Prediction of prostate cancer recurrence after radiation therapy using multiparametric magnetic resonance imaging and spectroscopy: assessment of prognostic factors on pretreatment imaging

Diagnostic efficacy and interobserver agreement among readers with variable experience of the Prostate Imaging for Recurrence Reporting system with whole-mount histology after androgen deprivation therapy as a reference

Background

The Prostate Imaging for Recurrence Reporting (PI-RR) system was recently proposed to assess the local recurrence of prostate cancer (PCa), but its exact performance for the prostate after radiotherapy or radical prostatectomy is difficult to determine. We aimed to evaluate the diagnostic performance and interreader agreement of this system using whole-mount histology of the prostate after androgen deprivation therapy (ADT) as the standard of reference.

Methods

In total, 119 patients with PCa post-ADT underwent multiparametric magnetic resonance imaging (mp-MRI) before prostatectomy. Three radiologists analyzed the MRI images independently, scoring imaging findings according to PI-RR. Spearman correlation was performed to assess the relationship between the percentage of sectors with residual cancer and PI-RR score. The diagnostic performance for detection of residual cancer was assessed on a per-sector basis. The chi-squared test was used to compare the cancer detection rate (CDR) among readers. Overall and pairwise interreader agreement in assigning PI-RR categories and residual cancer sectors with a score ≥3 or ≥4 were evaluated with the Cohen kappa coefficient.

Results

Histology revealed 209 sectors with residual cancer. The percentage of pathologically positive sectors increased with the increase in PI-RR score for all readers. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) at a cutoff of score 3 ranged from 74.2% to 83.7%, 86.4% to 92.7%, 51.3% to 64.3%, and 95.4% to 96.9%, respectively, and at a cutoff of score 4, they ranged from 47.4% to 56.5%, 97.9% to 98.6%, 82.5% to 85.3%, and 91.6% to 92.9%, respectively. There was no significant difference among the CDR of readers. In PI-RR categories and detection of residual cancer sectors, overall interreader agreement was moderate for all readers, but agreement was higher between the more experienced readers (moderate to substantial) than between the more and less experienced readers (fair to moderate).

Conclusions

MRI scoring with the PI-RR assessment provided accurate evaluation of PCa after ADT, but readers' experience influenced interreader agreement and cancer diagnosis.

Evaluation of Prostate Cancer Recurrence with MR Imaging and Prostate Imaging for Recurrence Reporting Scoring System

Detection of prostate cancer recurrence after whole-gland treatment with curative intent is critical to identify patients who may benefit from local salvage therapy. Among the different imaging modalities used in clinical practice, MR imaging is the most accurate in identifying local prostate cancer recurrence; indeed, it is an excellent technique for local recurrence detection superior to PET/CT, even at low PSA, but provides no information about extra-pelvic lymph nodes or bone metastasis. In 2021, a group of experts developed the Prostate Imaging for local Recurrence Reporting scoring system to standardize acquisition, interpretation, and reporting of prostate cancer recurrence.

The prognostic value of zonal origin in clinically localized prostate cancer: a systematic review and meta-analysis

Introduction

Correlation between zonal origin of clinically localized prostate cancer (PC) and biochemical recurrence (BCR) after treatment is still controversial.

Methods

We performed a meta-analysis of published articles to investigate the prognostic value of zonal origin in clinically localized PC. Literature was searched from Medline, Embase, Scopus, and Web of Science, from inception to Nov 1st, 2022. The risk of BCR was compared between PC originating from transition zone with peripheral zone. Relative risk (RR) was pooled in a random-effects model. Subgroup analysis and meta-regression were conducted to assess the source of heterogeneity.

Results

16 cohorts and 19,365 patients were included. PC originating from transition zone was associated with a lower risk of BCR (RR, 0.79, 95%CI; 0.69-0.92, I2, 76.8%). The association was consistent in studies with median follow-up time ≥60 months (RR, 0.65; 95%CI, 0.48 to 0.88, I2 56.8%), studies with NOS score ≥8 (RR, 0.70; 95%CI, 0.62 to 0.80, I2 32.4%), and studies using multivariate regression model (RR, 0.57; 95%CI, 0.48 to 0.69, I2 23%).

Discussion

This meta-analysis supported that transition zone origin was an independent prognostic factor of a better biochemical result in clinically localized prostate cancer after treatment.

Systematic review registration

10.37766/inplasy2023.11.0100, identifier INPLASY2023110100.

Emerging Role of Nuclear Medicine in Prostate Cancer: Current State and Future Perspectives

Prostate cancer is the most frequent epithelial neoplasia after skin cancer in men starting from 50 years and prostate-specific antigen (PSA) dosage can be used as an early screening tool. Prostate cancer imaging includes several radiological modalities, ranging from ultrasonography, computed tomography (CT), and magnetic resonance to nuclear medicine hybrid techniques such as single-photon emission computed tomography (SPECT)/CT and positron emission tomography (PET)/CT. Innovation in radiopharmaceutical compounds has introduced specific tracers with diagnostic and therapeutic indications, opening the horizons to targeted and very effective clinical care for patients with prostate cancer. The aim of the present review is to illustrate the current knowledge and future perspectives of nuclear medicine, including stand-alone diagnostic techniques and theragnostic approaches, in the clinical management of patients with prostate cancer from initial staging to advanced disease.