Is Likert better than PI-RADS at predicting prostate cancer on MRI and can a mathematical algorithm achieve similar results?

BACKGROUND: Prostate Imaging Reporting & Data System (PI-RADS) is an internationally recognized system to quantify risk of prostate cancer on magnetic resonance imaging (MRI). However, studies have suggested methods to improve predictive accuracy. PURPOSE: To assess two different methods that aim to improve the accuracy of PI-RADS scores: a subjective Likert score given by experienced reporters, and an objective Calculated Adjustment of PI-RADS Equivocal Score (CAPES). MATERIAL AND METHODS: Five experienced reporters in a quaternary referral unit used a standardized reporting template to prospectively collect PI-RADS and Likert scores for 1467 multiparametric MRI (mpMRI) scans between January 2021 and June 2022. Histology results were recorded for patients who underwent trans-perineal biopsy. The CAPES tool was retrospectively applied to the cases scoring PI-RADS 3. A theoretical standardized biopsy protocol (assuming all patients scoring ≥3 were referred for biopsy) was used to compare the three scoring systems for sensitivity, specificity, and positive predictive value (PPV). RESULTS: Across all reporters, significantly fewer equivocal "3" scores were given using Likert (15.7%) or CAPES (2.2%) compared to PI-RADS (24.1%). Assuming a protocol where all patients scoring ≥3 were biopsied, Likert had a higher specificity (69.0% vs. 54.4%), sensitivity (98.3% vs. 97.7%), and PPV (49.9% vs. 40.3%) than PI-RADS for identifying ISUP ≥2 cancer. The CAPES tool had an even higher specificity (81.4%) and PPV (61.2%) with only a slightly lower sensitivity (93.4%) resulting in 37.1% (n = 316) fewer biopsies than PI-RADS, and 22.4% (n = 155) fewer biopsies than Likert across 1467 patients. CONCLUSIONS: Compared to PI-RADS scoring, Likert scoring or CAPES can result in fewer equivocal scores, greater PPV, and fewer unnecessary biopsies.

Prediction of prostate tumour hypoxia using pre-treatment MRI-derived radiomics: preliminary findings.

PURPOSE: To develop a machine learning (ML) model based on radiomic features (RF) extracted from whole prostate gland magnetic resonance imaging (MRI) for prediction of tumour hypoxia pre-radiotherapy. MATERIAL AND METHODS: Consecutive patients with high-grade prostate cancer and pre-treatment MRI treated with radiotherapy between 01/12/2007 and 1/08/2013 at two cancer centres were included. Cancers were dichotomised as normoxic or hypoxic using a biopsy-based 32-gene hypoxia signature (Ragnum signature). Prostate segmentation was performed on axial T2-weighted (T2w) sequences using RayStation (v9.1). Histogram standardisation was applied prior to RF extraction. PyRadiomics (v3.0.1) was used to extract RFs for analysis. The cohort was split 80:20 into training and test sets. Six different ML classifiers for distinguishing hypoxia were trained and tuned using five different feature selection models and fivefold cross-validation with 20 repeats. The model with the highest mean validation area under the curve (AUC) receiver operating characteristic (ROC) curve was tested on the unseen set, and AUCs were compared via DeLong test with 95% confidence interval (CI). RESULTS: 195 patients were included with 97 (49.7%) having hypoxic tumours. The hypoxia prediction model with best performance was derived using ridge regression and had a test AUC of 0.69 (95% CI: 0.14). The test AUC for the clinical-only model was lower (0.57), but this was not statistically significant (p = 0.35). The five selected RFs included textural and wavelet-transformed features. CONCLUSION: Whole prostate MRI-radiomics has the potential to non-invasively predict tumour hypoxia prior to radiotherapy which may be helpful for individualised treatment optimisation.

European survey of imaging in non-accidental injury demonstrates a need for a consensus protocol.

BACKGROUND: Paediatric non-accidental injury is a considerable health problem, and imaging plays a fundamental role in its assessment. Since the introduction of joint guidelines published by the Royal College of Radiologists (RCR) and Royal College of Paediatrics and Child Health (RCPCH) in 2008, there has been a concerted effort to adopt a consensus approach to imaging in this area in the United Kingdom. OBJECTIVE: This study aims to establish current practice amongst European Society of Paediatric Radiology (ESPR) members within their institutions with regards to the use of imaging in suspected non-accidental injury. MATERIALS AND METHODS: A web-based survey was created and circulated to all active ESPR members. The responses were collated and analysed. RESULTS: We received 134 responses, accounting for 37% of the current membership across 24 European countries. These responses highlighted significant variation amongst institutions, with no consensus regarding radiographic and cross-sectional imaging in the investigation of suspected non-accidental injury. CONCLUSION: There is a need for a European consensus protocol to imaging in suspected non-accidental injury. We recommend implementing the joint RCR/RCPCH guidance, a move supported by the ESPR.

Does including histological outcomes in a multiparametric MRI report improve prostate biopsy decision making?

OBJECTIVES: To see if inserting audited histological outcome data for each Likert score into prostate mpMRI reports was helpful for clinicians counselling patients and influenced prostate biopsy uptake. METHODS: A single radiologist reported 791 mpMRI scans for query prostate cancer between 2017 and 2019. A structured template which included histological outcome data from this cohort was devised and included in 207 mpMRI reports between January and June 2021. The outcomes of the new cohort were compared with the historical cohort, and with 160 contemporaneous reports without histological outcome data from the four other radiologists in the department. The opinion of this template was sought from referring clinicians who counselled patients. RESULTS: The proportion of patients biopsied fell from 58.0 to 32.9% overall between the n = 791 cohort and the n = 207 cohort. This was most noticeable in those scoring Likert 3, where the proportion biopsied fell from 78.4 to 42.9%. This reduction was also seen when comparing the biopsy rates of patients scored Likert 3 by other reporters in a contemporaneous n = 160 cohort without the audit information (65.2%) with the n = 207 cohort (42.9%). 100% of counselling clinicians were in favour and 66.7% said it gave them greater confidence to advise the patient when they did not need a biopsy. CONCLUSION: Fewer low-risk patients choose unnecessary biopsies when audited histological outcomes for the radiologist's Likert scores are included in mpMRI reports. ADVANCES IN KNOWLEDGE: Clinicians welcome reporter-specific audit information in mpMRI reports which could result in fewer biopsies.

A real-world study evaluating ultrasound-guided percutaneous non-targeted liver biopsy needle failures and pathology sample-quality assessment in both end-cut and side-notch needles.

OBJECTIVES: To determine biopsy device failures, causative factors, complications and sample quality of the 16G end-cut Biopince™ and side-notch Bard™ needles. METHODS: All ultrasound-guided non-targeted liver biopsies between 01/01/2016 and 31/12/2018 were included. Operator, device, number of failures, complications and repeat biopsies were recorded. Histopathology samples were reviewed for all cases of needle failure and a group with no failures, and graded "yes/no" for the presence of steatosis, inflammation and fibrosis. The pathology slides from these cases were reviewed to assess biopsy sample quality (length and portal tract number). The failure and no-failure groups were compared in terms of device type/histology, and sample quality was compared between the needle types. RESULTS: 1004 patients were included. 93.8% (n = 942) required one needle pass to obtain a sample and 6.2% (n = 62) required >1 pass due to needle failure. Total of 76 needle failures, more with end-cut than side-notch needles (8.7% vs 2.9%) (p < 0.001). No needle failures resulted in complication. The presence of liver fibrosis was associated with fewer needle failures (p = 0.036). The major complication rate was 0.4% (4/1044). A biopsy with >10 portal tracts was obtained in 90.2% of specimens > 20 mm long, compared with 66% of 16-20 mm biopsies and 21% of <16 mm biopsies. The target of >10 portal tracts was achieved in 10/26 (38.5%) of side-notch biopsies and 64/90 (71.1%) of end-cut biopsies (p = 0.004). CONCLUSION: Ultrasound-guided liver biopsy is safe and sample quality is consistently good when a core >20 mm long is obtained. The end-cut biopsy device generated reliably good quality biopsy samples; however, the needle failure rate was significantly higher than the side-cut needle. ADVANCES IN KNOWLEDGE: Ultrasound-guided liver biopsy specimen quality is consistently good when a core >20 mm long is obtained which can be achieved with a single pass using the 16G BiopinceTM end-cut needle, although the needle failure rate is significantly higher than the 16G Max-Core™ Bard™ side-notch needle.

Efficacy and toxicity outcomes for patients treated with focal salvage high dose rate brachytherapy for locally recurrent prostate cancer.

INTRODUCTION: Isolated local recurrence of prostate cancer following primary radiotherapy or brachytherapy may be treated with focal salvage high dose rate brachytherapy, although there remains an absence of high quality evidence to support this approach. METHODS: Men with prostate cancer treated consecutively between 2015 and 2018 using 19 Gy in a single fraction high dose rate brachytherapy (HDR) for locally recurrent prostate cancer were identified from an institutional database. Univariable analysis was performed to evaluate the relationship between patient, disease and treatment factors with biochemical progression free survival (bPFS). RESULTS: 43 patients were eligible for evaluation. Median follow up duration was 26 months (range 1-60). Median bPFS was 35 months (95% confidence interval 25.6-44.4). Kaplan-Meier estimates for bPFS at 1, 2 and 3 years post salvage were 95.2%, 70.6% and 41.8% respectively. On univariable Cox regression analysis, only nadir PSA was significantly associated with bPFS although the majority of patients were also treated with androgen deprivation therapy. Only one late grade 3 genitourinary toxicity was observed. CONCLUSION: Focal salvage HDR brachytherapy may provide good biochemical control with a low risk of severe toxicity. Further evaluation within clinical trials are needed to establish its role in the management of locally recurrent prostate cancer.

A comparison of outcomes for patients with intermediate and high risk prostate cancer treated with low dose rate and high dose rate brachytherapy in combination with external beam radiotherapy.

INTRODUCTION: There is evidence to support use of external beam radiotherapy (EBRT) in combination with both low dose rate brachytherapy (LDR-EBRT) and high dose rate brachytherapy (HDR-EBRT) to treat intermediate and high risk prostate cancer. METHODS: Men with intermediate and high risk prostate cancer treated using LDR-EBRT (treated between 1996 and 2007) and HDR-EBRT (treated between 2007 and 2012) were identified from an institutional database. Multivariable analysis was performed to evaluate the relationship between patient, disease and treatment factors with biochemical progression free survival (bPFS). RESULTS: 116 men were treated with LDR-EBRT and 171 were treated with HDR-EBRT. At 5 years, bPFS was estimated to be 90.5% for the LDR-EBRT cohort and 77.6% for the HDR-EBRT cohort. On multivariable analysis, patients treated with HDR-EBRT were more than twice as likely to experience biochemical progression compared with LDR-EBRT (HR 2.33, 95% CI 1.12-4.07). Patients with Gleason ≥8 disease were more than five times more likely to experience biochemical progression compared with Gleason 6 disease (HR 5.47, 95% CI 1.26-23.64). Cumulative incidence of ≥grade 3 genitourinary and gastrointestinal toxicities for the LDR-EBRT and HDR-EBRT cohorts were 8% versus 4% and 5% versus 1% respectively, although these differences did not reach statistical significance. CONCLUSION: LDR-EBRT may provide more effective PSA control at 5 years compared with HDR-EBRT. Direct comparison of these treatments through randomised trials are recommended to investigate this hypothesis further.