Focal therapy: patients, interventions, and outcomes--a report from a consensus meeting

BACKGROUND

Focal therapy as a treatment option for localized prostate cancer (PCa) is an increasingly popular and rapidly evolving field.

OBJECTIVE

To gather expert opinion on patient selection, interventions, and meaningful outcome measures for focal therapy in clinical practice and trial design.

DESIGN, SETTING, AND PARTICIPANTS

Fifteen experts in focal therapy followed a modified two-stage RAND/University of California, Los Angeles (UCLA) Appropriateness Methodology process. All participants independently scored 246 statements prior to rescoring at a face-to-face meeting. The meeting occurred in June 2013 at the Royal Society of Medicine, London, supported by the Wellcome Trust and the UK Department of Health.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Agreement, disagreement, or uncertainty were calculated as the median panel score. Consensus was derived from the interpercentile range adjusted for symmetry level.

RESULTS AND LIMITATIONS

Of 246 statements, 154 (63%) reached consensus. Items of agreement included the following: patients with intermediate risk and patients with unifocal and multifocal PCa are eligible for focal treatment; magnetic resonance imaging-targeted or template-mapping biopsy should be used to plan treatment; planned treatment margins should be 5mm from the known tumor; prostate volume or age should not be a primary determinant of eligibility; foci of indolent cancer can be left untreated when treating the dominant index lesion; histologic outcomes should be defined by targeted biopsy at 1 yr; residual disease in the treated area of ≤3 mm of Gleason 3+3 did not need further treatment; and focal retreatment rates of ≤20% should be considered clinically acceptable but subsequent whole-gland therapy deemed a failure of focal therapy. All statements are expert opinion and therefore constitute level 5 evidence and may not reflect wider clinical consensus.

CONCLUSIONS

The landscape of PCa treatment is rapidly evolving with new treatment technologies. This consensus meeting provides guidance to clinicians on current expert thinking in the field of focal therapy.

PATIENT SUMMARY

In this report we present expert opinion on patient selection, interventions, and meaningful outcomes for clinicians working in focal therapy for prostate cancer.

Enhancing the efficacy of cytotoxic agents for cancer therapy using photochemical internalisation

Photochemical internalisation (PCI) is a technique for improving cellular delivery of certain bioactive agents which are prone to sequestration within endolysosomes. There is a wide range of agents suitable for PCI‐based delivery including toxins, oligonucleotides, genes and immunoconjugates which demonstrates the versatility of this technique. The basic mechanism of PCI involves triggering release of the agent from endolysosomes within the target cells using a photosensitiser which is selectively retained with the endolysosomal membranes. Excitation of the photosensitiser by visible light leads to disruption of the membranes via photooxidative damage thereby releasing the agent into the cytosol. This treatment enables the drugs to reach their intended subcellular target more efficiently and improves their efficacy. In this review we summarise the applications of this technique with the main emphasis placed on cancer chemotherapy.

Magnetic resonance imaging in active surveillance of prostate cancer: a systematic review

CONTEXT

There is great interest in using magnetic resonance imaging (MRI) for men on active surveillance for prostate cancer.

OBJECTIVE

To systematically review evidence regarding the use of MRI in men with low- or intermediate-risk prostate cancer suitable for active surveillance.

EVIDENCE ACQUISITION

Ovid Medline and Embase databases were searched for active surveillance, prostate cancer, and MRI from inception until April 25, 2014 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses process. Identified reports were critically appraised according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria.

EVIDENCE SYNTHESIS

A lesion on MRI suspicious for prostate cancer (positive MRI) is seen in two-thirds of men otherwise suitable for active surveillance. A positive MRI makes the identification of clinically significant disease at repeat biopsy more likely, especially when biopsies are targeted to suspicious MRI lesions. Radical prostatectomy data show that positive MRI is more likely to be associated with upgrading (Gleason score>3+3) than a negative MRI (43% vs 27%). A positive MRI is not significantly more likely to be associated with upstaging at radical prostatectomy (>T2) than a negative MRI (10% vs 8%). Although MRI is of interest in the monitoring of men on active surveillance, robust data on the use of repeat MRI in active surveillance are lacking. Prospective studies with clear definitions of radiological significance and progression are needed before this approach can be adopted.

CONCLUSIONS

MRI is useful for detection of clinically significant disease at initial assessment of men considering active surveillance. To use MRI as a monitoring tool in surveillance, it will be necessary to define both radiological significance and radiological progression.

PATIENT SUMMARY

This review assesses evidence for the use of magnetic resonance imaging (MRI) in men on active surveillance for prostate cancer. MRI at the start of surveillance can detect clinically significant disease in one-third to half of men. There are few data to assess the use of MRI as a monitoring tool during surveillance, so there is a need to define significant disease on MRI and significant changes over time.

Multiparametric magnetic resonance imaging in the management and diagnosis of prostate cancer: current applications and strategies

Magnetic resonance imaging (MRI) has become increasingly used worldwide in the diagnosis and management of prostate cancer. With advances in multiparametric MRI (mpMRI) technology, such as the use of dynamic contrast-enhanced and diffusion-weighted imaging sequences, observational studies have evaluated the utility for mpMRI in the continuum of prostate cancer management, from improving the detection of clinically significant prostate cancer, to planning radical prostatectomy and radiation therapy and the early detection of local recurrence. Furthermore, the potential for advanced imaging to reduce the burden of routine serial prostate needle biopsies for men on active surveillance is a promising area of research. MRI technology continues to evolve, and the potential applications in the management of prostate cancer care will require well-designed multi-institutional prospective clinical trials and rigorous efforts to standardize reporting and improve dissemination of expertise across institutions.

Tined lead versus percutaneous nerve evaluation for sacral nerve stimulator assessment

Purpose:

We compared the outcomes of percutaneous nerve evaluation (PNE) with first-stage tined lead placement (FSTLP) for the testing phase of sacral nerve neuromodulation (SNM), and we assessed the outcomes of these two techniques following implantation of a (second-stage) permanent sacral nerve stimulator (SNS).

Methods:

Seventy consecutive patients had either PNE ( n = 35) or FSTLP ( n = 35) evaluation, and conversion to a permanent SNS implant according to response. Primary outcomes were assessed using frequency-volume charts, pad testing, ICIQ/EQ5D questionnaires and global health perception visual analogue scale (VAS). Success was considered if they achieved greater than 50% improvement in their urinary symptoms. Success and failure rates were compared during the test phase and after implantation of the SNS.

Results:

Mean follow-up for the FSTLP group was 14 months (nine to 20) and for the PNE group was 22 months (eight to 27). Sixteen (46%) of the PNE tests and 20 (57%) of the FSTLP patients were converted to permanent implant. A significant correlation was noted between patients’ general health (VAS score) and a successful test phase ( r = 0.297, p = 0.013). Eighteen of 19 (95%) of tined lead patients have successful SNS implants, whereas five of 16 (31%) of PNE evaluations failed to convert test efficacy to the permanent SNS implant ( p = 0.042). Furthermore, two of PNE-SNS patients were successfully salvaged by the implantation of a second tined lead.

Conclusions:

FSTLP-SNS has a significantly higher success rate than PNE-SNS in converting the test phase to SNS implantation. This may be due in part to difficulties retaining accurate lead placement with the two-lead (PNE-SNS) approach. These findings have important cost and logistical implications for SNS services.

Multiparametric MRI followed by targeted prostate biopsy for men with suspected prostate cancer: a clinical decision analysis

OBJECTIVE

To compare the diagnostic outcomes of the current approach of transrectal ultrasound (TRUS)-guided biopsy in men with suspected prostate cancer to an alternative approach using multiparametric MRI (mpMRI), followed by MRI-targeted biopsy if positive.

DESIGN

Clinical decision analysis was used to synthesise data from recently emerging evidence in a format that is relevant for clinical decision making.

POPULATION

A hypothetical cohort of 1000 men with suspected prostate cancer.

INTERVENTIONS

mpMRI and, if positive, MRI-targeted biopsy compared with TRUS-guided biopsy in all men.

OUTCOME MEASURES

We report the number of men expected to undergo a biopsy as well as the numbers of correctly identified patients with or without prostate cancer. A probabilistic sensitivity analysis was carried out using Monte Carlo simulation to explore the impact of statistical uncertainty in the diagnostic parameters.

RESULTS

In 1000 men, mpMRI followed by MRI-targeted biopsy 'clinically dominates' TRUS-guided biopsy as it results in fewer expected biopsies (600 vs 1000), more men being correctly identified as having clinically significant cancer (320 vs 250), and fewer men being falsely identified (20 vs 50). The mpMRI-based strategy dominated TRUS-guided biopsy in 86% of the simulations in the probabilistic sensitivity analysis.

CONCLUSIONS

Our analysis suggests that mpMRI followed by MRI-targeted biopsy is likely to result in fewer and better biopsies than TRUS-guided biopsy. Future research in prostate cancer should focus on providing precise estimates of key diagnostic parameters.

The PICTURE study -- prostate imaging (multi-parametric MRI and Prostate HistoScanning™) compared to transperineal ultrasound guided biopsy for significant prostate cancer risk evaluation

OBJECTIVE

The primary objective of the PICTURE study is to assess the negative predictive value of multi-parametric MRI (mp-MRI) and Prostate HistoScanning™ (PHS) in ruling-out clinically significant prostate cancer.

PATIENTS AND METHODS

PICTURE is a prospective diagnostic validating cohort study conforming to level 1 evidence. PICTURE will assess the diagnostic performance of multi-parametric Magnetic Resonance Imaging (mp-MRI) and Prostate HistoScanning™ (PHS) ultrasound. PICTURE will involve validating both index tests against a reference test, transperineal Template Prostate Mapping (TPM) biopsies, which can be applied in all men under evaluation. Men will be blinded to the index test results and both index tests will be reported prospectively prior to the biopsies being taken to ensure reporter blinding. Paired analysis of each of the index tests to the reference test will be done at patient level. Those men with an imaging lesion will undergo targeted biopsies to assess the clinical utility of sampling only suspicious areas. The study is powered to assess the negative predictive value of these imaging modalities in ruling-out clinically significant prostate cancer.

DISCUSSION

The PICTURE study aims to assess the performance characteristics of two imaging modalities (mp-MRI and Prostate HistoScanning) for their utility in the prostate cancer pathway. PICTURE aims to identify if either imaging test may be useful for ruling out clinically significant disease in men under investigation, and also to examine if either imaging modality is useful for the detection of disease. Recruitment is underway and expected to complete in 2014.

TOOKAD(®) Soluble vascular-targeted photodynamic (VTP) therapy: determination of optimal treatment conditions and assessment of effects in patients with localised prostate cancer

OBJECTIVES

To evaluate the optimal treatment conditions and effects of TOOKAD(®) Soluble vascular-targeted photodynamic (VTP) therapy in patients with localised prostate cancer. To evaluate the safety and quality of life after TOOKAD(®) Soluble VTP treatment in patients with localised prostate cancer.

PATIENTS AND METHODS

Men (aged >18 years) diagnosed with localised prostate cancer, who were suitable for active surveillance, were invited to take part in the study. Patients who had received prior or current treatment for their cancer were excluded. There were two parts to the study: in part one, patients were assigned to one of two treatment groups based on the size of their prostates (patients with prostate size <60 mL would receive 4 mg/kg TOOKAD(®) Soluble and patients with prostate size ≥60 mL would receive 6 mg/kg TOOKAD(®) Soluble both activated with 200 J/cm light). In part two, patients were assigned to one of two treatment groups based on predefined criteria and received either 4 or 6 mg/kg TOOKAD(®) Soluble and 200 or 300 J/cm light. VTP was conducted under general anaesthesia using TOOKAD(®) Soluble administered intravenously and activated by light-diffusing fibres within the prostate via the perineum. Follow-up was conducted for 6 months. Magnetic resonance imaging (MRI) carried out at 1 week after VTP and transrectal prostate biopsy at 6 months were the key endpoints. Adverse event (AE) recording and patient-reported outcome measures were collected.

RESULTS

In all, 86 patients were enrolled in the study and 85 patients received treatment. Of the 85 treated patients, one patient discontinued (due to withdrawal of consent). At 6 months, 61/83 (74%) patients who underwent prostate biopsy had histopathology that was negative for prostate cancer (95% confidence interval (CI) 62.7-82.6%). Considering patients who received 4 mg/kg TOOKAD(®) Soluble and 200 J/cm light (unilateral), which are considered optimal treatment parameters, 38/46 (83%) patients had histopathology from the biopsies that was negative for prostate cancer at 6 months (95% CI 68.6-92.2%; P < 0.001). The mean percentage of necrosis of the targeted prostate tissue at 7 days after VTP was 78% overall (83 patients) with extraprostatic necrosis reported in 76% (63/83) of patients. Considering patients who received 4 mg/kg TOOKAD(®) Soluble and 200 J/cm light (unilateral), the mean 7-day necrosis percentage was 88% (46 patients) with extraprostatic necrosis reported in 72% (33/46) of patients. All occurrences of extraprostatic necrosis were considered clinically acceptable and none were associated with any clinical sequelae. The mean percentage prostate necrosis at 7 days was statistically significantly higher (P < 0.001) in patients treated with a therapeutic light density index (LDI) of ≥1 than those treated with a LDI of <1. The percentage of patients with negative biopsies at 6 months was also higher in patients treated with a therapeutic LDI of ≥1 than those treated with a LDI of <1 (78.6% and 63.0%, respectively). In all, 87% (75/86) of patients reported at least one treatment-emergent AE during the study. Most AEs were mild or moderate in intensity and considered related to the technical procedures of the study. No treated patients had hypotension or discontinued due to AEs. Eight patients (9.3%) had serious AEs; none resulted in discontinuation from the study.

CONCLUSIONS

Biopsy data, post-treatment dynamic contrast-enhancement MRI at 1 week after VTP and analysis of the safety data have shown that 4 mg/kg TOOKAD(®) Soluble and 200 J/cm light are the optimal treatment conditions for the VTP procedure resulting in >80% of patients treated with this regimen having a negative biopsy at 6 months. Overall, the treatment was well tolerated and exhibited early signs of efficacy for minimally invasive focal treatment of localised prostate cancer.

Multiparametric MR imaging for detection of clinically significant prostate cancer: a validation cohort study with transperineal template prostate mapping as the reference standard

PURPOSE

To evaluate the diagnostic performance of multiparametric (MP) magnetic resonance (MR) imaging for prostate cancer detection by using transperineal template prostate mapping (TTPM) biopsies as the reference standard and to determine the potential ability of MP MR imaging to identify clinically significant prostate cancer.

MATERIALS AND METHODS

Institutional review board exemption was granted by the local research ethics committee for this retrospective study. Included were 64 men (mean age, 62 years [range, 40-76]; mean prostate-specific antigen, 8.2 ng/mL [8.2 μg/L] [range, 2.1-43 ng/mL]), 51 with biopsy-proved cancer and 13 suspected of having clinically significant cancer that was biopsy negative or without prior biopsy. MP MR imaging included T2-weighted, dynamic contrast-enhanced and diffusion-weighted imaging (1.5 T, pelvic phased-array coil). Three radiologists independently reviewed images and were blinded to results of biopsy. Two-by-two tables were derived by using sectors of analysis of four quadrants, two lobes, and one whole prostate. Primary target definition for clinically significant disease necessary to be present within a sector of analysis on TTPM for that sector to be deemed positive was set at Gleason score of 3+4 or more and/or cancer core length involvement of 4 mm or more. Sensitivity, negative predictive value, and negative likelihood ratio were calculated to determine ability of MP MR imaging to rule out cancer. Specificity, positive predictive value, positive likelihood ratio, accuracy (overall fraction correct), and area under receiver operating characteristic curves were also calculated.

RESULTS

Twenty-eight percent (71 of 256) of sectors had clinically significant cancer by primary endpoint definition. For primary endpoint definition (≥ 4 mm and/or Gleason score ≥ 3+4), sensitivity, negative predictive value, and negative likelihood ratios were 58%-73%, 84%-89%, and 0.3-0.5, respectively. Specificity, positive predictive value, and positive likelihood ratios were 71%-84%, 49%-63%, and 2.-3.44, respectively. Area under the curve values were 0.73-0.84.

CONCLUSION

Results of this study indicate that MP MR imaging has a high negative predictive value to rule out clinically significant prostate cancer and may potentially have clinical use in diagnostic pathways of men at risk.

Intra-ureteric placement of a urinary catheter in the previously undiagnosed duplex ureter

We report the inadvertent insertion of a urinary catheter into the upper moiety ureter of a duplex kidney, in a full-term pregnant woman prior to an emergency caesarean section. The patient complained of severe pain during inflation of the catheter balloon. All measures to deflate the balloon and remove the catheter failed. Retrograde ureteric contrast examination showed the placement of the catheter in the proximal part the right upper moiety ureter of a duplex ureter. The catheter was removed with ureteroscopic forceps. We concluded that congenital variation of the urinary tract can complicate a simple catheterisation.

MAPPED study design: a 6 month randomised controlled study to evaluate the effect of dutasteride on prostate cancer volume using magnetic resonance imaging

OBJECTIVE

To evaluate the percentage change in volume of prostate cancer, as assessed by T2-weighted MRI, following exposure to dutasteride (Avodart) 0.5mg daily for six months.

PATIENTS AND METHODS

MRI in Primary Prostate cancer after Exposure to Dutasteride (MAPPED) is a double-blind, placebo-controlled trial, supported by GlaxoSmithKline (GSK). Men with prostate cancer suitable for active surveillance (low-intermediate risk prostate cancer on biopsy), and a visible lesion on T2-weighted MRI of at least 0.2 cc, were eligible for consideration. Forty-two men were randomised to 6 months of daily dutasteride 0.5mg or placebo. Multi-parametric MRI (mpMRI) scans were performed at baseline, 3 and 6 months. The percentage changes in cancer volume over time will be compared between the dutasteride and placebo groups. Planned analyses will examine the association between tumour volume and characteristics (perfusion and contrast washout) as seen on mpMRI, HistoScan ultrasound and biopsy histopathology in both groups.

DISCUSSION

MAPPED is the first randomised controlled trial to use mpMRI to look at the effect of dutasteride on the volume of prostate cancer. If dutasteride is shown to reduce the volume of prostate cancer, it might be considered as an adjunct for men on active surveillance. Analysis of the placebo arm will allow us to comment on the short-term natural variability of the MR appearance in men who are not receiving any treatment.

CONCLUSION

MAPPED will evaluate the short-term effect of dutasteride on prostate cancer volume, as assessed by mpMRI, in men undergoing active surveillance for low or intermediate risk prostate cancer. The study completed recruitment in January 2012.

Transperineal magnetic resonance image targeted prostate biopsy versus transperineal template prostate biopsy in the detection of clinically significant prostate cancer

PURPOSE

Multiparametric magnetic resonance imaging can be used to guide prostate biopsy by targeting biopsies to areas in the prostate at high risk for cancer. We compared the detection of clinically significant and insignificant cancer by transperineal magnetic resonance imaging targeted biopsy and transperineal template guided prostate biopsy.

MATERIALS AND METHODS

A total of 182 men with a lesion suspicious for cancer on multiparametric magnetic resonance imaging underwent transperineal magnetic resonance imaging targeted biopsy using a cognitive registration technique, followed by systematic transperineal template guided prostate biopsy. The primary outcome was the detection rate of clinically significant prostate cancer. Clinical significance was defined using maximum cancer core length 4 mm or greater and/or Gleason grade 3 + 4 or greater (University College London definition 2). We secondarily evaluated other commonly used thresholds of clinically significant disease, including maximum cancer core length 6 mm or greater and/or Gleason grade 4 + 3 or greater, maximum cancer core length 3 mm or greater and/or Gleason grade 3 + 4 or greater, and maximum cancer core length 2 or greater mm and/or Gleason grade 3 + 4 or greater. Strategies were statistically compared with the McNemar test.

RESULTS

Mean ± SD patient age was 63.3 ± 7.2 years. Median prostate specific antigen was 6.7 ng/ml (IQR 4.7-10.0). Clinically significant cancer was detected by magnetic resonance imaging targeted biopsy and template guided prostate biopsy in 103 (57%) and 113 of the 182 men (62%) (p = 0.174), and clinically insignificant cancer was detected in 17 (9.3%) and 31 (17.0%), respectively (p = 0.024).

CONCLUSIONS

Prostate biopsy targeted to suspicious lesions on multiparametric magnetic resonance imaging has encouraging rates of detection of clinically significant cancer while also decreasing the detection rate of clinically insignificant cancer. This is achieved with fewer biopsy cores than for systematic template guided biopsy. Further prospective, multicenter, comparative trials of the performance of targeting strategies are needed to consider magnetic resonance imaging targeted biopsy an alternative to conventional systematic biopsy.

Identifying candidates for active surveillance: an evaluation of the repeat biopsy strategy for men with favorable risk prostate cancer

PURPOSE

Active surveillance is increasingly recommended to reduce overtreatment in men with favorable risk prostate cancer. A repeat confirmatory biopsy has become the standard recommendation for these men to increase the precision of this risk attribution. We investigate the usefulness of this approach by comparing the current practice standard, repeat transrectal ultrasound biopsy, with template prostate mapping.

MATERIALS AND METHODS

A total of 124 men who were attributed a favorable risk prostate cancer status based on transrectal ultrasound guided biopsy and who were considering a policy of active surveillance underwent combined transrectal ultrasound biopsy and template prostate mapping as a confirmatory strategy. Maximum Gleason grade and disease burden were compared between the 2 confirmatory tests.

RESULTS

Depending on the definition used between 8% and 22% of men had prostate cancer reclassified as clinically important by repeat transrectal ultrasound biopsy whereas template guided prostate mapping reclassified the disease in 41% to 85% of the men. Repeat transrectal ultrasound biopsy failed to detect up to 80% of clinically important cancers detected by the reference standard. The sensitivity of repeat transrectal ultrasound biopsy to identify clinically important disease varied from 9% to 24% with the negative predictive value ranging from 23% to 60%.

CONCLUSIONS

When applied to a population of men initially deemed to have favorable risk prostate cancer, transrectal ultrasound biopsy will miss a large proportion of clinically important cancers compared to template guided prostate mapping. The usefulness of repeat transrectal ultrasound biopsy in ruling out clinically important prostate cancer needs to be reconsidered.

Image-guided prostate biopsy using magnetic resonance imaging-derived targets: a systematic review

CONTEXT

Technical improvements in prostate magnetic resonance imaging (MRI) have resulted in the use of MRI to target prostate biopsies.

OBJECTIVE

To systematically review the literature to compare the accuracy of MRI-targeted biopsy with standard transrectal biopsy in the detection of clinically significant prostate cancer.

EVIDENCE ACQUISITION

The PubMed, Embase, and Cochrane databases were searched from inception until December 3, 2011, using the search criteria 'prostate OR prostate cancer' AND 'magnetic resonance imaging OR MRI' AND 'biopsy OR target'. Four reviewers independently assessed 4222 records; 222 records required full review. Fifty unique records (corresponding to 16 discrete patient populations) directly compared an MRI-targeted with a standard transrectal approach.

EVIDENCE SYNTHESIS

Evidence synthesis was used to address specific questions. Where MRI was applied to all biopsy-naive men, 62% (374 of 599) had MRI abnormalities. When subjected to a targeted biopsy, 66% (248 of 374) had prostate cancer detected. Both targeted and standard biopsy detected clinically significant cancer in 43% (236 or 237 of 555, respectively). Missed clinically significant cancers occurred in 13 men using targeted biopsy and 12 using a standard approach. Targeted biopsy was more efficient. A third fewer men were biopsied overall. Those who had biopsy required a mean of 3.8 targeted cores compared with 12 standard cores. A targeted approach avoided the diagnosis of clinically insignificant cancer in 53 of 555 (10%) of the presenting population.

CONCLUSIONS

MRI-guided biopsy detects clinically significant prostate cancer in an equivalent number of men versus standard biopsy. This is achieved using fewer biopsies in fewer men, with a reduction in the diagnosis of clinically insignificant cancer. Variability in study methodology limits the strength of recommendation that can be made. There is a need for a robust multicentre trial of targeted biopsies.