Chan Maria F, Chui Chen S, Song Yulin, Burman Chandra, Yorke Ellen, Della-Biancia Cesar, Rosenzweig Kenneth E, Schupak Karen
Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA.
Radiother Oncol. 2006 May;79(2):218-23. doi: 10.1016/j.radonc.2006.04.007. Epub 2006 May 15.
To investigate the feasibility and potential benefits of combining electron and photon intensity modulated radiotherapy (IMRT) for patients with malignant pleural mesothelioma (MPM).
The planning CT images of 11 MPM patients, six after extrapleural pneumonectomy (EPP) and five after pleurectomy/decortication (P/D), were used for this study. These cases were planned with photon IMRT alone and photon IMRT combined with electrons (IMRT+e). The latter approach incorporated the electron dose into the inverse planning optimization. The resulting doses to the planning target volume (PTV) and relevant critical structures were compared.
For all patients, the PTV was well covered and doses to critical structures were clinically acceptable for all patients with both techniques. However, IMRT+e exhibited a distinct advantage in reducing the doses to the liver, ipsilateral kidney, contralateral kidney, and heart (P=0.002, 0.003, 0.025, and 0.001, respectively).
This study showed that IMRT or IMRT+e is a viable treatment modality for MPM patients. Both plans can provide excellent target coverage and normal tissue sparing, but with the addition of electron beams, the critical structures can be further spared. Additional refining of the electron contribution is expected to further reduce radiation-induced morbidity.
探讨电子束与光子调强放射治疗（IMRT）联合应用于恶性胸膜间皮瘤（MPM）患者的可行性及潜在益处。
本研究使用了11例MPM患者的计划CT图像，其中6例为胸膜外全肺切除术后（EPP），5例为胸膜剥脱术/去皮质术后（P/D）。这些病例分别采用单纯光子IMRT和光子IMRT联合电子束（IMRT+e）进行计划。后一种方法将电子束剂量纳入逆向计划优化中。比较了两种技术对计划靶区（PTV）和相关关键结构的剂量。
对于所有患者，两种技术均能很好地覆盖PTV，且关键结构的剂量在临床上均可接受。然而，IMRT+e在降低肝脏、同侧肾脏、对侧肾脏和心脏的剂量方面具有明显优势（P分别为0.002、0.003、0.025和0.001）。
本研究表明，IMRT或IMRT+e是MPM患者可行的治疗方式。两种计划均可提供良好的靶区覆盖和正常组织保护，但加入电子束后，关键结构可得到进一步保护。进一步优化电子束的贡献有望进一步降低放射诱导并发症的发生率。
