Gallium-68 [68Ga]Ga-prostate-specific membrane antigen (PSMA)-11 positron emission tomography (PET) used before systemic therapy has higher diagnostic accuracy for patients with primary oligometastatic prostate cancer, according to a study published in the June issue of European Urology Open Science.
Nicolai Huebner, MD, from the Medical University of Vienna, and colleagues compared the diagnostic accuracy of [68Ga]Ga-PSMA-11 PET images taken at baseline before initiation of systemic treatment with preoperative images for 20 patients with primary oligometastatic prostate cancer. The patients subsequently underwent cytoreductive radical prostatectomy and superextended pelvic lymph node dissection.
The researchers found that sensitivity, specificity, negative predictive value, positive predictive value, and diagnostic effectiveness were 95.65%, 78.22%, 98.39%, 57.89%, and 83.00%, and 56.52%, 98.05%, 88.30%, 89.66%, and 88.50% for baseline and preoperative [68Ga]Ga-PSMA-11 PET, respectively. The diagnostic accuracy was significantly better for [68Ga]Ga-PSMA-11 PET at baseline than postoperative [68Ga]Ga-PSMA-11 PET after systemic therapy, with an area under the curve of 0.87 and 0.77, respectively.
“If a patient is suitable for local treatment and complete resection of all residual tumor is intended, [68Ga]Ga-PSMA-11 PET images taken prior to systemic therapy are significantly more accurate in selecting the relevant lymph nodes for resection,” the authors write.