Assessment of Radio‐Guided Occult Lesion Localization Associated with Sonography in Non‐Palpable Breast Lesions

To the Editor: Currently detection of nonpalpable breast lesions has been improved due to screening imaging programs (1). Several methods are applied for localization of lesions prior to excision, the most common is wire replacement under ultrasonography guidance, which has some disadvantages such as interference with surgery field, wire movement, pneumothorax, high expenses of wire, and logistical constraints (2–4). Radio-guided occult lesion localization (ROLL) for nonpalpable breast masses is a relatively new method with more advantages and less complications. In this method liquid radiotracer, Tc-99m labeled colloid particles of human serum albumin is injected into the lesion (4) and the surgeon identifies the accurate location of target lesion based on the maximum radioactivity signal by a handheld gamma-probe (3,5). Being a new method in Iran, we applied ROLL in our institution and investigated its accuracy in localization and consequently complete excision of nonpalpable breast lesions. In this study, 42 patients with the mean age of 44 (26–70) years with nonpalpable breast lesions were enrolled. Inclusion criteria were an indication for excisional surgery based on either ACR BI-RADS standard system 2012, or physician and patient preference for resection. First, an experienced interventional radiologist injected 0.1–0.2 mL of Tc99m labeled sodium Phytate into the center of the lesion by a 20G needle under ultrasonography guidance, equivalent to 0.5–1 mCi, 1–10 hours before surgery. About 0.1 mL of air was injected with the radiotracer for better visualization and ensuring accurate localization and complete injection of the tracer (Fig. 1). The site of incision was determined by an experienced breast surgeon according to preoperative images and the point of intense radioactivity signal during surgery, and then the lesion was excised. The excision bed was then explored by the gamma probe for any residual radioactivity and if detected, excision was repeated. Accurate localization of lesion occurred in 38 patients (90.5%), which was lower than previous studies (5). Inaccurate localization was performed in four patients (9.5%) which was higher than previous researches (2,5–8), including spreading of radiotracer into subcutaneous tissue in two cases and adjacent ducts in another two patients, which made the surgeon confused. So in these four patients we had reexcision (9.5%) with larger volumes of specimen, and one of them underwent secondary surgery (2.4%) which was lower than other studies with larger sample size (2,6,7). Margin status after excision was clear in all patients (100%) which was lower than some studies with larger sample size (2,4,7,8). In one patient (2.4%) with atypical ductal hyperplasia, in spite of clear margin, pathologic involvement was extended near the margin. As the majority of histologic results were benign with a few number of malignant lesions (benign in 38 patients (90.5%) and malignant in four patients (9.5%)), margin status could not be accurately investigated in our practice. Mean excised tissue volume was 28.59 27.96 cm in all patients and 23.54 23.46 cm in patients with accurate localization which was higher than previous investigations (7,8). Our patients’ satisfaction level about postoperative cosmetic results was excellent in 33.3% and good in 66.6% of patients, which was lower than previous studies (2,8). Pain score was 3.21 0.6 (2–5) which was higher relative to previous studies (8). Mean duration of localization (1.80 0.42 minutes) and surgical procedure (26.78 8.10 minutes) were significantly lower and similar to previous studies, respectively (1,2,4,7,8). Mean duration of hospital stay Address correspondence and reprint requests to: Samaneh Sajjadi, MD, Assistant Professor, Department of Internal Medicine, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran, or e-mail: sajjadis@mums.ac. ir