TY - JOUR
T1 - Contralateral breast dose after whole-breast irradiation
T2 - An analysis by treatment technique
AU - Williams, Terence M.
AU - Moran, Jean M.
AU - Hsu, Shu Hui
AU - Marsh, Robin
AU - Yanke, Beth
AU - Fraass, Benedick A.
AU - Pierce, Lori J.
N1 - Funding Information:
Supported by research grants from the Breast Cancer Research Foundation (L.J.P., J.M.M., and R.M.).
Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/4/1
Y1 - 2012/4/1
N2 - Purpose: To investigate the contralateral breast dose (CBD) across a continuum of breast-conservation therapy techniques. Methods and Materials: An anthropomorphic phantom was CT-simulated, and six treatment plans were generated: open tangents, tangents with an external wedge on the lateral beam, tangents with lateral and medial external wedges, a simple segment plan (three segments per tangent), a complex segmental intensity-modulated radiotherapy (IMRT) plan (five segments per tangent), and a beamlet IMRT plan (>100 segments). For all techniques, the breast on the phantom was irradiated to 5000 cGy. Contralateral breast dose was measured at a uniform depth at the center and each quadrant using thermoluminescent detectors. Results: Contralateral breast dose varied with position and was 50 ± 7.3 cGy in the inner half, 24 ± 4.1 cGy at the center, and 16 ± 2.2 cGy in the outer half for the open tangential plan. Compared with an average dose of 31 cGy across all points for the open field, the average doses were simple segment 32 cGy (range, 99-105% compared with open technique), complex segment 34 cGy (range, 103-117% compared with open technique), beamlet IMRT 34 cGy (range, 103-124% compared with open technique), lateral wedge only 46 cGy (range, 133-175% compared with open technique), and medial and lateral wedge 96 cGy (range, 282-370% compared with open technique). Conclusions: Single or dual wedge techniques resulted in the highest CBD increases compared with open tangents. To obtain the desired homogeneity to the treated breast while minimizing CBD, segmental and IMRT techniques should be encouraged over external physical compensators.
AB - Purpose: To investigate the contralateral breast dose (CBD) across a continuum of breast-conservation therapy techniques. Methods and Materials: An anthropomorphic phantom was CT-simulated, and six treatment plans were generated: open tangents, tangents with an external wedge on the lateral beam, tangents with lateral and medial external wedges, a simple segment plan (three segments per tangent), a complex segmental intensity-modulated radiotherapy (IMRT) plan (five segments per tangent), and a beamlet IMRT plan (>100 segments). For all techniques, the breast on the phantom was irradiated to 5000 cGy. Contralateral breast dose was measured at a uniform depth at the center and each quadrant using thermoluminescent detectors. Results: Contralateral breast dose varied with position and was 50 ± 7.3 cGy in the inner half, 24 ± 4.1 cGy at the center, and 16 ± 2.2 cGy in the outer half for the open tangential plan. Compared with an average dose of 31 cGy across all points for the open field, the average doses were simple segment 32 cGy (range, 99-105% compared with open technique), complex segment 34 cGy (range, 103-117% compared with open technique), beamlet IMRT 34 cGy (range, 103-124% compared with open technique), lateral wedge only 46 cGy (range, 133-175% compared with open technique), and medial and lateral wedge 96 cGy (range, 282-370% compared with open technique). Conclusions: Single or dual wedge techniques resulted in the highest CBD increases compared with open tangents. To obtain the desired homogeneity to the treated breast while minimizing CBD, segmental and IMRT techniques should be encouraged over external physical compensators.
KW - Breast cancer
KW - Contralateral breast dose
KW - IMRT
KW - Second malignancies
KW - Whole-breast irradiation
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U2 - 10.1016/j.ijrobp.2011.01.049
DO - 10.1016/j.ijrobp.2011.01.049
M3 - Article
C2 - 21489713
AN - SCOPUS:84858698099
SN - 0360-3016
VL - 82
SP - 2079
EP - 2085
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 5
ER -