title: Incidence of Internal Mammary Lymph Nodes with Silicone Breast Implants at MR Imaging after Oncoplastic Surgery.
abstract: OBJECTIVE
  To assess the incidence of benign and malignant internal mammary lymph nodes (IMLNs) at magnetic resonance (MR) imaging among women with a history of treated breast cancer and silicone implant reconstruction.
  
  
  METHODS
  The institutional review board approved this HIPAA-compliant retrospective study and waived informed consent. Women were identified who (a) had breast cancer, (b) underwent silicone implant oncoplastic surgery, and (c) underwent postoperative implant-protocol MR imaging with or without positron emission tomography (PET)/computed tomography (CT) between 2000 and 2013. The largest IMLNs were measured. A benign IMLN was pathologically proven or defined as showing 1 year of imaging stability and/or no clinical evidence of disease. Malignant IMLNs were pathologically proven. Incidence of IMLN and positive predictive value (PPV) were calculated on a per-patient level by using proportions and exact 95% confidence intervals (CIs). The Wilcoxon rank sum test was used to assess the difference in axis size.
  
  
  RESULTS
  In total, 923 women with breast cancer and silicone implants were included (median age, 46 years; range, 22-89 years). The median time between reconstructive surgery and first MR imaging examination was 49 months (range, 5-513 months). Of the 923 women, 347 (37.6%) had IMLNs at MR imaging. Median short- and long-axis measurements were 0.40 cm (range, 0.20-1.70 cm) and 0.70 cm (range, 0.30-1.90 cm), respectively. Two hundred seven of 923 patients (22.4%) had adequate follow-up; only one of the 207 IMLNs was malignant, with a PPV of 0.005 (95% CI: 0.000, 0.027). Fifty-eight of 923 patients (6.3%) had undergone PET/CT; of these, 39 (67.2%) had IMLN at MR imaging. Twelve of the 58 patients (20.7%) with adequate follow-up had fluorine 18 fluorodeoxyglucose-avid IMLN, with a median standardized uptake value of 2.30 (range, 1.20-6.10). Only one of the 12 of the fluorodeoxyglucose-avid IMLNs was malignant, with a PPV of 0.083 (95% CI: 0.002, 0.385).
  
  
  CONCLUSIONS
  IMLNs identified at implant-protocol breast MR imaging after oncoplastic surgery for breast cancer are overwhelmingly more likely to be benign than malignant. Imaging follow-up instead of immediate metastatic work-up may be warranted.
authors.affiliation: From the Department of Radiology (E.J.S., E.J.W., G.G., M.S.J., D.D.D., E.A.M.) and Department of Epidemiology & Biostatistics (D.A.G., C.S.M.), Memorial Sloan-Kettering Cancer Center, 300 E 66th St, Suite 715, New York, NY 10065.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Sutton
authors.affiliation: From the Department of Radiology (E.J.S., E.J.W., G.G., M.S.J., D.D.D., E.A.M.) and Department of Epidemiology & Biostatistics (D.A.G., C.S.M.), Memorial Sloan-Kettering Cancer Center, 300 E 66th St, Suite 715, New York, NY 10065.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Watson
authors.affiliation: From the Department of Radiology (E.J.S., E.J.W., G.G., M.S.J., D.D.D., E.A.M.) and Department of Epidemiology & Biostatistics (D.A.G., C.S.M.), Memorial Sloan-Kettering Cancer Center, 300 E 66th St, Suite 715, New York, NY 10065.
authors.forename: Girard
authors.initials: G
authors.lastname: Gibbons
authors.affiliation: From the Department of Radiology (E.J.S., E.J.W., G.G., M.S.J., D.D.D., E.A.M.) and Department of Epidemiology & Biostatistics (D.A.G., C.S.M.), Memorial Sloan-Kettering Cancer Center, 300 E 66th St, Suite 715, New York, NY 10065.
authors.forename: Debra A
authors.initials: DA
authors.lastname: Goldman
authors.affiliation: From the Department of Radiology (E.J.S., E.J.W., G.G., M.S.J., D.D.D., E.A.M.) and Department of Epidemiology & Biostatistics (D.A.G., C.S.M.), Memorial Sloan-Kettering Cancer Center, 300 E 66th St, Suite 715, New York, NY 10065.
authors.forename: Chaya S
authors.initials: CS
authors.lastname: Moskowitz
authors.affiliation: From the Department of Radiology (E.J.S., E.J.W., G.G., M.S.J., D.D.D., E.A.M.) and Department of Epidemiology & Biostatistics (D.A.G., C.S.M.), Memorial Sloan-Kettering Cancer Center, 300 E 66th St, Suite 715, New York, NY 10065.
authors.forename: Maxine S
authors.initials: MS
authors.lastname: Jochelson
authors.affiliation: From the Department of Radiology (E.J.S., E.J.W., G.G., M.S.J., D.D.D., E.A.M.) and Department of Epidemiology & Biostatistics (D.A.G., C.S.M.), Memorial Sloan-Kettering Cancer Center, 300 E 66th St, Suite 715, New York, NY 10065.
authors.forename: D David
authors.initials: DD
authors.lastname: Dershaw
authors.affiliation: From the Department of Radiology (E.J.S., E.J.W., G.G., M.S.J., D.D.D., E.A.M.) and Department of Epidemiology & Biostatistics (D.A.G., C.S.M.), Memorial Sloan-Kettering Cancer Center, 300 E 66th St, Suite 715, New York, NY 10065.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Morris
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D018427:Breast Implants; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery*; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D015994:Incidence; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D016462:Mammaplasty; D008408:Mastectomy / Q000379:methods; D008875:Middle Aged; D064847:Multimodal Imaging; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012828:Silicones; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D012828:Silicones; D019788:Fluorodeoxyglucose F18