Yoshiki Kubota1, Tatsuya Ohno2, Motohiro Kawashima2, Kazutoshi Murata2, Noriyuki Okonogi3, Shin-Ei Noda4, Kazuhisa Tsuda5, Makoto Sakai2, Mutsumi Tashiro2, Takashi Nakano2. 1. Gunma University Heavy Ion Medical Center, Maebashi, Japan y_kubota@gunma-u.ac.jp. 2. Gunma University Heavy Ion Medical Center, Maebashi, Japan. 3. National Institute of Radiological Sciences Hospital, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan. 4. Department of Radiation Oncology, Saitama Medical University International Medical Center, Saitama, Japan. 5. Department of Radiology, Gunma University Hospital, Maebashi, Japan.
Abstract
AIM: We developed a vaginal immobilization device for external radiotherapy in gynaecological malignancies and evaluated its bowel dose-reduction effect during carbon-ion radiotherapy (CIRT) and intensity-modulated radiation therapy (IMRT) in patients with cervical cancer. PATIENTS AND METHODS: Computed tomographic images obtained with and without the device in seven patients with cervical cancer were assessed. Treatment plans for CIRT and IMRT were generated, and dose-volume parameters (V20, V25, V35, and D2cc) of the rectum, sigmoidal colon, and bladder were evaluated. RESULTS: The mean±standard deviation of the rectal volume in CIRT for V35 with and without the device were 2.1±2.1 and 13.6±4.4 ml, respectively, and those in IMRT were 2.0±2.2 and 13.7±3.8 ml, respectively; these values were significantly lower in CIRT and IMRT using this device. CONCLUSION: Using our novel vaginal immobilization device, high rectal doses were largely reduced in CIRT and IMRT. Copyright
AIM: We developed a vaginal immobilization device for external radiotherapy in gynaecological malignancies and evaluated its bowel dose-reduction effect during carbon-ion radiotherapy (CIRT) and intensity-modulated radiation therapy (IMRT) in patients with cervical cancer. PATIENTS AND METHODS: Computed tomographic images obtained with and without the device in seven patients with cervical cancer were assessed. Treatment plans for CIRT and IMRT were generated, and dose-volume parameters (V20, V25, V35, and D2cc) of the rectum, sigmoidal colon, and bladder were evaluated. RESULTS: The mean±standard deviation of the rectal volume in CIRT for V35 with and without the device were 2.1±2.1 and 13.6±4.4 ml, respectively, and those in IMRT were 2.0±2.2 and 13.7±3.8 ml, respectively; these values were significantly lower in CIRT and IMRT using this device. CONCLUSION: Using our novel vaginal immobilization device, high rectal doses were largely reduced in CIRT and IMRT. Copyright