Stevens Craig W, Wong Pei-Fong, Rice David, Jeter Melenda, Forster Kenneth, Zhu X Ronald
Department of Radiation Oncology, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
Lung Cancer. 2005 Jul;49 Suppl 1:S75-81. doi: 10.1016/j.lungcan.2005.03.023.
Malignant pleural mesothelioma (MPM) has been treated with extrapleural pneumonectomy (EPP) followed by IMRT. IMRT improved radiation dose distributions to the complex operative bed, and preliminary results suggested improved local control compared with conventional treatment planning. IMRT was initially developed on the Corvus treatment planning system. Other treatment planning systems are also IMRT-capable. Treatment plans from several systems were compared to determine the feasibility of using IMRT in a multi-institution trial.
Treatment plans were generated on Corvus, Eclipse, and Pinnacle for a right-sided MPM after EPP using 6 MV X-rays. Tissue heterogeneity corrections were used in dose calculation. Plans were optimized such that the clinical target volume received 50 Gy in 25 fractions. Dose distributions to the target and normal structures were evaluated. The treatment time and delivery efficiency were estimated.
Treatment plans could be calculated by all three planning systems without system failure. Larger volumes received 60Gy in Corvus plans (40%, 17% and 8% for Corvus, Pinnacle and Eclipse, respectively). Corvus used the most monitor units (2786 versus 1451 and 1813 for Pinnacle and Eclipse), and treated the most segments (1050 versus 267 and 173 for Pinnacle and Eclipse). Doses to spinal cord, lung, heart, liver, and contralateral kidney were acceptable for all planning systems.
IMRT plans can be calculated for MPM targets by at least three commonly available treatment planning systems. Pinnacle- and Eclipse-based plans seem more efficient, and may be delivered in a shorter time than Corvus-based plans.
恶性胸膜间皮瘤（MPM）一直采用胸膜外全肺切除术（EPP）联合调强放疗（IMRT）进行治疗。IMRT改善了对复杂手术床的放射剂量分布，初步结果表明与传统治疗计划相比，局部控制得到了改善。IMRT最初是在Corvus治疗计划系统上开发的。其他治疗计划系统也具备IMRT功能。比较了多个系统的治疗计划，以确定在多机构试验中使用IMRT的可行性。
使用6兆伏X射线，在Corvus、Eclipse和Pinnacle系统上为一名接受EPP后的右侧MPM患者生成治疗计划。剂量计算中使用了组织不均匀性校正。计划进行了优化，以使临床靶体积在25次分割中接受50 Gy的剂量。评估了靶区和正常结构的剂量分布。估计了治疗时间和递送效率。
所有三个计划系统均可计算治疗计划，未出现系统故障。在Corvus计划中，更大体积的组织接受了60 Gy的剂量（Corvus、Pinnacle和Eclipse分别为40%、17%和8%）。Corvus使用的监测单位最多（分别为2786个，而Pinnacle和Eclipse为1451个和1813个），且治疗的射野最多（分别为1050个，而Pinnacle和Eclipse为267个和173个）。所有计划系统对脊髓、肺、心脏、肝脏和对侧肾脏的剂量均可接受。
至少三种常用的治疗计划系统均可为MPM靶区计算IMRT计划。基于Pinnacle和Eclipse的计划似乎更高效，且可能比基于Corvus的计划在更短时间内完成递送。
