title: False-Positive [18F]fluorodeoxyglucose-avid lymph nodes on positron emission tomography-computed tomography after allogeneic but not autologous stem-cell transplantation in patients with lymphoma.
abstract: OBJECTIVE
  Determine the clinical significance of [(18)F]fluorodeoxyglucose (FDG)-avid lesions in patients with lymphoma treated with stem-cell transplantation.
  
  
  METHODS
  All patients who underwent stem-cell transplantation for lymphoma at Memorial Sloan-Kettering Cancer Center between January 2005 and December 2009 and had post-transplantation FDG positron emission tomography/computed tomography (PET/CT) examinations were included. PET/CT examinations were evaluated for FDG-avid lesions suggestive of disease. Clinical records, biopsy results, and subsequent imaging examinations were evaluated for malignancy.
  
  
  RESULTS
  Two hundred fifty-one patients were identified, 107 with allogeneic and 144 with autologous stem-cell transplantation. Of allogeneic stem-cell transplantation recipients, 50 had FDG-avid lesions suggestive of lymphoma, defined as FDG-avidity greater than liver background. However, only 29 of these 50 demonstrated lymphoma on biopsy, whereas biopsy attempts were benign in the other 21 patients. Sensitivity analysis determined that a 1.5-cm short axis nodal measurement distinguished patients with malignant from nonmalignant biopsies. In 21 of 22 patients with FDG-avid lymph nodes ≤ 1.5 cm, biopsy attempts were benign. In the absence of treatment, these nodes either resolved or were stable on repeat imaging. Disease-free survival of patients with FDG-avid ≤ 1.5 cm lymph nodes was comparable with patients without FDG-avid lesions. In comparison, autologous stem-cell transplantation patients rarely demonstrated FDG-avid lesions suggestive of disease without malignant pathology.
  
  
  CONCLUSIONS
  Twenty percent (21 of 107) of patients with an allogeneic stem-cell transplantation demonstrated FDG-avid lymph nodes up to 1.5 cm in short axis on PET/CT, which did not represent active lymphoma. After allogeneic stem-cell transplantation of patients with lymphoma, benign FDG-avid ≤ 1.5 cm lymph nodes can mimic malignancy.
authors.affiliation: All authors, Memorial Sloan-Kettering Cancer Center; and Gary A. Ulaner, Craig H. Moskowitz, and Andrew D. Zelenetz, Weill Cornell Medical College, New York, NY.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Ulaner
authors.forename: Joshua
authors.initials: J
authors.lastname: Lilienstein
authors.forename: Mithat
authors.initials: M
authors.lastname: Gönen
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Maragulia
authors.forename: Craig H
authors.initials: CH
authors.lastname: Moskowitz
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Zelenetz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D018572:Disease-Free Survival; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*; D008223:Lymphoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D008224:Lymphoma, Follicular / Q000175:diagnosis / Q000601:surgery; D016403:Lymphoma, Large B-Cell, Diffuse / Q000175:diagnosis / Q000601:surgery; D020522:Lymphoma, Mantle-Cell / Q000175:diagnosis / Q000601:surgery; D016399:Lymphoma, T-Cell / Q000175:diagnosis / Q000601:surgery; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D012008:Recurrence; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18