Assessment of change in prostate volume and shape following surgical resection through co-registration of in-vivo MRI and fresh specimen ex-vivo MRI.

AIM: To compare the size and shape of the prostate between in-vivo and fresh ex-vivo magnetic resonance imaging (MRI), in order to quantify alterations in the prostate resulting from surgical resection. MATERIAL AND METHOD: Ten patients who had undergone 3 T prostate MRI using a phased-array coil and who were scheduled for prostatectomy were included in this prospective study. The ex-vivo specimen underwent MRI prior to formalin fixation or any other histopathological processing. Prostate volume in vivo and ex vivo was assessed using planimetry. Prostate shape was assessed by calculating ratios between the diameters of the prostate in all three dimensions. RESULTS: Mean prostate volume was significantly smaller ex vivo than in vivo (39.7 ± 18.6 versus 50.8 ± 26.8 cm(3); p = 0.008), with an average change in volume of -19.5%. The right-to-left (RL)/anteroposterior (AP) ratio of the prostate, representing the shape of the prostate within its axial plane, was significantly larger ex vivo than in vivo (1.33 ± 0.14 versus 1.21 ± 0.12; p = 0.015), with an average percent change in RL/AP ratio of the prostate of +12.2%. There was no significant difference between in-vivo and ex-vivo acquisitions in terms of craniocaudal (CC)/AP (p = 0.963, median change = -2.1%) or RL/CC (p = 0.265, median change = +1.3%) ratios. CONCLUSION: The observed volume and shape change following resection has not previously been assessed by comparison of in-vivo and fresh ex-vivo MRI and likely represents loss of vascularity and of connective tissue attachments in the ex-vivo state. These findings have implications for co-registration platforms under development to facilitate improved understanding of the accuracy of MRI in spatial localization of prostate tumours.

Preliminary experience with a novel method of three-dimensional co-registration of prostate cancer digital histology and in vivo multiparametric MRI.

AIM: To assess a novel method of three-dimensional (3D) co-registration of prostate cancer digital histology and in-vivo multiparametric magnetic resonance imaging (mpMRI) image sets for clinical usefulness. MATERIAL AND METHODS: A software platform was developed to achieve 3D co-registration. This software was prospectively applied to three patients who underwent radical prostatectomy. Data comprised in-vivo mpMRI [T2-weighted, dynamic contrast-enhanced weighted images (DCE); apparent diffusion coefficient (ADC)], ex-vivo T2-weighted imaging, 3D-rebuilt pathological specimen, and digital histology. Internal landmarks from zonal anatomy served as reference points for assessing co-registration accuracy and precision. RESULTS: Applying a method of deformable transformation based on 22 internal landmarks, a 1.6 mm accuracy was reached to align T2-weighted images and the 3D-rebuilt pathological specimen, an improvement over rigid transformation of 32% (p = 0.003). The 22 zonal anatomy landmarks were more accurately mapped using deformable transformation than rigid transformation (p = 0.0008). An automatic method based on mutual information, enabled automation of the process and to include perfusion and diffusion MRI images. Evaluation of co-registration accuracy using the volume overlap index (Dice index) met clinically relevant requirements, ranging from 0.81-0.96 for sequences tested. Ex-vivo images of the specimen did not significantly improve co-registration accuracy. CONCLUSION: This preliminary analysis suggests that deformable transformation based on zonal anatomy landmarks is accurate in the co-registration of mpMRI and histology. Including diffusion and perfusion sequences in the same 3D space as histology is essential further clinical information. The ability to localize cancer in 3D space may improve targeting for image-guided biopsy, focal therapy, and disease quantification in surveillance protocols.

[Emergency nephrectomies: retrospective monocentric study, about eight cases]. / Néphrectomies réalisées dans un contexte d'urgence: étude rétrospective, monocentrique à propos de huit cas.

OBJECTIVE: Emergency nephrectomies are rare because of the improvement of the management of urinary tract infections and the development of radio-embolization. Few series of patients have been reported. The objective of our study is to assess the indication, the morbi-mortality and the outcome of the emergency nephrectomy performed in our hospital. PATIENTS: Between January 2011 and November 2012, eight patients underwent an emergency nephrectomy at the University Hospital Center of Caen. The present review reports the characteristics of this emergency nephrectomy and their morbi-mortality. RESULTS: Six women and two men were analyzed retrospectively between January 2011 and November 2012. All patients except one needed intensive care for a multiple-organ failure. All these eight emergency nephrectomies concerned a native kidney with a surgical approach as a lombotomy or subcostal laparotomy. Both patients survived. One patient need a renal dialysis support. CONCLUSION: Emergency nephrectomy are rare. Uncontrolled urinary sepsis represents the main indication. Identifying the population at risk of evolution to the toxic shock is indispensable for a better and faster care and to reduce the mortality bound to the sepsis.

[A new technique for ensuring negative surgical margins during partial nephrectomy: the ex vivo ultrasound control]. / Une nouvelle technique de contrôle des marges de résection au cours de la néphrectomie partielle : l'échographie ex vivo.

OBJECTIVE: To evaluate the feasibility and the efficiency of intraoperative ex vivo ultrasound of resection margins in patients undergoing partial nephrectomy by urologist. PATIENTS AND METHODS: Patients undergoing partial nephrectomy from July 2010 to November 2012 for T1-T2 renal tumors were included in analysis. Tumor margin status was immediately determined by ex vivo ultrasound done by the surgeon himself. Results were compared with margin status on definitive pathological evaluation. RESULTS: A total of 26 men and 15 women with a median age of 61 (30-82) years old were included in analysis. Intraoperative ex vivo ultrasound revealed negative surgical margins in 38 cases and positive margins in two. Final pathological results revealed negative margins in all except one case. Ultrasound sensitivity and specificity were 100% and 97%, respectively. Mean ultrasound duration was 1minute±1. Mean tumor and margin sizes were 3.4±1.8cm and 2.38±1.76mm, respectively. CONCLUSION: Intraoperative ex vivo ultrasound of resection margins in patients undergoing partial nephrectomy by a urologist seemed to be feasible, efficient and easy.