Katsuyuki Shirai1, Kyohei Fukata2, Akiko Adachi2, Jun-Ichi Saitoh2, Atsushi Musha3, Takanori Abe2, Tatsuaki Kanai2, Daijiro Kobayashi2, Yuka Shigeta2, Satoshi Yokoo4, Kazuaki Chikamatsu5, Tatsuya Ohno2, Takashi Nakano2. 1. Gunma University Heavy Ion Medical Center, Maebashi, Japan. Electronic address: kshirai@gunma-u.ac.jp. 2. Gunma University Heavy Ion Medical Center, Maebashi, Japan. 3. Gunma University Heavy Ion Medical Center, Maebashi, Japan; Department of Oral and Maxillofacial Surgery Plastic Surgery, Gunma University Graduate School of Medicine, Maebashi, Japan. 4. Department of Oral and Maxillofacial Surgery Plastic Surgery, Gunma University Graduate School of Medicine, Maebashi, Japan. 5. Department of Otolaryngology-Head and Neck Surgery, Gunma University Graduate School of Medicine, Maebashi, Japan.
Abstract
BACKGROUND AND PURPOSE: We aimed to evaluate the relationship between brainstem necrosis and dose-volume histograms in patients with head and neck tumors after carbon-ion radiotherapy. MATERIAL AND METHODS: We evaluated 85 patients with head and neck tumors who underwent carbon-ion radiotherapy and were followed-up for ≥12months. Brainstem necrosis was evaluated using the Common Terminology Criteria for Adverse Events (version 4.0). RESULTS: The median follow-up was 24months, and four patients developed grade 1 brainstem necrosis, with 2-year and 3-year cumulative rates of 2.8% and 6.5%, respectively. Receiver operating characteristic curve analysis revealed the following significant cut-off values: a maximum brainstem dose of 48Gy (relative biological effectiveness [RBE]), D1cm3 of 27Gy (RBE), V40Gy (RBE) of 0.1cm3, V30Gy (RBE) of 0.7cm3, and V20Gy (RBE) of 1.4cm3. Multivariate analysis revealed that V30Gy (RBE) was most significantly associated with brainstem necrosis. The 2-year cumulative rates were 33% and 0% for V30Gy (RBE) of ≥0.7cm3 and <0.7cm3, respectively (p<0.001). CONCLUSIONS: The present study indicated that the dose constraints might help minimize brainstem necrosis after carbon-ion radiotherapy.
BACKGROUND AND PURPOSE: We aimed to evaluate the relationship between brainstem necrosis and dose-volume histograms in patients with head and neck tumors after carbon-ion radiotherapy. MATERIAL AND METHODS: We evaluated 85 patients with head and neck tumors who underwent carbon-ion radiotherapy and were followed-up for ≥12months. Brainstem necrosis was evaluated using the Common Terminology Criteria for Adverse Events (version 4.0). RESULTS: The median follow-up was 24months, and four patients developed grade 1 brainstem necrosis, with 2-year and 3-year cumulative rates of 2.8% and 6.5%, respectively. Receiver operating characteristic curve analysis revealed the following significant cut-off values: a maximum brainstem dose of 48Gy (relative biological effectiveness [RBE]), D1cm3 of 27Gy (RBE), V40Gy (RBE) of 0.1cm3, V30Gy (RBE) of 0.7cm3, and V20Gy (RBE) of 1.4cm3. Multivariate analysis revealed that V30Gy (RBE) was most significantly associated with brainstem necrosis. The 2-year cumulative rates were 33% and 0% for V30Gy (RBE) of ≥0.7cm3 and <0.7cm3, respectively (p<0.001). CONCLUSIONS: The present study indicated that the dose constraints might help minimize brainstem necrosis after carbon-ion radiotherapy.
Authors: Jon Espen Dale; Silvia Molinelli; Barbara Vischioni; Viviana Vitolo; Maria Bonora; Giuseppe Magro; Andrea Mairani; Azusa Hasegawa; Tatsuya Ohno; Olav Dahl; Francesca Valvo; Piero Fossati Journal: Front Oncol Date: 2020-11-24 Impact factor: 6.244
Authors: Piero Fossati; Ana Perpar; Markus Stock; Petra Georg; Antonio Carlino; Joanna Gora; Giovanna Martino; Eugen B Hug Journal: Int J Part Ther Date: 2021-06-25