Objective To investigate the diagnostic performance of perilesional biopsies (PLBx) compared to other biopsy strategies, assessing the impact of the Prostate Imaging‐Reporting and Data System (PI‐RADS) score and biopsy history in patients with a visible lesion at multiparametric magnetic resonance imaging of the prostate (mpMRI), as the European Association of Urology guidelines recommend combining MRI‐targeted biopsies (TBx) with PLBx as an alternative to systematic biopsies (SBx) even though evidence is limited. Patients and Methods We relied on a cohort of 2852 patients with PI‐RADS ≥3 lesions undergoing TBx + SBx at three tertiary referral centres. The primary outcome was detection of clinically significant PCa (csPCa) (International Society of Urological Pathology Grade Group [ISUP GG] ≥2) of TBx + PLBx vs TBx + SBx. Results were stratified by PI‐RADS score and biopsy history. The PLBx cores were defined as samples taken from prostate sectors adjacent to the mpMRI lesion. We finally assessed insignificant PCa (insPCa, i.e., ISUP GG 1) detection across biopsy strategies. Differences were assessed using the chi‐square test. Results Detection of csPCa was 48%. Overall, TBx + SBx had a higher csPCa detection rate than TBx + PLBx (50% vs 45%, P = 0.03), particularly in PI‐RADS 3 lesions (26% vs 21%, P = 0.02) and active surveillance (AS) patients (46% vs 40%, P = 0.04). No significant differences were found in PI‐RADS 4 (53% vs 50%, P > 0.1) or PI‐RADS 5 (76% vs 75%, P > 0.1). In the biopsy naïve and previous negative biopsy groups, csPCa detection was similar between strategies ( P > 0.1). Conclusions Overall, TBx + SBx offers the highest detection of csPCa. Even though TBx + PLBx may be considered in PI‐RADS 4–5 lesions to reduce insPCa detection, TBx + SBx remains the preferred strategy for PI‐RADS 3 and AS patients.
Biparametric vs Multiparametric MRI for Prostate Cancer Diagnosis
Importance Multiparametric magnetic resonance imaging (MRI), with or without prostate biopsy, has become the standard of care for diagnosing clinically significant prostate cancer. Resource capacity limits widespread adoption. Biparametric MRI, which omits the gadolinium contrast sequence, is a shorter and cheaper alternative offering time-saving capacity gains for health systems globally. Objective To assess whether biparametric MRI is noninferior to multiparametric MRI for diagnosis of clinically significant prostate cancer. Design, Setting, and Participants A prospective, multicenter, within-patient, noninferiority trial of biopsy-naive men from 22 centers (12 countries) with clinical suspicion of prostate cancer (elevated prostate-specific antigen [PSA] level and/or abnormal digital rectal examination findings) from April 2022 to September 2023, with the last follow-up conducted on December 3, 2024. Interventions Participants underwent multiparametric MRI, comprising T2-weighted, diffusion-weighted, and dynamic contrast–enhanced (DCE) sequences. Radiologists reported abbreviated biparametric MRI first (T2-weighted and diffusion-weighted), blinded to the DCE sequence. After unblinding, radiologists reported the full multiparametric MRI. Patients underwent a targeted biopsy with or without systematic biopsy if either biparametric MRI or multiparametric MRI was suggestive of clinically significant prostate cancer. Main outcomes and measures The primary outcome was the proportion of men with clinically significant prostate cancer. Secondary outcomes included the proportion of men with clinically insignificant cancer. The noninferiority margin was 5%. Results Of 555 men recruited, 490 were included for primary outcome analysis. Median age was 65 (IQR, 59-70) years and median PSA level was 5.6 (IQR, 4.4-8.0) ng/mL. The proportion of patients with abnormal digital rectal examination findings was 12.7%. Biparametric MRI was noninferior to multiparametric MRI, detecting clinically significant prostate cancer in 143 of 490 men (29.2%), compared with 145 of 490 men (29.6%) (difference, −0.4 [95% CI, −1.2 to 0.4] percentage points; P = .50). Biparametric MRI detected clinically insignificant cancer in 45 of 490 men (9.2%), compared with 47 of 490 men (9.6%) with the use of multiparametric MRI (difference, −0.4 [95% CI, −1.2 to 0.4] percentage points). Central quality control demonstrated that 99% of scans were of adequate diagnostic quality. Conclusion and relevance In men with suspected prostate cancer, provided image quality is adequate, an abbreviated biparametric MRI scan, with or without targeted biopsy, could become the new standard of care for prostate cancer diagnosis. With approximately 4 million prostate MRIs performed globally annually, adopting biparametric MRI could substantially increase scanner throughput and reduce costs worldwide. Trial registration ClinicalTrials.gov Identifier: NCT04571840
P14.55 Quantitative muscle mass biomarkers are independent prognosis factors in primary central nervous system lymphoma: the role of L3-Skeletal Muscle Index and temporal muscle thickness
Abstract BACKGROUND Appropriate patient stratification is of paramount importance in patients with primary central nervous system lymphomas (PCNSL) in order to improve therapeutic choices and to reduce treatment-related neurotoxicity. Age and performance status, two widely used prognostic indicators, may not be the most appropriate parameters for an optimal patient stratification, as age seldom reveals the true biological frailty of a patient and performance status scores are subject to inter-rater variability. Quantitative muscle biomarkers such as the skeletal-muscle-index at the third lumbar vertebra (L3-SMI) and temporal muscle thickness (TMT) are associated with worse prognosis in several oncological diseases. We aim to evaluate the role of these biomarkers in predicting survival in patients with PCNSL undergoing high-dose methotrexate-based chemotherapy. MATERIAL AND METHODS L3-SMI and TMT were calculated on abdominal CT and brain high-resolution 3D-T1-weighted-MR images, respectively, using predefined validated methods. Standardized sex-specific cut-offs were used to divide patients in different risk categories. Kaplan-Meier plots were calculated, and survival analysis was performed using log-rank tests, univariate, and multivariable Cox-regression models, calculating hazard ratios (HR) and 95% confidence intervals (CI), also adjusting for potential confounders (age, sex, and performance status). RESULTS Forty-three patients were included in this study. Median follow-up was 23 months (interquartile range 12–40); at median follow-up, rates of progression-free and overall survival for the cohort were 46% and 57%, respectively. Thirteen (30%) and 11 (26%) patients showed L3-SMI or TMT values below the predefined cut-offs. Subgroup analyses showed a significant association between quantitative muscle mass biomarkers and progression-free and overall survival. One-year progression free and overall survival rates were 8% and 21% for the 13 patients with L3-SMI below the standard cut-off value, respectively, compared to 66% and 68% for the 30 patients with L3-SMI above the cut-off values. Likewise, one-year progression free and overall survival rates were 10% and 15% for the 11 patients with low TMT, respectively, compared to 61% and 70% for the 32 patients with high TMT. In Cox-regression multivariable analysis patients with low L3-SMI or TMT showed significantly worse progression-free (HR 4.40, 95%CI 1.66–11.61, p = 0.003; HR 4.40, 95%CI 1.68–11.49, p=0.003, respectively) and overall survival (HR 3.16, 95%CI 1.09–9.11, p = 0.034; HR 4.93, 95%CI 1.78–13.65, p=0.002, respectively) compared to patients with high L3-SMI or TMT. CONCLUSION Quantitative muscle mass evaluation assessed by both L3-SMI and TMT is a promising tool to identify PCNSL patients at high risk of negative outcome. Confirmatory studies on larger independent series are warranted.
Multiparametric magnetic resonance imaging of the prostate underestimates tumour volume of small visible lesions
Objective To assess the relationship between the volume of the index lesion (IL) measured at multiparametric magnetic resonance imaging (mpMRI; MRIvol) and at radical prostatectomy (RPvol), stratifying it according to Prostate Imaging‐Reporting and Data System (PI‐RADS) score. Patients and Methods We identified 332 men with a positive mpMRI (single lesion with PI‐RADS ≥3) who underwent systematic plus targeted biopsy and subsequent RP at two tertiary referral centres between 2013 and 2018. All mpMRIs were reviewed by experienced radiologists using PI‐RADS scores. The study outcome was to assess the relationship between MRIvol (based on planimetry from MRI sequence best showing tumour) and RPvol (based on tumour involved area of each RP pathology slice). To achieve this endpoint, we performed a multivariable linear regression analysis (LRA) to predict RPvol using PI‐RADS, prostate‐specific antigen level, prostate volume, age, digital rectal examination, Gleason score at MRI‐targeted biopsy, biopsy history and time from mpMRI to RP as covariates. Non‐parametric locally estimated scatterplot smoothing (LOESS) function was used to graphically explore the relationship between MRIvol and RPvol, stratifying for PI‐RADS score. Results Overall, 24%, 49% and 27% of men had visible PI‐RADS 3, 4 and 5 lesions at mpMRI. The median (interquartile range [IQR]) MRIvol and RPvol were 0.67 (0.29–1.76) mL and 1.39 (0.58–4.23) mL. At LRA, MRIvol was significantly correlated with a RPvol underestimation (slope: 2.4, 95% confidence interval [CI] 0.1–46.3). The non‐parametric LOESS analysis showed a non‐linear relationship between MRIvol and RPvol. Significant underestimation was reported across all volumes with the highest differences between MRIvol and RPvol in the low volume range (<2 mL), where RPvol almost doubled MRIvol. A similar effect was observed across all PI‐RADS scores subgroups. Conclusions In the present study, mpMRI significantly underestimated the exact volume of the IL, especially for small visible lesions, regardless of PI‐RADS score. This should be considered when planning tailored focal therapy approaches often delivered to men with smaller prostatic lesions.