Buschmann Martin, Seppenwoolde Yvette, Wiezorek Tilo, Weibert Kirsten, Georg Dietmar
Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/AKH Wien, Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria.
Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/AKH Wien, Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria.
Phys Med. 2016 Mar;32(3):465-73. doi: 10.1016/j.ejmp.2016.03.002. Epub 2016 Apr 3.
Radiation treatment planning inherently involves multiple conflicting planning goals, which makes it a suitable application for multicriteria optimization (MCO). This study investigates a MCO algorithm for VMAT planning (VMAT-MCO) for prostate cancer treatments including pelvic lymph nodes and uses standard inverse VMAT optimization (sVMAT) and Tomotherapy planning as benchmarks.
For each of ten prostate cancer patients, a two stage plan was generated, consisting of a stage 1 plan delivering 22Gy to the prostate, and a stage 2 plan delivering 50.4Gy to the lymph nodes and 56Gy to the prostate with a simultaneous integrated boost. The single plans were generated by three planning techniques (VMAT-MCO, sVMAT, Tomotherapy) and subsequently compared with respect to plan quality and planning time efficiency.
Plan quality was similar for all techniques, but sVMAT showed slightly better rectum (on average Dmean -7%) and bowel sparing (Dmean -17%) compared to VMAT-MCO in the whole pelvic treatments. Tomotherapy plans exhibited higher bladder dose (Dmean +42%) in stage 1 and lower rectum dose (Dmean -6%) in stage 2 than VMAT-MCO. Compared to manual planning, the planning time with MCO was reduced up to 12 and 38min for stage 1 and 2 plans, respectively.
MCO can generate highly conformal prostate VMAT plans with minimal workload in the settings of prostate-only treatments and prostate plus lymph nodes irradiation. In the whole pelvic plan manual VMAT optimization led to slightly improved OAR sparing over VMAT-MCO, whereas for the primary prostate treatment plan quality was equal.
放射治疗计划本质上涉及多个相互冲突的计划目标，这使其成为多标准优化（MCO）的合适应用。本研究调查了一种用于前列腺癌治疗（包括盆腔淋巴结）的容积调强弧形治疗（VMAT）计划的MCO算法（VMAT-MCO），并将标准逆向VMAT优化（sVMAT）和螺旋断层放射治疗计划作为基准。
对于十名前列腺癌患者中的每一位，生成了一个两阶段计划，包括一个向前列腺输送22Gy的1期计划，以及一个向淋巴结输送50.4Gy并同时对前列腺进行同步推量照射56Gy的2期计划。通过三种计划技术（VMAT-MCO、sVMAT、螺旋断层放射治疗）生成单个计划，随后在计划质量和计划时间效率方面进行比较。
所有技术的计划质量相似，但在全盆腔治疗中，与VMAT-MCO相比，sVMAT在直肠保护（平均Dmean -7%）和肠道保护（Dmean -17%）方面表现略好。螺旋断层放射治疗计划在1期显示出更高的膀胱剂量（Dmean +42%），在2期显示出比VMAT-MCO更低的直肠剂量（Dmean -6%）。与手动计划相比，MCO的计划时间在1期和2期计划中分别减少了多达12分钟和38分钟。
在仅前列腺治疗和前列腺加淋巴结照射的情况下，MCO可以以最小的工作量生成高度适形的前列腺VMAT计划。在全盆腔计划中，手动VMAT优化在危及器官保护方面比VMAT-MCO略有改善，而对于原发性前列腺治疗计划质量相当。
