K. Reno5, A. Kuritzky1, B. Mooney2, W. Sun1, J. Zhou3, Z. Ma3, M. C. Lee1, C. Laronga1 1Moffitt Cancer Center,Breast Surgery,Tampa, FLORIDA, USA 2Moffitt Cancer Center,Radiology,Tampa, FLORIDA, USA 3Moffitt Cancer Research Center,Biostatistics,Tampa, FLORIDA, USA 5University Of South Florida,College Of Medicine,Tampa, FLORIDA, USA
Introduction: Breast cancer treatment utilizing Intraoperative radiation (IORT) concurrently with breast conserving surgery (BCT) is an evolving therapy. The IORT cavity changes radiographically on short time follow up (<1yr), but data regarding long-term (>1yr) changes is sparse. Our aim was to assess long-term imaging findings following BCT/IORT.
Methods: An IRB-approved, retrospective chart review of cases from a single-institution, BCT + IORT prospective database between 01/11-02/14 was conducted. Clinical-pathologic reports and surveillance (physical and radiographic) exams at 6 months, and yrs 1-5 were recorded. Ultrasound (US) of the lumpectomy cavity was performed at 6 months postop as standard operating procedure. All US data was re-reviewed by an independent breast radiologist. Demographics are summarized using descriptive statistics. Statistical analysis was performed using Wilcoxon rank-sum and Kruskal-Wallis Fisher exact test.
Results: During the study period, 114pts underwent BCT/IORT. The median age was 71yrs [range 51-88]; median tumor size was 1.0cm [range 0.2-3.5cm]. The median follow up was 3.25yrs [range 0.25-5.4]. US > 1 yr was performed for symptoms or mammographic changes. Of the 65pts that received US at 6 months 63(96.9%) pts had a seroma with 14(21.5%) being symptomatic; Of the 43 pts that received US, at 1yr follow-up 38(88.4%) had seroma with 7(16.3%) symptomatic. Of the 7 pts that received a 3yr US, 1(14.3%) was symptomatic and of the 4 that received a 4yr US, 3(75%) were symptomatic. In all patients, size of seroma decreased overtime from 10.7cm3 at 6 months, to 8.5cm3 at 1yr, to 5.75cm3 at 2yrs, and to 5.3cm3 at 3yrs. Of the 106pts with 6 month mammogram, the most common findings were post lumpectomy changes in 68(64.2%) pts. BiRADS scores range from 1–5 with a median of BiRADS 2 at 6 months, 2 at yr 1, 2 at yr 2, and 2 at yrs 3-5. Percentage of pts with BiRADS 3 progressively decreased from 16(15.1%) at 6 months to 5(5.2%) at 2yrs and to 0 by 4 yrs. In this time frame, 7pts were found to have in-breast recurrences; 6 were detected mammographically and one by punch biopsy of skin lesion. Median time from surgery to recurrence was 36 months (range 12-65). In these 7 pts, mammographic findings were BiRADS 2-3 at 6months followed by a new abnormality designated as a BiRADS 4b or 4c finding at yrs 1-5.
Conclusion: In pts receiving BCT/IORT, seroma cavity size decreased over time with the largest change at 2yrs as seroma resolved. Mammographic BiRADs stabilized by yr 2 with the majority of pts receiving a score of 2 for benign findings after yr 2. IORT did not interfere with mammographic interpretation, especially local recurrence findings.
