RPS 1107 - Prostate lesions scoring and treatment

Purpose:

The PRECISE scoring system evaluates the likelihood of radiological progression in patients on active surveillance (AS) for prostate cancer (PCa) with serial multiparametric magnetic resonance imaging (mpMRI). A score of 1-2 denotes radiological regression, a score of 3 implies stability, and a score of 4-5 denotes progression. We assessed the inter-reader reproducibility of different apparent diffusion coefficient (ADC) calculations and their relationship to the PRECISE scores.

Methods and materials:

Two radiologists retrospectively evaluated baseline and follow-up scans (performed on the same MR systems) in 30 patients from two different institutions. A PRECISE score was initially given in consensus. After at least 6 weeks to reduce the likelihood of being influenced by the consensus reading, each radiologist independently calculated the ADC for the lesion, non-cancerous tissue, and urine in the bladder. Normalised ADC ratios were calculated with respect to normal prostatic tissue (npADC) and urine. Spearman’s correlation (ρ), intraclass correlation coefficients (ICC), differences in ADC, and ROC curves were computed.

Results:

Interobserver reproducibility was very good (ρ>0.8; ICC>0.90). When considering patients with radiological regression/stability versus progression at follow-up mpMRI, lesion ADC was different between these groups (0.91 vs 0.73 × 10⁻³ mm²/s; p=0.025). Differences between the two groups were seen in npADC ratio (0.68 vs 0.53; p=0.012). Cut-offs of 0.77 × 10⁻³ mm²/s (lesion ADC) and 0.59 (npADC ratio) could differentiate the two groups (areas under the curve: 0.74 and 0.77, respectively).

Conclusion:

The ADC correlates well with the PRECISE scores and it holds promise in the evaluation of radiological progression of PCa over time.

Limitations:

A small cohort of patients and the absence of tissue verification by means of radical prostatectomy.

Ethics committee approval

n/a

Funding:

European School of Radiology (2019 BRACCO fellowship) and ERASMUS+ programme.

Purpose:

To assess the interobserver reproducibility of the PRECISE score for magnetic resonance imaging (MRI) in patients on active surveillance (AS) for prostate cancer (PCa).

Methods and materials:

The PRECISE scoring system assesses the radiological progression of PCa over time. A score of 1 or 2 means regression of a previously visible lesion, a score of 3 denotes stability, and 4 or 5 suggests radiological progression. We retrospectively evaluated serial MRI scans in 80 men on AS from two different academic centres (40 from each centre) with biopsy-confirmed low- or intermediate-risk PCa (i.e. ≤ Gleason 3+4 and a prostate specific antigen ≤ 20 ng/ml) and ≥ 2 MR scans. Two radiologists reported all scans independently and gave a PRECISE score from the second scan onwards. Cohen’s κ coefficients and percent agreement were computed.

Results:

The agreement was substantial, both at a per-patient and a per-scan level (κ=0.71 and 0.61; percent agreement=79% and 81%, respectively) for each PRECISE score. The agreement was greater (κ=0.83 and 0.67; percent agreement=90% and 91%, respectively) when the PRECISE scores were grouped according to the absence/presence of radiological progression (PRECISE 1-3 vs 4-5). A higher inter-reader agreement was observed for the scans performed at one centre (κ=0.81 vs 0.55 on a per-patient level, and κ=0.70 vs 0.48 on a per-scan level, respectively). The discrepancies between institutions were less evident for percent agreement (80% vs 78% and 86% vs 75%, respectively).

Conclusion:

We observed substantial reproducibility for PRECISE scoring of radiological change in men on AS, particularly when the clinical cut off a PRECISE score ≥ 4 for MRI-directed biopsy was used.

Limitations:

Not all men underwent targeted rebiopsy during follow-up.

Ethics committee approval

n/a

Funding:

2019 Bracco Fellowship and Erasmus+ programme.

Purpose:

To assess the adherence in literature to technical parameters required by PI-RADSv2 guidelines.

Methods and materials:

Multiple medical literature databases were systematically assessed by 3 investigators. Original studies regarding prostate magnetic resonance imaging (MRI) published after January 2016 were retrieved using an appropriate search string. Information about technical acquisition protocols and patient enrolment were collected from full text and/or supplemental materials for the analysis. Technical parameters were dichotomised in relation to their adherence to PI-RADSv2 guidelines.

Results:

A total of 150 studies were included in the analysis. Of all papers, 15% reported protocol details regarding all technical specifications requested for T2-weighted (T2w) sequences, only 8% for diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps, whereas 10% did the same for dynamic contrast-enhanced (DCE) sequences. Overall, only 5% of all studies reported every technical parameter requested by PI-RADSv2, none of which completely met guidelines specifications.

Only 19% of studies were in line with PI-RADSv2 for all reported technical parameters. In particular, the adherence was lowest for T2w frequency in-plane resolution (12%), ADC maps low-b value (27%), and DCE imaging temporal resolution (43%). Furthermore, only 59% of studies reporting DWI high-b value followed recommendations.

Conclusion:

Compliance to PI-RADSv2 in literature is greatly heterogeneous. Our results point out the need for a better diffusion of protocol standardisation and for less stringent indications of some technical parameters.

Limitations:

Our analysis was limited to a relatively short period of time (34 months), even if it included exams from a wider range (2006–2018). The number of studies collected was high, while there was heterogeneous reporting of imaging protocol details.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To validate the predictive value of the prostate cancer radiological estimation of change in sequential evaluation (PRECISE) MRI system in the follow-up of prostate cancer (PCa) patients on active surveillance (AS) and its correlation to disease progression on AS.

Methods and materials:

305 men enrolled in an AS programme between 2011 and 2018 were included. Disease progression on AS was defined as the end-point. Receiver operating characteristic curve analysis was performed, with the area under the curve (AUC) for PRECISE scores estimated for detection of progression. Kaplan–Meier curves compared progression-free survival (PFS) between PRECISE scores.

Results:

Progression rate for the cohort was 16.7% (51/305) over a median follow-up of 52 months. The AUC, specificity, sensitivity, PPV, and NPV of the PRECISE system were 0.83, 0.77, 0.89, 0.57, and 0.95, respectively. PSA-Density and the Likert lesion-probability score were the only significant baseline parameters predictive of progression in multivariate analysis (OR=5575.0, p=0.008 and 1.7, p<0.001, respectively). Diagnostic performance of PRECISE was increased to AUC=0.92 (PPV=0.69 and NPV=0.94) when combined with the significant baseline predictors. Kaplan-Meier curves showed a significant difference in PFS between PRECISE scores 1-3 (94%) versus scores 4-5 (35.5%) at 5 years; p<0.001.

Conclusion:

PRECISE MRI scoring has a good predictive value for men with PCa on AS. The high NPV of PRECISE can reduce the need for re-biopsy, whilst the moderate PPV for progression should trigger either closer monitoring or re-biopsy.

Limitations:

A retrospective design. In 8 cases, PRECISE score 5 (i.e. T3a/T3b disease) triggered a direct switch to treatment, with pathological progression not definitively being confirmed.

Ethics committee approval

The Local Ethics Committee waived the need for informed consent.

Funding:

No funding was received for this work.

Purpose:

To evaluate the agreement among readers with different expertise in detecting suspicious lesions at prostate multiparametric MRI using prostate imaging reporting and data system version 2.1.

Methods and materials:

We evaluated 200 consecutive biopsy naïve or previous negative biopsied men who underwent MRI for clinically suspicious prostate cancer (PCa) between May and September 2017. Of them, 132 patients underwent prostate biopsy. 7 radiologists (4 dedicated uro-radiologists and 3 non-dedicated abdominal radiologists) reviewed and scored all MRI examinations according to PI-RADS v2.1. Agreement on index lesion detection was evaluated with Conger’s k coefficient, AC1 coefficient, percentage of agreement (PA), and indexes of specific positive and negative agreement. Clinical and radiological features that may influence variability were evaluated.

Results: Conclusion: Limitations:

A retrospective study, limited to a single-tertiary-care referral centre.

Ethics committee approval

This study was approved by our Institutional Review Board and written informed consent was obtained.

Funding:

No funding was received for this work.

Purpose:

To assess whether a risk model solely based on clinical parameters can reduce MRI-targeted biopsies of PI-RADSv2 category 3 index lesions without missing clinically significant (cs) prostate cancer (PCa) (ISUP≥grade 2).

Methods and materials:

We retrospectively analysed 278 patients without a prior PCa diagnosis who underwent multiparametric MRI and MRI-targeted biopsy at 2 institutions. A multivariate model was fitted to the training cohort (institution 1; n=202), using the following clinical parameters: prostate volume, prior biopsy status, PSA density (PSAd), and age. Decision thresholds to rule out csPCa were determined within the PI-RADSv2 3 subgroup of the training cohort (n=115). The validation cohort (institution 2) consisted of 76 men with PI-RADSv2 3 index lesions. Using the area under the ROC curve (AUC), the performance of our model in the validation cohort was compared to PSAd, normalised ADC (nADC), lesion volume, and the MRI European randomised study of screening for PCa risk calculator (MRI-ERSPC-RC).

Results:

Our model (AUC=0.80) outperformed PSAd (AUC=0.60; p=0.01), lesion volume (AUC=0.45; p=0.03), and the MRI-ERSPC-RC (AUC=0.39; p=0.0002), and was not inferior to nADC (AUC=0.68; p=0.13). Predefined thresholds for nADC and lesion volume resulted in a minor biopsy reduction by 5% (4/76) and 4% (3/76), respectively; the published threshold for the MRI-ERSPC-RC would have reduced biopsies by 93% (71/76), however, missing 83% (5/6) of csPCas. At a PSAd ≥0.083 ng/ml/ml and a risk threshold ≥0.082 for the multivariate model, the percentage of men who may have avoided biopsy was 21% (16/76) and 33% (25/76), respectively, without missing any csPCa (0/6).

Conclusion:

Applying a risk model based on clinical parameters in men with PI-RADSv2 3 index lesions could result in 33% fewer biopsies being performed without missing any csPCa.

Limitations:

A retrospective study.

Ethics committee approval

IRB-approved study.

Funding:

OICR; DFG-fellowship [DE 3207/1-1].

Purpose:

To assess the feasibility of a 2^nd generation MR-compatible remote-controlled manipulator (RCM) as an aid to perform transrectal MRI-guided focal laser ablation in men with histologically proven prostate cancer (PCa).

Methods and materials:

Between March 2016 and May 2018, 17 consecutive patients with at least one focus of histologically proven PCa (Gleason ≥7) underwent transrectal MRI-guided focal laser ablation. An MR-compatible RCM (Soteria Medical) was used to steer the needle guide. Depending on the size of the lesion, several ablations were performed. For the evaluation of the workflow, the procedure times, the manipulation times, and the number of ablations were recorded. Complications were registered according to the clinical practice guidelines proposed by the Society of Interventional Radiology (SIR).

Results:

All lesions were reachable with the MR-compatible RCM. The median procedure time was 125 minutes (range, 77-169 minutes) and the median manipulation time for laser-fibre movement was 34 minutes (range, 8-60 minutes). Per lesion, a median number of 5 ablations was performed (range, 2–7). One SIR grade B (urine-retention) and one grade C/D (urosepsis) complication were reported.

Conclusion:

It is safe and feasible to perform transrectal MRI-guided focal laser ablation using a MR-compatible RCM.

Limitations:

n/a

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To assess the efficacy, safety, and economic impact of transperineal laser ablation (TPLA) in the treatment of benign prostatic hyperplasia (BPH).

Methods and materials:

30 patients (age 73.4 ± 8.4 years) with lower urinary tract symptoms underwent TPLA under local anaesthesia. Under ultrasound guidance by US/MRI fusion software, up to four 21G applicators were inserted into the prostatic tissue. The primary endpoint was the absence of relevant complications intra- and early (15 days) post-intervention. Secondary endpoints included the evaluation of total intervention time, ablation time, energy deployed, observation time, catheterisation time, IPSS, quality of life (QoL), peak urinary flow rates, post-void residual (PVR), and prostatic morphology and volume, evaluated with 3T mpMRI at 3, 6, and 12 months.

Results:

No complications occurred intra- or early post-intervention. The mean ablation time was 33.3 minutes (range 25.3 min-max 42.4), the mean energy deployed was 12,137 J (range 7,204.4-max 14,3483 J), the mean hospital stay was 113 minutes, and the mean catheterisation time was 7.1 days (range 1.1-max 9.3 days). At 3 months, the mean IPSS improved from 22.3 to 7.4 (P < 0.001), the mean QoL from 3.4 to 1.7 (P < 0.001), the mean Q max from 5.1 to 12.5 mL/s, the mean PVR from 148.3 to 87.1, and the mean prostate volume from 54.9 to 42.3 mL.

Conclusion:

TPLA is feasible, safe, and economical in the treatment of BPH. Our preliminary data demonstrates significant clinical results at 6 and 12 months.

Limitations:

A small number of treated patients, short follow-up, and our first expierence with this technique.

Ethics committee approval

Protocol approved by the ethical committee of the Tor Vergata Hospital.

Funding:

No funding was received for this work.