Proton Therapy for Reirradiation: Clinical and Technical Advances
Description
Proton therapy offers distinct dosimetric advantages for reirradiation (reRT) due to its finite range and Bragg peak, allowing potential tumor dose escalation with reduced normal tissue exposure compared to photon-based reRT. However, these benefits come with unique technical and biological challenges. Range uncertainties and sharp distal dose fall-off may place critical structures at risk, while motion interplay effects can compromise plan robustness. The assumption of a fixed RBE of 1.1 overlooks biological variability, particularly at the distal edge, with implications for toxicity. Furthermore, dose accumulation, image registration, and adaptive workflows remain underdeveloped in the reRT setting, where prior dose distributions are complex and heterogeneous. This symposium will bring together experts in proton therapy physics to address these challenges and opportunities. Topics will include workflow integration and QA for proton reRT, image registration and robustness evaluation, adaptive planning strategies, and future directions for biologically guided approaches. Attendees will gain practical insights into balancing efficacy and safety in reirradiation, supported by real-world clinical and technical experiences.