title: Diagnostic value of Thallium-201 scintigraphy in differentiating malignant bone tumors from benign bone lesions.
abstract: OBJECTIVE
  This retrospective study aims to evaluate the diagnostic capacity of thallium-201 (201Tl) scintigraphy for differentiating malignant bone tumors from benign bone lesions.
  
  
  METHODS
  Between January 2006 and December 2012, 279 patients with bone lesions (51 malignant and 228 benign) underwent 201Tl scintigraphy before treatment. To evaluate 201Tl uptake, we investigated tumor-to-background contrast (TBC) as well as TBC washout rate (WR). The differences of TBC on early and delayed images and WR were estimated by the Mann-Whitney U test. Receiver operating characteristic (ROC) analyses were used to determine the cut-off TBC values for differentiating malignant bone tumors from benign bone lesions.
  
  
  RESULTS
  There were statistically significant differences in median TBC between malignant tumors and benign lesions. These differences occurred for early imaging (1.57 vs. 0.09, p < 0.001) as well as for delayed imaging (0.83 vs. 0.07, p < 0.001). However, there was no statistical difference in WR between malignant tumors and benign lesions (44 vs. 43 %, NS). The chosen TBC cut-off value was 0.68 for early imaging and 0.38 for delayed imaging. Using these cut-off values, the prediction of malignancy had a 77 % sensitivity, 74 % specificity, and 75 % accuracy for early imaging and an 80 % sensitivity, 76 % specificity, and 77 % accuracy for delayed imaging.
  
  
  CONCLUSIONS
  201Tl scintigraphy may have the ability to distinguish malignant bone tumors from benign bone lesions.
authors.affiliation: Department of Radiology, Okayama University Hospital, 2-5-1 Shikatacho, Kita-ku, Okayama, Okayama, 700-8558, Japan. mogmog@jb3.so-net.ne.jp.
authors.forename: Ryota
authors.initials: R
authors.lastname: Inai
authors.affiliation: Department of Radiology, Okayama University Hospital, 2-5-1 Shikatacho, Kita-ku, Okayama, Okayama, 700-8558, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Shinya
authors.affiliation: Department of Radiology, Okayama University Hospital, 2-5-1 Shikatacho, Kita-ku, Okayama, Okayama, 700-8558, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tada
authors.affiliation: Department of Radiology, Okayama University Hospital, 2-5-1 Shikatacho, Kita-ku, Okayama, Okayama, 700-8558, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Sato
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Hospital, Okayama, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Fujiwara
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Hospital, Okayama, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Takeda
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Hospital, Okayama, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kunisada
authors.affiliation: Department of Pathology, Okayama University Hospital, Okayama, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yanai
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Hospital, Okayama, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Ozaki
authors.affiliation: Department of Radiology, Okayama University Hospital, 2-5-1 Shikatacho, Kita-ku, Okayama, Okayama, 700-8558, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanazawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D059629:Signal-To-Noise Ratio; D013794:Thallium Radioisotopes; D055815:Young Adult
chemical_list: D013794:Thallium Radioisotopes
keywords: Benign bone tumor; Malignant bone tumor; Receiver operating characteristic (ROC) analysis; Thallium-201 scintigraphy; Tumor-to-background contrast (TBC)