Hypofractionated radiation therapy in the management of locally advanced NSCLC: a narrative review of the literature on behalf of the Italian Association of Radiation Oncology (AIRO)-Lung Working Group

A systematic literature was performed to assess the benefit in terms of effectiveness and feasibility of hypofractionated radiotherapy (HypoRT), with or without chemotherapy (CT), in the treatment of locally advanced non-small cell lung cancer (NSCLC). We have identified all studies, published from 2007 onwards, on patients with locally advanced NSCLC treated with HypoRT with radical intent, with a minimal dose per fraction of 2.4 Gy, with or without concurrent chemotherapy. Twenty-nine studies were identified, for a total of 2614 patients. Patients were divided in the concurrent chemo-radiation therapy group (CT-RT) and radiotherapy alone (RT). In RT group, the delivered dose ranged from 45 to 85.5 Gy, with a dose/fraction from 2.4 to 4 Gy. Actuarial 2-year PFS ranged from 13 to 57.8%, and 1, 2- and 3-year overall survival (OS) ranged from 51.3 to 95%, from 22 to 68.7%, and from 7 to 32%, respectively. Acute Grade ≥ 3 esophagitis occurred in 0-15%, while late esophageal toxicity was 0-16%. Acute pneumonitis occured in 0-44%, whereas late pneumonitis occured in 0-47%, most commonly grade ≤ G3. In CT-RT group, the delivered dose ranged from 52.5 to 75 Gy, with a dose/fraction ranging from 2.4 to 3.5 Gy. Actuarial 2-year PFS ranged from 19 to 57.8%, and OS at 1, 2 and 3 years ranged from 28 to 95%, 38.6 to 68.7%, and 31 to 44%, respectively. Acute Grade 2 and 3 esophagitis occurred in 3-41.7%, while late esophageal toxicity occurred in 0-8.3%. Acute pneumonitis ranged from 0 to 23%, whereas late pneumonitis occured 0-47%. HypoRT seems to be safe in patients with locally advanced NSCLC. The encouraging survival results of several studies analyzed suggest that hypofractionated radiation schemes should be further investigated in the future.