Accelerated intensity-modulated radiotherapy (IMRT) was well tolerated and led to high loco-regional control (LRC) among patients with locally advanced lung cancer, according to a study published in Radiation Oncology.1

The standard of care for advanced unresectable or inoperable lung cancer is standard-dose radiotherapy plus platinum-based chemotherapy, but long-term survival outcomes are poor. Previous studies have shown that IMRT limits dose toxicity, is organ-sparing, and may be effective in locally advanced tumors.

For this retrospective study, researchers assessed the outcomes of 73 patients with unresectable advanced NSCLC who were treated using 2 different schedules of IMRT: simultaneous modulated accelerated radiotherapy (SMART; 30 x 2.2 Gy over 6 weeks) with or without chemotherapy, or moderate hypofractionated radiotherapy (H-RT; 24 x 2.75 Gy over 4 weeks) for patients unfit for chemotherapy. Patients were deemed ineligible for stereotactic body radiation therapy due to tumor size or localization.

After a median follow-up of 44 months, 1-year loco-regional control (LRC) rate was 76% (95% CI, 66-87), 2-year LRC was 62% (95% CI, 49-77), and 4-year LRC was 55% (95% CI, 41-75); the median LRC time was not reached.

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The 1-year overall survival (OS) rate was 72% (95% CI, 63-83), 2-year OS rate was 54% (95% CI, 43-68), and 4-year OS rate was 29% (95% CI, 19-45); the median OS was 27 months.

The most frequently reported grade 3 to 4 adverse events were pneumonitis and esophagitis, occurring in 7% and 1% of patients, respectively.

No significant differences were observed between SMART and H-RT in regard to LRC (P = .26), OS (P = .6), and rates of toxicity.

The authors concluded that the “encouraging toxicity profile and efficacy of this technique warrants further investigation in a prospective clinical trial, especially in combination with immunotherapy.”

Reference

  1. Jaksic N, Chajon E, Bellec J, et al. Optimized radiotherapy to improve clinical outcomes for locally advanced lung cancer [published online August 13, 2018]. Radiat Oncol. doi: 10.1186/s13014-018-1094-y