To explore whether the new 68Ga-PSMA-PET/CT (Gallium-68 prostate-specific membrane antigen positron emission tomography-computed tomography) scan could be used as a single imaging modality over conventional imaging.

This prospective study was conducted in the Department of Urology, AIIMS, New Delhi included 169 of 285 registered patients after obtaining informed consent. Patients with biopsy-proven intermediate and high-risk prostate adenocarcinoma were enrolled from July 2019 to May 2023. They underwent multiparametric MRI (mpMRI) Technetium 99m-methyl diphosphonate(99mTc-MDP) bone scan, and CT as a conventional staging, followed by 68Ga-PSMA-PET/CT. Furthermore, we evaluated the diagnostic efficacy, sensitivity, and specificity of 68Ga-PSMA-PET/CT with conventional imaging.

The mean age of patients was 65.5 years, and the median serum PSA was 23.08 ng/ml. Most patients (147) were high-risk, and 22 were intermediate risk. Among them, 90 underwent robotic-assisted radical prostatectomy. PSMAPET/CT showed statistically significant superiority in detecting regional lymph node invasion (37.8%vs18.3%), non-regional lymph node invasion (17.2% vs 5.9%), and bony metastasis (23%vs16.5%). It had comparable efficacy to conventional imaging for seminal vesicle involvement and visceral metastasis. PSMA PET/CT upstaged N and M status in 10.6 % and 8.8% of patients, respectively. In these 8.8% of upstaged M1 cases, there was a shift in the treatment approach from curative to palliative intent.

68Ga-PSMA-PET/CT exhibits superior detection rates over conventional imaging, particularly for regional lymph node, bone, and distant metastases. This modality significantly improves staging accuracy, which is essential for precise and timely treatment planning, thereby playing a critical role in the detection and management of prostate cancer.