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.
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.
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.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.