This critical review dissects the proton-versus-photon debate for post-mastectomy radiation through the lens of reconstruction outcomes. While protons offer clear dosimetric advantages—particularly cardiac sparing—multiple high-volume institutional series (notably from MGH and Northwestern) consistently report higher rates of capsular contracture (~30% with protons vs ~10% with photons) when objective surgical endpoints (e.g., capsulectomy) and multivariable models are used. The more expansive argument is that conflicting data in this space reflects deeper methodological flaws: inconsistent endpoint definitions, failure to stratify by reconstruction type, inadequate confounder adjustment, and overreliance on retrospective comparisons lacking time-to-event analyses. | Naoum, Int J Radiat Oncol Biol Phys 2026
