Radiation Oncology

PD‑1/PD‑L1 plus RT—especially SBRT or hypo‑RT—improves lung cancer survival without more severe pneumonitis

This meta-analysis pooled 15 RCTs of lung cancer patients receiving RT or chemoradiotherapy with or without immune checkpoint inhibitors (ICIs). Adding ICIs improved progression-free survival (HR 0.76, 95% CI 0.70–0.83) and overall survival (HR 0.83, 95% CI 0.75–0.92). PFS benefit was strongest with SBRT (HR 0.38) and hypofractionated RT (HR 0.49), and with consolidation rather than concurrent ICIs. PD‑1 and PD‑L1 inhibitors both improved PFS, and PD‑L1 blockade also improved OS. 1

APOLO: induction atezolizumab‑chemo before CRT and IO maintenance in unresectable stage III NSCLC

APOLO was a multicenter phase 2 single‑arm trial of unresectable stage IIIA–IIIC NSCLC using induction atezolizumab plus carboplatin/paclitaxel before concurrent CRT and atezolizumab maintenance. Among 38 patients with median follow‑up 29.6 months, 12‑month and 24‑month PFS were 68.4% and 50.0%, respectively. Overall survival was 86.8% at 12 months and 60.5% at 24 months, suggesting activity versus historical CRT benchmarks. After induction, 47.4% had partial response, 36.8% stable disease, and 13.2% progression before CRT. 2

Late GU toxicity common after prostate MHRT/SBRT; motion management and margin reduction mitigate risk

This systematic review covered 32 phase III trials comparing fractionation schemes including moderately hypofractionated RT (MHRT) and SBRT for prostate cancer. Late grade ≥2 GU toxicity after MHRT ranged 12–46% with isodose and 15–45% with dose‑escalated schedules, indicating substantial symptom burden. SBRT showed a flare of grade ≥2 GU toxicity at 12–24 months, increasing 5‑year cumulative GU toxicity despite acceptable early profiles. Baseline IPSS was repeatedly suggested as a predictor of late grade ≥2 GU toxicity after both MHRT and SBRT. 3

ACNS0831: no survival benefit from adding post‑RT chemotherapy in resected pediatric ependymoma

ACNS0831 randomized 325 patients aged 1–21 years with intracranial ependymoma and GTR/NTR or CR to RT alone versus RT followed by chemotherapy. Five‑year EFS was 63.7% with RT alone and 69.2% with RT‑CHEMO (HR 0.866; one‑sided p=0.299), showing no significant benefit. Five‑year OS was 86.9% with RT alone and 88.3% with RT‑CHEMO (HR 0.757; one‑sided p=0.172), again without clear advantage. Patients with subtotal resection assigned to RT‑CHEMO had 5‑year EFS 33.6% and OS 74.0%, highlighting the prognostic weight of extent of resection. 4