A novel radiation therapy technique for malignant pleural mesothelioma combining electrons with intensity-modulated photons

Radiotherapy and Oncology. 2006 May 12; [Epub ahead of print] [Link]

Maria F. Chana, Chen S. Chuia, Yulin Songa, Chandra Burmana, Ellen Yorkea, Cesar Della-Bianciaa, Kenneth E. Rosenzweigb and Karen Schupakb

aDepartment of Medical Physics, and
bDepartment of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, USA

Received 13 September 2005;  revised 7 March 2006;  accepted 19 April 2006.  Available online 15 May 2006.

Abstract

Background and purpose: To investigate the feasibility and potential benefits of combining electron and photon intensity modulated radiotherapy (IMRT) for patients with malignant pleural mesothelioma (MPM).

Patients and methods: 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.

Results: 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).

Conclusions: 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.

Keywords: IMRT; Mesothelioma; Radiotherapy; Extrapleural pneumonectomy