B21
Single dose radiotherapy during surgery for breast cancer patients where external beam radiation was not feasible: results after 3 years of follow-up
Mohammed Keshtgar1, Jayant S Vaidya2, Anke Keller3, Frederik Wenz3, Tammy Corica4, David Joseph4, Chris Stacey5, Jeffrey S Tobias5, Norman R Williams2, Michael Baum2
1Royal Free Hospital, London, UK, 2University College London, UK, 3Universittsmedizin Mannheim, Germany, 4Sir Charles Gairdner Hospital, Perth, Australia, 5University College London Hospital, UK
Aim
Intra-operative radiotherapy (IORT) with Intrabeam (Carl Zeiss, Germany) has been used since 2000 in the international randomised TARGIT Trial to determine if there is equivalence between the novel IORT technique and conventional external beam radiotherapy (EBRT) in women with early breast cancer. Some patients were unsuitable for inclusion in our trial for a number of reasons and were given IORT as a single treatment off-trial.
Method
Patients with invasive breast cancer underwent wide local excision followed by IORT (n=74). Low energy x-rays are emitted from the point source, delivering 20Gy radiation dose to the breast tissue at the surface of the tumour bed. Radiotherapy is delivered directly into the area of interest, following which women can then proceed to have chemotherapy and/or adjuvant hormonal therapy as required. In addition, patients who were deemed unfit for surgery (n=3) received interstitial radiotherapy alone under local anaesthetic. Women were followed-up for local recurrence.
Results
Over the past 7 years in centres in 3 countries (UK, Germany and Australia), 77 patients have been treated in this way, with median age of 66 (56-77 IQR) years and a median follow-up of 37 (25-54 IQR) months. To date there have been two local recurrences, which gives an estimated annual local recurrence rate of 0.78% (95%CI 0.09% to 2.77%).
Conclusion
This cohort adds to the evidence that targeted radiotherapy using IORT could offer a safe and effective method of delivering radiotherapy to breast cancer patients in whom EBRT is not feasible or is not an option.
