Pros and Cons of Intraoperative Radiotherapy: Comparison of Two Clinical Trials in Breast Cancer Management

Context: Intraoperative radiotherapy (IORT) is an accepted standard treatment for early stages of breast cancer in the selected cases. This is proven in two large clinical trials including ELIOT and TARGIT-A ones, which are based on high energy electron beam and low kV X-ray energy, respectively. Published results of two trials aimed at evaluating the local recurrence as the final outcome. In ELIOT study, the local recurrence rate is 4.4% versus 0.4% in patients, who received IORT and External Beam Radiotherapy (EBRT), in comparison to 3.2% and 1.3% in TARGIT-A trial. These differences need to be further evaluated regarding the efficacy and beneficence of IORT. The aim of this study is to further analyze the data of these two trials to confirm the strategy of IORT in breast cancer as boost or radical modality. Evidence Acquisition: Two main breast IORT trials were considered in this study. To this end, a computerized search was performed through MEDLINE, PubMed, PubMed Central, ISI web of knowledge, and reference list of related articles. All of the published data from these trials were gathered and their subjects were analyzed and compared. Statistical analysis revealed that in patients with matching clinical, pathological, and biological profiles in both trials, radical IORT using either electron or low kV X-ray is effective and acceptable. It seems that in patients with low risk factors, IORT is more effective than EBRT. Patient selection according to America Society of Radiation Oncology or European Society of Radiation Therapy classification guidelines confirmed that the local recurrence rate of ELIOT in low risk patients, similar to TARGIT, was less than 1.9%. We compared the ELIOT and TARGIT-A trial documents and found all of similarities and differences referred to these two trials recommend, using IORT for selected cases of breast cancer with at least non inferiority in Disease free survival (DFS) and overall survival (OS) as well as superiority in cosmetic, non-breast cancer death, and more.