A novel radiation therapy technique for malignant pleural mesothelioma combining electrons with intensity-modulated photons.
OBJECTIVE
To investigate the feasibility and potential benefits of combining electron and photon intensity modulated radiotherapy (IMRT) for patients with malignant pleural mesothelioma (MPM).


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.
Chan
Maria F
MF
Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA. chanm@mskcc.org
Chui
Chen S
CS
Song
Yulin
Y
Burman
Chandra
C
Yorke
Ellen
E
Della-Biancia
Cesar
C
Rosenzweig
Kenneth E
KE
Schupak
Karen
K
D000465:Algorithms; D004583:Electrons; D006801:Humans; D008654:Mesothelioma / Q000532:radiotherapy* / Q000601:surgery; D017785:Photons; D010997:Pleural Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D011013:Pneumonectomy; D011832:Radiation Injuries / Q000517:prevention & control; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies