@article {Even-Sapir272, author = {Einat Even-Sapir and Ur Metser and Gideon Flusser and Limor Zuriel and Yehuda Kollender and Hedva Lerman and Gennady Lievshitz and Ilan Ron and Eyal Mishani}, title = {Assessment of Malignant Skeletal Disease: Initial Experience with 18F-Fluoride PET/CT and Comparison Between 18F-Fluoride PET and 18F-Fluoride PET/CT }, volume = {45}, number = {2}, pages = {272--278}, year = {2004}, publisher = {Society of Nuclear Medicine}, abstract = {18F-Fluoride PET/CT was performed on 44 oncologic patients to evaluate its diagnostic accuracy in assessing malignant osseous involvement and in differentiating malignant from benign bone lesions. Methods: 18F-Fluoride PET and 18F-fluoride PET/CT were interpreted separately. Lesions showing increased 18F-fluoride uptake were categorized as malignant, benign, or inconclusive. The final diagnosis of lesions was based on histopathology, correlation with contemporaneous diagnostic CT or MRI, or clinical follow-up of at least 6 mo (mean, 10 {\textpm} 3 mo). Results: Increased 18F-fluoride uptake was detected at 212 sites, including 111 malignant lesions, 89 benign lesions, and 12 lesions for which the final diagnosis could not be determined. In a lesion-based analysis, the sensitivity of PET alone in differentiating benign from malignant bone lesions was 72\% when inconclusive lesions were considered false negative and 90\% when inconclusive lesions were considered true positive. On PET/CT, 94 of 111 (85\%) metastases presented as sites of increased uptake with corresponding lytic or sclerotic changes, and 16 of the 17 remaining metastases showed normal-appearing bone on CT, for an overall sensitivity of 99\% for tumor detection. For only 1 metastasis was PET/CT misleading, suggesting the false diagnosis of a benign lesion. The specificity of PET/CT was significantly higher than that of PET alone (97\% vs. 72\%, P \< 0.001). PET/CT identified benign abnormalities at the location exactly corresponding to the scintigraphic increased uptake for 85 of 89 (96\%) benign lesions. In a patient-based analysis, the sensitivity of PET and PET/CT was 88\% and 100\%, respectively (P \< 0.05) and the specificity was 56\% and 88\%, respectively (not statistically significant). Among the 12 patients referred for 18F-fluoride assessment because of bone pain despite negative findings on 99mTc-methylene diphosphonate bone scintigraphy, 18F-fluoride PET/CT suggested malignant bone involvement in all 4 patients with proven skeletal metastases, a potential benign cause in 4 of 7 patients who had no evidence of metastatic disease, and a soft-tissue tumor mass invading a sacral foramen in 1 patient. Conclusion: The results indicate that 18F-fluoride PET/CT is both sensitive and specific for the detection of lytic and sclerotic malignant lesions. It accurately differentiated malignant from benign bone lesions and possibly assisted in identifying a potential cause for bone pain in oncologic patients. For most lesions, the anatomic data provided by the low-dose CT of the PET/CT study obviates the performance of full-dose diagnostic CT for correlation purposes.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/45/2/272}, eprint = {https://jnm.snmjournals.org/content/45/2/272.full.pdf}, journal = {Journal of Nuclear Medicine} }