Safety and efficacy of radioactive seed localization with I-125 prior to lumpectomy and/or excisional biopsy

PurposeTo evaluate the safety and efficacy of pre-operative I-125 radioactive seed localization (RSL) as an alternative to wire localization (WL).MethodsA waiver was granted by the institutional review board for this HIPAA compliant study. Review of 356 consecutive single site nonpalpable mammographic and ultrasound guided I-125 RSLs done between November 2011 and April 2012 was conducted. Preoperative mammograms and specimen radiographs were reviewed for seed-target distance, lesion location, and target/seed removal. During a brief surgical training period, 35 of 356 women had both RSL and wire localization (WL) of the same lesion. Chi-square and single sample t-tests were used to compare margin status and duration of procedures.ResultsOf the 356 RSLs, 303 (85.1%) were performed ≥1 day before surgery. Mammographic guidance was used in 330 (93%) and ultrasound in 26 (7%). Mean seed to target distance was 1 mm (range 0–20 mm); all targeted lesions were retrieved. In 31 women in whom mammographic guidance was used for both RSL and WL, median procedure time was not significantly different (RSL 9.0 min; WL 7.0 min; p = 0.91), and median seed migration distance was <1 mm (range 0–15 mm). No difference was detected between margin status with RSL alone versus WL (p = 0.40 and p = 0.65 for positive and <1 mm margins, respectively). Two adverse events occurred requiring an additional wire/surgery.ConclusionRSL ≥ 1 day before surgery is a safe effective procedure for pre-operative localization, with few adverse events and surgical outcomes comparable to those achieved with wire localization.