FDG-PET in differential diagnosis and grading of chondrosarcomas.

PURPOSE: The purpose of this work was to investigate the usefulness of PET with [18F]2-deoxy-2-fluoro-D-glucose (FDG) in the differential diagnosis and grading of chondrosarcomas.

METHOD: Four enchondromas, one osteochondroma, and six chondrosarcomas were prospectively studied by FDG-PET. The significance of the standardized uptake value (SUV) was evaluated in comparison with clinical, radiological, and histopathological findings of the tumors.

RESULTS: The SUV ranged from 0.7 to 1.3 (mean 0.96+/-0.22) in benign cartilage tumors and from 1.3 to 3.3 (2.23+/-0.80) in chondrosarcomas. This SUV difference between benign and malignant tumors was statistically significant (p = 0.011) in contrast to considerable overlap of clinical and radiological findings. Among chondrosarcomas, the SUV of one Grade I tumor was 1.3; those of four Grade II tumors were 1.3, 1.9, 2.5, and 3.1; and that of one Grade III tumor was 3.3.

CONCLUSION: Our preliminary study showed that FDG-PET could be an objective and quantitative adjunct in the differential diagnosis and grading of chondrosarcomas.