Localization and restaging of carcinoma prostate by 68 Gallium prostate-specific membrane antigen positron emission tomography computed tomography in patients with biochemical recurrence

• Published in: Indian journal of urology Vol. 36; no. 3; p. 191
• Main Authors: Seniaray, Nikhil, Verma, Ritu, Khanna, Sudhir, Belho, Ethel, Pruthi, Ankur, Mahajan, Harsh
• Format: Journal Article
• Language: English
• Published: India 01.07.2020
• ISSN: 0970-1591
• DOI: 10.4103/iju.IJU_275_19

Radical prostatectomy (RP) and radical radiotherapy (RT) are well established primary curative options for localized prostate cancer. Despite technical improvements, prostate-specific antigen (PSA)-recurrence after RP and RT is a common clinical scenario. We aimed to assess the role of Gallium ( Ga) prostate-specific membrane antigen positron emission tomography computed tomography (PSMA PET/CT) in patients with biochemical recurrence of prostate cancer after RP or RT for the detection and localization recurrent and metastatic disease. We ambispectively (70 retrospective and 100 prospective) analyzed the data of men with biochemical recurrence post-RP and post-RT who were evaluated by Ga PSMA PET/CT at our institute. We aimed to assess the relationship between serum PSA levels and the probability of having a positive scan in patients with recurrent prostate cancer. The study included 170 men, all had adenocarcinoma of the prostate, 124/170 had previous RP and 46/170 had prior RT. The median serum PSA in the RP group was 1.8 ng/ml and 5.2 ng/ml in the RT group. In the post-RP cohort, the detection rate of Ga PSMA PET/CT was 39.3% for PSA 0.2 to <0.5 ng/ml, 47.3% for PSA 0.5 to <1 ng/ml, 68.4% for PSA 1 to <2 ng/ml and 93.1% for PSA ≥2 ng/ml. In the post-RT group, the detection rate was 88.8% for PSA 2 to <4 ng/ml and 100% for PSA ≥4 ng/ml. Ga PSMA PET/CT provides a novel imaging modality for the detection of prostate cancer recurrence and metastases at low posttreatment PSA levels, which may help in directing appropriate salvage treatments.