Risk of metastatic disease using [18F]PSMA-1007 PET/CT for primary prostate cancer staging

Abstract

Background Accurate prostate cancer imaging is critical for patient management. Multiple studies have demonstrated superior diagnostic accuracy of [68Ga]-PSMA-11 PET/CT over conventional imaging for disease detection, with validated clinical and biochemical predictors of disease detection. More recently [18F]PSMA-1007 offers theoretical imaging advantages, but there is limited evidence of clinical and biochemical predictors of scan findings in the staging population. This study investigates the association of clinical variables with imaging characteristics among patients who underwent [18F]PSMA-1007 PET/CT for primary staging of men with histopathologically confirmed prostate carcinoma. A retrospective review of 194 consecutive patients imaged between May 2019 to May 2020 was performed. Association between imaging variables (presence and distribution of metastatic disease, primary tumour SUVmax) and clinical variables (EAU risk criteria) were assessed using descriptive statistics, logistic regression model and ROC analysis. Results The median age, PSA level and ISUP grade were 70 years, 10 ng/mL and ISUP grade 3, respectively. There were 36.6% of patients with intermediate-risk and 60.8% of patients with high-risk disease. ISUP grade was associated with the presence of metastasis overall (p = 0.008) as well as regional nodal (p = 0.003), non-regional nodal (p = 0.041) and bone (p = 0.006) metastases. PSA level was associated with metastatic disease overall (p = 0.001), regional (p = 0.001) and non-regional nodal metastases (p = 0.004), but not with bone metastases (p = 0.087). There were too few visceral metastases for meaningful analysis. SUVmax of the primary prostatic tumour was associated with ISUP grade (p = 0.004), PSA level (p < 0.001) and AJCC stage (p = 0.034). PSA > 20 ng/mL and ISUP grade > 3 had a specificity of 85% (95% CI 78–91%) and 60% (95% CI 50–68%) and a sensitivity of 36% (95% CI 25–49%) and 62% (95% CI 49–74%), respectively, for detection of metastatic disease. Conclusion Metastatic disease according to [18F]PSMA-1007 PET/CT was associated with ISUP grade and PSA level. This is the largest study using [18F]PSMA-1007 PET/CT to confirm a positive correlation of PSA level, ISUP grade and stage with primary prostate tumour SUVmax.

An Australian experience using Tc‐PSMA SPECT/CT in the primary diagnosis of prostate cancer and for staging at biochemical recurrence after local therapy

“…We found a moderately strong relationship between all Tc‐PSMA uptake measures in the primary tumor and pSUV and ISUP grade, the likelihood of metastatic disease, and PSA. The relationship between pSUV and biopsy has been noted in both a previous Tc‐PSMA study and several Ga‐PSMA studies 6,26 . Other studies have shown a relationship between pSUV and histopathology at the surgery for Ga‐PSMA 27 .…”

The Detection Performance of 18F–Prostate-Specific Membrane Antigen-1007 PET/CT in Primary Prostate Cancer

“…Giesel et al denoted no significant difference between 18 F-PSMA-1007 and 18 F-DCFPyL 17 . Consistent with 68 Ga-PSMA-11 and 18 F-DCFPyL, the SUV max of the focal lesion was positively correlated with the grade groups and serum PSA level 14,15,33,40,42,51–53 …”

“…14,15,17,[29][30][31][32][33][34]36 Of all included studies, the Gleason scores were between 7 and 9 in 12 studies (Table 1). 14,15,17,18,[29][30][31][32][33][34][35][36] Technical Aspects of 18 F-PSMA-1007 PET/CT in the Included Studies…”

“…17 Consistent with 68 Ga-PSMA-11 and 18 F-DCFPyL, the SUV max of the focal lesion was positively correlated with the grade groups and serum PSA level. 14,15,33,40,42,[51][52][53] In the studies by both Giesel et al 17 and Kuten et al, 18 a nearly negligible uptake of 18 F-PSMA-1007 was observed in the urinary bladder. 17,18 For intraprostatic lesions, the uptake of 18 F-PSMA-1007 was similar to that of 18 F-DCFPyL, and clear intraprostatic lesions were observed; in contrast, 18 F-PSMA-1007 was more evident as a multifocal lesion than 68 Ga-PSMA-11 17,18 (Supplement Fig.…”

“…According to the classification of the International Society of Urological Pathology (ISUP) grade group, 3 of the 9 studies demonstrated that the SUV max of the focal lesion was positively correlated with ISUP grade 14,15,33 ; however, 1 of the 9 studies mentioned an insignificant correlation between ISUP and the SUV max for focal lesions (Supplement Table 2, Supplemental Digital Content, http://links.lww.com/CNM/A377). 35 Moreover, 1 study reported that the SUV max of the focal lesion increased with an increasing serum PSA level 14 …”