Early experience with ultrasound features after intrabeam intraoperative radiation for early stage breast cancer.

Background: Intraoperative radiation therapy (IORT) is an emerging option for partial breast radiotherapy in select women with early stage breast cancer. We assessed short-term clinical and sonographic findings after breast conservation (BCT) and IORT.

Methods: An IRB-approved, single institution retrospective chart review was conducted of patients (pts) treated with BCT/IORT from 1/2011 to 6/2012. Follow-up clinical breast exams and ultrasounds (US) obtained 6 and 12 months after BCT/IORT were retrospectively reviewed by a single breast radiologist (JD) for sonographic findings. P values were calculated using McNemar's test, Wilcoxon Rank Sum Test, and Chi-square.

Results: Seventy-one pts underwent BCT/IORT and 38 pts had an US. All 38 pts had a seroma, 10/38 (26%) pts were symptomatic. Eighteen pts had deep tissue closure (DTC) of the lumpectomy cavity with 5/18 (28%) DTC pts being symptomatic at follow-up versus 5/33 (15%) without DTC (P = 0.296). At 6 months, DTC resulted in smaller seroma cavity volumes compared to those without DTC (P = 0.03).

Conclusion: Presence of a seroma is commonplace post BCT/IORT; symptomatic seromas are uncommon. DTC generated smaller seromas. Longer follow-up with serial US performed in all BCT/IORT pts could be considered to document natural progression/regression of symptoms and seromas.