Over the last three decades, breast-conserving surgery (BCS) followed by whole-breast irradiation (WBI) consisting of 5 weeks of daily external beam radiotherapy (RT) with or without additional irradiation to the tumour bed became the standard of care for the treatment of early-stage breast carcinoma. However, the necessity of giving WBI for all patients after BCS has been questioned, and several centers have evaluated the feasibility and efficacy of accelerated partial-breast rradiation (APBI).
The results of ongoing clinical trials showed that APBI with proper patient selection and quality assurance (QA) yields similar results to those achieved with standard WBI. Parallel with the growing evidence obtained from phase I–II studies supporting the use of APBI for selected early stage breast cancer patients, at least seven phase III trials comparing different techniques of APBI to conventional WBI have been initiated in the last decade in Europe, Canada and the USA. The use of APBI outside the framework of a clinical trial has markedly increased, even as we await the results of randomized clinical trials comparing APBI with conventional WBI. During the past few years the concept of APBI has been widely accepted by patients and treating physicians and more than 30,000 patients have been treated outside clinical trials worldwide. For another example, to date more than 32,000 women in the United States have been treated with the MammoSite (Cytyc, Marlborough, MA) breast brachytherapy catheter.
The rationale for the use of APBI is based on the observation that 70 – 80% of patients might not have additional benefit from whole-breast irradiation, since the majority of local recurrences occur in close proximity to the tumor bed. Furthermore, the 6 - week course of conventional radiation therapy might be a significant burden on women, especially after months of chemotherapy, and finally might worsen the cosmetic outcome.
Accelerated partial-breast irradiation offers decreased overall treatment time and several theoretical advantages over WBI, including a decrease in the radiation dose delivered to uninvolved portions of the breast and adjacent organs. However, there are several theoretical disadvantages to APBI, principally the possibility that occult foci of cancer exist elsewhere in the breast and will not be treated. In past years, few data were available to define which patients could be safely treated with APBI and which patients should receive WBI. However, in light of increasing evidence that WBI improves long-term overall survival, it has become clear that conservative patient selection criteria for APBI should be followed until additional data indicate otherwise.
The results of ongoing clinical trials showed that APBI with proper patient selection and quality assurance (QA) yields similar results to those achieved with standard WBI. Parallel with the growing evidence obtained from phase I–II studies supporting the use of APBI for selected early stage breast cancer patients, at least seven phase III trials comparing different techniques of APBI to conventional WBI have been initiated in the last decade in Europe, Canada and the USA. The use of APBI outside the framework of a clinical trial has markedly increased, even as we await the results of randomized clinical trials comparing APBI with conventional WBI. During the past few years the concept of APBI has been widely accepted by patients and treating physicians and more than 30,000 patients have been treated outside clinical trials worldwide. For another example, to date more than 32,000 women in the United States have been treated with the MammoSite (Cytyc, Marlborough, MA) breast brachytherapy catheter.
The rationale for the use of APBI is based on the observation that 70 – 80% of patients might not have additional benefit from whole-breast irradiation, since the majority of local recurrences occur in close proximity to the tumor bed. Furthermore, the 6 - week course of conventional radiation therapy might be a significant burden on women, especially after months of chemotherapy, and finally might worsen the cosmetic outcome.
Accelerated partial-breast irradiation offers decreased overall treatment time and several theoretical advantages over WBI, including a decrease in the radiation dose delivered to uninvolved portions of the breast and adjacent organs. However, there are several theoretical disadvantages to APBI, principally the possibility that occult foci of cancer exist elsewhere in the breast and will not be treated. In past years, few data were available to define which patients could be safely treated with APBI and which patients should receive WBI. However, in light of increasing evidence that WBI improves long-term overall survival, it has become clear that conservative patient selection criteria for APBI should be followed until additional data indicate otherwise.