Radioactive Seed Localization With 125I For Nonpalpable Lesions Prior to Breast Lumpectomy and/or Excisional Biopsy: Methodology, Safety, and Experience of Initial Year.

*Department of Medical Physics, Memorial Sloan-Kettering CancerCenter, New York, NY
Health physics (Impact Factor: 0.92). 10/2013; 105(4):356-65. DOI: 10.1097/HP.0b013e31829c03e1
Source: PubMed

ABSTRACT The use of radioactive seed localization (RSL) as an alternative to wire localizations (WL) for nonpalpable breast lesions is rapidly gaining acceptance because of its advantages for both the patient and the surgical staff. This paper examines the initial experience with over 1,200 patients seen at a comprehensive cancer center. Radiation safety procedures for radiology, surgery, and pathology were implemented, and radioactive material inventory control was maintained using an intranet-based program. Surgical probes allowed for discrimination between I seed photon energies from Tc administered for sentinel node testing. A total of 1,127 patients (median age of 57.2 y) underwent RSL procedures with 1,223 seeds implanted. Implanted seed depth ranged from 10.3-107.8 mm. The median length of time from RSL implant to surgical excision was 2 d. The median I activity at time of implant was 3.1 MBq (1.9 to 4.6). The median dose rate from patients with a single seed was 9.5 μSv h and 0.5 μSv h at contact and 1 m, respectively. The maximum contact dose rate was 187 μSv h from a superficially placed seed. RSL performed greater than 1 d before surgery is a viable alternative to WL, allowing flexibility in scheduling, minimizing day of surgery procedures, and improving workflow in breast imaging and surgery. RSL has been shown to be a safe and effective procedure for preoperative localization under mammographic and ultrasound guidance, which can be managed with the use of customized radiation protection controls.

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    ABSTRACT: Wire localization (WL) of nonpalpable breast cancers on the day of surgery is uncomfortable for patients and impacts operating room efficiency. Radioactive seed localization (RSL) before the day of surgery avoids these disadvantages. In this study we compare outcomes of our initial 6-month experience with RSL to those with WL in the preceding 6 months. Lumpectomies for invasive or intraductal cancers localized with a single (125)iodine seed (January-June 2012) were compared with those using 1 wire (July-December 2011). Surgeons and radiologists did not change. Positive and close margins were defined as tumor on ink and tumor ≤1 mm from ink, respectively. Demographic and clinical characteristics and outcomes were compared between RSL and WL patients. There were 431 RSL and 256 WL lumpectomies performed. Clinicopathologic characteristics did not differ between groups. Most seeds (90 %) were placed before the day of surgery. Positive margins were present in 7.7 % of RSL versus 5.5 % of WL patients, and 16.9 % of RSL versus 19.9 % of WL had close margins (p = 0.38). The median operative time was longer for lumpectomy and sentinel lymph node biopsy (SLNB) in the RSL group (55 vs. 48 min, p < 0.0001). There was no significant difference in the volume of tissue excised between groups. In the first 6 months of RSL, operative scheduling was simplified, while rates of positive and close margins were similar to those seen after many years of experience with WL. Operative time was slightly longer for RSL lumpectomy and SLNB; we anticipate this will decrease with experience.
    Annals of Surgical Oncology 08/2013; · 3.94 Impact Factor