TY - JOUR
T1 - Target Volume Coverage and Organ at Risk Doses for Left-sided Whole-breast Irradiation With or Without Internal Mammary Chain Irradiation
T2 - A Comparison Between Three Techniques Representing the Past and the Present
AU - Bogers, S. L.C.
AU - Petoukhova, A. L.
AU - Penninkhof, J. J.
AU - Mast, M. E.
AU - Poortmans, P. M.
AU - Hoogeman, M. S.
AU - Struikmans, H.
N1 - Publisher Copyright: © 2022 The Royal College of Radiologists
PY - 2022/8
Y1 - 2022/8
N2 - Aims: The 15-year results of the EORTC 229922-10925 phase III trial showed a significant reduction in breast cancer mortality and breast cancer recurrences after internal mammary chain (IMC) and medio-supraclavicular irradiation. Unexpectedly, cardiac death was not increased, and the incidence of cardiac events did not differ between left- and right-sided cases, although target volume coverages and organ at risk doses were unknown. Therefore, a planning study was carried out comparing the past and the present, to eventually enable, thereafter, an increased therapeutic ratio of IMC irradiation. Materials and methods: A planning study was carried out on target volume coverage and organ at risk doses for whole-breast irradiation (WBI) ± IMC comparing the results between two-dimensional radiotherapy (free-breathing), hybrid intensity-modulated radiotherapy (IMRT; breath-hold) and robust intensity-modulated proton therapy (IMPT; free-breathing) for 10 left-sided breast cancer cases. Two-dimensional radiotherapy consisted of two tangential wedged photon breast fields and mixed electron/photon beams for the IMC. Hybrid IMRT included two tangential photon breast fields (70%) complemented with IMRT (30%). IMPT plans were created using multi-field robust optimisation (5 mm set-up and 3% range uncertainties) with two (WBI) or three (WBI + IMC) beams. Results: Target volume dose objectives were met for hybrid IMRT and IMPT. For two-dimensional radiotherapy, target coverage was 97% and 83% for breast and IMC, respectively. The mean heart dose for WBI only was <2 Gy for all techniques. For WBI + IMC, heart doses (mean heart dose, mean left anterior descending region, volume of the heart receiving 5 Gy (V5) were significantly higher for two-dimensional radiotherapy when compared with contemporary techniques. The V5 left anterior descending region reduced from 100% (two-dimensional radiotherapy) to 70% and 20% for hybrid IMRT and IMPT, respectively. Conclusion: Contemporary radiotherapy techniques result in improved target volume coverage and significantly decreased heart doses for WBI + IMC radiotherapy. Hence, nowadays an increased therapeutic ratio of elective IMC irradiation may be anticipated.
AB - Aims: The 15-year results of the EORTC 229922-10925 phase III trial showed a significant reduction in breast cancer mortality and breast cancer recurrences after internal mammary chain (IMC) and medio-supraclavicular irradiation. Unexpectedly, cardiac death was not increased, and the incidence of cardiac events did not differ between left- and right-sided cases, although target volume coverages and organ at risk doses were unknown. Therefore, a planning study was carried out comparing the past and the present, to eventually enable, thereafter, an increased therapeutic ratio of IMC irradiation. Materials and methods: A planning study was carried out on target volume coverage and organ at risk doses for whole-breast irradiation (WBI) ± IMC comparing the results between two-dimensional radiotherapy (free-breathing), hybrid intensity-modulated radiotherapy (IMRT; breath-hold) and robust intensity-modulated proton therapy (IMPT; free-breathing) for 10 left-sided breast cancer cases. Two-dimensional radiotherapy consisted of two tangential wedged photon breast fields and mixed electron/photon beams for the IMC. Hybrid IMRT included two tangential photon breast fields (70%) complemented with IMRT (30%). IMPT plans were created using multi-field robust optimisation (5 mm set-up and 3% range uncertainties) with two (WBI) or three (WBI + IMC) beams. Results: Target volume dose objectives were met for hybrid IMRT and IMPT. For two-dimensional radiotherapy, target coverage was 97% and 83% for breast and IMC, respectively. The mean heart dose for WBI only was <2 Gy for all techniques. For WBI + IMC, heart doses (mean heart dose, mean left anterior descending region, volume of the heart receiving 5 Gy (V5) were significantly higher for two-dimensional radiotherapy when compared with contemporary techniques. The V5 left anterior descending region reduced from 100% (two-dimensional radiotherapy) to 70% and 20% for hybrid IMRT and IMPT, respectively. Conclusion: Contemporary radiotherapy techniques result in improved target volume coverage and significantly decreased heart doses for WBI + IMC radiotherapy. Hence, nowadays an increased therapeutic ratio of elective IMC irradiation may be anticipated.
UR - http://www.scopus.com/inward/record.url?scp=85130515743&partnerID=8YFLogxK
U2 - 10.1016/j.clon.2022.04.004
DO - 10.1016/j.clon.2022.04.004
M3 - Article
C2 - 35606251
AN - SCOPUS:85130515743
SN - 0936-6555
VL - 34
SP - 537
EP - 544
JO - Clinical Oncology
JF - Clinical Oncology
IS - 8
ER -
