A systematic review of intraoperative radiotherapy in early breast cancer

A systematic review was undertaken to assess the safety and efficacy of intraoperative radiotherapy (IORT) in early breast cancer compared with breast conserving surgery with postoperative radiotherapy. Literature databases were searched up to March 2002 inclusive. IORT studies of any design and breast conserving therapy randomised controlled trials with sample sizes greater than 500 patients (with at least one arm of breast conserving therapy (BCT)) and systematic reviews on BCT published since 1992, were included for comparison. Seven unique IORT studies were located; one randomised controlled trial, one study with a concurrent control group and five case series. Minor postoperative complications were reported following IORT. Short-term results were similar for both treatment modalities in terms of local recurrence, disease-free and overall survival. However, the current evidence base is poor, making definitive assessment on IORT very difficult. Further research is required to clarify several issues such as identification of the most appropriate subgroups of patients for IORT, a comparison of the currently available mobile IORT technologies, establishing whether IORT is most appropriate as a boost replacement dose or replacement for all postoperative radiotherapy, the examination of how biological repair processes may differ between the two treatment modalities and determining precisely where local recurrences originate with respect to the original tumour site.