Accelerated, Partial Breast Irradiation Overview

Abstract

The Halsted radical mastectomy was introduced in 1894 and became the standard of care for the surgical management of primary breast cancer. As mortality from breast cancer declined with this new treatment, women increasingly sought medical attention earlier in the natural history of the disease. This was associated with a progressive decrease in tumor size at presentation. The trend towards smaller lesions was further accelerated by the introduction of screening mammography. For some, this observation raised the question as to whether removal of the entire breast was necessary for all women. In the 1970’s, clinical trials in early stage breast cancer first began to demonstrate that breast conservation surgery followed by whole breast radiotherapy could provide equivalent survival to mastectomy as well as comparable local control. Subsequently, investigators questioned whether a parallel paradigm shift was possible from whole breast radiotherapy to partial breast irradiation. Although early clinical studies of partial breast irradiation demonstrated high rates of ipsilateral breast tumor recurrence, refinements in patient selection, breast conservation surgery technique, and radiation treatment planning have since yielded promising results with partial breast irradiation at 5 years of follow-up. This chapter provides an overview of ongoing efforts, including phase III clinical trials, designed to test the safety and efficacy of accelerated, partial breast irradiation.