Although use of lower-dose stereotactic body radiotherapy is becoming more common, a recent retrospective study has found that use of higher doses may result in a survival benefit for patients with stage I non-small cell lung cancer (NSCLC).

The study looked at more than 25,000 patients with NSCLC who were diagnosed between 2004 and 2014 and treated with stereotactic body radiotherapy (SBRT) as a primary curative therapy — either low biologically effective doses (LowBED; 100 to 129 Gy) or high biologically effective doses (HighBED; 130 Gy or higher). These patients were matched based on patient and tumor characteristics to compare overall survival.

“There is an increasing body of literature on improved outcomes with higher BED10 regimens,” the researchers wrote. “Despite this, our evaluation of SBRT prescription patterns spanning over a decade show a national shift in the popularity of HighBED SBRT to a more conservative approach with LowBED regimens.”

During the study period, the use of HighBED decreased. The use of HighBED peaked at 42% in 2007 and then declined sharply to only 7% of all cases in 2014. A simultaneous increase in the adoption of LowBED occurred from 2007 to 2014, rising from 5% to 34% of all SBRT cases during this period

Overall survival was higher for patients treated with HighBED compared with LowBED (47 months vs 42 months, respectively). Multivariable analysis showed that LowBED was associated with worse outcomes (hazard ratio; 1.046; 95% CI, 1.004–1.090; P =.032).

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“Because most guidelines assume near equipoise of the effectiveness of one regimen over another, adopting a more conservative and potentially safer approach while still achieving a BED10 greater than 100 Gy may be a conscious choice that many physicians adopt,” the researchers wrote. “Our findings suggest that SBRT regimens delivering BED10 doses greater than 100 Gy may not be equivalent, but that an incremental gain may result from delivering higher BED10 doses.”

Disclosure: Dr Lin has received research funding from Hitachi Chemical Diagnostics, Inc., Roche/Genentech, New River Labs, and Beyond Spring Pharmaceuticals, and serves on the advisory board for AstraZeneca. For a full list of disclosures, please refer to the original study.

Reference

Moreno AC, Fellman B, Hobbs BP, et al. Biologically effective dose in stereotactic body radiotherapy and survival for patients with early-stage NSCLC. J Thorac Oncol. 2020;15(1):101-109.