N. Girouin

Evaluation of T2-weighted and dynamic contrast-enhanced MRI in localizing prostate cancer before repeat biopsy

We assessed the accuracy of T2-weighted (T2w) and dynamic contrast-enhanced (DCE) 1.5-T magnetic resonance imaging (MRI) in localizing prostate cancer before transrectal ultrasound-guided repeat biopsy. Ninety-three patients with abnormal PSA level and negative prostate biopsy underwent T2w and DCE prostate MRI using pelvic coil before repeat biopsy. T2w and DCE images were interpreted using visual criteria only. MR results were correlated with repeat biopsy findings in ten prostate sectors. Repeat biopsy found prostate cancer in 23 patients (24.7%) and 44 sectors (6.6%). At per patient analysis, the sensitivity, specificity, positive and negative predictive values were 47.8%, 44.3%, 20.4% and 79.5% for T2w imaging and 82.6%, 20%, 24.4% and 93.3% for DCE imaging. When all suspicious areas (on T2w or DCE imaging) were taken into account, a sensitivity of 82.6% and a negative predictive value of 100% could be achieved. At per sector analysis, DCE imaging was significantly less specific (83.5% vs. 89.7%, p < 0.002) than T2w imaging; it was more sensitive (52.4% vs. 32.1%), but the difference was hardly significant (p = 0.09). T2w and DCE MRI using pelvic coil and visual diagnostic criteria can guide prostate repeat biopsy, with a good sensitivity and NPV.

Prostate cancer transrectal HIFU ablation: detection of local recurrences using T2-weighted and dynamic contrast-enhanced MRI

The objective was to evaluate T2-weighted (T2w) and dynamic contrast-enhanced (DCE) MRI in detecting local cancer recurrences after prostate high-intensity focused ultrasound (HIFU) ablation. Fifty-nine patients with biochemical recurrence after prostate HIFU ablation underwent T2-weighted and DCE MRI before transrectal biopsy. For each patient, biopsies were performed by two operators: operator 1 (blinded to MR results) performed random and colour Doppler-guided biopsies (“routine biopsies”); operator 2 obtained up to three cores per suspicious lesion on MRI (“targeted biopsies”). Seventy-seven suspicious lesions were detected on DCE images (n = 52), T2w images (n = 2) or both (n = 23). Forty patients and 41 MR lesions were positive at biopsy. Of the 36 remaining MR lesions, 20 contained viable benign glands. Targeted biopsy detected more cancers than routine biopsy (36 versus 27 patients, p = 0.0523). The mean percentages of positive cores per patient and of tumour invasion of the cores were significantly higher for targeted biopsies (p < 0.0001). The odds ratios of the probability of finding viable cancer and viable prostate tissue (benign or malignant) at targeted versus routine biopsy were respectively 3.35 (95% CI 3.05–3.64) and 1.38 (95% CI 1.13–1.63). MRI combining T2-weighted and DCE images is a promising method for guiding post-HIFU biopsy towards areas containing recurrent cancer and viable prostate tissue.

Prostate Cancer Ablation with Transrectal High-Intensity Focused Ultrasound: Assessment of Tissue Destruction with Contrast-enhanced US

PURPOSE To assess contrast material-enhanced ultrasonographic (US) findings seen after high-intensity focused ultrasound (HIFU) ablation of prostate cancer and correlate the US findings with post-HIFU biopsy findings. MATERIALS AND METHODS The study was ethics committee approved. Written informed consent was obtained from all patients. Twenty-eight patients referred for HIFU prostate cancer ablation underwent contrast-enhanced prostate US before treatment, gadolinium-enhanced magnetic resonance (MR) imaging and repeat contrast-enhanced US 1-3 days after treatment, and contrast-enhanced US-guided biopsy 30-45 days after treatment. The contrast-enhanced US enhancement patterns of the biopsy sites--assigned a score of S0 for no enhancement, S1 for mild and/or patchy enhancement, or S2 for marked enhancement--were compared with corresponding biopsy findings, which were assigned a score of B0 for necrosis and/or fibrosis without viable prostate gland tissue, B1 for vascularized tissue without viable gland tissue, or B2 for viable gland tissue (benign or malignant). Then, six additional patients underwent contrast-enhanced prostate US 15-30 minutes and 1 day after HIFU ablation, and the results of these two US examinations were compared. RESULTS Contrast-enhanced US performed on days 1-3 and days 30-45 after HIFU ablation depicted a large devascularized zone with peripheral enhancing areas that were localized anteriorly in all 28 patients, posteriorly in nine, laterally in five, and at the apex in 20 patients. MR findings were concordant. At biopsy, viable gland tissue was found at nine (6.2%) of 146 S0 sites, 10 (34%) of 29 S1 sites, and 44 (60%) of 73 S2 sites. The odds ratios for finding viable tissue (score B1 or B2) at S1 and S2 sites as opposed to S0 sites were 21 (95% confidence interval [CI]: 6, 71) and 73 (95% CI: 22, 243), respectively (P < .0001). Contrast-enhanced US performed 15-30 minutes and 1 day after treatment in the six additional patients had similar findings. CONCLUSION Contrast-enhanced US is a promising tool for distinguishing between ablated (devascularized) and viable (enhancing) tissue immediately after HIFU treatment.

Détection par IRM des récidives locales du cancer de prostate après traitement par ultrasons focalisés de haute intensité (HIFU) transrectaux : étude préliminaire

Resume MR detection of local prostate cancer recurrence after transrectal highintensity focused US treatment: preliminary results. J Radiol 2008;89:571-7 Purpose. To assess T2W and dynamic: contrast-enhanced (DCE) MR imaging in the detection of local tumor recurrence after transrectal high-intensity focused US (HIFU) treatment. Materials and methods. Fifteen patients treated by HIFU for prostate cancer were referred for MR due to biological evidence of tumor recurrence. Axial, sagittal and coronal T2W images and DCE images (12 3-mm thick axial images, temporal resolution: 15 seconds) were obtained first. Transrectal biopsies were then obtained under US guidance. MR findings were compared to biopsy results for 10 prostate sectors. Results. Biopsies demonstrated tumor recurrence in 13/15 patients (23/ 108 sectors). On T2W images, the treated prostate tissue was diffusely hypointense which interfered with interpretation. Three patients (5 sectors) had suspicious areas of T2W signal abnormality and 15 patients (29 sectors) had suspicious areas on DCE scans. An analysis per sector for T2W and DCE imaging showed sensitivity, specificity, positive predictive and negative predictive values respectively of 0.13, 0.98, 0.6 and 0.81 and 0.70, 0.85, 0.55 and 0.91. DCE MR was strongly predictive of positive biopsy results (Odds ratio: 12.8 (95% confidence interval: 4.4-37.3)) whereas T2W imaging was not (Odds ratio: 4.0 (95% confidence interval: 0.5-30)). Conclusion. MR, especially DCE MR, is promising for the detection and localization of local prostate cancer recurrence after transrectal HIFU treatment. Objectif. Evaluer l’IRM T2 et dynamique dans la detection des

Location of residual cancer after transrectal high-intensity focused ultrasound ablation for clinically localized prostate cancer.

Study Type – Therapy (case series)

Endovascular Treatment of Juxta-anastomotic Venous Stenoses of Forearm Radiocephalic Fistulas: Long-term Results and Prognostic Factors

PURPOSE To evaluate long-term results of endovascular procedures in treatment of venous juxta-anastomotic stenoses (JASs) of native forearm radiocephalic arteriovenous fistulas (AVFs) and to identify prognostic factors influencing these results. MATERIALS AND METHODS During a 124-month period, 147 endovascular interventions were performed in 75 forearm radiocephalic AVFs with JASs defined as stenoses located within the first 5 cm of the outflow vein. Prognostic factors included patient characteristics (age, sex, diabetes), AVF-related characteristics (location on forearm, age, maturity), stenosis-related characteristics (position relative to anastomosis, length, and degree), and degree of residual stenosis and delay of restenosis after the first endovascular procedure. RESULTS At 1 and 3 years, access primary patency (PP) rates were 46.6% (95% confidence interval [CI], 36.3%-59.9%) and 25.5% (95% CI, 15.7%-41.6%) and assisted PP (APP) rates were 81.3% (95% CI, 72.6%-91.1%) and 63.2% (95% CI, 50.6%-79.0%), respectively. Stenosis degree of 50%-75% (P = .017), stenosis length of 10 mm or more (P = .017), and time before first restenosis of less than 6 months (P = .03) significantly increased the frequency of endovascular procedures during follow-up. However, only the degree of residual stenosis after the first endovascular treatment significantly affected long-term APP (P = .039). When residual stenosis was less than 50%, 1- and 2-year access APP rates were 84.6% (95% CI, 75.8%-94.4%) and 76.1% (95% CI, 64.6%-89.6%), respectively. When it was at least 50%, the respective APP rates were 62.3% (95% CI, 38.9%-99.9%) and 46.8% (95% CI, 22.4%-97.7%). CONCLUSIONS Endovascular treatment of JASs in forearm radiocephalic AVFs provides good long-term results except when the residual stenosis after the first procedure is 50% or more. In that case, the optimal treatment remains to be determined.

Scanner abdomino-pelvien en phase portale : pensons à la prostate !

e cancer de prostate est une patho-logie tres frequente, au premierrang des cancers de l’homme, dontle depistage repose sur le couple toucherrectal (TR)/ dosage des PSA qui seracomplete par des ponctions biopsiesprostatiques echo-guidees en cas d’ano-malie (1). L’IRM est surtout utiliseepour le bilan d’extension local (2). Si lescanner peut etre utile pour rechercherune extension ganglionnaire dans lestumeurs a risque (3), il est courammentadmis que sa sensibilite n’est pas suffi-sante pour detecter de petites tumeursintraprostatiques.Nous rapportons un cas ou le diagnosticde cancer de prostate a ete evoque, nonpas devant une anomalie du TR ou uneelevation des PSA, mais devant uneanomalie de decouverte fortuite sur unscanner realise pour une toute autre pa-thologie.

Localisation des recidives locales apres traitement du cancer de prostate par ultrasons focalises

Objectifs Definir les localisations preferentielles des recidives locales du cancer de prostate apres traitement par ultrasons focalises de haute intensite (HIFU). Materiels et methodes Etude retrospective de 317 biopsies de prostate (PBP) apres traitement HIFU. Les PBP etaient realisees systematiquement 3-6 mois apres traitement (« PBP systematiques ») ou en cas de hausse ulterieure des PSA (« Recidive biologique ») ; 136 biopsies de vesicules seminales ont ete realisees en cas de recidive biologique ou de baisse insuffisante du taux de PSA apres traitement. Resultats Le taux de positivite des « PBP systematiques » etait de 32 % pour les traitements initiaux et de 54 % pour les retraitements. 49,2 % des sextants positifs etaient a l’apex, 28,4 % en partie moyenne et 22,4 % a la base, soit une atteinte apicale significativement plus frequente que sur les biopsies pre-therapeutiques (p Conclusion Les recidives apres traitement HIFU du cancer de prostate sont plus frequentes a l’apex, vraisemblablement du fait de la marge de securite imposee par le sphincter externe. Les recidives dans les vesicules seminales ne sont pas exceptionnelles.

AGU12 IRM prostatique : auto-apprentissage sur CD-ROM

Objectifs Proposer un outil pedagogique d’auto-formation pour le radiologue non specialiste permettant de connaitre les bases d’interpretation et les pieges principaux de l’IRM prostatique. Materiels et methodes A partir d’une base de donnees comprenant environ 500 IRM de prostate realisees a 1.5T, dont 150 avec une correlation histologique (prostatectomie radicale), des dossiers didactiques ont ete colliges pour creer un outil d’auto-apprentissage multiplateforme (MAC/PC) sous forme d’un CD-Rom interactif. Les IRM comprennent toutes des sequences T2 et des sequences dynamiques. Les dossiers sont groupes autour de 3 chapitres : detection tumorale, bilan d’extension loco-regionale, malformations du carrefour uro-genital. Des dossiers simples, correspondant a des cas typiques sont d’abord proposes, puis des dossiers plus complexes permettant de discuter les pieges d’interpretation et les limites de l’examen. Resultats Cet outil d’auto-formation permet dans un temps court (45 minutes environ) de connaitre l’anatomie normale et les aspects pathologiques de la prostate en IRM, ainsi que les avantages et inconvenients des differentes sequences utilisees. Conclusion L’IRM occupe une place importante dans la prise en charge des pathologies prostatiques, notamment grâce aux progres des nouvelles machines et a l’apport des sequences dynamiques. Cet outil d’auto-formation permet d’apprendre les notions de base indispensables.

IRM dynamique de la prostate a faible resolution spatiale : est-ce bien raisonnable

Objectifs Evaluer une technique d’IRM dynamique tres simple (faible resolution temporelle, criteres diagnostiques visuels) dans la detection et la localisation des foyers d’adenocarcinome prostatique. Materiels et methodes Quarante-six patients ont ete explores par IRM avant prostatectomie radicale. En complement des sequences T2, une sequence dynamique (14 coupes, 30 secondes) a ete repetee 3 fois apres injection d’un bolus de Gd-DOTA. La prostate a ete divisee en 20 secteurs (12 pour la zone peripherique, 6 pour les zones transitionnelles, 2 pour les vesicules seminales). Trois lecteurs ont independamment relu les images dynamiques et T2 et precise la presence de cancer dans les 20 secteurs et le nombre de nodules tumoraux, en utilisant des criteres purement visuels. Les resultats ont ete compares aux resultats histologiques. Resultats Pour la detection des secteurs envahis, la sequence dynamique etait nettement plus sensible (0,46-0,58 versus 0,18-0,26, p Conclusion Meme avec une technique simple, l’IRM dynamique est significativement plus sensible que l’IRM T2 dans la detection des nodules tumoraux intra-prostatiques.