Kawashima Motohiro, Ozawa Shuichi, Haga Akihiro, Sakumi Akira, Kurokawa Chie, Sugimoto Satoru, Karasawa Kumiko, Nakagawa Keiichi, Sasai Keisuke
Graduate School of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
Radiol Phys Technol. 2013 Jan;6(1):14-20. doi: 10.1007/s12194-012-0164-3. Epub 2012 Jul 1.
We compared treatment plans for volumetric intensity-modulated arc therapy (VMAT) and step-and-shoot intensity-modulated radiation therapy (IMRT) in terms of their monitor unit (MU) and segment area at each control point to investigate the difference between the two methods. We investigated three sites: prostate (three cases), head and neck (three cases), and pleura (two cases). We used the total MU and the MU weighted average of segment area (MWSA) in each plan to compare VMAT and IMRT plans. VMAT plans tended to have a larger MWSA and a lower total MU than did IMRT plans in all sites, although there was little difference between dose indices in either irradiation technique. We conclude that VMAT is a better treatment technique due to its higher MU efficiency caused by the larger segment area.
我们比较了容积调强弧形放疗（VMAT）和静态调强放疗（IMRT）的治疗计划，从每个控制点的监测单位（MU）和射野面积方面来研究这两种方法之间的差异。我们研究了三个部位：前列腺（3例）、头颈部（3例）和胸膜（2例）。我们使用每个计划中的总MU和射野面积的MU加权平均值（MWSA）来比较VMAT和IMRT计划。在所有部位，VMAT计划的MWSA往往比IMRT计划更大，总MU更低，尽管两种照射技术的剂量指数差异不大。我们得出结论，由于射野面积较大导致MU效率更高，VMAT是一种更好的治疗技术。
