A Comparison of Bone Scan Using between F-18 NaF PET/CT and Tc-99m MDP

Objective: To study bone scintigraphy using between F-18 NaF PET/CT and Tc-99m MDP scan for detecting bone metastases. Material and Methods: Thirteen patients (5 males, mean age 55.4 years, range 34-74 years) who were suspected bone metastases with single or two equivocal lesions on Tc-99m MDP bone scan were recruited between October 2010 and October 2012. All these patients underwent F-18 NaF PET/CT scan within one week after Tc-99m MDP bone scan. The sensitivity, specificity and accuracy of Tc-99m MDP bone scan and F-18 NaF PET/CT in differentiating metastatic bone lesion from benign lesion by patientbased and lesion-based analyses were studied. Results: F-18 NaF PET/CT could identify all seven patients with malignant bone metastases that Tc-99m MDP bone scan was interpreted as malignancy in only three patients (42.9%) and equivocal in the rest of these patients. For lesion-based analysis of the overall 75 lesions, the sensitivity, specificity and accuracy of Tc-99m MDP bone scan were 48%, 83.3% and 70.7% and F-18 NaF PET/CT were 100% for all parameters. Besides the ability of F-18 NaF PET/CT to accurately identify malignancy from benign lesion, unenhanced CT portion of PET/CT can show extra-osseous findings that may change patient management. Conclusion: F-18 NaF PET/CT provides an excellent bone image quality and higher accuracy than Tc-99m MDP bone scan. Then F-18 NaF PET/CT is a good choice for evaluating bone metastases.