International Journal of Radiation Research

en Significant decrease in the radiation low-dose delivered to normal tissue in a novel cervical cancer VMAT plan using sub-arc collimator angle optimization Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;">Background: Traditionally, volumetric modulated arc therapy (VMAT) plans have depended on a predefined gantry range and a fixed collimator angle. Herein, we develop a novel sub-arc collimator angle optimization (SACAO) method for VMAT in cervical cancer. Materials and Methods: Twenty patients with cervical cancer were retrieved in the retrospective planning study. Two plans for traditional optimization were generated using dual arcs with two static collimator angles of 0˚ and 45˚ (named VMAT_0 and VMAT_45, respectively). A new plan was also developed using SACAO (named VMAT_SACAO). The dynamic gantry range segmentation of the full arc was calculated according to the continuity of the best conformity index (CI). The dose-volumetric parameters, average x-jaw size, and total monitor units (MUs) were compared. Results: The HI (uniformity index) and CI (conformity index) were improved in VMAT_SACAO compared to VMAT_0 and VMAT_45. The average x-jaw size of VMAT_SACAO was lower than VMAT_0 and VMAT_45 (18.7 ± 0.9 cm2, 20.7 ± 1.1 cm2, and 20.2 ± 1.0 cm2), as well as the total MUs (402 ± 19.0, 450 ± 18.8, and 432 ± 18.5). The average low-dose delivered to normal tissue was lowest in VMAT_SACAO compared to VMAT_0 and VMAT_45 (15.8 ± 0.4 Gy, 18.6 ± 0.3 Gy, and 17.0 ± 0.4 Gy). Conclusion: Compared to the two VMAT plans, the VMAT_SACAO improved the HI and CI, decreased the low-dose delivered to normal tissue, the V50, V45, and V15 of the small bowel, and the total MUs when applied in treating cervical cancer patients.</div> Radiotherapy, cervical cancer, volumetric modulated arc therapy, collimator angle optimization, normal tissue protection. 1079 1084 http://ijrr.com/browse.php?a_code=A-10-1-1439&slc_lang=en&sid=1 C. Chen 7900319475328460032571 7900319475328460032571 No Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Zhongnan Hospital of Wuhan University, 169 Donghu Street, Wuhan, China W. Xu 7900319475328460032572 7900319475328460032572 No Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Zhongnan Hospital of Wuhan University, 169 Donghu Street, Wuhan, China J. Shen 7900319475328460032573 7900319475328460032573 No Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Zhongnan Hospital of Wuhan University, 169 Donghu Street, Wuhan, China C. Xie 7900319475328460032574 7900319475328460032574 No Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Zhongnan Hospital of Wuhan University, 169 Donghu Street, Wuhan, China Y. Zhou 7900319475328460032575 7900319475328460032575 No Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Zhongnan Hospital of Wuhan University, 169 Donghu Street, Wuhan, China X. Wang 7900319475328460032576 7900319475328460032576 No Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Zhongnan Hospital of Wuhan University, 169 Donghu Street, Wuhan, China J. Zhang 7900319475328460032577 7900319475328460032577 No Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Zhongnan Hospital of Wuhan University, 169 Donghu Street, Wuhan, China D. Jiang 7900319475328460032578 7900319475328460032578 No Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Zhongnan Hospital of Wuhan University, 169 Donghu Street, Wuhan, China Y. Zhong doctorzyh73@163.com 7900319475328460032579 7900319475328460032579 Yes Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Zhongnan Hospital of Wuhan University, 169 Donghu Street, Wuhan, China H. Liu liuhui69_wh@hotmail.com 7900319475328460032580 7900319475328460032580 No Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Zhongnan Hospital of Wuhan University, 169 Donghu Street, Wuhan, China H. Yu haijunyu@whu.edu.cn 7900319475328460032581 7900319475328460032581 No Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Zhongnan Hospital of Wuhan University, 169 Donghu Street, Wuhan, China