Use of technetium-99m-labeled colloid albumin for preoperative and intraoperative localization of nonpalpable breast lesions

Background: Management of clinically occult breast lesions is still a major point of debate. Several techniques (eg, skin projection, guidewire locali zation) have been proposed, but all of them have technical limitations. Study Design: The aim of this study was to assess the efficacy of a new met hod to locate occult breast lesions using technetium-99m (Tc-99m)-labeled c olloid particles of human serum albumin (radioguided occult lesion localiza tion). We studied 647 consecutive patients (mean age 51.3 years; range 25 t o 77 years) with nonpalpable breast lesions detected mammographically or by ultrasonography. Within 24 hours before operation, 3.7 MBq (0.1 mCi) of Tc -99m-labeled colloid was injected directly into the center of the lesion us ing stereotactic mammographic guidance (when only microcalcifications were present) or ultrasonographic guidance (for opacities). Excision biopsy was performed with a gamma-detecting probe. After excision, the area was checke d for residual radioactivity and the specimen was radiographed to verify co mplete removal of the lesion. The material was then sent for pathologic exa mination. The absorbed dose to the inoculated area and the external irradia tion to staff were also determined. Results: In all 647 patients, the "hot spot" was located easily and quickly . X-ray and scintigraphy of the specimen verified the presence and centrici ty of the lesion in all patients but three (99.5%). Pathologic examination revealed 340 cancer lesions (52.6%). Of these patients, 339 (99.7%) were tr eated by breast-conserving operations and one (0.3%) received a modified ra dical mastectomy. No major surgical or postoperative complications were enc ountered. No recurrences were documented during follow-up. The absorbed dos e to the breast and other tissue was negligible (0.03 +/- 0.02 mGy/MBq), as was the dose to the surgeon's hands (7.5 +/- 5.0 mu Sv/h). The latter dose represents 0.015% and 0.002% of the recommended limits of the European Com munity for the general population and for exposed workers, respectively. Conclusions: Radioguided occult lesion localization seems to offer a simple and reliable method to locate occult breast lesions with a gamma-detecting probe, allowing complete removal of the lesion in 99.5% of patients. Becau se of the small quantity of radioactivity, the procedure is safe for both p atients and medical staff. (J Am Coll Surg 2000;190:692-699. (C) 2000 by th e American College of Surgeons).