Survival and Toxicity of Hypofractionated Intensity Modulated Radiation Therapy in 4 Gy Fractions for Unresectable Stage III Non-Small Cell Lung Cancer.

PURPOSE

To assess the survival, local and distant control, and toxicity in patients with unresectable locally advanced non-small cell lung cancer treated with radical-intent hypofractionated radiation therapy delivering approximately 60 Gy in 4-Gy fractions.

METHODS AND MATERIALS

Consecutive patients with unresectable stage III non-small cell lung cancer (n = 42) who received hypofractionated intensity modulated radiation therapy were retrospectively analyzed (2012-2016). Treatments consisted of first-line platinum-based doublet induction chemotherapy followed by an intended dose of 60 Gy in 15 fractions.

RESULTS

During a median follow-up period of 46 months (95% confidence interval, 41-59) the median overall survival was 47 months (95% confidence interval, 31 to not reached). The 1-, 2-, 3-, and 5-year overall survival rates were 81%, 69%, 64%, and 32%, respectively. The 1-, 2-, 3-, and 5-year progression-free survival rates were 58%, 35%, 25%, and 25%, respectively. An isolated locoregional recurrence was seen in 12% of the patients (n = 5). The incidence of grade (G) 3 or higher treatment-related lung toxicity was 14% (n = 6), among which G3 toxicity was 9.5% (n = 4) and G5 toxicity was 4.8% (n = 2). Twelve percent of patients (n = 5) experienced G3 radiation esophagitis, and 2% (n = 1) had G4 esophageal toxicity.

CONCLUSIONS

Patients with unresectable locally advanced non-small cell lung cancer treated with hypofractionated intensity modulated radiation therapy in doses up to 60 Gy at 4 Gy per fraction had promising survival, although high-grade esophageal and lung toxicities were seen. Our findings deserve further evaluation in prospective studies.