In a Canadian phase III trial (MITNEC-A1) reported in The Lancet Oncology, Bénard et al found that fluorine-18–sodium fluoride (F-18–NaF) positron-emission tomography-computed tomography (PET-CT) was more accurate in detecting skeletal metastases vs technetium-99m–methylene diphosphonate (Tc-99m–MDP) single-photon emission CT (SPECT) in intraindividual comparisons in patients with high-risk prostate or breast cancers.
Study Details
In the multicenter trial, 261 patients (204 with prostate cancer and 57 with breast cancer) with high risk/clinical suspicion for bone metastasis but no previously documented bone involvement, enrolled between July 2014 and March 2017, underwent both Tc-99m–MDP SPECT and F-18–NaF PET-CT scans within 14 days. Reviewers interpreted findings of each modality without knowledge of other imaging findings. A combination of histopathologic, clinical, and imaging follow-up for up to 24 months was used as the reference standard to assess imaging results.
Key Findings
Median follow-up was 735 days (interquartile range = 727–750 days). According to reference methods, 109 (42%) of the 261 patients had bone metastases.
F-18–NaF PET-CT was more accurate than Tc-99m–MDP SPECT in detecting metastatic lesions identified by reference methods: 84.3% (95% confidence interval [CI] = 79.9%–88.7%) vs 77.4% (95% CI = 72.3%–82.5%), with a difference of 6.9% (95% CI = 1.3%–12.5%, P = .016).
Sensitivity was 78.9% vs 63.3% (P = .0007); specificity was 88.2% vs 87.5% (P = .86); positive predictive value was 82.7% vs 78.4% (P = .38); and negative predictive value was 85.4% vs 76.9% (P = .0006).
No adverse events were reported.
The investigators concluded, “[F-18]-NaF has the potential to displace [Tc-99m]-MDP as the bone imaging radiopharmaceutical of choice in patients with high-risk prostate or breast cancer.”
François Bénard, MD, of BC Cancer Research Institute, Vancouver, is the corresponding author for The Lancet Oncology article.
Disclosure: The study was funded by the Canadian Institutes of Health Research. For full disclosures of the study authors, visit thelancet.com.
