Utility of Ga⁶⁸ prostate‐specific membrane antigen positron‐emission tomography for pre‐operative staging of high‐risk prostate cancer in a prospective cohort

Abstract

Introduction:To assess the yield of Ga68 PSMA PET/CT added to the conventional staging of high-risk prostate cancer in terms of altered staging and changes to management. Methods: Patients with high-risk prostate cancer without metastatic disease on conventional staging referred for Ga68 PSMA PET/CT at Mercy Radiology, Auckland, New Zealand, were prospectively recruited. Conventional staging was double read in a blinded fashion by oncology fellowship-trained radiologists, who were also experienced in PET/CT, followed by interpretation of the PSMA PET/CT by the same radiologists. Confirmation of changes in management decision was obtained from the treating surgeon and multidisciplinary team meeting records. Ethical approval was obtained from the Health and Disability Ethics Committee. All patients gave written informed consent. Results: A total of 49 patients were scanned. Three who were otherwise eligible for radical prostatectomy elected alternative treatments, leaving 46 patients included for analysis in the study. The addition of PSMA PET/CT was associated with highly statistically significant changes in both staging and management. The stage was changed in 32.6% (95% CI 20.8-47.1%, P < 0.001) patients upstaging in 60% and downstaging in 40%; clinical management in 34.8% (95% CI 22.6-49.3%; P < 0.001), with intramodality change in 25% and intermodality change in 75%. Factors predictive of a change in management with PSMA PET/CT included higher Gleason score and a greater proportion of prostatic cores positive for tumour. Conclusion: The addition of Ga68 PSMA PET/CT to conventional staging in high-risk prostate cancer frequently leads to changes in staging and management.

DEPROMP Trial: The additive value of PSMA-PET/CT-guided biopsy for prostate cancer management in biopsy naïve men – study protocol for a randomized controlled trial

“…The conduct of PET/MR-TB promises primarily improved assessment of tumor extent and grading and consecutively an optimized risk strati cation [16,17,28,29]. Furthermore, PSMA-PET/CT has an impact on the treatment plans of PCA patients in advanced tumor stages [18,23]. We hypothesized that introducing the additional PET-TB at the biopsy level will not only lead to additional diagnostic yields but also to signi cant changes in treatment plans.…”

“…The combined approach of PSMA-PET/CT and MRI results in improved csPCA detection with enhanced NPV of 91% in biopsy-naïve patients [16] and an optimized description of local tumor extension, both crucial for the management planning [17]. Moreover, a signi cant impact on treatment strategies by PSMA-PET/CT was demonstrated for PCA-proven men, resulting in intra-and inter-modal adjustments of management in up to 75% of men [18] and an optimized discrimination between unifocal, multifocal, and oligometastatic disease, decisive for individualized targeted and multimodal PCA-management [19,20]. However, the gain in information through optimized initial staging raises previously unanswered questions: Which ndings result in treatment changes and which patients bene t from altered therapy management?…”

“…There is no published data on management plan changes due to the initial diagnostic performance of PET-TB to derive an optimal robust power calculation. However, the power calculation was based on pilot data expecting inter-and intramodal management changes in the range of 25-75% of patients [18,23]. Hence, we will recruit up to 230 biopsy-naïve men.…”

DEPROMP Trial: the additive value of PSMA-PET/CT-guided biopsy for prostate cancer management in biopsy naïve men—study protocol for a randomized trial

“…There are no published data on treatment plan changes due to the initial diagnostic performance of PET-TB to derive an optimal robust power calculation. However, the power calculation was based on pilot data suggesting inter- and intra-modal PSMA-PET/CT-dependent changes in the management plan after the detection of prostate cancer in the order of 25–75% of patients [ 18 , 23 ]. Hence, we will recruit up to 230 biopsy-naïve men.…”

“…The combined approach of PSMA-PET/CT and MRI results in improved csPCA detection with enhanced NPV of 91% in biopsy-naïve patients [ 16 ] and an optimized description of local tumor extension, both crucial for the management planning [ 17 ]. Moreover, a significant impact on treatment strategies by PSMA-PET/CT was shown for PCA-proven men, resulting in intra- and inter-modal adjustments of management in up to 75% of men [ 18 ] and an optimized discrimination between unifocal, multifocal, and oligometastatic disease, decisive for individualized targeted and multimodal PCA-management [ 19 , 20 ]. However, the gain in information through optimized initial staging raises previously unanswered questions: Which findings result in treatment changes and which patients benefit from altered therapy management?…”