W. van den Bos

The safety and efficacy of irreversible electroporation for the ablation of prostate cancer: a multicentre prospective human in vivo pilot study protocol

Introduction Current surgical and ablative treatment options for prostate cancer have a relatively high incidence of side effects, which may diminish the quality of life. The side effects are a consequence of procedure-related damage of the blood vessels, bowel, urethra or neurovascular bundle. Ablation with irreversible electroporation (IRE) has shown to be effective in destroying tumour cells and harbours the advantage of sparing surrounding tissue and vital structures. The aim of the study is to evaluate the safety and efficacy and to acquire data on patient experience of minimally invasive, transperineally image-guided IRE for the focal ablation of prostate cancer. Methods and analysis In this multicentre pilot study, 16 patients with prostate cancer who are scheduled for a radical prostatectomy will undergo an IRE procedure, approximately 30 days prior to the radical prostatectomy. Data as adverse events, side effects, functional outcomes, pain and quality of life will be collected and patients will be controlled at 1 and 2 weeks post-IRE, 1 day preprostatectomy and postprostatectomy. Prior to the IRE procedure and the radical prostatectomy, all patients will undergo a multiparametric MRI and contrast-enhanced ultrasound of the prostate. The efficacy of ablation will be determined by whole mount histopathological examination, which will be correlated with the imaging of the ablation zone. Ethics and dissemination The protocol is approved by the ethics committee at the coordinating centre (Academic Medical Center (AMC) Amsterdam) and by the local Institutional Review Board at the participating centres. Data will be presented at international conferences and published in peer-reviewed journals. Conclusions This pilot study will determine the safety and efficacy of IRE in the prostate. It will show the radiological and histopathological effects of IRE ablations and it will provide data to construct an accurate treatment planning tool for IRE in prostate tissue. Trial registration number Clinicaltrials.gov database: NCT01790451.

Standardization of definitions in focal therapy of prostate cancer: report from a Delphi consensus project

PurposeTo reach standardized terminology in focal therapy (FT) for prostate cancer (PCa).MethodsA four-stage modified Delphi consensus project was undertaken among a panel of international experts in the field of FT for PCa. Data on terminology in FT was collected from the panel by three rounds of online questionnaires. During a face-to-face meeting on June 21, 2015, attended by 38 experts, all data from the online rounds were reviewed and recommendations for definitions were formulated.ResultsConsensus was attained on 23 of 27 topics; TargetedFT was defined as a lesion-based treatment strategy, treating all identified significant cancer foci; FT was generically defined as an anatomy-based (zonal) treatment strategy. Treatment failure due to the ablative energy inadequately destroying treated tissue is defined as ablation failure. In targeting failure the energy is not adequately applied to the tumor spatially and selection failure occurs when a patient was wrongfully selected for FT. No definition of biochemical recurrence can be recommended based on the current data. Important definitions for outcome measures are potency (minimum IIEF-5 score of 21), incontinence (new need for pads or leakage) and deterioration in urinary function (increase in IPSS >5 points). No agreement on the best quality of life tool was established, but UCLA-EPIC and EORTC-QLQ-30 were most commonly supported by the experts. A complete overview of statements is presented in the text.ConclusionFocal therapy is an emerging field of PCa therapeutics. Standardization of definitions helps to create comparable research results and facilitate clear communication in clinical practice.

Histopathological Outcomes after Irreversible Electroporation for Prostate Cancer: Results of an Ablate and Resect Study

PURPOSE Irreversible electroporation is a tissue ablation modality that uses high voltage electric energy to induce an increase in cell membrane permeability. This causes destabilization of the existing cellular transmembrane potential leading to cell death, due to the inability to maintain cellular homeostasis. This phase I-II study was designed to evaluate the histopathological outcomes of irreversible electroporation to prostate and surrounding tissue in radical prostatectomy specimens. MATERIALS AND METHODS Sixteen patients with prostate cancer underwent an irreversible electroporation ablation without curative intent, followed by radical prostatectomy scheduled 4 weeks later. For histopathological examination of the prostate, whole mounted tissue slices were examined by dedicated genitourinary pathologists. The borders of the ablation zone and residual tumor were outlined on the slides. RESULTS The irreversible electroporation ablation zones were characterized as areas of fibrosis, necrosis and loss of epithelial tissue in terms of denudation in the glandular structures. The ablation zone was well demarcated, showing trenchant delineations between viable and nonviable tissue. The ablated tissue showed mild to moderate inflammation, with atrophic cells in 1 case. The area was surrounded by hemorrhage at the location of the electrodes. No skip lesions or viable tissue was seen in the ablation zone. Fibrinoid necrosis of the neurovascular bundle was observed in 13 patients and denudation of the urothelium of the prostatic urethra was seen in 9. CONCLUSIONS Histopathological assessment of the prostate 4 weeks after irreversible electroporation ablation showed sharply demarcated fibrotic and necrotic tissue in the ablation zone. No viable tissue was observed in the irreversible electroporation ablation zone.

Customized Tool for the Validation of Optical Coherence Tomography in Differentiation of Prostate Cancer

Objective: To design and demonstrate a customized tool to generate histologic sections of the prostate that directly correlate with needle-based optical coherence tomography pullback measurements. Materials and Methods: A customized tool was created to hold the prostatectomy specimens during optical coherence tomography measurements and formalin fixation. Using the tool, the prostate could be sliced into slices of 4 mm thickness through the optical coherence tomography measurement trajectory. In this way, whole-mount pathology slides were produced in exactly the same location as the optical coherence tomography measurements were performed. Full 3-dimensional optical coherence tomography pullbacks were fused with the histopathology slides using the 3-dimensional imaging software AMIRA, and images were compared. Results: A radical prostatectomy was performed in a patient (age: 68 years, prostate-specific antigen: 6.0 ng/mL) with Gleason score 3 + 4 = 7 in 2/5 biopsy cores on the left side (15%) and Gleason score 3 + 4 = 7 in 1/5 biopsy cores on the right side (5%). Histopathology after radical prostatectomy showed an anterior located pT2cNx adenocarcinoma (Gleason score 3 + 4 = 7). Histopathological prostate slides were produced using the customized tool for optical coherence tomography measurements, fixation, and slicing of the prostate specimens. These slides correlated exactly with the optical coherence tomography images. Various structures, for example, Gleason 3 + 4 prostate cancer, stroma, healthy glands, and cystic atrophy with septae, could be identified both on optical coherence tomography and on the histopathological prostate slides. Conclusion: We successfully designed and applied a customized tool to process radical prostatectomy specimens to improve the coregistration of whole mount histology sections to fresh tissue optical coherence tomography pullback measurements. This technique will be crucial in validating the results of optical coherence tomography imaging studies with histology and can easily be applied in other solid tissues as well, for example, lung, kidney, breast, and liver. This will help improve the efficacy of optical coherence tomography in cancer detection and staging in solid organs.

29 Temperatuurontwikkeling gedurende irreversibele elektroporatie in varkensnieren

SamenvattingIrreversibele elektroporatie (IRE) is een ablatietechniek die gebruikmaakt van elektrische pulsen tussen twee of meer naaldelektroden, voor de destructie van weefsel. Hoewel IRE in theorie niet afhankelijk is van thermische energie voor weefseldestructie, zou het herhaaldelijk toedienen van elektrische pulsen van hoge intensiteit kunnen leiden tot temperatuurverhoging.

11 Van lichtverstrooiing tot Gleason-score: ex-vivo optische coherentietomografie (OCT) van de menselijke prostaat na radicale prostatectomie

Materialen en methoden Er zijn 6 naaldgeleide OCT-metingen uitgevoerd in 22 prostaten, direct na radicale prostatectomie. OCT-metingen werden gedaan met een St. Jude intravasculaire OCT-console. Voor het plaatsen van de OCT-probes werden IV-(infuus)naalden gebruikt. De hulzen werden na de meting in het weefsel achtergelaten voor markering van het gemeten traject. Van de ruwe OCTdata werd per locatie de μOCT uitgerekend. Deze μOCT’s werden vergeleken met een 3D-reconstructie van de pathologie. Door middel van ROC-curveanalyse en Mann-Whitney-U-test is het verschil tussen maligne en benigne weefsel geanalyseerd.