Long-Term Outcomes After Proton Therapy Versus Intensity Modulated Photon Radiation Therapy With Concurrent Chemotherapy for Locally Advanced Non-Small Cell Lung Cancer: Post Hoc Analysis of a Prospective Randomized Trial.
Tingshi Su, Ting Xu, Mei Chen et al.
✦ AI-curated · Sources linked
In 30 seconds
This post hoc analysis of a prospective randomized trial compared long-term outcomes after passive scattering proton therapy (PSPT) versus intensity modulated photon radiation therapy (IMRT), each given with concurrent chemotherapy, in 149 patients with locally advanced non-small cell lung cancer. Median follow-up was 28.5 months. Grade ≥3 radiation pneumonitis rates were similar: 10.9% with IMRT and 10.5% with PSPT (P = .98). Local failure, progression-free survival, and esophageal toxicity also did not differ. There were fewer definitely or possibly radiation-related major adverse cardiac events with PSPT, although the authors considered this finding potentially related to lower coronary artery doses.
Key findings
- Grade ≥3 radiation pneumonitis occurred in 10.9% of IMRT patients and 10.5% of PSPT patients (P = .98).
- There were no detected differences between groups in local failure, progression-free survival, or esophageal toxicity.
- Of 10 definitely or possibly radiation-related major adverse cardiac events, 1 occurred after PSPT and 9 after IMRT.
Why it matters
The randomized comparison suggests that, when both plans satisfy lung dose-volume constraints, proton therapy did not reduce severe pneumonitis or improve local control relative to IMRT. The imbalance in radiation-related cardiac events raises the possibility that limiting coronary artery exposure could matter, but the analysis does not establish a causal benefit. These findings help frame the trade-offs between radiation techniques alongside attention to organ-at-risk doses.
What to keep in mind
This was a post hoc analysis with median follow-up of 28.5 months; 7 patients were lost to follow-up. The cardiac-event finding is based on 10 events and is described as potentially associated with coronary artery dose.