Secondary cancer risk is a significant concern for women treated with breast radiation therapy due to im- proved long-term survival rates. We evaluated the potential of new advanced automated planning algo- rithms together with hybrid techniques to minimize the excess absolute risk (EAR) for secondary cancer in various organs after radiation treatment for early staged breast cancer. Using CT data set of 25 patients, we generated 4 different radiation treatment plans of different complexity, including 3-dimensional con- formal radiotherapy (3D-CRT), field-in-field (FinF), hybrid-IMRT (HMRT) and automated hybrid-VMAT (HVMAT) techniques. The organ-equivalent dose (OED) was calculated from differential dose-volume his- tograms on the basis of the "linear-exponential," "plateau," and "full mechanistic" dose-response models and was used to evaluate the EAR for secondary cancer in the contralateral breast (CB), contralateral lung (CL), and ipsilateral lung (IL). Statistical comparisons of data were performed by a Kruskal-Wallis anal- ysis of variance. The planning objectives were fulfilled with all the planning techniques for both target coverage and organs-at-risk sparing. The differences in EAR for CB, CL and IL secondary tumor induc- tion were not significant among the 4 techniques. For the CB and CL, the mean absolute difference did not reach 1 case of 10000 patient-years. For the IL, the mean absolute difference was up to 5 cases of 10,000 patient-years. In conclusion, the automated HVMAT technique allows an EAR reduction at the level of well-consolidated tangential 3D-CRT or FinF techniques, keeping all the HVMAT dosimetric im- provements unchanged. On the basis of this analysis, the adoption of the HVMAT technique poses no increase in EAR and could be considered safe also for younger patients.(c) 2023 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.
Risk evaluation of secondary malignancies after radiotherapy of breast cancer in light of the continuous development of planning techniques / Cilla, Savino; Deodato, Francesco; Romano, Carmela; Macchia, Gabriella; Buwenge, Milly; Boccardi, Mariangela; Pezzulla, Donato; Pierro, Antonio; Zamagni, Alice; Morganti, Alessio Giuseppe. - In: MEDICAL DOSIMETRY. - ISSN 0958-3947. - ELETTRONICO. - 48:4(2023), pp. 279-285. [10.1016/j.meddos.2023.07.003]
Risk evaluation of secondary malignancies after radiotherapy of breast cancer in light of the continuous development of planning techniques
Buwenge, Milly;Zamagni, Alice;Morganti, Alessio Giuseppe
2023
Abstract
Secondary cancer risk is a significant concern for women treated with breast radiation therapy due to im- proved long-term survival rates. We evaluated the potential of new advanced automated planning algo- rithms together with hybrid techniques to minimize the excess absolute risk (EAR) for secondary cancer in various organs after radiation treatment for early staged breast cancer. Using CT data set of 25 patients, we generated 4 different radiation treatment plans of different complexity, including 3-dimensional con- formal radiotherapy (3D-CRT), field-in-field (FinF), hybrid-IMRT (HMRT) and automated hybrid-VMAT (HVMAT) techniques. The organ-equivalent dose (OED) was calculated from differential dose-volume his- tograms on the basis of the "linear-exponential," "plateau," and "full mechanistic" dose-response models and was used to evaluate the EAR for secondary cancer in the contralateral breast (CB), contralateral lung (CL), and ipsilateral lung (IL). Statistical comparisons of data were performed by a Kruskal-Wallis anal- ysis of variance. The planning objectives were fulfilled with all the planning techniques for both target coverage and organs-at-risk sparing. The differences in EAR for CB, CL and IL secondary tumor induc- tion were not significant among the 4 techniques. For the CB and CL, the mean absolute difference did not reach 1 case of 10000 patient-years. For the IL, the mean absolute difference was up to 5 cases of 10,000 patient-years. In conclusion, the automated HVMAT technique allows an EAR reduction at the level of well-consolidated tangential 3D-CRT or FinF techniques, keeping all the HVMAT dosimetric im- provements unchanged. On the basis of this analysis, the adoption of the HVMAT technique poses no increase in EAR and could be considered safe also for younger patients.(c) 2023 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
