Double down.

Headline: 70 Gy in 35 daily fractions isn’t superior to 45 Gy in 30 BID fractions for limited stage small cell lung cancer. The CONVERT trial did not demonstrate superiority for 66 Gy in 33 fractions, and at ASCO ‘21 we got a peek at the initial results of the CALBG 30610/RTOG 0538 trial that compared 70Gy/35 with the stalwart 3-week BID regimen. Minus the patients initially randomized to an original third arm (concomitant boost), 638 patients were randomized to either daily or twice daily radiation and concurrent chemotherapy. There was no difference in median overall survival between arms (30.5 months QD, 28.7 months BID), no difference in 2-year OS (56% QD, 59% BID), and no difference in 4-year OS (39% QD, 35% BID). There was also no difference in PFS and no difference in the rates of overall and grade 3+ toxicity. On to the next wave of trials using either dose-escalated BID radiation or hypofractionation. | Bogart, ASCO 2021