Shi Chengyu, Peñagarícano Jose, Papanikolaou Niko
Cancer Therapy and Research Center, San Antonio, TX 78229, USA.
Med Dosim. 2008 Autumn;33(3):215-21. doi: 10.1016/j.meddos.2007.11.001. Epub 2008 Apr 7.
Intensity modulated radiotherapy (IMRT) is an advanced treatment technology for radiation therapy. There are several treatment planning systems (TPS) that can generate IMRT plans. These plans may show different inhomogeneity indices to the planning target volume (PTV) and integral dose to organs at risk (OAR). In this study, we compared clinical cases covering different anatomical treatment sites, including head and neck, brain, lung, prostate, pelvis, and cranio-spinal axis. Two treatment plans were developed for each case using Pinnacle(3) and helical tomotherapy (HT) TPS. The inhomogeneity index of the PTV and the non-tumor integral dose (NTID) were calculated and compared for each case. Despite the difference in the number of effective beams, in several cases, NTID did not increase from HT as compared to the step-and-shoot delivery method. Six helical tomotherapy treatment plans for different treatment sites have been analyzed and compared against corresponding step-and-shoot plans generated with the Pinnacle(3) planning system. Results show that HT may produce plans with smaller integral doses to healthy organs, and fairly homogeneous doses to the target as compared to linac-based step-and-shoot IMRT planning in special treatment site such as cranio-spinal.
调强放射治疗（IMRT）是一种先进的放射治疗技术。有几种治疗计划系统（TPS）可以生成IMRT计划。这些计划对计划靶区（PTV）可能显示出不同的不均匀性指数，对危及器官（OAR）的积分剂量也不同。在本研究中，我们比较了涵盖不同解剖治疗部位的临床病例，包括头颈部、脑部、肺部、前列腺、骨盆和颅脊髓轴。针对每个病例，使用Pinnacle(3)和螺旋断层放射治疗（HT）TPS制定了两种治疗计划。计算并比较了每个病例的PTV不均匀性指数和非肿瘤积分剂量（NTID）。尽管有效射束数量存在差异，但在一些病例中，与步进式照射方法相比，HT的NTID并未增加。分析了不同治疗部位的六个螺旋断层放射治疗计划，并与使用Pinnacle(3)计划系统生成的相应步进式计划进行了比较。结果表明，在颅脊髓等特殊治疗部位，与基于直线加速器的步进式IMRT计划相比，HT可能生成对健康器官积分剂量较小且对靶区剂量相当均匀的计划。
