Aim: The aim of this study was to compare (18)F-fluoride PET/CT and (99m)Tc-MDP bone scintigraphy in the detection of skeletal metastases in urinary bladder carcinoma.
Patients and methods: In this prospective study, 48 patients with urinary bladder carcinoma (44 male and 4 female patients, aged 35-80 years) underwent (99m)Tc-MDP planar and SPECT/CT bone scan (BS) followed by (18)F-fluoride PET/CT within 48 hours. Skeletal metastasis diagnosed on each of these techniques was compared against a final diagnosis based on contrast-enhanced CT, MRI, skeletal survey, clinical follow-up, and histological correlation.
Results: (18)F-fluoride PET/CT identified bony metastases and changed the management in 17 of 48 patients (35%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of (99m)Tc-MDP planar BS were 82.35%, 64.51%, 56%, 86.95%, and 70.83%; of (99m)Tc-MDP SPECT/CT were 88.23%, 74.19%, 65.21%, 92%, and 79.16%; and of (18)F-fluoride PET/CT were 100%, 87.09%, 80.95%, 100%, and 91.66%, respectively. Fair agreement between (99m)Tc-MDP planar BS and F-fluoride PET/CT (κ = 0.42) and excellent agreement between SPECT/CT and (18)F-fluoride PET/CT (κ = 0.74) were found.
Conclusions: ( 18)F-fluoride PET/CT has higher sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in detecting bone metastases in urinary bladder carcinoma than conventional (99m)Tc-MDP planar BS. SPECT/CT improves all these parameters compared with planar BS and may serve as a cost-effective screening procedure for the detection of skeletal metastases in high-risk patients.