• Abstract and Figures
• Public Full-text

Paper RADIOACTIVE SEED LOCALIZATION WITH 125I FOR NONPALPABLE LESIONS PRIOR TO BREAST LUMPECTOMY AND/OR EXCISIONAL BIOPSY: METHODOLOGY, SAFETY, AND EXPERIENCE OF INITIAL YEAR Lawrence T. Dauer,*† Cynthia Thornton,† Daniel Miodownik,* Daniel Boylan,* Brian Holahan,* Valencia King,‡ Edi Brogi,§ Monica Morrow,** Elizabeth A. Morris,† and Jean St. Germain* INTRODUCTION AbstractVThe use of radioactive seed localization (RSL) as an alternative to wire localizations (WL) for nonpalpable breast IMPROVEMENTS IN imaging techniques and increasing rates lesions is rapidly gaining acceptance because of its advantages of screening mammograms have resulted in the increased for both the patient and the surgical staff. This paper exam- ines the initial experience with over 1,200 patients seen at a detection of nonpalpable breast lesions that require locali- comprehensive cancer center. Radiation safety procedures for zation prior to surgery to allow excision for complete his- radiology, surgery, and pathology were implemented, and ra- tological evaluation or as part of breast-conserving therapy dioactive material inventory control was maintained using an (Harris et al. 1981; Homer 1983; Cady et al. 1996; Montrey intranet-based program. Surgical probes allowed for discrimina- tion between 125I seed photon energies from 99mTc administered for et al. 1996; Bartelink et al. 2001; Skinner et al. 2001; Hooley sentinel node testing. A total of 1,127 patients (median age et al. 2012; Nederend et al. 2012). Breast image-guided of 57.2 y) underwent RSL procedures with 1,223 seeds im- localization is performed on nonpalpable lesions after Y planted. Implanted seed depth ranged from 10.3 107.8 mm. marker clips are left in the breast following image-guided The median length of time from RSL implant to surgical excision was 2 d. The median 125I activity at time of implant was 3.1 MBq biopsy (i.e., stereotactic biopsy, ultrasound core biopsy, or (1.9 to 4.6). The median dose rate from patients with a single seed MRI core biopsy) of masses or calcifications. was 9.5 mSv hj1 and 0.5 mSv hj1 at contact and 1 m, re- To date, the most common method for preoperative j1 spectively. The maximum contact dose rate was 187 mSv h localization has been wire localization (WL), performed from a superficially placed seed. RSL performed greater than 1 d before surgery is a viable alternative to WL, allowing with a hooked wire (Frank et al. 1976). Because the wire is flexibility in scheduling, minimizing day of surgery procedures, in part external, this procedure has major limitations. The and improving workflow in breast imaging and surgery. RSL wire can be inadvertently pulled, displaced, or transected has been shown to be a safe and effective procedure for pre- before or during surgery, precluding accurate localization operative localization under mammographic and ultrasound guidance, which can be managed with the use of customized of the target lesion (Homer 1983; Montrey et al. 1996), or radiation protection controls. it can undergo incidental migration, kinking, or fracturing Health Phys. 105(4):356Y365; 2013 of the wire (Bronstein et al. 1988; Montrey et al. 1996). Key words: 125I; breast; diagnostic imaging; radiation protection Additionally, the wire skin entry site determined by the radiologist often is not at the ideal skin incision site for the surgeon, and identifying the wire within the breast may be difficult when the incision is not at the wire entry site (Homer 1983; Davis et al. 1988; Montrey et al. 1996; Besic *Department of Medical Physics, Memorial Sloan-Kettering Can- et al. 2002; Fleming et al. 2004). Finally, wire placement cer Center, New York, NY; †Department of Radiology, Memorial Sloan- needs to be done typically on the day of surgery, linking Kettering Cancer Center, New York, NY; ‡Washington Radiology operating room and radiology schedules (Davis et al. 1988) Associates Washington, DC; §Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY; **Department of Sur- and increasing the chance for conflicts that result in sig- gery, Memorial Sloan-Kettering Cancer Center, New York, NY. nificant delays in the operating room, and the potential for The authors declare no conflicts of interest. For correspondence contact: Lawrence T. Dauer, Departments of leakage of sentinel lymph node (SLN) mapping agents 99m Medical Physics and Radiology, Memorial Sloan-Kettering Cancer Center, (e.g., blue dye and/or Tc colloid). 1275 York Avenue, New York, NY 10021, or email at [email protected]. Initially, radio-guided occult lesion localization (ROLL), (Manuscript accepted 4 May 2013) 99m 0017-9078/13/0 direct intra-tumoral injection of Tc-labelled colloidal Copyright * 2013 Health Physics Society serum albumin, was developed as an alternative to wire DOI: 10.1097/HP.0b013e31829c03e1 localization (Nadeem et al. 2005; Mariscal Martinez et al. 356 www.health-physics.com Copyright © 2013 Health Physics Society. Unauthorized reproduction of this article is prohibited. Radioactive Seed Localization for Breast Surgery c L. T. DAUER ET AL. 357 2009). However, this technique is also subject to limita- (days from seed receipt in inventory to implant, days from tions, particularly since the injected material is not visible implant to surgical excision). on radiographs, and 99mTc is the same radiotracer used for SLN mapping, potentially creating confusion, partic- Radioactive seeds ularly with tumors in the upper outer quadrant (Nadeem Sealed radioactive seeds can be used as an effective et al. 2005; Mariscal Martinez et al. 2009). diagnostic imaging marker. Iodine-125 (125I) has a long Radioactive seed localization (RSL) is a recent al- decay time, emitting low-energy photons. Disintegration ternative to WL using a fully implanted 125I encapsulated of 125I occurs with a half-life of 59.4 d by absorption of titanium seed that is visible on both mammography and electrons and emission of low energy photons ranging in ultrasound. Given the relatively long half-life of 125I energy from 27.2Y35.5 keV (mean energy of 27 keV). This (È59 d), RSL does not need to be performed on the day photon energy signal differs from 99mTc (140 keV) used of surgery, and since it has a different photopeak from for concurrent sentinel node biopsy procedures, thereby 99mTc, it can be performed in conjunction with SLN map- enabling active discrimination during surgical excision. ping (Gray et al. 2004) if appropriate detection probes The initial 76 RSL procedures were performed using are calibrated and used. In addition, surgical studies have a standard 125I titanium seed (Standard 125I Source, Best suggested that RSL produces fewer positive margins and Medical International, Inc., distributed by MPM Medical, reoperation rates than WL and results in shorter operating Freehold, NJ). The remaining RSLs were performed using times than WL (Gray et al. 2001; Lovrics et al. 2011a a textured 125I titanium seed (Stranded Iodine-125 Source, and b; McGhan et al. 2011). In addition, bracketing of Best Medical International, Inc., distributed by MPM lesions and post-localization mammograms are not im- Medical, Freehold, NJ). The textured seed is coated with peded by wires. a bioabsorbable co-polymer made of L-lactide and poly- The purpose of this study was to evaluate, from the glycolide and assists in preventing seed migration from perspective of the radiation safety specialist, the meth- the initial implant location. The specified seed activity was odology, safety, and first year experience of preoperative initially 4.6 MBq per seed for the first 250 procedures, 125I RSL as an alternative to WL for lesions visible by but the activity was reduced to 3.7 MBq per seed for the mammographic and sonographic imaging techniques. remaining procedures consistent with the as low as rea- sonably achievable (ALARA) principle. The surgeons ex- perienced no difficulty detecting and localizing the seeds MATERIALS AND METHODS with the lowered activity. All seeds came preloaded into a Study Data Collection sterile 18-gauge needle (with a stylet fitted within the A waiver was granted by the institutional review board needle) ranging in needle length from 5Y15 cm. The as- (IRB) for this Health Insurance Portability and Account- sembly includes a plastic spacer, and the tip is occluded ability Act (HIPAA) compliant study. A retrospective review with bone wax (Fig. 1). Prepackaged sterile seed assem- of all mammographic and/or ultrasound guided 125I RSLs blies had vendor-determined and labeled expiration dates performed between 14 November 2011 and 14 November 2012 was conducted. One thousand two hundred twenty- three (1,223) consecutive RSLs were performed in 1,127 women prior to lumpectomy and/or excisional biopsy. Clinical and pathologic data were recorded from the electronic medical record. In addition, seed-to-target dis- tance was measured on preoperative mammograms for a subset of the study population, and specimen radiographs were reviewed for the presence of target and seed for all cases. In 35 women, during an initial brief surgical training period, a modified Kopans wire was placed as a WL in addition to the RSL in order to ensure localization during surgery. In these cases, wire placement occurred on the day of surgery. For this study, the following information was also collected: patient demographics (age, indications for RSL, targets, target depth, and localization method), RSL seed activity, needle size used, radiation exposure rate on Fig. 1. RSL needle shown with stainless steel shielding in place and contact with the skin and at 1 m, and lifecycle tracking needle showing with bone wax, 125I seed, plastic spacer, and stylet. www.health-physics.com Copyright © 2013 Health Physics Society. Unauthorized reproduction of this article is prohibited. 358 Health Physics October 2013, Volume 105, Number 4 based on sterilization duration requirements (e.g., 2 mo). Therefore, seeds decayed over time and were maintained within the inventory. The activity in each seed was de- termined at the time of implant.

Load more

  10

Copy Link