The Role of Multiparametric MRI and MRI-targeted Biopsy in the Diagnosis of Radiorecurrent Prostate Cancer: An Analysis from the FORECAST Trial.

BACKGROUND: The role of multiparametric magnetic resonance imaging (MRI) for detecting recurrent prostate cancer after radiotherapy is unclear. OBJECTIVE: To evaluate MRI and MRI-targeted biopsies for detecting intraprostatic cancer recurrence and planning for salvage focal ablation. DESIGN, SETTING, AND PARTICIPANTS: FOcal RECurrent Assessment and Salvage Treatment (FORECAST; NCT01883128) was a prospective cohort diagnostic study that recruited 181 patients with suspected radiorecurrence at six UK centres (2014 to 2018); 144 were included here. INTERVENTION: All patients underwent MRI with 5 mm transperineal template mapping biopsies; 84 had additional MRI-targeted biopsies. MRI scans with Likert scores of 3 to 5 were deemed suspicious. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: First, the diagnostic accuracy of MRI was calculated. Second, the pathological characteristics of MRI-detected and MRI-undetected tumours were compared using the Wilcoxon rank sum test and chi-square test for trend. Third, four biopsy strategies involving an MRI-targeted biopsy alone and with systematic biopsies of one to two other quadrants were studied. Fisher's exact test was used to compare MRI-targeted biopsy alone with the best other strategy for the number of patients with missed cancer and the number of patients with cancer harbouring additional tumours in unsampled quadrants. Analyses focused primarily on detecting cancer of any grade or length. Last, eligibility for focal therapy was evaluated for men with localised (≤T3bN0M0) radiorecurrent disease. RESULTS AND LIMITATIONS: Of 144 patients, 111 (77%) had cancer detected on biopsy. MRI sensitivity and specificity at the patient level were 0.95 (95% confidence interval [CI] 0.92 to 0.99) and 0.21 (95% CI 0.07 to 0.35), respectively. At the prostate quadrant level, 258/576 (45%) quadrants had cancer detected on biopsy. Sensitivity and specificity were 0.66 (95% CI 0.59 to 0.73) and 0.54 (95% CI 0.46 to 0.62), respectively. At the quadrant level, compared with MRI-undetected tumours, MRI-detected tumours had longer maximum cancer core length (median difference 3 mm [7 vs 4 mm]; 95% CI 1 to 4 mm, p < 0.001) and a higher grade group (p = 0.002). Of the 84 men who also underwent an MRI-targeted biopsy, 73 (87%) had recurrent cancer diagnosed. Performing an MRI-targeted biopsy alone missed cancer in 5/73 patients (7%; 95% CI 3 to 15%); with additional systematic sampling of the other ipsilateral and contralateral posterior quadrants (strategy 4), 2/73 patients (3%; 95% CI 0 to 10%) would have had cancer missed (difference 4%; 95% CI -3 to 11%, p = 0.4). If an MRI-targeted biopsy alone was performed, 43/73 (59%; 95% CI 47 to 69%) patients with cancer would have harboured undetected additional tumours in unsampled quadrants. This reduced but only to 7/73 patients (10%; 95% CI 4 to 19%) with strategy 4 (difference 49%; 95% CI 36 to 62%, p < 0.0001). Of 73 patients, 43 (59%; 95% CI 47 to 69%) had localised radiorecurrent cancer suitable for a form of focal ablation. CONCLUSIONS: For patients with recurrent prostate cancer after radiotherapy, MRI and MRI-targeted biopsy, with or without perilesional sampling, will diagnose cancer in the majority where present. MRI-undetected cancers, defined as Likert scores of 1 to 2, were found to be smaller and of lower grade. However, if salvage focal ablation is planned, an MRI-targeted biopsy alone is insufficient for prostate mapping; approximately three of five patients with recurrent cancer found on an MRI-targeted biopsy alone harboured further tumours in unsampled quadrants. Systematic sampling of the whole gland should be considered in addition to an MRI-targeted biopsy to capture both MRI-detected and MRI-undetected disease. PATIENT SUMMARY: After radiotherapy, magnetic resonance imaging (MRI) is accurate for detecting recurrent prostate cancer, with missed cancer being smaller and of lower grade. Targeting a biopsy to suspicious areas on MRI results in a diagnosis of cancer in most patients. However, for every five men who have recurrent cancer, this targeted approach would miss cancers elsewhere in the prostate in three of these men. If further focal treatment of the prostate is planned, random biopsies covering the whole prostate in addition to targeted biopsies should be considered so that tumours are not missed.

Focal therapy versus radical prostatectomy and external beam radiotherapy as primary treatment options for non-metastatic prostate cancer: results of a cost-effectiveness analysis.

AIMS: Focal therapy treats individual areas of tumour in non-metastatic prostate cancer in patients unsuitable for active surveillance. The aim of this work was to evaluate the cost-effectiveness of focal therapy versus prostatectomy and external beam radiotherapy (EBRT). MATERIALS AND METHODS: A Markov cohort health state transition model with four health states (stable disease, local recurrence, metastatic disease and death) was created, evaluating costs and utilities over a 10-year time horizon for patients diagnosed with non-metastatic prostate cancer. National Health Service (NHS) for England perspective was used, based on direct healthcare costs. Clinical transition probabilities were derived from prostate cancer registries in patients undergoing radical prostatectomy, EBRT and focal therapy using cryotherapy (Boston Scientific) or high-intensity focused ultrasound (HIFU) (Sonablate). Propensity score matching was used to ensure that at-risk populations were comparable. Variables included age, prostate-specific antigen (PSA), International Society of Urological Pathology (ISUP) grade group, maximum cancer core length (mm), T-stage and year of treatment. RESULTS: Focal therapy was associated with a lower overall cost and higher quality-adjusted life year (QALY) gains than either prostatectomy or EBRT, dominating both treatment strategies. Positive incremental net monetary benefit (NMB) values confirm focal therapy as cost-effective versus the alternatives at a willingness to pay (WTP) threshold of £30,000/QALY. One-way deterministic sensitivity analyses revealed consistent results. LIMITATIONS: Data used to calculate the transition probabilities were derived from a limited number of hospitals meaning that other potential treatment options were excluded. Limited data were available on later outcomes and none on quality of life data, therefore, literature-based estimates were used. CONCLUSIONS: Cost-effectiveness modelling demonstrates use of focal therapy (cryotherapy or HIFU) is associated with greater QALY gains at a lower overall cost than either radical prostatectomy or EBRT, representing good value for money in the NHS.

Focal therapy can be used for the primary treatment of individual areas of cancer in those patients with prostate cancer whose disease has not spread (localized or non-metastatic prostate cancer) and whose disease is unsuitable for active monitoring. Focal therapy in these patients results in similar control of the cancer to more invasive therapies, such as surgical removal of the prostate and radiotherapy, with the benefit of fewer sexual, urinary and rectal side effects. This work considered whether using focal therapy (either freezing the cancer cells using cryotherapy or using high-intensity focused ultrasound [HIFU] to destroy cancer cells) was good value for money in the National Health Service (NHS) compared with surgery or radiotherapy. An economic model was developed which considered the relative impact of treatment with focal therapies, surgery or radiotherapy within the NHS in England. Previously collected information from people undergoing treatment for their prostate cancer, together with published literature and clinical opinion, was used within the model to predict the treatment pathway, costs incurred and the results of treatment in terms of patient benefits (effectiveness and quality of life). The model showed that focal therapy using either cryotherapy or HIFU was associated with a lower overall cost and higher patient benefit than either surgery or radiotherapy, indicating that focal therapy represents good value for money in the NHS.

External validation of a risk model predicting failure of salvage focal ablation for prostate cancer.

OBJECTIVES: To externally validate a published model predicting failure within 2 years after salvage focal ablation in men with localised radiorecurrent prostate cancer using a prospective, UK multicentre dataset. PATIENTS AND METHODS: Patients with biopsy-confirmed ≤T3bN0M0 cancer after previous external beam radiotherapy or brachytherapy were included from the FOcal RECurrent Assessment and Salvage Treatment (FORECAST) trial (NCT01883128; 2014-2018; six centres), and from the high-intensity focussed ultrasound (HIFU) Evaluation and Assessment of Treatment (HEAT) and International Cryotherapy Evaluation (ICE) UK-based registries (2006-2022; nine centres). Eligible patients underwent either salvage focal HIFU or cryotherapy, with the choice based predominantly on anatomical factors. Per the original multivariable Cox regression model, the predicted outcome was a composite failure outcome. Model performance was assessed at 2 years post-salvage with discrimination (concordance index [C-index]), calibration (calibration curve and slope), and decision curve analysis. For the latter, two clinically-reasonable risk threshold ranges of 0.14-0.52 and 0.26-0.36 were considered, corresponding to previously published pooled 2-year recurrence-free survival rates for salvage local treatments. RESULTS: A total of 168 patients were included, of whom 84/168 (50%) experienced the primary outcome in all follow-ups, and 72/168 (43%) within 2 years. The C-index was 0.65 (95% confidence interval 0.58-0.71). On graphical inspection, there was close agreement between predicted and observed failure. The calibration slope was 1.01. In decision curve analysis, there was incremental net benefit vs a 'treat all' strategy at risk thresholds of ≥0.23. The net benefit was therefore higher across the majority of the 0.14-0.52 risk threshold range, and all of the 0.26-0.36 range. CONCLUSION: In external validation using prospective, multicentre data, this model demonstrated modest discrimination but good calibration and clinical utility for predicting failure of salvage focal ablation within 2 years. This model could be reasonably used to improve selection of appropriate treatment candidates for salvage focal ablation, and its use should be considered when discussing salvage options with patients. Further validation in larger, international cohorts with longer follow-up is recommended.

Evaluation of Outcomes Following Focal Ablative Therapy for Treatment of Localized Clinically Significant Prostate Cancer in Patients >70 Years: A Multi-institute, Multi-energy 15-Year Experience.

PURPOSE: In older patients who do not wish to undergo watchful waiting, focal therapy could be an alternative to the more morbid radical treatment. We evaluated the role of focal therapy in patients 70 years and older as an alternative management modality. MATERIALS AND METHODS: A total of 649 patients across 11 UK sites receiving focal high-intensity focused ultrasound or cryotherapy between June 2006 and July 2020 reported within the UK-based HEAT (HIFU Evaluation and Assessment of Treatment) and ICE (International Cryotherapy Evaluation) registries were evaluated. Primary outcome was failure-free survival, defined by need for more than 1 focal reablation, progression to radical treatment, development of metastases, need for systemic treatment, or prostate cancer-specific death. This was compared to the failure-free survival in patients undergoing radical treatment via a propensity score weighted analysis. RESULTS: Median age was 74 years (IQR: 72, 77) and median follow-up 24 months (IQR: 12, 41). Sixty percent had intermediate-risk disease and 35% high-risk disease. A total of 113 patients (17%) required further treatment. Sixteen had radical treatment and 44 required systemic treatment. Failure-free survival was 82% (95% CI: 76%-87%) at 5 years. Comparing patients who had radical therapy to those who had focal therapy, 5-year failure-free survival was 96% (95% CI: 93%-100%) and 82% (95% CI: 75%-91%) respectively (P < .001). Ninety-three percent of those in the radical treatment arm had received radiotherapy as their primary treatment with its associated use of androgen deprivation therapy, thereby leading to potential overestimation of treatment success in the radical treatment arm, especially given the similar metastases-free and overall survival rates seen. CONCLUSIONS: We propose focal therapy to be an effective management option for the older or comorbid patient who is unsuitable for or not willing to undergo radical treatment.

Regional Histopathology and Prostate MRI Positivity: A Secondary Analysis of the PROMIS Trial.

Background The effects of regional histopathologic changes on prostate MRI scans have not been accurately quantified in men with an elevated prostate-specific antigen (PSA) level and no previous biopsy. Purpose To assess how Gleason grade, maximum cancer core length (MCCL), inflammation, prostatic intraepithelial neoplasia (PIN), or atypical small acinar proliferation within a Barzell zone affects the odds of MRI visibility. Materials and Methods In this secondary analysis of the Prostate MRI Imaging Study (PROMIS; May 2012 to November 2015), consecutive participants who underwent multiparametric MRI followed by a combined biopsy, including 5-mm transperineal mapping (TPM), were evaluated. TPM pathologic findings were reported at the whole-prostate level and for each of 20 Barzell zones per prostate. An expert panel blinded to the pathologic findings reviewed MRI scans and declared which Barzell areas spanned Likert score 3-5 lesions. The relationship of Gleason grade and MCCL to zonal MRI outcome (visible vs nonvisible) was assessed using generalized linear mixed-effects models with random intercepts for individual participants. Inflammation, PIN, and atypical small acinar proliferation were similarly assessed in men who had negative TPM results. Results Overall, 161 men (median age, 62 years [IQR, 11 years]) were evaluated and 3179 Barzell zones were assigned MRI status. Compared with benign areas, the odds of MRI visibility were higher when a zone contained cancer with a Gleason score of 3+4 (odds ratio [OR], 3.1; 95% CI: 1.9, 4.9; P < .001) or Gleason score greater than or equal to 4+3 (OR, 8.7; 95% CI: 4.5, 17.0; P < .001). MCCL also determined visibility (OR, 1.24 per millimeter increase; 95% CI: 1.15, 1.33; P < .001), but odds were lower with each prostate volume doubling (OR, 0.7; 95% CI: 0.5, 0.9). In men who were TPM-negative, the presence of PIN increased the odds of zonal visibility (OR, 3.7; 95% CI: 1.5, 9.1; P = .004). Conclusion An incremental relationship between cancer burden and prostate MRI visibility was observed. Prostatic intraepithelial neoplasia contributed to false-positive MRI findings. ClinicalTrials.gov registration no. NCT01292291 © RSNA, 2022 Supplemental material is available for this article. See also the editorial by Harmath in this issue.

Magnetic Resonance Imaging and Targeted Biopsies Compared to Transperineal Mapping Biopsies Before Focal Ablation in Localised and Metastatic Recurrent Prostate Cancer After Radiotherapy.

BACKGROUND: Recurrent prostate cancer after radiotherapy occurs in one in five patients. The efficacy of prostate magnetic resonance imaging (MRI) in recurrent cancer has not been established. Furthermore, high-quality data on new minimally invasive salvage focal ablative treatments are needed. OBJECTIVE: To evaluate the role of prostate MRI in detection of prostate cancer recurring after radiotherapy and the role of salvage focal ablation in treating recurrent disease. DESIGN, SETTING, AND PARTICIPANTS: The FORECAST trial was both a paired-cohort diagnostic study evaluating prostate multiparametric MRI (mpMRI) and MRI-targeted biopsies in the detection of recurrent cancer and a cohort study evaluating focal ablation at six UK centres. A total of 181 patients were recruited, with 155 included in the MRI analysis and 93 in the focal ablation analysis. INTERVENTION: Patients underwent choline positron emission tomography/computed tomography and a bone scan, followed by prostate mpMRI and MRI-targeted and transperineal template-mapping (TTPM) biopsies. MRI was reported blind to other tests. Those eligible underwent subsequent focal ablation. An amendment in December 2014 permitted focal ablation in patients with metastases. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Primary outcomes were the sensitivity of MRI and MRI-targeted biopsies for cancer detection, and urinary incontinence after focal ablation. A key secondary outcome was progression-free survival (PFS). RESULTS AND LIMITATIONS: Staging whole-body imaging revealed localised cancer in 128 patients (71%), with involvement of pelvic nodes only in 13 (7%) and metastases in 38 (21%). The sensitivity of MRI-targeted biopsy was 92% (95% confidence interval [CI] 83-97%). The specificity and positive and negative predictive values were 75% (95% CI 45-92%), 94% (95% CI 86-98%), and 65% (95% CI 38-86%), respectively. Four cancer (6%) were missed by TTPM biopsy and six (8%) were missed by MRI-targeted biopsy. The overall MRI sensitivity for detection of any cancer was 94% (95% CI 88-98%). The specificity and positive and negative predictive values were 18% (95% CI 7-35%), 80% (95% CI 73-87%), and 46% (95% CI 19-75%), respectively. Among 93 patients undergoing focal ablation, urinary incontinence occurred in 15 (16%) and five (5%) had a grade ≥3 adverse event, with no rectal injuries. Median follow-up was 27 mo (interquartile range 18-36); overall PFS was 66% (interquartile range 54-75%) at 24 mo. CONCLUSIONS: Patients should undergo prostate MRI with both systematic and targeted biopsies to optimise cancer detection. Focal ablation for areas of intraprostatic recurrence preserves continence in the majority, with good early cancer control. PATIENT SUMMARY: We investigated the role of magnetic resonance imaging (MRI) scans of the prostate and MRI-targeted biopsies in outcomes after cancer-targeted high-intensity ultrasound or cryotherapy in patients with recurrent cancer after radiotherapy. Our findings show that these patients should undergo prostate MRI with both systematic and targeted biopsies and then ablative treatment focused on areas of recurrent cancer to preserve their quality of life. This trial is registered at ClinicalTrials.gov as NCT01883128.

Cancer Control Outcomes Following Focal Therapy Using High-intensity Focused Ultrasound in 1379 Men with Nonmetastatic Prostate Cancer: A Multi-institute 15-year Experience.

BACKGROUND: Focal therapy aims to treat areas of cancer to confer oncological control whilst reducing treatment-related functional detriment. OBJECTIVE: To report oncological outcomes and adverse events following focal high-intensity focused ultrasound (HIFU) for treating nonmetastatic prostate cancer. DESIGN, SETTING, AND PARTICIPANTS: An analysis of 1379 patients with ≥6 mo of follow-up prospectively recorded in the HIFU Evaluation and Assessment of Treatment (HEAT) registry from 13 UK centres (2005-2020) was conducted. Five or more years of follow-up was available for 325 (24%) patients. Focal HIFU therapy used a transrectal ultrasound-guided device (Sonablate; Sonacare Inc., Charlotte, NC, USA). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Failure-free survival (FFS) was primarily defined as avoidance of no evidence of disease to require salvage whole-gland or systemic treatment, or metastases or prostate cancer-specific mortality. Differences in FFS between D'Amico risk groups were determined using a log-rank analysis. Adverse events were reported using Clavien-Dindo classification. RESULTS AND LIMITATIONS: The median (interquartile range) age was 66 (60-71) yr and prostate-specific antigen was 6.9 (4.9-9.4) ng/ml with D'Amico intermediate risk in 65% (896/1379) and high risk in 28% (386/1379). The overall median follow-up was 32 (17-58) mo; for those with ≥5 yr of follow-up, it was 82 (72-94). A total of 252 patients had repeat focal treatment due to residual or recurrent cancer; overall 92 patients required salvage whole-gland treatment. Kaplan-Meier 7-yr FFS was 69% (64-74%). Seven-year FFS in intermediate- and high-risk cancers was 68% (95% confidence interval [CI] 62-75%) and 65% (95% CI 56-74%; p = 0.3). Clavien-Dindo >2 adverse events occurred in 0.5% (7/1379). The median 10-yr follow-up is lacking. CONCLUSIONS: Focal HIFU in carefully selected patients with clinically significant prostate cancer, with six and three of ten patients having, respectively, intermediate- and high-risk cancer, has good cancer control in the medium term. PATIENT SUMMARY: Focal high-intensity focused ultrasound treatment to areas of prostate with cancer can provide an alternative to treating the whole prostate. This treatment modality has good medium-term cancer control over 7 yr, although 10-yr data are not yet available.

Conventional radical versus focal treatment for localised prostate cancer: a propensity score weighted comparison of 6-year tumour control.

BACKGROUND: For localised prostate cancer, focal therapy offers an organ-sparing alternative to radical treatments (radiotherapy or prostatectomy). Currently, there is no randomised comparative effectiveness data evaluating cancer control of both strategies. METHODS: Following the eligibility criteria PSA < 20 ng/mL, Gleason score ≤ 7 and T-stage ≤ T2c, we included 830 radical (440 radiotherapy, 390 prostatectomy) and 530 focal therapy (cryotherapy, high-intensity focused ultrasound or high-dose-rate brachytherapy) patients treated between 2005 and 2018 from multicentre registries in the Netherlands and the UK. A propensity score weighted (PSW) analysis was performed to compare failure-free survival (FFS), with failure defined as salvage treatment, metastatic disease, systemic treatment (androgen deprivation therapy or chemotherapy), or progression to watchful waiting. The secondary outcome was overall survival (OS). Median (IQR) follow-up in each cohort was 55 (28-83) and 62 (42-83) months, respectively. RESULTS: At baseline, radical patients had higher PSA (10.3 versus 7.9) and higher-grade disease (31% ISUP 3 versus 11%) compared to focal patients. After PSW, all covariates were balanced (SMD < 0.1). 6-year weighted FFS was higher after radical therapy (80.3%, 95% CI 73.9-87.3) than after focal therapy (72.8%, 95% CI 66.8-79.8) although not statistically significant (p = 0.1). 6-year weighted OS was significantly lower after radical therapy (93.4%, 95% CI 90.1-95.2 versus 97.5%, 95% CI 94-99.9; p = 0.02). When compared in a three-way analysis, focal and LRP patients had a higher risk of treatment failure than EBRT patients (p < 0.001), but EBRT patients had a higher risk of mortality than focal patients (p = 0.008). CONCLUSIONS: Within the limitations of a cohort-based analysis in which residual confounders are likely to exist, we found no clinically relevant difference in cancer control conferred by focal therapy compared to radical therapy at 6 years.

Outcomes of the RAFT trial: robotic surgery after focal therapy.

OBJECTIVES: To report toxicity of treatment observed in men participating in the Robotic surgery After Focal Therapy (RAFT) clinical trial. PATIENTS AND METHODS: Men were eligible for this prospective single group interventional study if they had histologically confirmed recurrent/residual prostate adenocarcinoma following primary FT. The short-form Expanded Prostate Cancer Index Composite (EPIC-26) measured prior to salvage robotic prostatectomy (S-RARP) and 3-monthly post-operatively together with Clavien-Dindo complications (I-IV). Secondary outcomes included biochemical recurrence-free survival (BCFS) following surgery and need for salvage treatment after surgery. This study is registered with ClinicalTrials.gov NCT03011606. RESULTS: Twenty-four men were recruited between February 2016 and September 2018. 1 patient withdrew from the trial after consenting and before S-RARP. 23 men completed 12-month post S-RARP follow-up. Median EPIC-26 urinary continence scores initially deteriorated after 3 months (82.4 vs 100) but there was no statistically significant difference from baseline at 12 months (100 vs 100, P = 0.31). Median lower urinary tract symptom scores improved after 12 months compared to baseline (93.8 vs 87.5, P = 0.01). At 12 months, 19/23 (83%) were pad-free and 22/23 (96%) required 0/1 pads. Median sexual function subscale scores deteriorated and remained low at 12 months (22.2 vs 58.3, P < 0.001). Utilising a minimally important difference of nine points, at 12 months after surgery 17/23 (74%) reported urinary continence to be 'better' or 'not different' to pre-operative baseline. The corresponding figure for sexual function (utilising a minimally important difference of 12 points) was 7/23 (30%). There was no statistically significant difference on median bowel/hormonal subscale scores. Only a single patient had a post-operative complication (Clavien-Dindo Grade I). BCFS at 12 months after surgery was 82.6% (95% confidence interval [CI]: 60.1-93.1%) while 4/23 (17%) received salvage radiation. CONCLUSIONS: The RAFT clinical trial suggests toxicity of surgery after FT is low, with good urinary function outcomes, albeit sexual function deteriorated overall. Oncological outcomes at 12 months appear acceptable.

Assessment of Return to Baseline Urinary and Sexual Function Following Primary Focal Cryotherapy for Nonmetastatic Prostate Cancer.

BACKGROUND: The oncological outcomes in men with clinically significant prostate cancer following focal cryotherapy are promising, although functional outcomes are under-reported. OBJECTIVE: To determine the impact of focal cryotherapy on urinary and sexual function, specifically assessing return to baseline function. DESIGN, SETTING, AND PARTICIPANTS: Between October 2013 and November 2016, 58 of 122 men who underwent focal cryotherapy for predominantly anterior clinically significant localised prostate cancer within a prospective registry returned patient-reported outcome measure questionnaires, which included International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF-15) questionnaires. INTERVENTION: Standard cryotherapy procedure using either the SeedNet or the Visual-ICE cryotherapy system. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Primary outcome was return to baseline function of IPSS score and IIEF erectile function (EF) subdomain. Cumulative incidence and Cox-regression analyses were performed. RESULTS AND LIMITATIONS: Probability of returning to baseline IPSS function was 78% at 12 mo and 87% at both 18 and 24 mo, with recovery seen up to 18 mo. For IIEF (EF domain), the probability of returning to baseline function was 85% at 12 mo and 89% at both 18 and 24 mo, with recovery seen up to 18 mo. Only the preoperative IIEF-EF score was associated with a poor outcome (hazard ratio 0.96, 95% confidence interval 0.93-0.999, p = 0.04). The main limitation was that only half of the patients returned their questionnaires. CONCLUSIONS: In men undergoing primary focal cryotherapy, there is a high degree of preservation of urinary and erectile function with return to baseline function occurring from 3 mo and continuing up to 18 mo after focal cryotherapy. PATIENT SUMMARY: In men who underwent focal cryotherapy for prostate cancer, approximately nine in 10 returned to their baseline urinary and sexual function. Keeping in mind that level 1 evidence and long-term data are still needed, in men who wish to preserve urinary and sexual function, focal cryotherapy may be considered an alternative treatment option to radical therapy.

False Positive Multiparametric Magnetic Resonance Imaging Phenotypes in the Biopsy-naïve Prostate: Are They Distinct from Significant Cancer-associated Lesions? Lessons from PROMIS.

BACKGROUND: False positive multiparametric magnetic resonance imaging (mpMRI) phenotypes prompt unnecessary biopsies. The Prostate MRI Imaging Study (PROMIS) provides a unique opportunity to explore such phenotypes in biopsy-naïve men with raised prostate-specific antigen (PSA) and suspected cancer. OBJECTIVE: To compare mpMRI lesions in men with/without significant cancer on transperineal mapping biopsy (TPM). DESIGN, SETTING, AND PARTICIPANTS: PROMIS participants (n=235) underwent mpMRI followed by a combined biopsy procedure at University College London Hospital, including 5-mm TPM as the reference standard. Patients were divided into four mutually exclusive groups according to TPM findings: (1) no cancer, (2) insignificant cancer, (3) definition 2 significant cancer (Gleason ≥3+4 of any length and/or maximum cancer core length ≥4mm of any grade), and (4) definition 1 significant cancer (Gleason ≥4+3 of any length and/or maximum cancer core length ≥6mm of any grade). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Index and/or additional lesions present in 178 participants were compared between TPM groups in terms of number, conspicuity, volume, location, and radiological characteristics. RESULTS AND LIMITATIONS: Most lesions were located in the peripheral zone. More men with significant cancer had two or more lesions than those without significant disease (67% vs 37%; p< 0.001). In the former group, index lesions were larger (mean volume 0.68 vs 0.50 ml; p< 0.001, Wilcoxon test), more conspicuous (Likert 4-5: 79% vs 22%; p< 0.001), and diffusion restricted (mean apparent diffusion coefficient [ADC]: 0.73 vs 0.86; p< 0.001, Wilcoxon test). In men with Likert 3 index lesions, log2PSA density and index lesion ADC were significant predictors of definition 1/2 disease in a logistic regression model (mean cross-validated area under the receiver-operator characteristic curve: 0.77 [95% confidence interval: 0.67-0.87]). CONCLUSIONS: Significant cancer-associated MRI lesions in biopsy-naïve men have clinical-radiological differences, with lesions seen in prostates without significant disease. MRI-calculated PSA density and ADC could predict significant cancer in those with indeterminate MRI phenotypes. PATIENT SUMMARY: Magnetic resonance imaging (MRI) lesions that mimic prostate cancer but are, in fact, benign prompt unnecessary biopsies in thousands of men with raised prostate-specific antigen. In this study we found that, on closer look, such false positive lesions have different features from cancerous ones. This means that doctors could potentially develop better tools to identify cancer on MRI and spare some patients from unnecessary biopsies.

Focal HIFU therapy for anterior compared to posterior prostate cancer lesions.

OBJECTIVE: To compare cancer control in anterior compared to posterior prostate cancer lesions treated with a focal HIFU therapy approach. MATERIALS AND METHODS: In a prospectively maintained national database, 598 patients underwent focal HIFU (Sonablate®500) (March/2007-November/2016). Follow-up occurred with 3-monthly clinic visits and PSA testing in the first year with PSA, every 6-12 months with mpMRI with biopsy for MRI-suspicion of recurrence. Treatment failure was any secondary treatment (ADT/chemotherapy, cryotherapy, EBRT, RRP, or re-HIFU), tumour recurrence with Gleason ≥ 3 + 4 on prostate biopsy without further treatment or metastases/prostate cancer-related mortality. Cases with anterior cancer were compared to those with posterior disease. RESULTS: 267 patients were analysed following eligibility criteria. 45 had an anterior focal-HIFU and 222 had a posterior focal-HIFU. Median age was 64 years and 66 years, respectively, with similar PSA level of 7.5 ng/ml and 6.92 ng/ml. 84% and 82%, respectively, had Gleason 3 + 4, 16% in both groups had Gleason 4 + 3, 0% and 2% had Gleason 4 + 4. Prostate volume was similar (33 ml vs. 36 ml, p = 0.315); median number of positive cores in biopsies was different in anterior and posterior tumours (7 vs. 5, p = 0.009), while medium cancer core length, and maximal cancer percentage of core were comparable. 17/45 (37.8%) anterior focal-HIFU patients compared to 45/222 (20.3%) posterior focal-HIFU patients required further treatment (p = 0.019). CONCLUSION: Treating anterior prostate cancer lesions with focal HIFU may be less effective compared to posterior tumours.

What Type of Prostate Cancer Is Systematically Overlooked by Multiparametric Magnetic Resonance Imaging? An Analysis from the PROMIS Cohort.

BACKGROUND: All risk stratification strategies in cancer overlook a spectrum of disease. The Prostate MR Imaging Study (PROMIS) provides a unique opportunity to explore cancers that are overlooked by multiparametric magnetic resonance imaging (mpMRI). OBJECTIVE: To summarise attributes of cancers that are systematically overlooked by mpMRI. DESIGN, SETTING, AND PARTICIPANTS: PROMIS tested performance of mpMRI and transrectal ultrasonography (TRUS)-guided biopsy, using 5 mm template mapping (TPM) biopsy as the reference standard. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Outcomes were overall and maximum Gleason scores, maximum cancer core length (MCCL), and prostate-specific antigen density (PSAD). Cancer attributes were compared between cancers that were overlooked and those that were detected. RESULTS AND LIMITATIONS: Of men with cancer, 7% (17/230; 95% confidence interval [CI] 4.4-12%) had significant disease overlooked by mpMRI according to definition 1 (Gleason ≥ 4 + 3 of any length or MCCL ≥ 6 mm of any grade) and 13% (44/331; 95% CI 9.8-17%) according to definition 2 (Gleason ≥ 3 + 4 of any length or MCCL ≥ 4 mm). In comparison, TRUS-guided biopsy overlooked 52% (119/230; 95% CI 45-58%) of significant disease by definition 1 and 40% (132/331; 95% CI 35-45%) by definition 2. Prostate cancers undetected by mpMRI had significantly lower overall and maximum Gleason scores (p = 0.0007; p < 0.0001) and shorter MCCL (median difference: 3 mm [5 vs 8 mm], p < 0.0001; 95% CI 1-3) than cancers that were detected. No tumours with overall Gleason score > 3 + 4 (Gleason Grade Groups 3-5; 95% CI 0-6.4%) or maximum Gleason score > 4 + 3 (Gleason Grade Groups 4-5; 95% CI 0-8.0%) on TPM biopsy were undetected by mpMRI. Application of a PSAD threshold of 0.15 reduced the proportion of men with undetected cancer to 5% (12/230; 95% CI 2.7-8.9%) for definition 1 and 9% (30/331; 95% CI 6.2-13%) for definition 2. Application of a PSAD threshold of 0.10 reduced the proportion of men with undetected disease to 3% (6/230; 95% CI 1.0-5.6%) for definition 1 cancer and to 3% (11/331; 95% CI 1.7-5.9%) for definition 2 cancer. Limitations were post hoc analysis and uncertain significance of undetected lesions. CONCLUSIONS: Overall, a small proportion of cancers are overlooked by mpMRI, with estimates ranging from 4.4% (lower boundary of 95% CI for definition 1) to 17% (upper boundary of 95% CI for definition 2). Prostate cancers undetected by mpMRI are of lower grade and shorter length than cancers that are detected. PATIENT SUMMARY: Prostate cancers that are undetected by magnetic resonance imaging (MRI) are smaller and less aggressive than those that are detected, and none of the most aggressive cancers are overlooked by MRI.

An Exploratory Study of Dose Escalation vs Standard Focal High-Intensity Focused Ultrasound for Treating Nonmetastatic Prostate Cancer.

Objective: Analysis of treatment success regarding oncological recurrence rate between standard and dose escalation focal high-intensity focused ultrasound (HIFU) of prostate cancer. Materials and Methods: In this analysis of our prospectively maintained HIFU (Sonablate® 500) database, 598 patients were identified who underwent a focal HIFU (Sonablate 500) between March 2007 and November 2016. Follow-up occurred with 3-monthly clinic visits and prostate specific antigen (PSA) testing in the first year. Thereafter, PSA was measured 6-monthly or annually at least. Routine and for-cause multiparametric MRI (mpMRI) was conducted with biopsy for MRI suspicion of recurrence. Treatments were delivered in a quadrant or hemiablation fashion depending on the gland volume as well as tumor volume and location. Before mid-2015, standard focal HIFU was used (two HIFU blocks); after this date, some urologists conducted dose escalation focal HIFU (three overlapping HIFU blocks). Propensity matching was used to ensure two matched groups, leading to 162 cases for this analysis. Treatment failure was defined by any secondary treatment (systemic therapy, cryotherapy, radiotherapy, prostatectomy, or further HIFU), metastasis from prostate cancer without further treatment, tumor recurrence with Gleason score ≥7 (≥3 + 4) on prostate biopsy without further treatment, or prostate cancer-related mortality. Complications and side-effects were also compared. Results: Median age was 64.5 years (interquartile range [IQR] 60-73.5) in the standard focal-HIFU group and 64.5 years (IQR 60-69) in the dose-escalation group. Median prostate volume was 37 mL (IQR 17-103) in the standard group and 47.5 mL (IQR 19-121) in the dose-escalation group. As tumor volume on mpMRI and Gleason score were major matching criteria, these were identical with 0.43 mL (IQR 0.05-2.5) and Gleason 3 + 3 = 6 in 1 out of 32 (3%), 3 + 4 = 7 in 27 out of 32 (84%), and 4 + 3 = 7 in 4 out of 32 (13%). Recurrence in treated areas was found in 10 out of 32 (31%) when standard treatment zones were applied, and in 6 out of 32 (19%) of dose-escalation focal HIFU (p = 0.007). Conclusion: This exploratory study shows that dose escalation focal HIFU may achieve higher rates of disease control compared with standard focal HIFU. Further prospective comparative studies are needed.

Evaluation of functional outcomes after a second focal high-intensity focused ultrasonography (HIFU) procedure in men with primary localized, non-metastatic prostate cancer: results from the HIFU Evaluation and Assessment of Treatment (HEAT) registry.

OBJECTIVES: To assess change in functional outcomes after a second focal high-intensity focused ultrasonography (HIFU) treatment compared with outcomes after one focal HIFU treatment. PATIENTS AND METHODS: In this multicentre study (2005-2016), 821 men underwent focal HIFU for localized non-metastatic prostate cancer. The patient-reported outcome measures of International Prostate Symptom Score (IPSS), pad usage and erectile function (EF) score were prospectively collected for up to 3 years. To be included in the study, completion of at least one follow-up questionnaire was required. The primary outcome was comparison of change in functional outcomes between baseline and follow-up after one focal HIFU procedure vs after a second focal HIFU procedure, using IPSS, Expanded Prostate Cancer Index Composite (EPIC) and International Index of Erectile Function (IIEF) questionnaires. RESULTS: Of 821 men, 654 underwent one focal HIFU procedure and 167 underwent a second focal HIFU procedure. A total of 355 (54.3%) men undergoing one focal HIFU procedure and 65 (38.9%) with a second focal HIFU procedure returned follow-up questionnaires, respectively. The mean age and prostate-specific antigen level were 66.4 and 65.6 years, and 7.9 and 8.4 ng/mL, respectively. After one focal HIFU treatment, the mean change in IPSS was -0.03 (P = 0.02) and in IIEF (EF score) it was -0.4 (P = 0.02) at 1-2 years, with no subsequent decline. Absolute rates of erectile dysfunction increased from 9.9% to 20.8% (P = 0.08), leak-free continence decreased from 77.9% to 72.8% (P = 0.06) and pad-free continence from 98.6% to 94.8% (P = 0.07) at 1-2 years, respectively. IPSS prior to second focal HIFU treatment compared to baseline IPSS prior to first focal HIFU treatment was lower by -1.3 (P = 0.02), but mean IPSS change was +1.4 at 1-2 years (P = 0.03) and +1.2 at 2-3 years (P = 0.003) after the second focal HIFU treatment. The mean change in EF score after the second focal HIFU treatment was -0.2 at 1-2 years (P = 0.60) and -0.5 at 2-3 years (P = 0.10), with 17.8% and 6.2% of men with new erectile dysfunction. The rate of new pad use was 1.8% at 1-2 years and 2.6% at 2-3 years. CONCLUSION: A second focal HIFU procedure causes minor detrimental effects on urinary function and EF. These data can be used to counsel patients with non-metastatic prostate cancer prior to considering HIFU therapy.

Prostate Specific Antigen Criteria to Diagnose Failure of Cancer Control following Focal Therapy of Nonmetastatic Prostate Cancer Using High Intensity Focused Ultrasound.

PURPOSE: We determined whether prostate specific antigen criteria after focal high intensity focused ultrasound to treat prostate cancer could diagnose treatment failure. MATERIALS AND METHODS: A total of 598 patients in a prospectively maintained national database underwent focal high intensity focused ultrasound with a Sonablate® 500 device from March 2007 to November 2016. Followup consisted of 3-month clinic visits and prostate specific antigen testing in year 1 with prostate specific antigen measurement every 6 to 12 months and multiparametric magnetic resonance imaging with biopsy for magnetic resonance imaging suspicious for recurrence. Treatment failure was considered any secondary treatment, tumor recurrence with Gleason 3 + 4 or greater disease on prostate biopsy without further treatment or metastasis and/or prostate cancer related mortality. To diagnose failure we evaluated a series of nadir + x thresholds with x values of 0.1 to 2.0 ng/ml. RESULTS: Median patient age was 65 years (IQR 60-71) and the median Gleason score was 7 (range 6-9). Gleason 3 + 4 or greater disease was present in 80% of cases. Tumors were radiologically staged as T1c-T2c in 522 of the 596 patients (88%) and as T3a/b in 74 (12.4%). Baseline median prostate specific antigen was 7.80 ng/ml (IQR 5.96-10.45) in failed cases and 6.77 ng/ml (IQR 2.65-9.71) in cases without failure. Optimal performance according to the Youden index to indicate the most appropriate nadir + x at all analyzed time points at 3-month intervals showed that nadir + 1.0 ng/ml would have 27.3% to 100% sensitivity and 39.4% to 85.6% specificity depending on the time of evaluation in the first 3 years. Nadir + 1.5 ng/ml showed 18.2% to 100% sensitivity and 60.6% to 91.8% specificity with nadir + 2.0 ng/ml leading to similar sensitivity and specificity ranges. Nadir + 1.0 ng/ml at 12 months and nadir + 1.5 ng/ml at 24 and 36 months had 100% sensitivity and 96.1% to 100% negative predictive value. CONCLUSIONS: Following focal high intensity focused ultrasound a prostate specific antigen nadir of 1.0 ng/ml at 12 months and 1.5 ng/ml at 24 to 36 months might be used to triage men requiring magnetic resonance imaging and biopsy. These data need prospective validation.