PET-CT Versus SPECT for Prostate Cancer at High Risk for Skeletal Metastases

By Zachary Bessette - December 5, 2022

18F-sodium fluoride (18F-NaF) positron emission tomography-computed tomography (PET-CT) may better detect skeletal metastases in patients with high-risk prostate cancer, according to a multicenter phase 3 trial published in The Lancet Oncology.

The Canadien MITNEC-A1 study compared the diagnostic performance of 99mTc-methylene diphosphonate (99mTc-MDP) single-photon emission CT (SPECT) with 18F-NaF PET-CT for detecting osseous metastases in patients with high-risk prostate cancer, but without previously documented bone involvement. Of the 290 patients screened, 224 were enrolled with prostate cancer and 64 with breast cancer. A total of 261 patients underwent both 99mTc-MDP SPECT and 18F-NaF PET-CT and completed the required follow-up for analysis.

After a median follow-up of 735 days, 42% of patients (n=109) had bone metastases. Researchers noted that 18F-NaF PET-CT (84.3% [95% CI, 79.9-88.7]) was more accurate than 99mTc-MDP SPECT (77.4% [95% CI, 72.3-82.5]) in detecting metastases (P=.016).

No adverse events were reported among the total patient population, the researchers added.

Considering these results, the researchers concluded that “18F-NaF has the potential to displace 99mTc-MDP as the bone imaging radiopharmaceutical of choice in patients with high-risk prostate or breast cancer.”