Comparison of Oral and IV 18F-NaF PET/CT Administration in the Assessment of Bone Metastases in Patients With Breast or Prostate Cancers

Abstract

The aim of this study was to compare oral and IV administrations of 18 F-NaF PET/CT for detection of suspicious bone metastatic lesions of breast and prostate cancers. Patients and Methods: Thirty-six patients with breast (n = 23) or prostate (n = 13) cancers and high risk for bone metastases were prospectively evaluated. All patients underwent 2 PET/CT studies after IV and oral 18 F-NaF administration within a 2 to 23 days interval between them. The maximum SUVs from the same suspicious lesions (≤5 index lesions per patient) in both studies were measured. The target-to-background ratio (TBR), defined as the relation between the lesion maximum SUV and the whole skeletal mean SUV, was calculated for each lesion. The TBRs in the same lesion calculated using the 2 administration routes were compared. The agreements between 2 physicians in the definition of the number of lesions in both studies were also assessed using weighted κ. Results: One hundred thirty-four pairs of lesions were analyzed. There was no significant statistical difference between the median TBRs ( P = 0.212) for IV (10.33) and oral (10.85). Excellent intraobserver agreement was observed between IVand oral routes: weighted κ of 1.0 (95% confidence interval, 0.92-1.0) and 0.92 (95% confidence interval, 0.81-0.99) for physicians 1 and 2, respectively. The interobserver coefficients were 0.82 and 0.87 for "oral versus oral" and "IV versus IV," respectively. Conclusions: 18 F-NaF PET/CT studies using oral and IV routes present comparable performance; thus, it is possible to use oral route in patients with difficult venous access.