#1166

Diagnostic efficacy of 68Ga-PSMA-PET/CT scan as a single staging modality in prostate cancer: Evidence from a tertiary healthcare centre

S. Kumar¹, A. Seth¹, R. Kumar², S. Sharma³, S. Kaushal⁴, V. Aggarwal¹, L. Lokesh¹, R. Gupta⁵

¹All India Institute of Medical Sciences, Urology, Delhi, India
²All India Institute of Medical Sciences, Nuclear Medicine, Delhi, India
³All India Institute of Medical Sciences, Radiology, Delhi, India
⁴All India Institute of Medical Sciences, Pathology, Delhi, India
⁵ESI hospital, Radiology, Delhi, India

Introduction:

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.

Material and methods:

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.

Results:

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.