Masashi Koto1, Azusa Hasegawa2, Ryo Takagi2, Akira Fujikawa2, Takamichi Morikawa2, Riwa Kishimoto2, Keiichi Jingu3, Hirohiko Tsujii2, Tadashi Kamada2. 1. Research Center for Charged Particle Therapy Hospital, National Institute of Radiological Sciences, Chiba, Japan. Electronic address: koto@nirs.go.jp. 2. Research Center for Charged Particle Therapy Hospital, National Institute of Radiological Sciences, Chiba, Japan. 3. Department of Radiation Oncology, Tohoku University School of Medicine, Sendai, Japan.
Abstract
BACKGROUND AND PURPOSE: This study aimed to determine the risk factors for radiation-induced brain injury (RIBI) after carbon ion radiotherapy (CIRT) for treating skull base tumors. MATERIALS AND METHODS: Between April 1997 and January 2009, CIRT at a total dose of 48.0-60.8Gy equivalent (GyE) was administered in 16 fractions to 47 patients with skull base tumors. Of these patients, 39 who were followed up with magnetic resonance imaging (MRI) for more than 24months were analyzed. RIBI was assessed according to the MRI findings based on the Late Effects of Normal Tissue-Subjective, Objective, Management, Analytic criteria; clinical symptoms were assessed according to the Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer tables. The correlations of clinical and dosimetric parameters with incidence of ⩾grade 2 RIBI were retrospectively analyzed. RESULTS: The median follow-up period was 67months. The 5-year actuarial likelihoods of ⩾grade 2 RIBI and ⩾grade 2 clinical symptoms were 24.5% and 7.0%, respectively. Multivariate analysis demonstrated that the brain volume receiving more than 50GyE (V50) was a significant risk factor for the development of ⩾grade 2 RIBI (p=0.004). CONCLUSION: V50 was a significant risk factor for ⩾grade 2 RIBI after CIRT using a 16-fraction regimen.
BACKGROUND AND PURPOSE: This study aimed to determine the risk factors for radiation-induced brain injury (RIBI) after carbon ion radiotherapy (CIRT) for treating skull base tumors. MATERIALS AND METHODS: Between April 1997 and January 2009, CIRT at a total dose of 48.0-60.8Gy equivalent (GyE) was administered in 16 fractions to 47 patients with skull base tumors. Of these patients, 39 who were followed up with magnetic resonance imaging (MRI) for more than 24months were analyzed. RIBI was assessed according to the MRI findings based on the Late Effects of Normal Tissue-Subjective, Objective, Management, Analytic criteria; clinical symptoms were assessed according to the Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer tables. The correlations of clinical and dosimetric parameters with incidence of ⩾grade 2 RIBI were retrospectively analyzed. RESULTS: The median follow-up period was 67months. The 5-year actuarial likelihoods of ⩾grade 2 RIBI and ⩾grade 2 clinical symptoms were 24.5% and 7.0%, respectively. Multivariate analysis demonstrated that the brain volume receiving more than 50GyE (V50) was a significant risk factor for the development of ⩾grade 2 RIBI (p=0.004). CONCLUSION: V50 was a significant risk factor for ⩾grade 2 RIBI after CIRT using a 16-fraction regimen.
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