title: Differentiation of malignant and benign cardiac tumors using 18F-FDG PET/CT.
abstract: In the diagnostic algorithm of cardiac tumors, the noninvasive determination of malignancy and metastatic spread is of major interest to stratify patients and to select and monitor therapies. In the diagnostic work-up, morphologic imaging modalities such as echocardiography or magnetic resonance tomography offer information on, for example, size, invasiveness, and vascularization. However, preoperative assessment of malignancy may be unsatisfactory. The aim of this study was to evaluate the diagnostic value of (18)F-FDG PET and the incremental diagnostic value of an optimized CT score in this clinical scenario.
  
  
  METHODS
  (18)F-FDG PET/CT scans (whole-body imaging with low-dose CT) of 24 consecutive patients with newly diagnosed cardiac tumors were analyzed (11 men, 13 women; mean age ± SD, 59 ± 13 y). The maximum standardized uptake values (SUV(max)) of the tumors were measured. Patients were divided into 2 groups: benign cardiac tumors (n = 7) and malignant cardiac tumors (n = 17) (cardiac primaries [n = 8] and metastases [n = 9]). SUV(max) was compared between the 2 groups. Results were compared with contrast-enhanced CT, using standardized criteria of malignancy. Histology served as ground truth.
  
  
  RESULTS
  Mean SUV(max) was 2.8 ± 0.6 in benign cardiac tumors and significantly higher both in malignant primary and in secondary cardiac tumors (8.0 ± 2.1 and 10.8 ± 4.9, P < 0.01). Malignancy was determined with a sensitivity of 100% and specificity of 86% (accuracy, 96%), after a cutoff with high sensitivity (SUV(max) of 3.5) was chosen to avoid false-negatives. Morphologic imaging reached a sensitivity of 82% and a specificity of 86% (accuracy, 83%). Both false-positive and false-negative decisions in morphology could be corrected in all but 1 case using a metabolic threshold with an SUV(max) of 3.5. In addition, extracardiac tumor manifestations were detected in 4 patients by whole-body (18)F-FDG PET/CT.
  
  
  CONCLUSIONS
  (18)F-FDG PET/CT can aid the noninvasive preoperative determination of malignancy and may be helpful in detecting metastases of malignant cardiac tumors.
authors.affiliation: Department of Nuclear Medicine, University of Münster, Münster, Germany. rahbar@uni-muenster.de
authors.forename: Kambiz
authors.initials: K
authors.lastname: Rahbar
authors.forename: Harald
authors.initials: H
authors.lastname: Seifarth
authors.forename: Michael
authors.initials: M
authors.lastname: Schäfers
authors.forename: Lars
authors.initials: L
authors.lastname: Stegger
authors.forename: Andreas
authors.initials: A
authors.lastname: Hoffmeier
authors.forename: Tilmann
authors.initials: T
authors.lastname: Spieker
authors.forename: Klaus
authors.initials: K
authors.lastname: Tiemann
authors.forename: David
authors.initials: D
authors.lastname: Maintz
authors.forename: Hans Heinrich
authors.initials: HH
authors.lastname: Scheld
authors.forename: Otmar
authors.initials: O
authors.lastname: Schober
authors.forename: Matthias
authors.initials: M
authors.lastname: Weckesser
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism; D006338:Heart Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose