inoperable NSCLC patients not suitable for stereotactic ablative radiotherapy. Continuous hyperfractionated accelerated radiotherapy (CHART, 54\u202fGy, 36 fractions over 12\u202fdays) and hypofractionated accelerated radiotherapy (55\u202fGy, 20 fractions over 4\u202fweeks) are recommended UK schedules. In this single-centre retrospective analysis, we compare both fractionation schemes for patients treated at our institution from 2010 to 15.\n\n\nMATERIALS AND METHODS\nClinical demographic, tumour and survival data were collected alongside radiotherapy dosimetric data from the Varian Eclipse Scripting application programming interface. Differences were assessed using independent samples t-tests. Multivariate survival analysis was performed using Cox regression.\n\n\nRESULTS\nWe identified 563 eligible patients; 43% received CHART and 57% hypofractionated radiotherapy. Median age was 71\u202fyears, 56% were male, 95% PET staged with 53% WHO performance status 0-1. 30%, 14%, 50% and 6% were stage I, II, III and IV, respectively. 38% of patients underwent induction chemotherapy. 99% completed their prescribed radiotherapy treatment. Overall response rate was 50% with a 6.5% 90-day mortality rate. Median disease-free survival was 19\u202fmonths, 50% recurred locally. Median overall survival was 22.5\u202fmonths with 48% alive at 2\u202fyears. Multivariate analysis identified histology, stage, performance status, chemotherapy and radiotherapy response as independent predictors of survival; no significant differences between radiotherapy regimes were observed.\n\n\nCONCLUSION\nIn our centre, CHART and hypofractionated accelerated radiotherapy produce similar outcomes. Dose escalation studies are in progress to develop these schedules to match outcomes reported in concurrent chemo-radiation studies.