Hypofractionated Radiation Therapy Safer, Halves Treatment Time in NSCLC

Hypofractionated radiation therapy is less toxic and just as effective as conventional radiation therapy in patients with non-small cell lung cancer (NSCLC), according to research presented at the 58th Annual Meeting of the American Society for Radiation Oncology (ASTRO) in Boston, MA (September 25-28, 2016).

Due to the presence of comorbidities or poor performance status, many patients who present with stage III NSCLC are unable to receive standard treatment of concurrent chemotherapy and radiation therapy. However, results of an earlier phase I clinical trial showed that using modern technologies to increase the daily dose and precision of radiation treatment could offset the need for chemotherapy while improving survival and quality of life.
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In a phase III trial, the investigators assessed differences in overall survival among patients receiving hypofractionated versus conventional radiation therapy. They also measured several secondary endpoints, including progression-free survival, toxicity, quality of life, and cost effectiveness.

At the ASTRO annual meeting, the investigators presented interim data on 60 of the patients included in the trial, all of whom had stage II or III NSCLC. Patients with stage II disease could not undergo surgery and those with stage III NSCLC were not candidates to receive radiation therapy and chemotherapy concurrently. Patients were randomly assigned to receive hypofractionated radiation therapy (n = 32 patients) or conventional radiation therapy (n = 28).

At 24 months, investigators found that the choice of treatment did not significantly impact survival. A Kaplan-Meier analysis of the 48 evaluable patients showed that overall and progression-free survival was 14 months and 11.5 months, respectively, for both groups.

However, while there was no difference in survival, investigators did find that patients who received accelerated radiation therapy experienced fewer grade 3 adverse events (10 reported for conventional radiation therapy vs 6 for hypofractionated radiation therapy) and a lower rate of death from hypoxia (2 for conventional RT vs 1 for hypofractionated RT).

Thus, they concluded that the use of hypofractionated radiation therapy for NSCLC may be an effective way of delivering larger doses of treatment safely with no difference in overall survival versus conventional radiation therapy.

“The patients in the study who were treated with hypofractionation were able to finish therapy in three weeks, compared to the six weeks needed for the conventionally treated patients. Additionally, I predict that at the completion of our study, despite the higher doses given per treatment in the experimental accelerated, hypofractionated [radiation therapy] arm, there will be no increased toxicity with this regimen.” Puneeth Iyengar, MD, PhD, lead author of the study and an assistant professor of radiation oncology at the University of Texas Southwestern Medical Center in Dallas. “If hypofractionated radiation with curative intent can reduce the treatment time for lung cancer patients by half with no greater toxicity, and with equivalent—if not better— tumor control and survival outcomes, this research could result in a change in the paradigm of how a large subset of locally advanced NSCLC patients are treated.”