title: Thallium-201 scintigraphy is an effective diagnostic modality to distinguish malignant from benign soft-tissue tumors.
abstract: BACKGROUND
  The aim of this study is to evaluate whether thallium-201 (201-Tl) scintigraphy can differentiate malignant from benign soft-tissue tumors.
  
  
  METHODS
  Between April 1995 and December 2005, 192 patients with soft-tissue tumors (85 malignant and 107 benign) underwent 201-Tl scintigraphy before treatment. Isotope uptake was used as a proxy for tumor-to-background ratio (TBR). The accuracy of TBR on early and delayed imaging was evaluated using the Mann-Whitney U and χ(2) tests.
  
  
  RESULTS
  There was a statistically significant difference in mean TBR on early and delayed imaging of malignant and benign soft-tissue tumors (124% ± 109% vs. 22% ± 42%, and 82% ± 83% vs. 12% ± 25%, P < 0.0001). A TBR cutoff of 20% indicated the probability of malignancy on early and delayed imaging (82% sensitivity and 77% specificity; 82% sensitivity and 84% specificity, P < 0.0001). Well-differentiated liposarcomas showed low isotope accumulation, while pigmented villonodular synovitis and giant cell tumors of the tendon sheath showed high isotope accumulation.
  
  
  CONCLUSIONS
  Thallium-201 scintigraphy can distinguish malignant from benign tumors with relatively high accuracy. With the exception of low grade liposarcomas and locally aggressive benign tumors, 201-Tl scintigraphy may be an effective diagnostic modality to differentiate malignant from benign soft-tissue tumors.
authors: Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
authors: Naoaki
authors: N
authors: Kawakami
authors: Toshiyuki
authors: T
authors: Kunisada
authors: Shuhei
authors: S
authors: Sato
authors: Yuki
authors: Y
authors: Morimoto
authors: Masato
authors: M
authors: Tanaka
authors: Tsuyoshi
authors: T
authors: Sasaki
authors: Shinsuke
authors: S
authors: Sugihara
authors: Hiroyuki
authors: H
authors: Yanai
authors: Susumu
authors: S
authors: Kanazawa
authors: Toshifumi
authors: T
authors: Ozaki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D013794:Thallium Radioisotopes; D055815:Young Adult
chemical_list: D013794:Thallium Radioisotopes