Intraopertive radiation therapy for breast cancer.

The rapid patient accrual observed in the European breast IORT studies reported since 2000 indicates that surgeons, radiation oncologists, and women who have breast cancer are no longer content to continue to travel down the well-worn path of disfiguring ablative treatment. Breast conservation is currently viewed as the preferred mode of therapy for early-stage breast cancer in most clinical situations. Determination of the optimal combination of whole breast EBRT and localized IORT, for dose and fractionation, is a critical issue that only recently has been addressed [20,21]. Clearly, such clinical investigative endeavors should be regarded as high priority. The very low incidence of local in-breast recurrence of cancer to date suggests that another avenue for investigation might be the determination of the extent to which the lumpectomy procedure can be safely minimized when used in conjunction with IORT. For example, physicians might ask, "Are microscopically negative surgical margins still mandatory when IORT is applied at the time of lumpectomy?" If the answer to that question should turn out to be "no," then it should be much easier for surgeons to achieve the desired excellent cosmetic results when dealing with early-stage breast cancer. Another question remaining to be addressed pertains to the utility of IORT in the management of in-breast recurrence of cancer following conservative therapy. The incidence of local failure after organ-conserving treatment is generally reported to be approximately 5% to 10%. Currently, the preferred mode of salvage therapy in such a clinical situation is mastectomy. The proven efficacy of IORT concurrent with lumpectomy in the primary treatment of early-stage breast cancer suggests that even local recurrences following conventional conservative treatment might be dealt with effectively and expeditiously by means of local excision plus IORT. Such treatment, if safe and effective, could prove to be much less disfiguring than mastectomy. Because breast irradiation routinely produces a desmoplastic tissue response in the breast, there seems to be an opportunity here to address local recurrences of breast cancer with local surgical extirpation enhanced by IORT. Because there are currently few data regarding the use of IORT in this clinical situation, pilot studies would seem to be justified. The remarkably low incidence of local recurrence of breast malignancy observed in every breast IORT study reported to date may portend an important advancement in physicians' ability to better achieve local control of mammary carcinoma. It is hoped that such a putative improvement in the local control of breast cancer will soon translate into improved patient survival rates for this common malignancy.