ReIMAGINE: a prostate cancer research consortium with added value through its patient and public involvement and engagement.

BACKGROUND: ReIMAGINE aims to improve the current prostate specific antigen (PSA)/biopsy risk stratification for prostate cancer (PCa) and develop a new image-based method (with biomarkers) for diagnosing high/low risk PCa in men. ReIMAGINE's varied patient and public involvement (PPI) and engagement (PE) strategy maximises the impact of its scientific output by informing and shaping the different stages of research. AIMS: Through including the voice of patients and the public, the ReIMAGINE Consortium aims to translate these different perspectives into the design and implementation process. This will improve the overall quality of the research by: reflecting the needs and priorities of patients and the public, ensuring methods and procedures are feasible and appropriate ensuring information is relevant and accessible to those being recruited to the study identifying dissemination channels relevant to patients/the public and developing outputs that are accessible to a lay audience With support from our patient/user groups, the ReIMAGINE Consortium aims to improve our ability to derive prognostic information and allocate men to the most appropriate and effective therapies, using a novel image-based risk stratification with investigation of non-imaging biomarkers. FINDINGS: We have been working with patients and the public from initiation of the project to ensure that the research is relevant to men and their families. Our PPI Sub-Committee, led by a PCa patient, has been involved in our dissemination strategy, outreach activities, and study design recommendations. For example, the sub-committee have developed a variety of informative videos relevant and accessible to those being recruited, and organised multiple online research engagement events that are accessible to a lay audience. As quoted by one of the study participants, "the more we present the benefits and opportunities to patients and the public, the more research commitment we obtain, and the sooner critical clinical questions such as PCa diagnostics will be addressed".

One in eight men will be diagnosed with prostate cancer (PCa). Most will not die of it, but our ability to identify those men whose cancer poses the greatest threat to life has, thus far, been poor. Some men are diagnosed with small cancers which will never cause them a problem, some will have treatment which is unnecessary, others will have their cancers missed, and others will be misclassified as either having low risk cancer and will therefore miss out on the appropriate treatment, or told their cancer is high risk and have unnecessary treatment. Nowhere else in modern medicine are these errors of over-diagnosis, over-treatment, missed-diagnoses, and poor risk-stratification more common. The ReIMAGINE Consortium has been developed to undertake discoveries that will correct these four key errors in the PCa diagnostic pathway. We will investigate how to best identify which men have, or will develop, aggressive prostate cancer using imaging combined with advanced biomarker analyses of blood and urine (i.e., OMICs technologies such as whole genome sequencing, targeted sequencing (e.g.: = , methylation). We will achieve this by building on established partnerships between patients, advocacy organisations, clinicians, imaging experts, molecular biologists, methodologists, and a broad range of industrial partners.The Patient and Public Involvement (PPI) sub-committee is an integral part of the study workflow, contributing to study design and recruitment, results analysis, and dissemination. The committee, led by a funded PPI co-ordinator and a patient chair, have given invaluable insight into the study modifications due to COVID-19 restrictions.

Introduction to the National Cancer Imaging Translational Accelerator (NCITA): a UK-wide infrastructure for multicentre clinical translation of cancer imaging biomarkers.

The National Cancer Imaging Translational Accelerator (NCITA) is creating a UK national coordinated infrastructure for accelerated translation of imaging biomarkers for clinical use. Through the development of standardised protocols, data integration tools and ongoing training programmes, NCITA provides a unique scalable infrastructure for imaging biomarker qualification using multicentre clinical studies.

Similarities and differences between Likert and PIRADS v2.1 scores of prostate multiparametric MRI: a pictorial review of histology-validated cases.

The UK National Institute for Health and Care Excellence (NICE) 2019 "Prostate cancer: diagnosis and management" guidelines have recommended that all patients suspected of prostate cancer undergo multiparametric magnetic resonance imaging (mpMRI) prior to biopsy. The Likert scoring system is advocated for mpMRI reporting based on multicentre studies that have demonstrated its effectiveness within the National Health Service (NHS). In recent years, there has been considerable drive towards standardised prostate reporting, which led to the development of "Prostate Imaging-Reporting And Data System" (PI-RADS). The PI-RADS system has been adopted by the majority of European countries and within the US. This paper reviews these systems indicating the similarities and specific differences that exist between PI-RADS and Likert assessment through a series of histologically proven clinical cases.

Intratumoural evolutionary landscape of high-risk prostate cancer: the PROGENY study of genomic and immune parameters.

BACKGROUND: Intratumoural heterogeneity (ITH) is well recognised in prostate cancer (PC), but its role in high-risk disease is uncertain. A prospective, single-arm, translational study using targeted multiregion prostate biopsies was carried out to study genomic and T-cell ITH in clinically high-risk PC aiming to identify drivers and potential therapeutic strategies. PATIENTS AND METHODS: Forty-nine men with elevated prostate-specific antigen and multiparametric-magnetic resonance imaging detected PC underwent image-guided multiregion transperineal biopsy. Seventy-nine tumour regions from 25 patients with PC underwent sequencing, analysis of mutations, copy number and neoepitopes combined with tumour infiltrating T-cell subset quantification. RESULTS: We demonstrated extensive somatic nucleotide variation and somatic copy number alteration heterogeneity in high-risk PC. Overall, the mutational burden was low (0.93/Megabase), but two patients had hypermutation, with loss of mismatch repair (MMR) proteins, MSH2 and MSH6. Somatic copy number alteration burden was higher in patients with metastatic hormone-naive PC (mHNPC) than in those with high-risk localised PC (hrlPC), independent of Gleason grade. Mutations were rarely ubiquitous and mutational frequencies were similar for mHNPC and hrlPC patients. Enrichment of focal 3q26.2 and 3q21.3, regions containing putative metastasis drivers, was seen in mHNPC patients. We found evidence of parallel evolution with three separate clones containing activating mutations of ß-catenin in a single patient. We demonstrated extensive intratumoural and intertumoural T-cell heterogeneity and high inflammatory infiltrate in the MMR-deficient (MMRD) patients and the patient with parallel evolution of ß-catenin. Analysis of all patients with activating Wnt/ß-catenin mutations demonstrated a low CD8+/FOXP3+ ratio, a potential surrogate marker of immune evasion. CONCLUSIONS: The PROGENY (PROstate cancer GENomic heterogeneitY) study provides a diagnostic platform suitable for studying tumour ITH. Genetic aberrations in clinically high-risk PC are associated with altered patterns of immune infiltrate in tumours. Activating mutations of Wnt/ß-catenin signalling pathway or MMRD could be considered as potential biomarkers for immunomodulation therapies. CLINICAL TRIALS.GOV IDENTIFIER: NCT02022371.

Measurement of liver and spleen interstitial volume in patients with systemic amyloid light-chain amyloidosis using equilibrium contrast CT.

OBJECTIVES: To investigate equilibrium contrast-enhanced CT (EQ-CT) measurement of extracellular volume fraction (ECV) in patients with systemic amyloid light-chain (AL) amyloidosis, testing the hypothesis that ECV becomes elevated in the liver and spleen and ECV correlates with other estimates of organ amyloid burden. METHODS: 26 patients with AL amyloidosis underwent EQ-CT, and ECV was measured in the liver and spleen. Patients also underwent serum amyloid P (SAP) component scintigraphy with grading of liver and spleen involvement. Mann-Whitney U test was used to test for a difference between patients with amyloid deposition (SAP grade 1-3) and those without (SAP grade 0). Variation in ECV across SAP grades was assessed using the Kruskal-Wallis test and association between ECV and SAP grades with Spearman correlation. RESULTS: Mean ECV in the spleen and liver was significantly greater (p < 0.0005) in amyloidotic organs (SAP grade 1-3) [spleen, liver: 0.430, 0.375] compared with healthy tissues [spleen, liver: 0.304, 0.269]. ECV increased with increasing amyloid burden, showing positive correlation with SAP grade in both the liver (r = 0.758) and spleen (r = 0.867). CONCLUSION: In patients with systemic AL amyloidosis, EQ-CT can demonstrate increased spleen and liver ECV, which is associated with amyloid disease burden.

Magnetic resonance imaging targeted transperineal prostate biopsy: a local anaesthetic approach.

BACKGROUND: Despite high rates of disease misclassification and sepsis, the use of transrectal biopsy remains commonplace. Transperineal mapping biopsies mitigate these problems but carry increased cost and patient burden. Local anaesthetic, multiparametric magnetic resonance imaging (MRI)-targeted transperineal biopsy may offer an alternative. Here, we aim to determine the feasibility, tolerability and detection rates of clinically significant prostate cancer using a local anaesthetic, transperineal, MRI-targeted biopsy technique. METHODS: Tertiary referral centre in which 181 consecutive men underwent local anaesthetic, transperineal MRI-targeted prostate biopsy (September 2014 to January 2016). A standardized local anaesthetic technique was used to obtain targeted biopsies using visual estimation with the number of targeted cores determined by each of a number of users. We assessed adverse events, patient visual analogue pain scores and detection rates of clinically significant cancer (defined by University College London (UCL) definitions one and two and separately by the presence of dominant and non-dominant Gleason pattern 4). We secondarily assessed detection of any cancer, rates of detection by MRI (Likert) score and by presenting PSA. Differences were assessed using Chi-squared tests (P<0.05). RESULTS: One hundred eighty-one men with 243 lesions were included. There were no episodes of sepsis or re-admissions and one procedure was abandoned owing to patient discomfort. Twenty-three out of 25 (92%) men would recommend the procedure to another. Median visual analogue pain score was 1.0 (interquartile range: 0.0-2.4). A total 104/181 (57%) had UCL definition 1 disease (Gleason ⩾4+3 and/or maximum cancer length ⩾6 mm) and 129/181 (71%) had UCL definition 2 cancer (Gleason ⩾3+4 and/or maximum cancer length ⩾4 mm). Fifty-four out of 181 (30%) and 124/181 (69%) had dominant and non-dominant pattern 4 disease or greater (irrespective of cancer length). Any cancer was detected in 142/181 (78%). Significant disease was more likely in higher MRI-scoring lesions and in men with PSAs ⩾10 ng ml-1. CONCLUSIONS: This approach to prostate biopsy is feasible, tolerable and can be performed in ambulatory settings.

Transperineal Magnetic Resonance Imaging-targeted Biopsy versus Transperineal Template Prostate Mapping Biopsy in the Detection of Localised Radio-recurrent Prostate Cancer.

AIMS: Multi-parametric magnetic resonance imaging (mpMRI) may identify radio-recurrent intra-prostatic cancer accurately. We aimed to compare visually directed MRI-targeted biopsies (MRI-TB) to an accurate reference standard - transperineal prostate mapping (TPM) biopsies with 5 mm sampling - in the detection of clinically significant cancer in men with biochemical failure after radiotherapy. MATERIALS AND METHODS: A retrospective registry analysis between 2006 and 2014 identified 77 men who had undergone mpMRI followed by MRI-TB and TPM. Clinical significance was set at two definitions of disease. Definition 1 was Gleason ≥ 4+3 and/or maximum cancer core length ≥ 6 mm. Definition 2 was Gleason ≥ 3+4 and/or maximum cancer core length ≥ 4 mm. RESULTS: Of the 77 patients included, the mean age was 70 years (range 61-82; standard deviation 5.03). The median prostate-specific antigen (PSA) at the time of external beam radiotherapy (EBRT) was 14 ng/ml (interquartile range 7.83-32.50). The most frequent EBRT dose given was 74 Gy over 37 fractions. Eight patients had iodine-seed implant brachytherapy or high dose rate brachytherapy. Neoadjuvant/adjuvant hormonal therapy use was reported in 38. The time from EBRT to biochemical recurrence was a median of 60 months (interquartile range 36.75-85.00). The median PSA at the time of mpMRI was 4.68 ng/ml (interquartile range 2.68-7.60). The median time between mpMRI and biopsy was 2.76 months (interquartile range 1.58-4.34). In total, 2392 TPM and 381 MRI-TB cores were taken with 18% and 50% cancer detection, respectively. Detection rates of definition 1 clinically significant cancer were 52/77 (68%) versus 55/77 (71%) for MRI-TB and TPM, respectively. MRI-TB was more efficient requiring 1 core versus 2.8 cores to detect definition 2 cancer. CONCLUSION: MRI-TB seems to have encouraging detection rates for clinically significant cancer with fewer cores compared with TPM, although TPM had higher detection rates for smaller lower grade lesions.

Evolution of multi-parametric MRI quantitative parameters following transrectal ultrasound-guided biopsy of the prostate.

BACKGROUND: To determine the evolution of prostatic multi-parametric magnetic resonance imaging (mp-MRI) signal following transrectal ultrasound (TRUS)-guided biopsy. METHODS: Local ethical permission and informed written consent was obtained from all the participants (n=14, aged 43-69, mean 64 years). Patients with a clinical suspicion of prostate cancer (PSA range 2.2-11.7, mean 6.2) and a negative (PIRAD 1-2/5) pre-biopsy mp-MRI (pre-contrast T1, T2, diffusion-weighted and dynamic-contrast-enhanced MRI) who underwent 10-core TRUS-guided biopsy were recruited for additional mp-MRI examinations performed at 1, 2 and 6 months post biopsy. We quantified mp-MRI peripheral zone (PZ) and transition zone (TZ) normalized T2 signal intensity (nT2-SI); T1 relaxation time (T10); diffusion-weighted MRI, apparent diffusion coefficient (ADC); dynamic contrast-enhanced MRI, maximum enhancement (ME); slope of enhancement (SoE) and area-under-the-contrast-enhancement-curve at 120 s (AUC120). Significant changes in mp-MRI parameters were identified by analysis of variance with Dunnett's post testing. RESULTS: Diffuse signal changes were observed post-biopsy throughout the PZ. No significant signal change occurred following biopsy within the TZ. Left and right PZ mean nT2-SI (left PZ: 5.73, 5.16, 4.90 and 5.12; right PZ: 5.80, 5.10, 4.84 and 5.05 at pre-biopsy, 1, 2 and 6 months post biopsy, respectively) and mean T10 (left PZ: 1.02, 0.67, 0.78, 0.85; right PZ: 1.29, 0.64, 0.78, 0.87 at pre-biopsy, 1, 2 and 6 months post biopsy, respectively) were reduced significantly (P<0.05) from pre-biopsy values for up to 6 months post biopsy. Significant changes (P<0.05) of PZ-ME and AUC120 were observed at 1 month but resolved by 2 months post biopsy. PZ ADC did not change significantly following biopsy (P=0.23-1.0). There was no significant change of any TZ mp-MRI parameter at any time point following biopsy (P=0.1-1.0). CONCLUSIONS: Significant PZ (but not TZ) T2 signal changes persist up to 6 months post biopsy, whereas PZ and TZ ADC is not significantly altered as early as 1 month post biopsy. Caution must be exercised when interpreting T1- and T2-weighted imaging early post biopsy, whereas ADC images are more likely to maintain clinical efficacy.

The FORECAST study - Focal recurrent assessment and salvage treatment for radiorecurrent prostate cancer.

BACKGROUND: One-third of men may experience biochemical failure by 8years following radical radiotherapy for localised prostate cancer. Over 90% of men are started on androgen deprivation therapy (ADT) which is non-curative and confers systemic side-effects. Focal salvage therapy (FST) limits collateral tissue damage and may improve therapeutic ratios. In order to deliver FST, distant disease must be ruled-out and intra-prostatic disease must be accurately detected, localised and characterised. AIM: FORECAST - Focal Recurrent Assessment and Salvage Treatment - is a study designed to evaluate a novel imaging-based diagnostic and therapeutic complex intervention pathway for men who fail radiotherapy. METHODS: Men with biochemical failure following radical prostate radiotherapy, prior to salvage therapy will be recruited. They will undergo whole-body multi-parametric MRI (WB-MRI), choline PET/CT, bone-scan and pelvic-mpMRI and then MRI transperineal-targeted biopsies (MRI-TB) and Transperineal Template Prostate Mapping Biopsy (TPM). Those suitable for FST will undergo either high intensity focused ultrasound (HIFU) or cryotherapy. RESULTS: Primary outcome measures: a) the accuracy of WB-MRI to detect distant metastatic disease; b) accuracy of prostate mpMRI in local detection of radiorecurrent prostate cancer; c) detection accuracy of MRI-TB; and d) rate of urinary incontinence following FST. CONCLUSION: Focal salvage therapy may confer lower rates of morbidity whilst retaining disease control. In order to deliver FST, intra- and extra-prostatic disease must be detected early and localised accurately. Novel diagnostic techniques including WB-MRI and MRI-TB may improve the detection of distant and local disease whilst reducing healthcare burdens compared with current imaging and biopsy strategies.

Multiparametric MRI for detection of radiorecurrent prostate cancer: added value of apparent diffusion coefficient maps and dynamic contrast-enhanced images.

BACKGROUND: Multiparametric magnetic resonance imaging (mp-MRI) is increasingly advocated for prostate cancer detection. There are limited reports of its use in the setting of radiorecurrent disease. Our aim was to assess mp-MRI for detection of radiorecurrent prostate cancer and examine the added value of its functional sequences. METHODS: Thirty-seven men with mean age of 69.7 (interquartile range, 66-74) with biochemical failure after external beam radiotherapy underwent mp-MRI (T2-weighted, high b-value, multi-b-value apparent diffusion coefficient (ADC) and dynamic contrast-enhanced (DCE) imaging); then transperineal systematic template prostate mapping (TPM) biopsy. Using a locked sequential read paradigm (with the sequence order above), two experienced radiologists independently reported mp-MRI studies using score 1-5. Radiologist scores were matched with TPM histopathology at the hemigland level (n=74). Accuracy statistics were derived for each reader. Interobserver agreement was evaluated using kappa statistics. RESULTS: Receiver-operator characteristic area under curve (AUC) for readers 1 and 2 increased from 0.67 (95% confidence interval (CI), 0.55-0.80) to 0.80 (95% CI, 0.69-0.91) and from 0.67 (95% CI, 0.55-0.80) to 0.84 (95% CI, 0.76-0.93), respectively, between T2-weighted imaging alone and full mp-MRI reads. Addition of ADC maps and DCE imaging to the examination did not significantly improve AUC for either reader (P=0.08 and 0.47 after adding ADC, P=0.90 and 0.27 after adding DCE imaging) compared with T2+high b-value review. Inter-reader agreement increased from k=0.39 to k=0.65 between T2 and full mp-MRI review. CONCLUSIONS: mp-MRI can detect radiorecurrent prostate cancer. The optimal examination included T2-weighted imaging and high b-value DWI; adding ADC maps and DCE imaging did not significantly improve the diagnostic accuracy.

The use of molecular imaging combined with genomic techniques to understand the heterogeneity in cancer metastasis.

Tumour heterogeneity has, in recent times, come to play a vital role in how we understand and treat cancers; however, the clinical translation of this has lagged behind advances in research. Although significant advancements in oncological management have been made, personalized care remains an elusive goal. Inter- and intratumour heterogeneity, particularly in the clinical setting, has been difficult to quantify and therefore to treat. The histological quantification of heterogeneity of tumours can be a logistical and clinical challenge. The ability to examine not just the whole tumour but also all the molecular variations of metastatic disease in a patient is obviously difficult with current histological techniques. Advances in imaging techniques and novel applications, alongside our understanding of tumour heterogeneity, have opened up a plethora of non-invasive biomarker potential to examine tumours, their heterogeneity and the clinical translation. This review will focus on how various imaging methods that allow for quantification of metastatic tumour heterogeneity, along with the potential of developing imaging, integrated with other in vitro diagnostic approaches such as genomics and exosome analyses, have the potential role as a non-invasive biomarker for guiding the treatment algorithm.

Clinical and research applications of simultaneous positron emission tomography and MRI.

Evaluation of the molecular processes responsible for disease pathogenesis and progression represents the new frontier of clinical radiology. Multimodality imaging lies at the cutting edge, combining the power of MRI for tissue characterization, microstructural appraisal and functional assessment together with new positron emission tomography (PET) tracers designed to target specific metabolic processes. The recent commercial availability of an integrated clinical whole-body PET-MRI provides a hybrid platform for exploring and exploiting the synergies of multimodal imaging. First experiences on the clinical and research application of hybrid PET-MRI are emerging. This article reviews the rapidly evolving field and speculates on the potential future direction.

Role of focal salvage ablative therapy in localised radiorecurrent prostate cancer.

Up to one-third of men can fail radical external beam radiotherapy for primary prostate cancer. Most of these men have expectant management with delayed hormones. However, around half of these men have localised recurrence. Challenges remain in identifying such men accurately, in order to enable them to undergo local salvage therapy which is potentially curative. Currently, this includes radical prostatectomy, brachytherapy and ablative whole-gland therapies, such as cryotherapy and high intensity focused ultrasound, all of which can carry significant morbidity. New approaches may involve targeting the area of recurrence alone--focal salvage therapy--in order to reduce tissue damage and thus reduce morbidity. This requires accurate localisation of intraprostatic recurrent disease and precision targeted ablation.

Small bowel strictures in Crohn's disease: a quantitative investigation of intestinal motility using MR enterography.

BACKGROUND: Intestinal stricturing and aberrant small bowel motility are common complications in patients with Crohn's disease (CD) leading to significant morbidity. A retrospective study was performed quantifying small bowel motility within and upstream of strictures in CD patients using magnetic resonance enterography (MRE). METHODS: A total of 91 subjects with stricturing CD (mean age 36 range 18-88) and undergoing MRE with dynamic motility imaging were identified. Of this cohort, 84 subjects were scanned at 1.5 T field strength with the remainder at 3 T. Linear regions of interest (ROI) were placed at the stricture, immediately upstream of the stricture, and in a proximal normal segment of bowel. Maximum bowel calibre (mm) and motility (Arbitrary units) at each ROI were calculated using previously validated software. Diameters and motility were compared using repeat measures anova and diameter correlated with motility score. In 21 subjects with follow-up MRE, ROIs were duplicated and percentage diameter and motility change across the two time points correlated. KEY RESULTS: Mean diameter within the normal, prestricture and strictured bowel was 20, 30, and 15 mm (p < 0.001) with motility score 0.43, 0.28, and 0.15 AU, respectively (p < 0.001). There was a negative correlation between prestricture bowel diameter and motility (Pearson's R = -0.47, p < 0.001). For patients with follow-up MRE, there was a negative correlation between percentage change in prestricture diameter and motility, Spearman's Rho -0.6 p = 0.007. CONCLUSIONS & INFERENCES: Quantified small bowel motility during MRE differs significantly between normal, prestricture, and strictured bowel. As prestricture bowel dilates, motility decreases, although this appears reversible in some.

Prostate MRI: who, when, and how? Report from a UK consensus meeting.

The current pathway for men suspected of having prostate cancer [transrectal biopsy, followed in some cases by magnetic resonance imaging (MRI) for staging] results in over-diagnosis of insignificant tumours, and systematically misses disease in the anterior prostate. Multiparametric MRI has the potential to change this pathway, and if performed before biopsy, might enable the exclusion of significant disease in some men without biopsy, targeted biopsy in others, and improvements in the performance of active surveillance. For the potential benefits to be realized, the setting of standards is vital. This article summarizes the outcome of a meeting of UK radiologists, at which a consensus was achieved on (1) the indications for MRI, (2) the conduct of the scan, (3) a method and template for reporting, and (4) minimum standards for radiologists.

Quantitative MRI of colonic mural enhancement: segmental differences exist in endoscopically proven normal colon.

OBJECTIVES: Abnormal contrast enhancement on MRI is advocated as a biomarker for inflammation in colitis, although the enhancement kinetics of normal colon are poorly described. Our purpose was to quantitatively assess mural enhancement in normal colon and test for intersegmental differences. METHODS: Eight patients without prior history of inflammatory bowel disease underwent standard MRI colonography followed by normal same-day colonoscopy. Acquired sequences included a volumetric interpolated breath-hold examination (VIBE) to encompass the whole colonic volume, performed at 5°, 10° and 35° flip angles for T(1) quantitation and then at a fixed 35° flip angle three times prior to and every 30 s following intravenous gadoterate meglumine for 220 s. Ascending colon, descending colon and rectal R(1) (1/T(1)) was plotted against time. Mean pre-contrast R(1), initial change of R(1) (ΔR(1)), early and late "plateau phase" enhancement and the area under the R(1)-time (AUC-R(1)) curve were compared between segments using the Student's paired t-test. RESULTS: There was no significant difference of pre-contrast R(1) between segments (p=0.49 to 0.62). ΔR(1) was higher for ascending colon compared with descending colon (0.0023±0.0012 ms(-1) vs 0.0010±0.0011 ms(-1), p=0.03). There was no significant difference for early or late plateau phase R(1) between colonic segments (p=0.08 to 1.00). AUC-R(1) was greater for ascending than descending colon (0.54±0.19 vs 0.30±0.14, p=0.03). CONCLUSIONS: Intersegmental differences in colonic enhancement are present and should be considered when interpreting differential segmental enhancement.

Prostatic cancer surveillance following whole-gland high-intensity focused ultrasound: comparison of MRI and prostate-specific antigen for detection of residual or recurrent disease.

OBJECTIVE: This retrospective study compares dynamic contrast-enhanced (DCE) MRI with the serial prostate-specific antigen (PSA) measurement for detection of residual disease following whole-gland high-intensity focused ultrasound (HIFU) therapy of prostate cancer. METHODS: Patients in whom post-HIFU DCE-MRI was followed within 3 months by ultrasound-guided transrectal biopsy were selected from a local database. 26 patients met the study inclusion criteria. Serial PSA levels following HIFU and post-HIFU follow-up MRI were retrieved for each patient. Three radiologists unaware of other investigative results independently assessed post-HIFU MRI studies for the presence of cancer, scoring on a four-point scale (1, no disease; 2, probably no disease; 3, probably residual disease; and 4, residual disease). Sensitivity, specificity and receiver operating characteristic (ROC) analysis were performed for each reader, post-HIFU PSA nadir and pre-biopsy PSA level thresholds of >0.2 and >0.5 ng ml(-1). RESULTS: The sensitivity of DCE-MRI for detection of residual disease for the three readers ranged between 73% and 87%, and the specificity between 73% and 82%. There was good agreement between readers (κ = 0.69-0.77). The sensitivity and specificity of PSA thresholds was 60-87% and 73-100%, respectively. The area under the ROC curve was greatest for pre-biopsy PSA (0.95). CONCLUSION: DCE-MRI performed following whole-gland HIFU has similar sensitivity and specificity and ROC performance to serial PSA measurements for detection of residual or recurrent disease.