PT  - JOURNAL ARTICLE
AU  - Camila Stasiak
AU  - Athos Cardillo
AU  - Sergio Altino de Almeida
AU  - Daniella Braz Parente
AU  - Rosana Souza Rodrigues
AU  - Paulo Henrique Rosado-de-Castro
TI  - Pre-operative Evaluation Of Prostate Cancer By Positron Emission Tomography / Computed Tomography (Pet-ct) With Psma-68ga: Correlation With Prostate Magnetic Resonance And Histopathological Findings
DP  - 2021 May 01
TA  - Journal of Nuclear Medicine
PG  - 1335--1335
VI  - 62
IP  - supplement 1
4099  - http://jnm.snmjournals.org/content/62/supplement_1/1335.short
4100  - http://jnm.snmjournals.org/content/62/supplement_1/1335.full
SO  - J Nucl Med2021 May 01; 62
AB  - 1335Introduction: PET-CT image with Gallium-68 is a non-invasive diagnostic method to assess the biological behavior of prostate cancer. This method is already used to detect biochemical recurrence and has the potential to be used to diagnose high-risk tumors and for staging. The objective of this study is to evaluate the accuracy of preoperative PET-CT with 68Ga-PSMA to detect and stage prostate cancer, as well as to compare PET-CT with 68Ga-PSMA with prostate magnetic resonance imaging (MRI) using post-operative histopathological findings as the reference standard.METHODS: Sixty-five patients with prostate cancer were included in this retrospective study. All patients underwent PET-CT with 68Ga-PSMA and prostate MRI followed by radical prostatectomy. Results: The mean age of the patients was 70.1 ± 8.3 years. The mean PSA before PET-CT with 68Ga-PSMA was 13.0 ± 21.0 ng/mL. PET-CT with 68Ga-PSMA showed radiotracer uptake in the prostate in 92.3% patients. The average SUVmax in the prostate was 10.7 ± 9.4. Thirteen (22%) patients had one or more lymph nodes with radiotracer uptake. In addition, PET-CT with 68Ga-PSMA identified 4 patients with bone uptake. PET-CT and MRI showed similar results in 35 patients (54%). Overall, PET-CT with 68Ga-PSMA had an accuracy of 42% to detect the site of the primary tumor and MRI had an accuracy of 22% compared to the post-operative histopathological findings. The positivity rate of PET-CT with 68Ga-PSMA in the prostate was 92% and prostate MRI identified at least one lesion classified as PI-RADS 3 or more in 91% of patients. In the evaluation of metastatic lymph nodes, PET-PSMA correctly diagnosed 67% of the negative and 63% of the positive lymph nodes, with an accuracy of 66%. The accuracy of MRI to detect positive lymph nodes was 69%, with identification of 85% of true positive lymph nodes and 25% of true negative lymph nodes.CONCLUSION: The performance of PET-PSMA was similar to MRI to detect the tumor site. PET-PSMA was superior to MRI to detect true positive lymph nodes, and MRI was superior to detect true negative lymph nodes. PET-PSMA is a promising tool to detect the primary tumor and to identify positive lymph nodes and distant metastases, which may change treatment. Figure 1. 58-year-old patient. Magnetic resonance imaging showed no changes, being classified as PI-RADS 2 (A: axial diffusion (DWI), B: axial T2) and PET-CT with PSMA-68Ga showed uptake of the radiopharmaceutical in focus centrally located in the middle and base third of the prostate and with extension to the right side at the level of the middle third, with SUVmax of 7.2 (C: CT fusion and axial PET, D: axial PET). The histopathology of the surgery confirmed Gleason 4 + 3 prostate adenocarcinoma in the right lobe.