Accelerated hypofractionated radiation therapy (AHRT) for non-small-cell lung cancer: can we leave standard fractionation?

Abstract

To report interim results from a single-institution study conducted to assess accelerated hypofractionated radiotherapy (AHRT) delivered with 3D conformal radiotherapy in two groups of patients with non-small cell lung cancer: (1) patients with early stage disease unable to tolerate surgery and ineligible for stereotactic body radiation therapy, and (2) patients with locally advanced disease unsuitable for concurrent chemoradiotherapy. A total of 83 patients (51 stage I-II, 32 stage III) were included. Radiotherapy targets included the primary tumor and positive mediastinal areas identified on the pre-treatment PET-CT. Mean age was 77.8±7.8years. ECOG performance status (PS) was ≥2 in 50.6% of cases. Radiotherapy was delivered in daily fractions of 2.75Gy to a total dose of 66Gy (BED10 84Gy). Acute and late toxicities were evaluated according to NCI CTC criteria. At a median follow-up of 42months, median overall survival (OS) and cause-specific survival (CSS) were 23 and 36months, respectively. On the multivariate analysis, PS [HR 4.14, p=0.0001)], stage [HR 2.51, p=0.005)], and maximum standardized uptake values (SUVmax) [HR 1.04, p=0.04)] were independent risk factors for OS. PS [HR 5.2, p=0.0001)] and stage [HR 6.3, p=0.0001)] were also associated with CSS. No cases of severe acute or late treatment-related toxicities were observed. OS and CSS rates in patients treated with AHRT for stage I-II and stage III NSCLC were good. Treatment was well tolerated with no grade three or higher treatment-related toxicity. PS, stage, and SUV max were predictive for OS and CSS.