This multicenter phase 2 trial tackled one of radiation oncology’s major challenges: reirradiation of marginal or in-field recurrences in the lung. It included 60 patients with recurrent NSCLC or SCLC within 5cm of the prior radiation field (defined as 50 Gy EQD2 (alpha/beta=10) or higher from the prior plan). Most (83%) had direct overlap of the original and reirradiation PTVs. The trial called for a reirradiation dose of at least 45 Gy EQD2, but treating physicians could use SBRT or conventional fractionation. Most were treated with conventional fractionation (63%) with a median EQD2 of 53 Gy most commonly from 50 Gy in 25 fractions or 60 Gy in 33 fractions. The median EQD2 was 77 Gy with SBRT most commonly using 52.5 Gy in 7 fractions. Crucially, OAR constraints took precedence with summed Dmax limits of ~75 Gy3 (cord), 100 Gy3 (esophagus), and 110 Gy3 (trachea/mainstem bronchus). Outcomes were encouraging with a median OS of 30.1 months (2-yr OS 56%), far exceeding an 8-month historical benchmark. Two-year local recurrence was 39% overall, but notably lower with SBRT (19% vs 50% for CFRT). Median DFS was 13.6 months. | Cammerari, Int J Radiat Oncol Biol Phys 2025
