Details

Autor(en) / Beteiligte

• Bogers, S.L.C.
• Petoukhova, A.L.
• Penninkhof, J.J.
• Mast, M.E.
• Poortmans, P.M.
• Hoogeman, M.S.
• Struikmans, H.

Titel

Target Volume Coverage and Organ at Risk Doses for Left-sided Whole-breast Irradiation With or Without Internal Mammary Chain Irradiation: A Comparison Between Three Techniques Representing the Past and the Present

Ist Teil von

• Clinical oncology (Royal College of Radiologists (Great Britain)), 2022-08, Vol.34 (8), p.537-544

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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. 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. 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. •Past and present radiotherapy techniques for WBI and (yes or no) elective IMC were compared dosimetrically.•Contemporary radiotherapy techniques show better IMC coverage and lower heart doses.•An improved therapeutic ratio may be anticipated for elective IMC radiotherapy.•Previous assumptions concerning late radiation-induced heart disease are challenged.