Potential toxicity benefit and inter-fraction robustness of proton arc therapy compared to IMPT and VMAT for nasopharyngeal cancer patients

作者：Bas A. de Jong, Anneke Maring, Chimène I. Werkman, Johan Sundström, Daniele Cannavò, A. van der Schaaf, D. Scandurra, Erik Engwall, Erik W. Korevaar, Guillaume Janssens, Johannes A. Langendijk, Stefan Both · 发表于：Physics in Medicine and Biology · 年份：2025 · DOI：10.1088/1361-6560/add103 · 被引用次数：4 · 研究领域：Radiation Therapy and Dosimetry、Advanced Radiotherapy Techniques、Head and Neck Cancer Studies

OBJECTIVE: 
Radiotherapy (RT) in nasopharyngeal cancer (NPC) patients presents challenges due to proximity of many anatomical structures to the target volume. Furthermore, inter-fractional changes must be considered to assure target coverage. Proton arc therapy (PAT) potentially reduces healthy tissue dose compared to IMPT and VMAT. The impact of PAT on dose to organs-at-risk (OARs), predicted acute- and late radiation toxicities and robust target coverage to inter-fraction changes in NPC patients were investigated.
Approach:
Robustly optimized PAT plans were compared to clinical VMAT and IMPT plans for 10 NPC patients treated with 70.00 Gy to the primary target (CTV 7000) and 54.25 Gy to the prophylactic lymph nodal area (CTV 5425). Integral body dose and mean and max in 0.03cc dose (Dmean and max D0.03cc) in OARs were compared. Normal tissue complication probability (NTCP) values for 22 acute and late radiation-induced toxicities were evaluated. A PAT "base approach" and nine PAT planning approaches to improve PAT inter-fraction robust target coverage were investigated. Target coverage was evaluated on in total 54 weekly repeated CT images (rCTs).
Main Results:
PAT integral dose reduced by on average 55% and 15% compared with clinical VMAT and IMPT, respectively. Compared to IMPT, average Dmean and max D0.03cc were significantly reduced in all evaluated neurological structures. Compared to IMPT, in the PAT plans Dmean was reduced most in the arytenoids, ...