942 TRANSRECTAL HIFU ABLATION OF PROSTATE CANCER: ASSESSMENT OF TISSUE DESTRUCTION WITH CONTRAST-ENHANCED ULTRASOUND

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Tissue Characterisation (HistoScanning) for detection of prostate cancer: Interim results from the exploratory phase of a prospective multi-centre trial

Transrectal HIFU ablation of prostate cancer: Assessment of tissue destruction with contrastenhanced ultrasound

Govindaraju S.K.1, Ahmed H.U.1, Tuernicht K.2, Jarmulowicz M.2, Bleiberg H.3, Braeckman J.4, Michielson D.4, Romics I.5, Záťura F.6, Peltier A.7, Emberton M.1

Rouviere O.1, Glas L.1, Girouin N.1, Mege-Lechevallier F.2, Gelet A.3, Chapelon J.Y.4, Lyonnet D.1

University College London, Division of Surgery and Interventional Sciences, London, United Kingdom, Bostwick Laboratories, Dept. of Urology, London, United Kingdom, 3Advanced Medical Diagnostics, Medical affairs, Waterloo, Belgium, 4Universiteit Hospital Brussels, Dept. of Urology, Brussels, Belgium, 5Semmelweis Medical University, Dept. of Urology, Budapest, Hungary, 6Faculty Hospital Olomouc, Dept. of Urology, Czech Republic, 7Institut Jules Bordet Brussels, Dept. of Urology, Brussels, Belgium

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Introduction & Objectives: Current ultrasound technology characterises prostate cancer rather poorly. As a result, more and more biopsies are done in order to reduce sampling error. MRI may have a role in aiding diagnosis but is still expensive, time consuming and requires interpretation by both dedicated and expert radiologists. At EAU 2008 we presented promising yet very initial results of a single centre study done at Brussels demonstrating the use of novel tissue characterization technology for aiding the detection of prostate cancer. Today, we present the interim results from a multi-centre European trial aimed at a more thorough evaluation of this same novel ultrasound based tissue characterisation technology – Prostate HistoScanning™ Material & Methods: Men diagnosed with prostate cancer underwent Prostate HistoScanning using a readily available transrectal probe (motorised BK 8818) prior to scheduled radical prostatectomy as part of an ethics committee approved multi-center European trial. The index test comprised radio-frequency data from the transrectal ultrasound signal ‘backscatter’. These data were analysed using tissue specific characterisation algorithms. The reference test comprised systematic, grid based analysis of 3mm step sectioned radical prostatectomy whole mount specimen. The accuracy of HistoScanning detection for cancer was determined by dividing the prostate into regions of interest (ROI): a) 4 quadrants, b) 8 (octants) and c) on a section-by-section level, with each further divided into quadrants (range 36 -60 ROI’s). The analysis undertaken tests the ability of the index test to predict the presence or absence of any tumour foci, irrespective of size, against the reference test (whole mount pathology). Results: 10 paired datasets were available for a planned interim analysis, prior to the blinded phase commencing. A total of 588 paired analysis were performed. The results are summarised in the table. ROI’s per prostate 4 8 46.8

Total no. ROIs

Sensitivity

Specificity

40 80 468

96.3 % 84.1 % 68.9 %

53.8 % 77.8 % 89 %

Positive Predictive Value 81.3 % 82.2 % 77.4 %

Negative Predictive Value 87.5 % 80 % 84 %

The index lesion (largest tumour) was identified in all cases. Correlation between the predicted maximum diameter of the index lesion (mean - 1.97cm, range 1.3 to 2.9) against that observed by histology (mean 2.2cm, range 1.1 to 3.0), proved strong (r = 0.88).

Hospices Civils de Lyon, Dept. of Genitourinary and Vascular Imaging, Lyon, France, Hospices Civils de Lyon, Dept. of Pathology, Lyon, France, 3Hospices Civils de Lyon, Dept. of Urology, Lyon, France, 4Inserm, Unit 556, Lyon, France

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Introduction & Objectives: To assess contrast-enhanced ultrasound in distinguishing residual viable prostate tissue from ablated tissue after HIFU prostate ablation. Material & Methods: This prospective study included 21 patients addressed for HIFU ablation of prostate cancer (n=12) or salvage HIFU ablation of a local recurrence after radiation therapy (n=9). No patient had history of hormonal deprivation. All patients underwent transrectal prostate B-mode, Color/Power Doppler and contrast-enhanced (Sonovue) ultrasound the day before HIFU ablation and 1-5 days and 30-45 days after treatment. During this last examination, contrast-enhanced ultrasound-guided prostate biopsy was obtained. The biopsy operator scored the enhancement pattern of each biopsy site according to a three-point scale (S0 = no enhancement, S1 = mild and patchy enhancement, S2 = marked enhancement). All biopsy cores were reviewed by a single pathologist and classified as “ablated tissue” (coagulation necrosis and/or fibrosis with no viable gland and no vascularized tissue) or “living tissue” (viable glands (with or without coagulation necrosis) and/or vascularized fibromuscular tissue). All patients also underwent a contrast-enhanced prostate MRI 1-5 days after treatment. Results: Unlike B mode or Color/Power Doppler, contrast-enhanced ultrasound showed a clear delineation between a large devascularized area concerning most of the gland and some residual enhancing prostate tissue localized anteriorly (all patients), posteriorly (6 patients) or at the apex (15 patients). There was a good agreement between contrast ultrasound and MRI data concerning the size of residual enhancing prostate tissue. 91.3% (94/103), 45.8% (11/24) and 18.5% (10/54) of the biopsies obtained in S0, S1 and S2 territories respectively showed totally ablated tissue (p<0.001). If only the cores showing viable glands were considered (8 cores for S0 sites, 38 cores for S1/S2 sites), viable glands were visible on a mean length of 1 ± 0.5 mm in S0 sites and of 4.5 ± 3 mm in S1/S2 sites (p< 0.001).

Conclusions: These interim results taken from the un-blinded exploratory phase of the study demonstrate reasonable precision in ruling out and ruling in cancer of any volume. Further analyses need to be done to define the performance of the Histoscanning at key tumour volumes. The blinded verification phase will, as a result of these data, be initiated in the near future in order to confirm the status of HistoScanning in diagnosis, monitoring, targeting and assessing response to therapy.

Conclusions: Contrast-enhanced ultrasound is a promising tool for showing the extent of ablated (devascularized) and living (enhancing) tissue after HIFU treatment. If performed at the end of the treatment, in the operating room, it might allow immediate retreatment in case of incomplete tissue destruction.



P56 PENIS AND TESTIS TUMOURS Friday, 20 March, 15.45-17.15, Room A3

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Vascular inflow of the prostate evaluated by power Doppler spectrum ultrasonography: Evidence of tumour angiogenesis in Prostate cancer Tsai Y-S., Tzai T-S., Chen Y-H., Tong Y-C. National Cheng Kung University, Dept. of Urology, Tainan, Taiwan Introduction & Objectives: To evaluate prostatic vascular inflow by measuring the peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI) of vessels of bilateral neurovascular bundles (NVB) using power Doppler ultrasonography, in patients with benign prostatic hyperplasia (BPH), or clinically suspicious prostate cancer. Material & Methods: From Jan., 2007 to Oct., 2008, 228 men (83 with BPH and 145 with clinically suspicious prostate cancer; Mean age 66 years) were prospectively evaluated by power Doppler ultrasonography. Clinically suspicious prostate cancer patients who had either rinsing PSA (more than 4.0 ng/ml) or abnormal digital rectal examination (DRE) were categorized into benign or malignant disease according to transrectal ultrasound-guided biopsy report. The biopsy strategy is bilateral randomly six to ten biopsy cores. BPH patients only who had neither any previous BPH therapy nor clinically suspicious prostate cancer were enrolled as a control. The values of PSV, EDV, and RI of bilateral NVB vessels were assessed by one investigator. The differences of prostate blood inflow among three groups were compared side by side using unpaired or paired t-test. Results: Biopsy results from 145 patients with clinically suspicious prostate cancer demonstrated that there were 48 with bilateral malignancy, 24 with unilateral malignancy, and 73 with benign diseases. The differences of Doppler spectral parameters were illustrated as two figures. Totally, the malignant prostate halves had significantly higher PSV and EDV, lower RI of NVB vessels (Figure 1). Among three parameters, EDV also showed the consistent significance from the paired ttest (Figure 2). Conclusions: The existence of malignant prostate tumours was associated with larger blood inflow and lower vascular resistance, indicative of requirements of oxygen and nutrition. EDV was the most significant parameter.

Eur Urol Suppl 2009;8(4):356

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Post-chemotherapy retroperitoneal lymph node dissection for testicular germ cell tumours: Is surgery indicated in all and is bilateral template necessary? Kakiashvili D., Anson-Cartwright L., Moore M., Sturgeon G.F.G., Zuniga A., Warde P.R., Chung P., Liu J., Ma C., Jewett M.A.S. University of Toronto, Dept. of Surgical Oncology (Urology), Toronto, Canada Introduction & Objectives: Post-chemotherapy (PC) bilateral retroperitoneal lymph node dissection with sympathetic nerve sparing (NS pc-RPLND) when feasible for testicular germ cell residual masses has been our standard of care. We have not routinely performed lumpectomy (resection of gross residual disease only) or modified template dissection (MTD). We have retrospectively evaluated our experience to assess the theoretical efficacy of lumpectomy and MTD in comparison to full bilateral dissection. We assessed safety of observation only in patients with clinically normal retroperitoneum (RP) after chemotherapy. Material & Methods: The charts of the 346 consecutive patients from the Princess Margaret Hospital Testis Tumour Clinic with residual normalized tumour marker RP disease after primary chemotherapy from 1978 to July 2007 were reviewed. Full bilateral pc-RPLND with postganglionic sympathetic nerve preservation where possible was done in 235(5/240 incomplete or MTD). However, 106 who had normal PC retroperitoneum (mass size <1 cm) underwent observation only. The pathological characteristics of the resected residual mass including size (<=2, 2 - 5 and > 5 cm) and location (left para-aortic, inter-aorto-caval or right para-caval zones) were recorded. The mass seen on CT was an identifiable separate specimen. The hypothetical efficacy of less surgery limited to lumpectomy or MTD was assessed. Possible association of mass location, size and histology with less surgery was calculated by logistic regression. Results: The median residual mass size was 6.5 cm (0.5-21). NS was feasible in 52.8% of cases. Histology of the residual mass was carcinoma [Ca ± teratoma(T)] in 39(16.6 %), T only in 129(54.9%), or necrosis/fibrosis (N) in 67 (28.5%), respectively. In the last 134, 18(13.4%) were Ca. Tumour, usually T, was present outside the lumpectomy or MTD specimen in 50 (21.4 %) and 11(4.7%) of cases respectively (p<0.0001). Only mass histology correlated with the risk of incomplete resection with lumpectomy [Ca 23.1, T 30.2 and N 3 % (p = 0.002)]. No patients from those 106 with normal post-chemotherapy RP relapsed. Conclusions: Full bilateral template should be standard of care in post-chemotherapy setting. Lumpectomy and MTD result in incomplete resection of residual disease. The significance of microscopic residual disease is uncertain and those with complete radiological RP response might not need pc-RPLND. NS is feasible in >50% of pc-RPLND despite residual mass.