Intensity-modulated radiotherapy following extrapleural pneumonectomy for the treatment of malignant mesothelioma: clinical implementation.
OBJECTIVE
New insight into the extent of the target volume for the postoperative irradiation of malignant pleural mesothelioma as determined during surgery has indicated that standard conformal radiotherapy (IMRT) is not sufficient for curative treatment. We describe a novel technique for implementing intensity-modulated radiotherapy (IMRT) to deliver higher doses to treat the full extent of these complex target volumes.


METHODS
After extrapleural pneumonectomy, 7 patients underwent simulation, treatment planning, and treatment with IMRT to the involved hemithorax and adjacent abdomen. The target volumes encompassed the entire operative bed, including the ipsilateral mediastinum, anterior pleural reflection, and ipsilateral pericardium and the insertion of the diaphragm and crura. These were extensively marked during surgery with radiopaque markers to facilitate target delineation.


RESULTS
Setup uncertainty and respiratory-dependent motion were found to be small. Coverage of the planning target volume was very good, with the crus of the diaphragm the most difficult volume to irradiate. The radiation doses to normal structures were acceptable.


CONCLUSIONS
IMRT for treatment of malignant mesothelioma after extrapleural pneumonectomy results in more potentially curative doses to large, complex target volumes with acceptable doses to normal tissues.
Forster
Kenneth M
KM
Department of Radiation Physics, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA. kmforster@mdanderson.org
Smythe
W Roy
WR
Starkschall
George
G
Liao
Zhongxing
Z
Takanaka
Tsuyoshi
T
Kelly
Jason F
JF
Vaporciyan
Ara
A
Ahamad
Anesa
A
Dong
Lei
L
Salehpour
Mohammad
M
Komaki
Ritsuko
R
Stevens
Craig W
CW
D006801:Humans; D008654:Mesothelioma / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000601:surgery; D019047:Phantoms, Imaging; D010865:Pilot Projects; D010997:Pleural Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000601:surgery; D011013:Pneumonectomy / Q000379:methods; D011184:Postoperative Period; D011829:Radiation Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome