CTRI

Prostate cancer (PCa) is the most common solid malignancy in men and the third leading cause of cancer-related death in western Europe and the United States. The biochemical recurrence (BR) defined as increasing the value of serum PSA after radical therapy, is a common occurrence and occurs in about 20-30% of patients treated with radical prostatectomy (RP) and up to 60% in patients treated primary with external beam radiotherapy (EBRT). In accordance with the nomograms, local recurrence in prostate bed after RP can be predicted with an accuracy of about 80% in patients in whom there is a BR in more than 3 years after RP, a PSA doubling time (PSADT)> 11 months, Gleason Score (GS) <7 and a pT3apN0 and pTxN1. In contrast, systemic recurrence can be predicted with an accuracy of about 80% in patients in whom there is a BR distance of less than 1 year after RP, PSADT of about 4-6 months, GS> 7 and stage of pT3b and pTxpN1. Further studies in the literature and conducted in larger patient populations with BR after radical therapy, showed excellent diagnostic power of ⁶⁸Ga-PSMA PET/CT in restaging patients with biochemical recurrence of the disease even when serum PSA values â€‹â€‹very low. In recent months, the use of this tracer has been the subject of particular and growing interest of the scientific community [15-20]. This radiopharmaceutical has also showed high specificity (> 90%) in studies using histological analysis as a reference standard for validation of PET results. Finally, none of the studies in the literature have reported adverse events or clinically detectable pharmacological effects concurrently and after executing the PET/CT ⁶⁸Ga-PSMA. For the reasons explained above, the PSMA could be an excellent molecular target for the development of radiotracers for PET/CT imaging that could detect early relapse of disease. This type of information would be even more relevant especially in emerging countries and different heath care systems around the world.

Aim: To evaluate the utility of ⁶⁸Ga-PSMA PET/CT in detecting the presence of local and/ or systemic disease in early laboratory recurrence of ⁶⁸Ga-PSMA PET/CT in detecting the presence of local and/ or systemic disease in early laboratory recurrence.

Objectives:

Primary: To evaluate the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) in detecting the presence of local and/ or systemic disease in early laboratory recurrence.

Design: Observational, prospective, non-randomised, multi centre study

Inclusion criteria

1. Patients with histologically proven diagnosis of PCa

2. Patients with PCa that following RP or EBRT (with or without any adjuvant therapy) with serum levels of PSA between 0.2 ng/mL and 4 ng/mL, or PSA between 4-10 ng/mL with necessary negtive imaging investigation (BS, MR, CT).

3. Gleason Score â‰¥ 7

4. Age â‰¥ 35 years

Study Duration:

Total project period: 48 months (enrollment for 24 months and collection of follow up data for 24 months)

Study Site: Tata Memorial Centre

Efficacy assessments

⁶⁸Ga-PSMA PET/CT findings will be compared with:

1) Histology (when necessary in the judgment of the clinician as expected in the normal care pathway), using ultrasound-guided biopsy in suspected local recurrence in prostate bed or during the pelvic lymph node dissection and / or Extraperitoneal in cases of suspected nodal recurrence

2) Comparison of PET data with those derived from conventional imaging methods carried out under the normal care pathway, such as: CT with contrast, MRI pelvic multiparametric, axial MRI and bone scan.

3) Compared with clinical and laboratory data (eg PSA serum) provided in the normal care pathway.

Variables to be estimated â€“ Sensitivity, Specificity, PPV and NPV.