Dosimetric Evaluation of Beam-specific PTV and Worst-case Optimization Methods for Liver Proton Therapy

• Published in: In vivo (Athens) 2024-11, Vol.38 (6), p.3059-3067
• Main Authors: Yamano, Akihiro, Inoue, Tatsuya, Shiba, Shintaro, Shimo, Takahiro, Yamanaka, Masashi, Shirata, Ryosuke, Matsumoto, Kazuki, Yagihashi, Takayuki, Tokuuye, Koichi, Chang, Weishan
• Format: Article
• Language: English
• Subjects: Aged; Carcinoma, Hepatocellular - pathology; Carcinoma, Hepatocellular - radiotherapy; Female; Humans; Liver Neoplasms - radiotherapy; Male; Middle Aged; Organs at Risk - radiation effects; Proton Therapy - methods; Radiometry - methods; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted - methods; Tumor Burden
• ISSN: 0258-851X; 1791-7549; 1791-7549
• DOI: 10.21873/invivo.13790

In spot-scanning proton therapy, intra-fractional anatomical changes by organ movement can lead to deterioration in dose distribution due to beam range variation. To explore a more robust treatment planning method, this study evaluated the dosimetric characteristics and robustness of two proton therapy planning methods for liver cancer. Two- or three-field treatment plans were created for 11 patients with hepatocellular carcinoma or metastatic liver cancer using a single-field uniform dose (SFUD) technique. The plans were optimized using either beam-specific planning target volume (BSPTV) or worst-case optimization (WCO). The target coverage for the gross tumor volume (GTV), planning target volume (PTV), and organs at risk (OAR) parameters related to toxicity were calculated from the perturbed dose distributions, considering setup and range uncertainties. Statistical analyses of the BSPTV and WCO plans were performed using the Wilcoxon signed-rank sum test (p