Radiofrequency ablation of invasive breast carcinoma followed by delayed surgical excision

Radiofrequency ablation (RFA) is gaining acceptance as a treatment modality for several tumor types. However, its use in patients with breast carcinoma remains investigational. The current study was undertaken to determine the feasibility of treating small breast malignancies with RFA and to evaluate the postablation magnetic resonance imaging scans (MRI) and histologic findings.

Patients with core-needle biopsy-proven invasive carcinoma (< 2 cm in greatest dimension) underwent ultrasound-guided RFA under local anesthesia. Surgical excision was undertaken 1-3 weeks later. All patients had breast MRI scans performed before ablation and repeated within 24 hours of surgery.

Ten patients completed the treatment and experienced minimal or no discomfort. The mean tumor size was 1.2 cm (range, 0.8-1.6 cm). The mean time required for ablation was 13.8 minutes (range, 7-21 minutes). There were no treatment-related complications other than minimal breast ecchymosis. A pre-RFA MRI scan showed enhancing tumors in 9 of 10 (90%) patients. A post-RFA MRI scan revealed no residual lesion enhancement in 8 of these 9 patients (89%), and the zone of ablation was demonstrated in all patients. One patient had residual enhancement anteriorly consistent with residual tumor, which was confirmed histologically. Evaluation of the remaining ablated lesions revealed a spectrum of changes ranging from no residual tumor to coagulation necrosis with recognizable malignant cells. Immunostains for cytokeratin 8/18 were negative in these recognizable malignant cells.

RFA of small breast malignancies can be performed under local anesthesia in an office-based setting. A postablation MRI scan appears to predict histologic findings, although tumor viability needs to be assessed in a long-term study.