Accelerator.

Does accelerated treatment (60 Gy in 25 fractions) improve outcomes for stage III non-small cell lung cancer (NSCLC)? KROG 0903 was a randomized phase 3 trial of 303 patients receiving definitive chemoradiation for stage III NSCLC. The GTV/ITV was defined by PET/CT and 4D-CT, which included nodes that were histologically confirmed or ≥1 cm. A 0.5-1.0 cm CTV margin was used. In the standard arm, the initial PTV (CTV + 1 cm craniocaudal and 0.5 cm radial) received 44 Gy in 22 fractions followed by a cone-down boost to the GTV + 0.5 cm margin of 16 Gy in 8 fractions for a total of 60 Gy in 30 fractions. In the accelerated arm, the larger PTV received 45 Gy in 25 fractions with a simultaneous integrated boost of 60 Gy to the GTV. Accelerated RT did not improve the ambitious primary outcome of median OS (26 v 27 months). There was no improvement in OS with accelerated RT at 2 years (50.7% v 50.4%) or 5 years (30.2% v 25.8%). Nor was there an improvement in local tumor control at 2 years (62.4% v 54.0%) and 5 years (51.0% v 48.6%). The cumulative rate of grade 3+ esophagitis was 5.8% with conventional RT compared to 2.1% with accelerated RT, and the cumulative rates of grade 3+ pneumonitis were 7.6% v 3.1%. | Kim, Int J Radiat Oncol Biol Phys 2022