Hypofractionated Intensity-Modulated Radiotherapy for Patients With Non-Small-Cell Lung Cancer

Alternative treatment regimens are needed for patients with non-small cell lung cancer (NSCLC) who cannot receive definitive treatment with concurrent chemoradiotherapy, surgery, or stereotactic ablative radiotherapy (SABR).

We report survival, patterns of failure and toxicity outcomes for patients with NSCLC who were not eligible for surgical resection, concurrent chemoradiotherapy, or SABR and underwent hypofractionated intensity-modulated radiotherapy (IMRT). Kaplan-Meier survival analysis was used to evaluate the progression-free and overall survival. Competing risk analysis was used to evaluate in-field, locoregional, and distant failure.

A total of 42 patients treated to 52.5 to 60 Gy in 15 fractions were included. Most of the patients had metastatic or recurrent disease (64%) and a relatively large, centrally located tumor burden (74%). The median follow-up period was 13 months (interquartile range, 6-18 months). All patients received the total prescribed dose. The median survival was 15.1 months. The overall and progression-free survival rates at 1 year were 63% and 22.5%, respectively. The pattern of failure was predominantly distant, with only 2% of patients experiencing isolated in-field recurrence. The cumulative incidence of in-field failure at 6 and 12 months was 2.5% (95% confidence interval, 0.4%-15.6%) and 16.1% (95% confidence interval, 7.5%-34.7%), respectively. The risk of esophageal toxicity was associated with the esophageal mean dose, maximal point dose, and dose to the 5 cm³ volume. The risk of pneumonitis was associated with the lung mean dose and volume receiving 18 Gy.

Hypofractionated IMRT without concurrent chemotherapy provides favorable rates of local control and survival for well-selected patients with NSCLC who cannot tolerate standard definitive therapy.