Arnauld Villers

Combined Multiparametric MRI and Targeted Biopsies Improve Anterior Prostate Cancer Detection, Staging, and Grading

OBJECTIVESnTo assess the efficacy of magnetic resonance imaging (MRI) in detection of suspicious anterior prostate lesions, and its role in staging and grading of anterior prostate cancer (APC).nnnMETHODSnBetween January 2008 and August 2009, 243 patients had prostate cancer diagnosed at 12-cores posterior systematic biopsies and additional 2-cores transrectal ultrasound-guided, free-hand-targeted biopsy at any area suspicious for malignancy at prebiopsy multiparametric MRI. We conducted a retrospective study of 45 of 243 (19%) patients with an area suspicious for malignancy at MRI predominantly located in the anterior part of the gland, for which targeted biopsies were positive. Targeted vs systematic biopsy cancer detection rate and upgrading based on length of cancer in the most involved core and Gleason score were measured.nnnRESULTSnOf the 45 patients, 46 separate APCs were identified at MRI with positive targeted biopsies. APC was not detected by systematic biopsies in 21 (46%) cases and detected in 25 (54%) cases. For these 25 cases, median cancer length of the most involved core in targeted compared with systematic biopsies was 8 mm vs 1 mm (P <.001), respectively. Significant Gleason score upgrading was observed in 11 of 25 (44%) cases. Correlation coefficient between the cancer length on targeted biopsies and the antero-posterior diameter of the area suspicious for malignancy on MRI was r(2) = .6 (P <.001). Separate posterior cancer was diagnosed in 26 patients.nnnCONCLUSIONSnTargeted biopsies based on a prebiopsy MRI-detected lesion improved detection rate, volume, and grade of APC compared with currently used 12-cores systematic biopsies.

Prostate cancer characterization on MR images using fractal features

PURPOSEnComputerized detection of prostate cancer on T2-weighted MR images.nnnMETHODSnThe authors combined fractal and multifractal features to perform textural analysis of the images. The fractal dimension was computed using the Variance method; the multifractal spectrum was estimated by an adaptation of a multifractional Brownian motion model. Voxels were labeled as tumor/nontumor via nonlinear supervised classification. Two classification algorithms were tested: Support vector machine (SVM) and AdaBoost.nnnRESULTSnExperiments were performed on images from 17 patients. Ground truth was available from histological images. Detection and classification results (sensitivity, specificity) were (83%, 91%) and (85%, 93%) for SVM and AdaBoost, respectively.nnnCONCLUSIONSnClassification using the authors model combining fractal and multifractal features was more accurate than classification using classical texture features (such as Haralick, wavelet, and Gabor filters). Moreover, the method was more robust against signal intensity variations. Although the method was only applied to T2 images, it could be extended to multispectral MR.

Focal laser interstitial thermotherapy (LITT) at 980 nm for prostate cancer: treatment feasibility in Dunning R3327‐AT2 rat prostate tumour

Whats known on the subject? and What does the study add?

An image guided treatment platform for prostate cancer photodynamic therapy

This study describes a multimodality images based platform to drive photodynamic therapies of prostate cancer using WST 11 TOOKAD Soluble drug. The platform integrates a pre-treatment planning tool based on magnetic resonance imaging and a per-treatment guidance tool based on transrectal ultrasound images. Evaluation of the platform on clinical data showed that prediction of the therapy outcome was possible with an accuracy of 90 %.

Quantified analysis of histological components and architectural patterns of gleason grades in apparent diffusion coefficient restricted areas upon diffusion weighted MRI for peripheral or transition zone cancer locations: Low ADC and Malignant Glands Density

To quantify and compare the histological components and architectural patterns of Gleason grades in cancerous areas with restriction on apparent diffusion coefficient (ADC) maps.

Magnetic Resonance Microscopy May Enable Distinction Between Normal Histomorphological Features and Prostate Cancer in the Resected Prostate Gland.

To determine imaging protocol parameters for characterization of prostate tissue at histological length scales.

Computer-aided analysis of prostate multiparametric MR images: an unsupervised fusion-based approach

ObjectiveThe aim of this study is to provide an automatic framework for computer-aided analysis of multiparametric magnetic resonance (mp-MR) images of prostate.MethodWe introduce a novel method for the unsupervised analysis of the images. An evidential C-means classifier was adapted for use with a segmentation scheme to address multisource data and to manage conflicts and redundancy.ResultsExperiments were conducted using data from 15 patients. The evaluation protocol consisted in evaluating the method abilities to classify prostate tissues, showing the same behaviour on the mp-MR images, into homogeneous classes. As the actual diagnosis was available, thanks to the correlation with histopathological findings, the assessment focused on the ability to segment cancer foci. The method exhibited global sensitivity and specificity of 70 and 88xa0%, respectively.ConclusionThe preliminary results obtained by these initial experiments showed that the method can be applied in clinical routine practice to help making decision especially for practitioners with limited experience in prostate MRI analysis.

Thérapie photodynamique et carcinomes urothéliaux

PURPOSEnPhotodynamic therapy (PDT) is an innovative therapeutic modality in urologic oncology.nnnMATERIAL AND METHODSnWe reviewed the current literature on principles and modalities of PDT in urothelial and penile oncology.nnnRESULTSnPDT has been tested for the treatment recurrent superficial bladder tumors and in situ carcinoma. Carcinologic efficacy has been observed with first generation photosensitizer. The lack of selectivity for tumoral cells was responsible of serious adverse events. Development of selective photosensitizers has reduced the importance of side effects. Data concerning PDT for upper urinary tract and urethra carcinoma are still limited.nnnCONCLUSIONnFirst PDT clinical applications in urothelial oncology have shown some effectiveness at the cost of significant morbidity. The development of selective photosensitizers should help to reduce side effects.

Low-risk prostate cancer selected for active surveillance with negative MRI at entry: can repeat biopsies at 1 year be avoided? A pilot study

PurposeIn patients considered for active surveillance (AS), the use of MRI and targeted biopsies (TB) at entry challenges the approach of routine “per protocol” repeat systematic biopsies (SB) at 1xa0year. This pilot study aimed to assess whether an approach of performing repeat biopsies only if PSA kinetics are abnormal would be safe and sufficient to detect progression.MethodsProspective single-centre study of 149 patients on AS with low-risk PCa, a negative MRI at entry, followed for a minimum of 12xa0months between 01/2007 and 12/2015. Group 1 (nu2009=u200978) patients had per-protocol 12-month repeat SB; group 2 (nu2009=u200971) patients did not. Surveillance tests for tumour progression were for both groups: for cause SB and MRI-TB biopsies if PSA velocity (PSA-V)u2009>u20090.75xa0ng/ml/year, or PSA doubling time (PSADT)u2009<u20093xa0years. The main objectives are to compare the 2-year rates of tumour progression and AS discontinuation between groups. The secondary objectives are to estimate the diagnostic power of PSA-V and PSA-DT, to predict the risk of tumour progression.ResultsOverall, 21 out of 149 patients (14.1%) showed tumour progression, 17.1% for group 1 and 12.3% for group 2, and 31 (21.2%) discontinued AS at 2xa0years. There was no difference between the 2 groups (pu2009=u20090.56). The area under the PSA-V and PSADT curves to predict tumour progression was 0.92 and 0.83, respectively.ConclusionsWe did not find any significant difference for progression and AS discontinuation rate between the 2 groups. The PSA kinetic seems accurate as a marker of tumour progression. These results support the conduct of a multi-centre prospective trial to confirm these findings.