Tumour–capsule interface measured on 18F‐DCFPyL PSMA positron emission tomography/CT imaging comparable to multi‐parametric MRI in predicting extra‐prostatic extension of prostate cancer at initial staging

Abstract

Introduction: Nerve-sparing prostatectomy is recommended in cases of organconfined prostate cancer but is generally contraindicated in patients with suspected extra-prostatic extension (EPE). PSMA ligand imaging has been shown to be valuable in predicting EPE when performed on a hybrid PET/MRI scanner; however, the majority of PSMA-PET imaging is performed using PET/CT. To our knowledge, there are no established PET/CT criteria for assessing EPE. In this study, we aim to provide a reproducible method for evaluating EPE on PSMA-PET/CT imaging and assess its utility compared with MRI. Methods: Imaging findings and histopathology were reviewed for 100 consecutive patients who underwent a radical prostatectomy after imaging with MRI and 18F-DCFPyL PSMA-PET/CT. Results: A broad tumour-capsule interface measured using a standardised technique on fused PSMA-PET/CT imaging is associated with a higher risk for established EPE (P < 0.001). In our cohort, applying the criteria of tumourcapsule contact ≥ 10 mm measured on PET/CT was as sensitive as applying PI-RADS version 2 criteria to mpMRI imaging for predicting EPE (74% and 79%, respectively, P = 0.11) and had superior specificity (86% and 61%, respectively, P = 0.035). 93% of MRI-occult lesions were visualised on PSMA-PET/CT. Applying the proposed PET/CT criteria for EPE to this subgroup of 14 patients yielded a sensitivity of 67% and specificity of 92%. Conclusion: Our results suggest that tumour-capsule interface measured on fused F18-DCFPyL PSMA-PET/CT imaging is comparable to MRI criteria for predicting the presence of EPE. Applying PET/CT criteria may be of particular benefit in predicting EPE in patients with MRI-occult prostate cancer.

Comparing the Detection Performance Between Multiparametric Magnetic Resonance Imaging and Prostate-Specific Membrane Antigen PET/CT in Patients With Localized Prostate Cancer

“…The current meta-analysis included a total of 39 studies comprising 3630 patients, published between 2016 and 2022, 7,8,[10][11][12] with 38.5% (15 studies) of the studies being prospective studies. 12,22,23,28,29,34,35,[37][38][39][45][46][47]49,50 In all included studies, the 68 Ga-PSMA radiotracer was predominantly used (82.1%), whereas 68 Ga-PSMA-11 was the major radiotracer (n = 23).…”

“…12,22,23,28,29,34,35,[37][38][39][45][46][47]49,50 In all included studies, the 68 Ga-PSMA radiotracer was predominantly used (82.1%), whereas 68 Ga-PSMA-11 was the major radiotracer (n = 23). 7,[20][21][22][24][25][26][27][28][30][31][32]35,36,39,[42][43][44][46][47][48][49]51,52 Only a few studies used the radiotracers 18 F-DCFPyL 8,11,29,38,40 and 18 F-PSMA-1007 10,41 (Table 1).…”

“…28,31,39,49 The injected activity of 68 G-PSMA was 74 to 185 MBq. 23,34,50 In addition to the radiotracer 68 Ga-PSMA, the median median/mean injected activity of 18 F-DCFPyL was 294.6 MBq (range, 250-329.5 MBq), 8,29,38,40 and that of 18 F-PSMA-1007 was 256 MBq. 41 The median of median/ mean interval time between radiotracer injection and PET scanning was 60 minutes (range, 45-180 minutes) 7,8,10,11,21,22,24,[26][27][28][29][30]32,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53] (Supplementary Table 1, Supplemental Digital Content, http://links.…”

“…Among the 39 included studies, 3.0 Twas the most commonly used diagnostic equipment for mpMRI (64%), 8,[10][11][12][20][21][22]24,[26][27][28][29]31,32,34,37,39,40,44,45,[47][48][49]52,53 and 69% of the mpMRI sequence used T2-weighted and diffusion-weighted. [8][9][10][11]20,[22][23][24][25]29,34,35,37,39,40,[42][43][44][45][46][47][48][49][50][51][52][53]<...…”

“…All 39 included studies were pathologically verified, but only 31 of them clearly estimated the number of lesions that were TP/FP and negative, including localized tumors (23 studies) 8,10,11,[20][21][22]24,[26][27][28][29]32,34,35,37,38,40,[44][45][46]49,52,53 and T staging (8 studies). 7,8,23,25,33,39,41 For localized prostate tumors, the pooled sensitivity and specificity of PSMA PET were 0.84 (95% CI, 0.83-0.86) and 0.72 (95% CI, 0.57-0.83), whereas those of mpMRI were 0.84 (95% CI, 2).…”