MRI-derived PRECISE scores for predicting pathologically-confirmed radiological progression in prostate cancer patients on active surveillance

Abstract

Objectives: To assess the predictive value and correlation to pathological progression of the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) scoring system in the follow-up of prostate cancer (PCa) patients on active surveillance (AS).

Methods: A total of 295 men enrolled on an AS programme between 2011 and 2018 were included. Baseline multiparametric magnetic resonance imaging (mpMRI) was performed at AS entry to guide biopsy. The follow-up mpMRI studies were prospectively reported by two sub-specialist uroradiologists with 10 years and 13 years of experience. PRECISE scores were dichotomized at the cut-off value of 4, and the sensitivity, specificity, positive predictive value and negative predictive value were calculated. Diagnostic performance was further quantified by using area under the receiver operating curve (AUC) which was based on the results of targeted MRI-US fusion biopsy. Univariate analysis using Cox regression was performed to assess which baseline clinical and mpMRI parameters were related to disease progression on AS.

Results: Progression rate of the cohort was 13.9% (41/295) over a median follow-up of 52 months. With a cut-off value of category ≥ 4, the PRECISE scoring system showed sensitivity, specificity, PPV and NPV for predicting progression on AS of 0.76, 0.89, 0.52 and 0.96, respectively. The AUC was 0.82 (95% CI = 0.74-0.90). Prostate-specific antigen density (PSA-D), Likert lesion score and index lesion size were the only significant baseline predictors of progression (each p < 0.05).

Conclusion: The PRECISE scoring system showed good overall performance, and the high NPV may help limit the number of follow-up biopsies required in patients on AS.

Key points: • PRECISE scores 1-3 have high NPV which could reduce the need for re-biopsy during active surveillance. • PRECISE scores 4-5 have moderate PPV and should trigger either close monitoring or re-biopsy. • Three baseline predictors (PSA density, lesion size and Likert score) have a significant impact on the progression-free survival (PFS) time.

Keywords: Active surveillance; Magnetic resonance imaging; Prostate cancer.

Fig. 1

PRECISE score 1. A 62-year-old patient at enrolment, with PSA of 4.53 ng/ml. Top row: T2 axial; bottom row: ADC maps. a, b MRI shows Likert 3 lesion at the right apex PZ (arrows), with mild-to-moderate restricted diffusion. Targeted biopsy shows Gleason 3 + 3 = 6 in 1/2 cores, 2 mm, 5%. c, d MRI at 24 months shows almost a complete resolution of T2 intermediate signal intensity change (c) and no restricted diffusion on ADC (d)

Fig. 2

PRECISE score 2. A 70-year-old patient at enrolment, with PSA of 3.4 ng/ml. Top row: T2 axial; bottom row: ADC maps. a, b 2014 MRI shows Likert 3 lesion at the left apex PZ (arrows). Targeted biopsy shows Gleason 3 + 3 = 6 in 1/3 cores, < 5%. c, d MRI at 12 months shows more geographical features on T2 (c) and reduced conspicuity on ADC (arrow in d)

Fig. 3

PRECISE score 4. A 66-year-old patient at AS enrolment, with PSA of 3.09 ng/ml. Top row: T2 axial; bottom row: ADC maps. a, b 2013 MRI shows a Likert 5 lesion in the right mid PZ measuring 12 mm × 7 mm (arrows). Initial biopsy showed Gleason 3 + 3 disease. c, d 2015 MRI lesion increased to 15 mm × 9 mm (PRECISE 4). e, f 2017 MRI lesion further increased in size to 17 mm × 10 mm. Targeted biopsy shows Gleason 3 + 4 = 7 up to 6 mm and replacing 85% of both cores. Patient underwent radiotherapy

Fig. 4

PRECISE score 5. A 68-year-old patient at the time of AS enrolment, with PSA stable at 5.1 ng/ml. Top row: T2 axial; bottom row: ADC maps. a, b Baseline MRI shows a 9 mm × 7 mm lesion at the left base PZ (arrows). Targeted biopsy showed Gleason 3 + 3 = 6, in 2/2 cores, 45%. c, d MRI at 30 months shows the lesion has increased in size to 21 mm × 10 mm, with broad capsular contact and irregularity consistent with ECE. Repeat biopsy showed 3 + 4 disease, 62% of cores. Patient underwent hormone and radiotherapy

Fig. 5

Flowchart for the study inclusion and results

Fig. 6

Kaplan-Meier curves for patients with and without MRI-visible baseline lesion