68Ga-PSMA-11 PET/CT in Newly Diagnosed Prostate Adenocarcinoma

Abstract

Introduction Prostate-specific membrane antigen (PSMA) ligand PET/CT is an emerging modality to detect the metastatic disease, especially in intermediate- and high-risk prostate cancer (PCa). In this study, we analyzed the contribution of 68Ga-PSMA-11 PET/CT in staging and therapy management of newly diagnosed PCa. Materials and Methods A total of 78 patients with biopsy-proven PCa who were referred for 68Ga-PSMA-11 PET/CT for primary staging were retrospectively analyzed. The patients were divided into risk groups according to the D'Amico risk stratification criteria. All of the patients had undergone pelvic MRI, and 65 patients had bone scintigraphy also. The findings of 68Ga-PSMA-11 PET/CT were compared with these conventional imaging (CI) methods for staging of the disease. The relations between SUVmax of the primary tumors and Gleason scores (GSs), prostate-specific antigen (PSA) levels, and metastatic extent of the disease were analyzed. Results Of 78 patients, 5 patients were in low-risk group, 18 patients were in intermediate-risk group, and 55 patients were in high-risk group. Metastatic disease was found in 40 (51.2%) of 78 patients in 68Ga-PSMA-11 PET/CT. Ten patients had regional lymph node metastases, and 30 patients had distant metastases. 68Ga-PSMA-11 PET/CT changed the staging in 44 (56.4%) of 78 patients compared with CI. There was significant difference between the SUVmax of the tumors with GSs of 6 and 7 compared with GSs of 8, 9, and 10 (P = 0.003). The SUVmax were significantly different between the patients with no metastasis (n = 38) and patients with regional lymph node metastases or distant metastases (n = 40; 16.1 ± 10.9, 28.7 ± 25.8, P = 0.003, respectively). There was significant difference between the SUVmax of patients with PSA level less than 10 ng/mL compared with patients with PSA level of 10 or greater and less than 20 ng/mL and PSA 20 ng/mL or greater (P = 0.009). A weak correlation between PSA and primary tumor SUVmax was also found (r = 0.21). Conclusions 68Ga-PSMA-11 PET/CT is an important imaging modality for primary evaluation of newly diagnosed PCa changing the disease stage substantially. Also the SUVmax of the primary tumor has a relation with GS, metastatic extent of disease, and PSA levels defining the prognosis.

The Value of 18F-PSMA-1007 PET/CT in Identifying High-Risk Prostate Cancer

“…But it is worth noting that the SUV max of primary tumor between these two subgroups has no statistical difference with a median SUV max of 8.76 (GS 7a) and 14.30(GS 7b), (P > 0.05). This nding was consistent with previous studies on 68 Ga-PSMA [23,24], which may Figure 4 showed the result of the ROC curve analysis for high-risk PCa. The AUC of the SUV max was 0.873.…”

“…Thus, we also made the pairwise comparison between different GS subgroups and found that there were statistically signi cant differences in SUV max between the subgroups of GS 6 and GS 7a, and the subgroups of GS 8-10 (P < 0.001). There was no statistical difference in SUVmax value between tumors with 7b and those with GS of 8-10, which was different from the result of previous studies on 68 Ga-PSMA [23,24]. Reasons for these discrepancies remain speculative.…”

“…Typical pitfalls such as PSMA uptake in sacral and coeliac ganglia or in the stellate ganglia were frequently observed but were not considered pathological [20]. This interpretation criterion comes from the result of our clinical experience and consistent with published literature [21][22][23][24].…”

“…PSMA-PET/CT, as a noninvasive imaging diagnostic strategy, may compensate for these shortcomings. Recent studies found a statistically signi cant positive correlation between GS/PSA value and SUV max of primary tumors on PSMA-PET/CT [13,23]. Kesch et al proved 18 F-PSMA-1007 PET/CT and multiparametric magnetic resonance imaging had similar diagnostic performance in local staging of PCa [15].…”

Comparison of preoperative locoregional Ga‐68 PSMA‐11 PET‐CT and mp‐MRI results with postoperative histopathology of prostate cancer

“…Positron emission tomography in combination with computed tomography (PET/CT) imaging with Gallium‐68‐labeled (Ga‐68) prostate‐specific membrane antigen ligands (PSMA) has entered clinical practice for staging, restaging, treatment planning, and evaluating treatment response of PCa patients since 2012 . PSMA is a cell surface protein with high expression in PCa cells .…”