Jameson Michael G, Ohanessian Lucy, Batumalai Vikneswary, Patel Virendra, Holloway Lois C
Liverpool and Macarthur Cancer Therapy Centres Liverpool, New South Wales, Australia ; Centre for Medical Radiation Physics, University of Wollongong Wollongong, New South Wales, Australia ; Ingham Institute of Applied Medical Research Liverpool, New South Wales, Australia.
Liverpool and Macarthur Cancer Therapy Centres Liverpool, New South Wales, Australia.
J Med Radiat Sci. 2015 Jun;62(2):168-74. doi: 10.1002/jmrs.107. Epub 2015 May 20.
There are a number of different dwell positions and time optimisation options available in the Oncentra® Brachy (Elekta Brachytherapy Solutions, Veenendaal, The Netherlands) brachytherapy treatment planning system. The purpose of this case study was to compare graphical (GRO) and inverse planning by simulated annealing (IPSA) optimisation techniques for interstitial head and neck (HN) and prostate plans considering dosimetry, modelled radiobiology outcome and planning time. Four retrospective brachytherapy patients were chosen for this study, two recurrent HN and two prostatic boosts. Manual GRO and IPSA plans were generated for each patient. Plans were compared using dose-volume histograms (DVH) and dose coverage metrics including; conformity index (CI), homogeneity index (HI) and conformity number (CN). Logit and relative seriality models were used to calculate tumour control probability (TCP) and normal tissue complication probability (NTCP). Approximate planning time was also recorded. There was no significant difference between GRO and IPSA in terms of dose metrics with mean CI of 1.30 and 1.57 (P > 0.05) respectively. IPSA achieved an average HN TCP of 0.32 versus 0.12 for GRO while for prostate there was no significant difference. Mean GRO planning times were greater than 75 min while average IPSA planning times were less than 10 min. Planning times for IPSA were greatly reduced compared to GRO and plans were dosimetrically similar. For this reason, IPSA makes for a useful planning tool in HN and prostate brachytherapy.
在Oncentra® Brachy（荷兰维嫩达尔的医科达近距离放射治疗解决方案公司）近距离放射治疗治疗计划系统中，有许多不同的驻留位置和时间优化选项。本案例研究的目的是比较图形化（GRO）和通过模拟退火的逆向计划（IPSA）优化技术，用于头颈部（HN）间质和前列腺计划，考虑剂量学、模拟放射生物学结果和计划时间。本研究选择了4例回顾性近距离放射治疗患者，2例复发性HN患者和2例前列腺强化治疗患者。为每位患者生成手动GRO和IPSA计划。使用剂量体积直方图（DVH）和剂量覆盖指标（包括适形指数（CI）、均匀性指数（HI）和适形数（CN））对计划进行比较。使用逻辑模型和相对串联模型计算肿瘤控制概率（TCP）和正常组织并发症概率（NTCP）。还记录了近似计划时间。GRO和IPSA在剂量指标方面无显著差异，平均CI分别为1.30和1.57（P>0.05）。IPSA实现的HN平均TCP为0.32，而GRO为0.12，前列腺方面无显著差异。GRO的平均计划时间大于75分钟，而IPSA的平均计划时间小于10分钟。与GRO相比，IPSA的计划时间大幅减少，且计划在剂量学上相似。因此，IPSA在HN和前列腺近距离放射治疗中是一种有用的计划工具。
