High-dose-rate surface brachytherapy to boost elongated, curvilinear incisional scars after extrapleural pneumonectomy for malignant pleural mesothelioma treated with adjuvant intensity-modulated radiation therapy.
OBJECTIVE
Providing adequate dosimetric coverage of elongated, curvilinear incisions during adjuvant intensity-modulated radiation therapy (IMRT) after extrapleural pneumonectomy (EPP) for malignant pleural mesothelioma (MPM) creates technical challenges. We explored high-dose-rate (HDR) surface brachytherapy to supplement dose to multiple curvilinear incisions. This modality circumvents the technical limitations of relying on multiple en face electron fields while minimizing dose to adjacent normal tissues.


METHODS
A 59-year-old man presented with a left-sided, Stage III, T3N2M0, epithelioid MPM. After undergoing a left EPP, adjuvant IMRT was recommended to improve local control. An eight-field IMRT plan was designed to encompass the postoperative hemithorax. Incisional scars were lengthy and extended beyond the hemithoracic target volume. Both en face electron and surface HDR plans were prepared and evaluated based on dosimetric coverage of the incisional scars, dose to normal tissues, reliability of setup, and treatment delivery.


RESULTS
HDR was preferred. The patient was planned and treated in the right lateral decubitus position. HDR source catheters were placed along the incisions atop 5-mm bolus. A composite plan including IMRT and brachytherapy dose contributions was produced. Boosts of incisional scars were performed in six fractions (three fractions per week) of 3 Gy prescribed to 12 mm from the catheter. HDR brachytherapy was well tolerated.


CONCLUSIONS
Surface HDR brachytherapy is a viable option for supplemental dose to incisional scars at risk of local recurrence after EPP for MPM. Advantages over electron beam therapy include avoidance of field abutments and feathering, less tissue-bone interface dose uncertainty and reproducibility of treatment delivery.
Doyle
Laura A
LA
Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Bodine Center for Cancer Treatment, 111 South 11th Street, Philadelphia, PA 19107, USA. laura.doyle@jeffersonhospital.org
Showalter
Timothy N
TN
Werner-Wasik
Maria
M
Weksler
Benny
B
Xiao
Ying
Y
Yu
Yan
Y
Macrone
Andrea
A
Liu
Haisong
H
Harrison
Amy
A
D001918:Brachytherapy / Q000379:methods*; D002921:Cicatrix / Q000209:etiology* / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008654:Mesothelioma / Q000532:radiotherapy*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology / Q000532:radiotherapy*; D010997:Pleural Neoplasms / Q000532:radiotherapy*; D011013:Pneumonectomy / Q000009:adverse effects*; D018714:Radiotherapy, Adjuvant; D020266:Radiotherapy, Conformal / Q000379:methods*; D016896:Treatment Outcome