Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea.
Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
PLoS One. 2018 Oct 4;13(10):e0205229. doi: 10.1371/journal.pone.0205229. eCollection 2018.
This study aimed to compare the inverse planning simulated annealing (IPSA) stochastic algorithm with the hybrid inverse planning and optimization (HIPO) algorithm for interstitial tongue high-dose-rate (HDR) brachytherapy.
Twenty patients who received radiotherapy for tongue cancer using interstitial HDR brachytherapy were retrospectively selected for this study. Oncentra Brachy v. 4.3 was used for IPSA and HIPO planning. Four to eight fixed catheter configurations were determined according to the target shape. During the optimization process, predetermined constrain values were used for each IPSA and HIPO plan. The dosimetric parameters and dwell time were analyzed to evaluate the performances of the plans.
The total dwell time using IPSA was 4 seconds longer than that of HIPO. The number of active positions per catheter for the IPSA plans were approximately 2.5 fewer than those of the HIPO plans. The dose-volumetric parameters related to the clinical target volume with IPSA were lower than those with HIPO. In terms of the dose-volumetric parameters related to normal tissue, HIPO tended to associate with slightly higher values than IPSA, without statistical significance. After GrO, the target coverages were satisfied to clinical goal for all patients. The total dwell times was approximately increased by 10%.
The IPSA and HIPO dose optimization algorithms generate similar dosimetric results. In terms of the dwell time, HIPO appears to be more beneficial.
本研究旨在比较反向计划模拟退火（IPSA）随机算法与混合反向计划和优化（HIPO）算法在间质舌部高剂量率（HDR）近距离放疗中的应用。
回顾性选择 20 名接受间质 HDR 近距离放疗治疗舌癌的患者进行本研究。使用 Oncentra Brachy v.4.3 进行 IPSA 和 HIPO 计划。根据靶形确定 4 到 8 个固定导管配置。在优化过程中，为每个 IPSA 和 HIPO 计划使用预定的约束值。分析剂量学参数和驻留时间以评估计划的性能。
IPSA 的总驻留时间比 HIPO 长 4 秒。IPSA 计划每个导管的活动位置数比 HIPO 计划少约 2.5 个。与 HIPO 相比，IPSA 计划的与临床靶体积相关的剂量体积参数较低。在与正常组织相关的剂量体积参数方面，HIPO 倾向于比 IPSA 略高，但无统计学意义。在 GrO 之后，所有患者的靶区覆盖率均满足临床目标。总驻留时间大约增加了 10%。
IPSA 和 HIPO 剂量优化算法产生相似的剂量学结果。就驻留时间而言，HIPO 似乎更有利。
