Both a visual and a semiquantitative analysis for differentiating benign from malignant chondrogenic bone tumors using Tc-99m (V) DMSA scintigraphy: a prospective study.
OBJECTIVE
The aims of this prospective study were to assess the relationship between tumor aggressiveness and Tc-99m (V) dimercaptosuccinic acid (DMSA) uptake in chondrogenic bone tumors and the value of Tc-99m (V) DMSA scintigraphy for differentiating benign from malignant tumors.


METHODS
Twenty-four patients with chondrogenic tumors (19 benign and five malignant) underwent Tc-99m DMSA (V) scintigraphy. Radiopharmaceutical uptake was classified using a three-point scale to allow a visual-only analysis, and a tumor-to-background contrast (TBC) was computed using regions of interest to provide a semiquantitative analysis. Spearman's correlation coefficient was used to assess the correlation between tumor aggressiveness and TBC. The difference in TBC between benign and malignant tumors was analyzed with the Mann-Whitney U-test. An appropriate cutoff value of TBC was chosen for the diagnosis of malignancy of a tumor using receiver operating characteristic analysis.


RESULTS
Six benign tumors showed negative uptake (uptake score 0), whereas 13 benign tumors showed positive uptake (n=10 uptake score 1; n=3 uptake score 2). All chondrosarcomas showed positive uptake (n=2 uptake score 1; n=3 uptake score 2). A significant correlation was found between tumor aggressiveness and TBC. A significant difference was seen in TBC between benign and malignant tumors. With the chosen cutoff value of TBC equal to 0.611, the sensitivity was 80.0%, specificity was 78.9%, the positive predictive value was 50.0%, and the negative predictive value was 93.8%.


CONCLUSIONS
Tc-99m (V) DMSA scintigraphy may have the potential to improve diagnostic methods for detecting chondrosarcomas using visual and/or semiquantitative analyses.
Departments of aRadiology bPathology, Okayama University Hospital Departments of cMedical Materials for Musculoskeletal Reconstruction dOrthopaedic Surgery, Okayama University Graduate School of Medicine, Okayama, Japan.
Takayoshi
T
Shinya
Shuhei
S
Sato
Toshiyuki
T
Kunisada
Ryota
R
Inai
Hiroyuki
H
Yanai
Toshifumi
T
Ozaki
Susumu
S
Kanazawa
D000328:Adult; D000368:Aged; D001692:Biological Transport; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D020219:Chondrogenesis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019783:Technetium Tc 99m Dimercaptosuccinic Acid / Q000378:metabolism
D019783:Technetium Tc 99m Dimercaptosuccinic Acid