ABSTRACT
Introduction: A positron emission tomography (PET) scan and a computed tomography (CT) scan are an integral part of oncological imaging and other modalities such as magnetic resonance imaging, CT or bone scintigraphy have some limitations in staging the workup of prostate carcinoma. Combined with tissue-specific markers like prostate-specific membrane antigen (PSMA), positron emitter-based functional imaging results have improved. Our study aimed to determine the Standardised Uptake Value (SUVmax) in prostate adenocarcinoma that is confined to the organ in Ga-68-PSMA PET-CT scans and how it correlates with prostate-specific antigen (PSA) levels and Gleason score (GS). Materials and Methods: This cross-sectional study was conducted at Sindh Institute of Urology and Transplantation (SIUT), Karachi, and includes subjects referred for a Ga68-PSMA PET-CT scan from September 2017 to January 2022. Histopathologic-proven adenocarcinoma prostate patients with organ-confined disease and PSA levels obtained within 6 weeks before the PSMA-PET-CT scan were included in the study. PET-CT images were semi-quantitatively analysed by measuring SUVmax and the result was interpreted using statistical software SPSS version 22.0. Results: A total of 154 patients were analysed. The mean age of patients was 66.57 ± 8.86 years. The GS of all patients ranges from 6 to 10. The mean and median PSA levels were 32.33 ng/mL (range: 0.004-306.00) and 14.20 ng/mL, respectively. The mean SUVmax of all prostatic lesions was 14.67 ± 12.58 and the median value was 10.76. SUVmax was higher in patients with a PSA level of more than ten than those with a <10. The correlation of SUVmax with PSA and GS showed a significant correlation. Conclusion: The SUVmax of organ-confined prostate cancer correlates well with PSA level and GS Median SUVmax and PSA directly relate to GS.
ABSTRACT
BACKGROUND: Prostate cancer is the cause of the highest cancer-related death in males, 5-year survival is 31% in metastatic disease, and bone is a common site of metastases. Bone scintigraphy is a routinely used imaging modality for detecting skeletal metastases. It has variable sensitivity of 52-100%, whereas PSMA PET/CT scans have better sensitivity approaching 100%, so we determined the diagnostic accuracy, sensitivity, and specificity of planar M.D.P. (Methylene diphosphonate) bone scintigraphy. METHODS: This analytical cross-sectional study was conducted at the N.M. & molecular imaging department of S.I.U.T. Karachi. Bone scans and PSMA-PET/CT scans of all patients who were visited from Janury-2018 to January 2023 were reviewed and interpreted by a nuclear physician& radiologist team. Inclusion criteria were histopathology-proven prostate cancer patients who had a bone scan and PSMA PET/CT scan within one month and had not received any treatment between scans. RESULTS: Among 70 scans, 38 (54.2%) were positive for bone lesions. A total of 18 (47%) patients had positive bony lesions on both PSMA-PET/CT and Bone scintigraphy. Among 38 bone lesions positive patients, in eleven patients, bone lesions were detected only on PET/CT scans, whereas nine were positive only on Bone scans. The mean S.U.V. max of all bony lesions was 19.15 (range 3.2-57.5). The bone scan's sensitivity, specificity, and accuracy were 62.07%, 78.05%, and 62.87%, respectively. CONCLUSIONS: PSMA-PET/CT is better than bone Scintigraphy for detecting skeletal metastases. However, outcomes of bone scintigraphy may be improved when Tc-PSMA receptor bone scintigraphy is used.
