A proof-of-concept study analyzing the clinical utility of fluorine-18-sodium fluoride PET-CT in skeletal staging of oncology patients with end-stage renal disease on dialysis.

Purpose: The quality of conventional bone scintigraphy can be poor in patients with end-stage renal disease (ESRD). Fluorine-18-sodium fluoride (F-NaF) PET-computed tomography (CT) has rapid single-pass extraction, fast clearance from the soft tissues and a better target to background ratio. The aim of the present study is to preliminarily assess the superior tracer kinetics of F-NaF in ESRD patients.

Materials And Methods: A cohort comprising of 13 patients with ESRD (mean age 65.5 years; median age 68.5 years; six men and seven women) and a control group of 20 patients with normal renal function (mean age 64±7.7 years, nine men and 11 women) were analyzed qualitatively and quantitatively. Both sets of patients were referred for osseous staging of malignancy. All patients underwent a PET-CT scan after an injection of 0.06 mCi/kg of F-NaF.

Results: Qualitative analysis of the ESRD and the control group did not show a significant difference. The signal to noise ratio in the ESRD group (26.24±10.5) and the control group was similar (22.06±10.9), P=0.35. The extraction of radiotracer in bone was higher in ESRD with a bone to soft tissue index of 4.03±2.2 versus 2.48±1.0 in control patients (P=0.01). F-NaF PET-CT was positive for bone metastases in three patients and negative in 10 patients. Of the 48 total lesions, 34 (71%) were classified as benign on F-NaF PET-CT, whereas 10 (21%) were classified as malignant and four (8%) were classified as equivocal. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of F-NaF PET-CT were 91, 89.5, 90, 71.4, and 89.7%, respectively (P<0.001).

Conclusion: The image quality of F-NaF PET-CT in patients with ESRD was comparable to imaging in patients with normal renal function. This can potentially translate into better diagnostic performance in patients with ESRD.