Early mammographic and sonographic findings after intraoperative radiotherapy (IORT) as a boost in patients with breast cancer

The aim of this study was to evaluate mammographic and sonographic changes at the surgical site within the first 2 years after IORT as a boost followed by whole-breast radiotherapy (WBRT), compared with a control group treated with WBRT alone. All patients had breast-conserving surgery for early-stage breast cancer. Group A: n = 27, IORT (20 Gy) followed by WBRT (46 Gy). Group B (control group): n = 27, WBRT alone (56-66 Gy). Mammography: fat necrosis in 14 group A versus four group B patients (P < 0.001); parenchymal scarring classified as unorganized at the last follow-up in 16 vs seven cases, respectively (P = 0.03). Ultrasound: overall number of patients with circumscribed findings 27 vs 18 (P < 0.001); particular hematomas/seromas in 26 vs 13 patients (P < 0.001). Synopsis of mammography and ultrasound: overall postoperative changes were significantly higher classified in group A (P = 0.01), but not judged to have a significantly higher impact on interpretation. Additional diagnostic procedures, due to unclear findings at the surgical site, were performed on four patients of both groups. Within the first 2 years after IORT as a boost, therapy-induced changes at the original tumor site are significantly more pronounced compared with a control group. There is no evidence that the interpretation of findings is complicated after IORT.