Characterization of cartilaginous tumors with 201Tl scintigraphy.
Histological diagnosis and grading of cartilaginous tumors are closely correlated with patient prognosis; consequently, they are essential elements. We attempted to clarify the characteristics of 201Tl uptake in various histological types of cartilaginous tumors and to assess its clinical value.


METHODS
Twenty-two cases with histologically proven cartilaginous tumors (3 enchondromas, 15 conventional chondrosarcomas (grade I = 9, II = 5, III = 1), 3 mesenchymal chondrosarcomas, and 1 de-differentiated chondrosarcoma) were examined retrospectively. Planar 201Tl images were recorded 15 min following intravenous injection of 201Tl (111 MBq). 201Tl uptake in the tumor was evaluated visually employing a five-grade scoring system: 0 = no appreciable uptake, 1 = faint uptake above the background level, 2 = moderate uptake, 3 = intense uptake but lower than heart uptake and 4 = uptake higher than heart uptake.


RESULTS
201Tl uptake scores were 0 in 3 of 3 enchondromas, 9 of 9 grade I, and 4 of 5 grade II conventional chondrosarcomas. 201Tl uptake scores were 1 among 1 of 5 grades II and a grade III conventional chondrosarcoma. Mesenchymal chondrosarcoma and de-differentiated chondrosarcoma displayed 201Tl uptake scores of 2 or 3.


CONCLUSIONS
Absence of elevated 201Tl uptake in cartilaginous tumors was indicative of enchondroma or low-grade conventional chondrosarcoma. However, in instances in which 201Tl uptake is obvious, high-grade chondrosarcoma or variant types should be considered.
Higuchi
Takahiro
T
Department of Biotracer Medicine, Kanazawa University Graduate School of Medical Sciences, Japan. taki@med.kanazawa-u.ac.jp
Taki
Junichi
J
Sumiya
Hisashi
H
Kinuya
Seigo
S
Nakajima
Kenichi
K
Namura
Masanobu
M
Tonami
Norihisa
N
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002356:Cartilage / Q000000981:diagnostic imaging* / Q000378:metabolism; D002812:Chondroma / Q000000981:diagnostic imaging / Q000378:metabolism; D002813:Chondrosarcoma / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D009372:Neoplasms, Connective Tissue / Q000000981:diagnostic imaging* / Q000378:metabolism; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D013793:Thallium / Q000493:pharmacokinetics*
D019275:Radiopharmaceuticals; C027549:thallium chloride; D013793:Thallium