SEATTLEUltrasound (US)-guided Mammotome biopsy is both effective and safe for sampling breast lesions, Nathalie Duchesne, MD, a staff radiologist at the Hôpital du Saint-Sacrement, Quebec, said at the 101st Annual Meeting of the American Roentgen Ray Society (abstract 19). In fact, for most small lesions, the Mammotome permits complete excision of the lesion.
The low but persisting false-negative rate of core biopsy for small breast masses was a key impetus for the development of the Mammotome Breast Biopsy System (Biopsys Medical, Inc, Irvine, California), Dr. Duchesne said.
She and her colleagues prospectively studied the accuracy, feasibility, and reproducibility of the 11-gauge handheld Mammotome with ultrasound guidance for the sampling and removal of breast lesions. The Mammotome is inserted beneath breast lesions, whenever possible, and removes tissue by vacuum.
The researchers chose eight indications for the use of the Mammotome: small lesions (less than 1.5 cm); lesions that were close to the pectoralis muscle or implants; lesions that would have been difficult to sample by core biopsy because of features such as fibrosis; heterogeneous lesions; intracystic solid masses; lesions suspected of being recurrent in situ carcinoma; lesions with discordant core biopsy results; and lesions for which the patient expressed a preference for Mammotome biopsy.
The Mammotome obtains impressively large tissue specimens that patients may find distressing, Dr. Duchesne cautioned. "We offer the patients virtual reality glasses for use during the biopsy," she said. "About half of the patients choose to watch the ultrasound procedure, and the other half choose to see a movie showing a panoramic view of Canada."
The 61 ultrasound-guided Mammotome biopsies done in the initial 1-year study period (August 6, 1999, through August 6, 2000) comprised 34% of all ultrasound-guided biopsies performed at the institution. The lesions ranged in size from 4 mm to 50 mm. Complete excision was achieved in 55% of all cases and in 77% of cases with lesions measuring 10 mm or less. A marker clip was successfully positioned within 1 cm of the biopsy cavity in 70% of cases.