Hundvin Johanna Austrheim, Fjellanger Kristine, Pettersen Helge Egil Seime, Nygaard Britt, Revheim Kari, Sulen Turid Husevåg, Ekanger Christian, Hysing Liv Bolstad
Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway.
Institute of Physics and Technology, University of Bergen, Bergen, Norway.
Acta Oncol. 2021 Feb;60(2):237-244. doi: 10.1080/0284186X.2020.1828619. Epub 2020 Oct 8.
Manual volumetric modulated arc therapy (VMAT) treatment planning for high-risk prostate cancer receiving whole pelvic radiotherapy (WPRT) with four integrated dose levels is complex and time consuming. We have investigated if the radiotherapy planning process and plan quality can be improved using a well-tuned model developed through a commercial system for knowledge-based planning (KBP).
Treatment plans from 69 patients treated for high-risk prostate cancer with manually planned VMAT were used to develop an initial KBP model (RapidPlan, RP). Prescribed doses were 50, 60, 67.5, and 72.5 Gy in 25 fractions to the pelvic lymph nodes, prostate and seminal vesicles, prostate gland, and prostate tumour(s), respectively. This RP model was in clinical use from July 2019 to February 2020, producing another set of 69 clinically delivered treatment plans for a new patient group, which were used to develop a second RP model. Both models were validated on an independent group of 40 patients. Plan quality was compared by and the Paddick conformity index for targets, mean dose ( ) and generalised equivalent uniform dose (gEUD) for bladder, bowel bag and rectum, and number of monitor units (MU).
Target coverage and conformity was similar between manually created and RP treatment plans. Compared to the manually created treatment plans, the final RP model reduced average and gEUD with 2.7 Gy and 1.3 Gy for bladder, 1.2 Gy and 0.9 Gy for bowel bag, and 2.7 Gy and 0.8 Gy for rectum, respectively ( < .05). For rectum, the interpatient variation (i.e., 95% confidence interval) of DVHs was reduced by 23%.
KBP improved plan quality and consistency among treatment plans for high-risk prostate cancer. Model tuning using KBP-based clinical plans further improved model outcome.
对于接受全盆腔放疗（WPRT）且有四个综合剂量水平的高危前列腺癌患者，手动容积调强弧形放疗（VMAT）治疗计划复杂且耗时。我们研究了使用通过商业基于知识的计划（KBP）系统开发的经过良好调整的模型是否可以改善放射治疗计划过程和计划质量。
使用69例接受手动计划VMAT治疗的高危前列腺癌患者的治疗计划来开发初始KBP模型（RapidPlan，RP）。盆腔淋巴结、前列腺和精囊、前列腺腺体以及前列腺肿瘤的处方剂量分别为25次分割给予50、60、67.5和72.5 Gy。该RP模型于2019年7月至2020年2月投入临床使用，为一组新患者生成了另一组69个临床交付的治疗计划，这些计划用于开发第二个RP模型。两个模型均在一组40例独立患者中进行验证。通过靶区的 和帕迪克适形指数、膀胱、肠袋和直肠的平均剂量（ ）和广义等效均匀剂量（gEUD）以及监测单位（MU）数量比较计划质量。
手动创建的和RP治疗计划之间的靶区覆盖和适形性相似。与手动创建的治疗计划相比，最终的RP模型使膀胱的平均 和gEUD分别降低了2.7 Gy和1.3 Gy，肠袋降低了1.2 Gy和0.9 Gy，直肠降低了2.7 Gy和0.8 Gy（ <.05）。对于直肠，剂量体积直方图的患者间变异（即95%置信区间）降低了23%。
KBP提高了高危前列腺癌治疗计划的质量和一致性。使用基于KBP的临床计划进行模型调整进一步改善了模型结果。
