Detection Rate High for PET-PSMA in Advanced Prostate Cancer With Ongoing ADT

For patients with advanced prostate cancer receiving ongoing androgen deprivation therapy (ADT), positron emission tomography (PET) with prostate-specific membrane antigen (PSMA) has a high detection rate, according to a study published online June 29 in the Annals of Nuclear Medicine.

Saskia Fassbind, from the University of Zurich, and colleagues examined the detection rate and distribution of lesions using PSMA PET imaging in patients with advanced prostate cancer and ongoing ADT. Eighty-four patients with hormone-sensitive or hormone-resistant prostate cancer underwent 68Gallium [Ga]-PSMA-11 PET/magnetic resonance [MR] imaging or computed tomography. The detection of PSMA-positive lesions was examined overall and for three prostate-specific antigen (PSA) subgroups.

The researchers found that 94.0 percent of all patients had PSMA-positive lesions. According to PSA subgroup, the detection rates were 85.2, 97.3, and 100 percent for 0 to <1 ng/mL, 1 to <20 ng/mL, and >20 ng/mL, respectively. Only patients with a PSA >1 ng/mL had PSMA-positive visceral metastases. There was no difference observed in detection of PSMA-positive lesions for those with hormone-sensitive or hormone-resistant prostate cancer. Nineteen (22.6 percent) of the patients had oligometastatic prostate cancer; almost all of these patients would have been eligible for metastasis-directed radiotherapy (94.7 percent).

“In this retrospective study analyzing the detection rate of 68Ga-PSMA-11 PET/CT or PET/MR in patients with advanced prostate cancer and ongoing ADT, we found a high overall detection rate of 94.0 percent,” the authors write.