Sonier Marcus, Chu William, Lalani Nafisha, Erler Darby, Cheung Patrick, Korol Renee
Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada.
Med Dosim. 2016;41(4):323-328. doi: 10.1016/j.meddos.2016.09.001. Epub 2016 Oct 13.
To develop a volumetric modulated arc therapy (VMAT) treatment planning solution in the treatment of primary renal cell carcinoma and oligometastatic adrenal lesions with stereotactic body radiation therapy. Single-arc VMAT plans (n = 5) were compared with clinically delivered step-and-shoot intensity-modulated radiotherapy (IMRT) with planning target volume coverage normalized between techniques. Target volume conformity, organ-at-risk (OAR) dose, treatment time, and monitor units were compared. A VMAT planning solution, created from a combination of arc settings and optimization constraints, auto-generated treatment plans in a single optimization. The treatment planning solution was evaluated on 15 consecutive patients receiving kidney and adrenal stereotactic body radiation therapy. Treatment time was reduced from 13.0 ± 2.6 to 4.0 ± 0.9 minutes for IMRT and VMAT, respectively. The VMAT planning solution generated treatment plans with increased target homogeneity, improved 95% conformity index, and a reduced maximum point dose to nearby OARs but with increased intermediate dose to distant OARs. The conformity of the 95% isodose improved from 1.32 ± 0.39 to 1.12 ± 0.05 for IMRT and VMAT treatment plans, respectively. Evaluation of the planning solution showed clinically acceptable dose distributions for 13 of 15 cases with tight conformity of the prescription isodose to the planning target volume of 1.07 ± 0.04, delivering minimal dose to OARs. The introduction of a stereotactic body radiation therapy VMAT treatment planning solution improves the efficiency of planning and delivery time, producing treatment plans of comparable or superior quality to IMRT in the case of primary renal cell carcinoma and oligometastatic adrenal lesions.
为开发容积调强弧形放疗（VMAT）治疗计划方案，用于原发性肾细胞癌和寡转移肾上腺病变的立体定向体部放疗。将单弧VMAT计划（n = 5）与临床实施的静态调强放疗（IMRT）进行比较，使两种技术间的计划靶区覆盖归一化。比较靶区适形度、危及器官（OAR）剂量、治疗时间和监测单位。通过弧形设置和优化约束相结合创建的VMAT治疗计划方案，在单次优化中自动生成治疗计划。对15例接受肾脏和肾上腺立体定向体部放疗的连续患者评估该治疗计划方案。IMRT和VMAT的治疗时间分别从13.0±2.6分钟降至4.0±0.9分钟。VMAT治疗计划方案生成的治疗计划具有更高的靶区均匀性、改善的95%适形指数、降低对附近OAR的最大点剂量，但对远处OAR的中间剂量增加。IMRT和VMAT治疗计划的95%等剂量线适形度分别从1.32±0.39提高到1.12±0.05。对该计划方案的评估显示，15例中有13例的剂量分布在临床上可接受，处方等剂量线与计划靶区紧密适形，为1.07±0.04，对OAR的剂量最小。立体定向体部放疗VMAT治疗计划方案的引入提高了计划和交付时间的效率，在原发性肾细胞癌和寡转移肾上腺病变的情况下，生成的治疗计划质量与IMRT相当或更优。
