Introduction: Excision followed by RFA (eRFA) may allow improved cosmesis while ensuring negative margins in patients with breast cancer. This technique utilizes heat to create an additional tumor-free zone around the lumpectomy cavity. We hypothesized that eRFA will decrease the need for re-excision of inadequate margins.
Methods: Between July 2002 and January 2005, we conducted a multiphase trial of RFA of prophylactic mastectomy specimens and of women desiring lumpectomy. In both models, a lumpectomy was performed, the RFA probe was deployed 1 cm circumferentially into the walls of the lumpectomy cavity and maintained at 100 degrees C for 15 min. Whole mount slides were used to measure the zone of ablation for ex vivo specimens. Hematoxylin and eosin staining of in vivo lumpectomy margins < 3 mm was considered inadequate.
Results: Nineteen prophylactic mastectomy ablations revealed a consistent perimeter of ablation. Forty-one patients (mean age 63 +/- 14 years) had an average tumor size of 1.6 +/- 1.5 cm underwent in vivo eRFA, and 25% had inadequate margins: one focally positive, one < 2 mm, eight < 1 mm and one grossly positive. Only the grossly positive margin was re-excised. Overall complication rate of in vivo ablations was 7.5%. Twenty-four of 41 patients did not have post-eRFA XRT. No in-site local recurrences have occurred during a median follow-up of 24 months (12-45 months). Two patients have occurred elsewhere.
Conclusions: The ex vivo ablation model reliably created a 5-10 mm perimeter of ablation. In vivo, this zone reduced the need for re-excision for inadequate margins by 91% (10/11). Short-term follow-up suggests that eRFA could reduce re-excision surgery and local recurrence.