Pilot Trial of Cryoprobe-Assisted Breast-Conserving Surgery for Small Ultrasound-Visible Cancers

Abstract

Stereotactic and ultrasonography-guided large core needle biopsy has replaced wire localization biopsy as the diagnostic method of choice. Lumpectomy alternatives are being sought to eliminate the need for preoperative wire localization, to facilitate easier and more accurate resection, and to decrease positive margin rates. Cryoprobe-assisted lumpectomy (CAL) was investigated as an alternative. Patients with ultrasonographically visible breast cancers that otherwise would have required wire localization participated. Before lumpectomy, a cryoprobe (Visica; Sanarus, Pleasanton, CA) was inserted through a 3-mm skin incision and directed by ultrasonography through the center of the tumor. An ice ball was created that enveloped the tumor plus an adjacent 5-10 mm of sonographically normal breast tissue. Twenty-four CAL procedures were performed and all lesions were successfully localized. Mean (+/-SD) tumor size was 1.2 +/-.4 cm (range,.7-2.0 cm). Mean dimensions of the ice ball before excision were 3.9 +/-.3 cm by 2.5 +/-.5 cm, and the ice margin around the tumor was 8 +/- 2 mm. The size of the ice ball was controlled to the millimeter, and the ice ball itself provided a precise template around which to dissect. The margin re-excision rate was 5.6% among patients with an ice margin greater than 6 mm. CAL is a superior alternative to wire localization. Ultrasonographic visualization of the ice ball allows the size of the margin and tissue resected to be individually tailored and accurate within millimeters. The created template allows a precise lumpectomy, adding a dimension of control not previously realized with any other technology.