Mammographic and ultrasonographic comparison between intraoperative radiotherapy (IORT) and conventional external radiotherapy (RT) in limited-stage breast cancer, conservatively treated

OBJECTIVE: Assess mammographic and echographic modifications in mild cases of breast cancer (suitable for conservative surgery) after intraoperatory radio treatment (IORT) as opposed to conventional post-operative radiotherapy (RT). MATERIALS AND METHODS: We report data from 45 patients in each group (IORT and RT). All patients were examined using the same mammographic and ecographic equipment at 6, 12 and 24 months after treatment. We focused on structural alterations, edema and others, and quantified them using pre-established (unbiased) protocols. Both patient examination and subsequent assessment of the results were performed by radiologists with exepertise in breast cancer evaluation. RESULTS: At 6 months, IORT patients showed slightly more pronounced structural distortions and oedema than RT patients; these differences became more apparent at 12 months, with the addition of fat necrosis and/or calcifications. These alterations were evident and consistent under both mammographic and ecographic examination, and became even more pronounced at 24 months. At this stage, RT patients showed minimal alterations of the tissue (apart from normal post-surgical scarring), whereas IORT patients showed virtually no improvement over the preceding 12-month period. CONCLUSION: We show radiological alterations in post-operative breast cancer are significantly more pronounced in patients treated with IORT as opposed to RT.