Predictors of erectile dysfunction after transperineal template prostate biopsy

The additional value of 68Ga-PSMA PET/CT SUVmax in predicting ISUP GG ≥ 2 and ISUP GG ≥ 3 prostate cancer in biopsy

BACKGROUND

Prebiopsy magnetic resonance imaging (MRI) increases the detection rate of clinically significant prostate cancer (csPCa). Prostate-specific membrane antigen-positron emission tomography/computed tomography (PSMA PET/CT) maximum standardized uptake value (SUVmax) of the prostate may offer additional value in predicting the likelihood of csPCa in biopsy.

METHODS

A single-center cohort study involving patients with biopsy-proven PCa who underwent both MRI and PSMA PET/CT between 2020 and 2021. Logistic regression models were developed for International Society of Urological Pathology (ISUP) Grade Group (GG) ≥ 2 and GG ≥ 3 using noninvasive prebiopsy parameters: age, (log-)prostate-specific antigen (PSA) density, PI-RADS 5 lesion presence, extraprostatic extension (EPE) on MRI, and SUVmax of the prostate. Models with and without SUVmax were compared using Likelihood ratio tests and area under the curve (AUC). DeLong's test was used to compare the AUCs.

RESULTS

The study included 386 patients, with 262 (68%) having ISUP GG ≥ 2 and 180 (47%) having ISUP GG ≥ 3. Including SUVmax significantly improved both models' goodness of fit (p < 0.001). The GG ≥ 2 model had a higher AUC with SUVmax 89.16% (95% confidence interval [CI]: 86.06%-92.26%) than without 87.34% (95% CI: 83.93%-90.76%) (p = 0.026). Similarly, the GG ≥ 3 model had a higher AUC with SUVmax 82.51% (95% CI: 78.41%-86.6%) than without 79.33% (95% CI: 74.84%-83.83%) (p = 0.003). The SUVmax inclusion improved the GG ≥ 3 model's calibration at higher probabilities.

CONCLUSION

SUVmax of the prostate on PSMA PET/CT potentially improves diagnostic accuracy in predicting the likelihood of csPCa in prostate biopsy.

"Seeing Is Believing": Additive Utility of 68Ga-PSMA-11 PET/CT in Prostate Cancer Diagnosis

Widespread adoption of mpMRI has led to a decrease in the number of patients requiring prostate biopsies. 68Ga-PSMA-11 PET/CT has demonstrated added benefits in identifying csPCa. Integrating the use of these imaging techniques may hold promise for predicting the presence of csPCa without invasive biopsy. A retrospective analysis of 42 consecutive patients who underwent mpMRI, 68Ga-PSMA-11 PET/CT, prostatic biopsy, and radical prostatectomy (RP) was carried out. A lesion-based model (n = 122) using prostatectomy histopathology as reference standard was used to analyze the accuracy of 68Ga-PSMA-11 PET/CT, mpMRI alone, and both in combination to identify ISUP-grade group ≥ 2 lesions. 68Ga-PSMA-11 PET/CT demonstrated greater specificity and positive predictive value (PPV), with values of 73.3% (vs. 40.0%) and 90.1% (vs. 82.2%), while the mpMRI Prostate Imaging Reporting and Data System (PI-RADS) 4-5 had better sensitivity and negative predictive value (NPV): 90.2% (vs. 78.5%) and 57.1% (vs. 52.4%), respectively. When used in combination, the sensitivity, specificity, PPV, and NPV were 74.2%, 83.3%, 93.2%, and 51.0%, respectively. Subgroup analysis of PI-RADS 3, 4, and 5 lesions was carried out. For PI-RADS 3 lesions, 68Ga-PSMA-11 PET/CT demonstrated a NPV of 77.8%. For PI-RADS 4-5 lesions, 68Ga-PSMA-11 PET/CT achieved PPV values of 82.1% and 100%, respectively, with an NPV of 100% in PI-RADS 5 lesions. A combination of 68Ga-PSMA-11 PET/CT and mpMRI improved the radiological diagnosis of csPCa. This suggests that avoidance of prostate biopsy prior to RP may represent a valid option in a selected subgroup of high-risk patients with a high suspicion of csPCa on mpMRI and 68Ga-PSMA-11 PET/CT.

A Comprehensive Assessment of the Utility of Transperineal Template Prostate Mapping Biopsy: A 13-year Experience

OBJECTIVE

To assess Duke's experience on the utility of transperineal template mapping biopsy (TTMB) for re-evaluating patients with persistently elevated prostate-specific antigen after prior negative biopsy, with pre-existing prostate cancer (PCa) already on active surveillance (AS), or considering focal therapy (FT).

METHODS

We retrospectively reviewed Duke patients undergoing TTMB. Functional outcomes were evaluated using International Index of Erectile Function-5 (IIEF-5) and International Prostate Symptom Score (IPSS). Complications within 30 days were recorded. Nonparametric statistical analyses compared functional measures from baseline to 2 and 6 weeks post-TTMB.

RESULTS

From 8/2009 to 1/2021, 218 patients underwent TTMB, with 57-month median follow-up. Complication rate was 17.4%, with the majority Clavien I. Overall PCa detection was 72.9%, with clinically significant PCa in 53.2%; for those without prior PCa diagnosis (n = 117), overall detection was 64.1% with clinically significant PCa in 49.5%. Of those on AS at TTMB (n = 86), 36 (41.8%) had Gleason upgrading. TTMB changed management for 59 (68.6%) patients, with 38 (44.2%) proceeding to whole-gland therapy and 21 (24.4%) electing FT. Regarding functional outcomes, IPSS were insignificantly different from baseline at 6 weeks (P = NS). Overall functional score impacts were minimal across subgroups; in groups with significant declines in IIEF-5, median score drops were ≤1 point and caused minimal/no movement in IIEF-5 scoring category.

CONCLUSION

In this cohort, TTMB offered enhanced cancer detection with overall minimal impact to functional outcomes. We conclude from this comprehensive assessment that TTMB provides value to rule out PCa, prevent overtreatment of those that can remain on AS, evaluate FT candidacy, and identify those needing whole-gland management.

Clinically Significant Prostate Cancer Diagnosis Without Histological Proof: A Possibility in the Prostate-specific Membrane Antigen Era?

Magnetic resonance imaging (MRI) has resulted in a reduction in the number of patients indicated for prostate biopsy. Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has recently shown additional value in detecting clinically significant prostate cancer (csPCa). Combining these imaging modalities allows such specific prediction of the presence of csPCa that the need for histological confirmation may be obsolete. We retrospectively analyzed PSMA PET/CT scans performed in the primary staging of PCa in the past 2 yr in our center (n = 451). All 74 patients with a PSMA ligand maximum standardized uptake value (SUVmax) of ≥16 had csPCa (grade group ≥2). Of the 185 patients with a combination of a Prostate Imaging-Reporting and Data System score ≥4 and SUVmax ≥8, 98% had csPCa. A nomogram combining predictive factors should be developed to identify patients in whom biopsy could theoretically be avoided. Nevertheless, biopsy will remain indispensable in patients with indefinite risk of csPCa and can provide important additional information.

Patient summary

Using patient data from our center, we found that addition of a special type of scan based on prostate-specific membrane antigen could help in the diagnosis of clinically significant prostate cancer without the need for prostate biopsy. Direct therapy without biopsy confirmation of cancer might be possible for a highly select group of patients.