Multiparametric and functional MRI for response evaluation in rectal cancer after chemoradiotherapy

Le cancer colo-rectal est un problème de santé publique majeur dans les pays développés. Le cancer du rectum est défini comme une marge distale de la tumeur à moins de 15 cm de la marge anale. Sa prise en charge optimale impose une discussion entre une chirurgie mutilante emportant les sphincters ou une chirurgie conservatrice laissant en place l'appareil sphinctérien et évitant l'incontinence et la colostomie. L’Imagerie par résonance magnétique (IRM) est l’examen de référence pour le diagnostic de la tumeur initiale. Dans projet, nous avons utilisé des outils IRM modernes comme la volumétrie et l’imagerie de diffusion dans l’évaluation thérapeutique des cancers du rectum après chimioradiothérapie.Nous avons ainsi montré que la variation de volume tumoral au cours du traitement du cancer du rectum était associée à une survie sans récidive à 5 ans : les patients dont le volume tumoral diminuait d'au moins 70% au cours du traitement néoadjuvant avaient une survie à 5 ans sans récidive et un grade de régression histologique significativement plus élevée que chez les patients dont le volume diminuait de moins de 70%. En utilisant la même technique de volumétrie tumorale tridimensionnelle au cours d'un essai thérapeutique, nous avons également montré pour la première fois que la variation précoce de volume tumoral du rectum au cours du traitement néoadjuvant par chimiothérapie seule pouvait prédire le succès du traitement ultérieur par radio-chimiothérapie puis chirurgie. L'étude de la variation précoce de volume tumoral est actuellement utilisée dans un essai randomisé prospectif multicentrique dans lequel la variation de volume tumoral du rectum après radio-chimiothérapie néoadjuvante chez des patients avec tumeur avancée (T3c, T4) est le déterminant de la poursuite d'un traitement radio-chimiothérapique néoadjuvant ou le traitement chirurgical radical (essai GRECCAR4, ClinicalTrials.gov NCT01333709). Nous nous sommes ensuite intéressés à l’imagerie de diffusion et en particulier l’IVIM marqueur prédictif de réponse thérapeutique. Dans cette étude, la diffusion pure permettait d’obtenir des résultats prometteurs pour l’évaluation de la réponse au traitement néoadjuvant. Finalement, nous présenterons les perspectives de recherche concernant un type particulier de réponse, les réponses colloïdes.Colo-Rectal Cancer is the third most commonly diagnosed cancer in males and the second in females. Around 30% of all colorectal cancers are diagnosed in the rectum. Despite the major improvements that have been made management of rectal cancer still remains a challenge. Chemoradiotherapy (CRT) followed by surgery has been widely adopted for the management of locally advanced rectal cancers because this approach increases the probability of anal sphincter preservation, decreases the local recurrence rate and decreased the risk of colostomy. As we enter the era of personalized medicine with therapies stratified according to the risk of local or distant recurrence, imaging has become an essential tool in the preoperative decision making, to avoid both under- and overtreatment. Magnetic Resonance (MR) imaging is now an essential tool to enable the oncology team to make appropriate treatment decisions. First, we demonstrated that tumor shrinkage after preoperative chemotherapy–radiation therapy was associated with good response. Second, we demonstrated that early tumor volume decrease after induction chemotherapy before chemoradiotherapy was as well associated with good patient prognosis. Third, we demonstrated the added value of DW MR imaging for predicting tumor response using IVIM, a more sophisticated diffusion analytic approaches, which allows quantitative parameters that reflect tissue microcapillary perfusion and tissue diffusivity to be derived. In this study we demonstrated that true diffusion was associated with regression grade on pathology. Finally, we will present our perspectives especially in tumor response evaluation in patient with colloidal response

Apport de la volumétrie surrénalienne chez les patients en choc septique

MONTPELLIER-BU Médecine UPM (341722108) / SudocMONTPELLIER-BU Médecine (341722104) / SudocSudocFranceF

Gadolinium-Based Contrast Agent During Pelvic MRI: Contribution to Patient Management in Rectal Cancer

International audienceBACKGROUND:Few publications exist regarding gadolinium-enhanced sequences in rectal MRI. None have evaluated its potential impact on patient management.OBJECTIVE:This study aimed to assess whether gadolinium-enhanced sequences, including dynamic contrast enhancement, change radiologic interpretation and clinical management of rectal cancer.DESIGN:This is a retrospective analysis of 100 rectal MRIs (50 baseline and 50 postneoadjuvant treatment), both without and with gadolinium-enhanced sequences. Treatment plans were rendered based on each radiologic interpretation for each case by a single experienced surgeon. Differences in radiologic interpretation and management were statistically analyzed.SETTINGS:The study was conducted at the Memorial Sloan Kettering Cancer Center.PATIENTS:Patients undergoing rectal MRI between 2011 and 2015 for baseline tumor staging and/or postneoadjuvant restaging were included.MAIN OUTCOME MEASURES:Primary outcome measures were changes in radiologic tumor stage, tumor margins, and surgical planning with the use of gadolinium at baseline and postneoadjuvant time points.RESULTS:At baseline, tumor downstaging occurred in 8 (16%) of 50 and upstaging in 4 (8%) of 50 with gadolinium. Postneoadjuvant treatment, upstaging occurred in 1 (2%) of 50 from T2 to T3a. At baseline, mean distances from tumor to anorectal ring, anal verge, and mesorectal fascia were not statistically different with gadolinium. However, in 7 patients, differences could have resulted in treatment changes, accounted for by changes in relationships to anterior peritoneal reflection (n = 4), anorectal ring (n = 2), or anal verge (n = 1). Postneoadjuvant treatment, distances to anorectal ring and anal verge (in centimeters) were statistically smaller with gadolinium (p = 0.0017 and p = 0.0151) but could not have resulted in clinically significant treatment changes.LIMITATIONS:This study was limited by its retrospective design.CONCLUSIONS:The use of gadolinium at baseline MRI could have altered treatment in 24% of patients because of differences in tumor stage or position. Postneoadjuvant treatment, gadolinium resulted in statistically smaller distances to sphincters, which could influence surgical decision for sphincter-preserving rectal resection. See Video Abstract at http://links.lww.com/DCR/A444

Response.

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Cystic pancreatic lesions: From increased diagnosis rate to new dilemmas

International audienceCystic pancreatic lesions vary from benign to malignant entities and are increasingly detected on cross-sectional imaging. Knowledge of the imaging appearances of cystic pancreatic lesions may help radiologists in their diagnostic reporting and management. In this review, we discuss the morphologic classification of these lesions based on a diagnostic algorithm as well as the management of these lesions

Rectal cancer MR staging: pearls and pitfalls at baseline examination

International audienceIn recent years, rectal MRI has become a central diagnostic tool in rectal cancer staging. Indeed, rectal MR has the ability to accurately evaluate a number of important findings that may impact patient management, including distance of the tumor to the mesorectal fascia, presence of extramural vascular invasion (EMVI), presence of lymph nodes, and involvement of the peritoneum/anterior peritoneal reflection. Many of these findings are difficult to assess in nonexpert hands. In this review, we present a practical approach for radiologists to provide high-quality interpretations at initial baseline exams, based on recent guidelines from the Society of Abdominal Radiology, Rectal and Anal Cancer Disease Focused Panel. Practical pearls and pitfalls are discussed, focusing on optimization of technique including, patient preparation and protocol recommendations, interpretation, and essentials of reporting

Adrenal gland volume measurement in septic shock and control patients: a pilot study

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Locally recurrent rectal cancer: what the radiologist should know

International audienceDespite advances in surgical techniques and chemoradiation therapy, recurrent rectal cancer remains a cause of morbidity and mortality. After successful treatment of rectal cancer, patients are typically enrolled in a surveillance strategy that includes imaging as studies have shown improved prognosis when recurrent rectal cancer is detected during imaging surveillance versus based on development of symptoms. Additionally, patients who experience a complete clinical response with chemoradiation therapy may elect to enroll in a "watch-and-wait" strategy that includes imaging surveillance rather than surgical resection. Factors that increase the likelihood of recurrence, patterns of recurrence, and the imaging appearances of recurrent rectal cancer are reviewed with a focus on CT, PET CT, and MR imaging

Omental Flap for Hepatic Artery Coverage During Liver Transplantation

International audienceIn 1994, a technique of omental flap interposition to cover the celiac and mesenteric vessels after pancreaticoduodenectomy was described. It aimed to isolate the pancreatic anastomosis from the vessels dissected during pancreaticoduodenectomy. In liver transplantation (LT), the omental flap was initially used to reduce the risk of hepatic artery (HA) kinking. Currently, we use this technique to cover the dissected HA, reducing the consequences of postoperative biliary fistula (BF), particularly the risk of postoperative complications (thrombosis/bleeding). We describe this technique adding a simple modification consisting of covering the HA with an omental flap after completion of the biliary anastomosis. We performed LT with an omental flap to cover the HA vessels in 62 (55 %) of the 112 consecutive patients who underwent LT between January 2012 and July 2013. No postoperative deaths occurred. The rate of BF was 9.7 % (six cases). In the omental flap series, no postoperative thrombosis, HA pseudoaneurysm, or complications occurred. In the six cases of BF, the dissected HAs were completely isolated from the biloma. This simple technique has no specific morbidity; it isolates the HA from the biliary anastomosis and therefore may reduce the risk of severe postoperative HA complications after LT

Endometrial Cancer: Combined MR Volumetry and Diffusion-weighted Imaging for Assessment of Myometrial and Lymphovascular Invasion and Tumor Grade

International audiencePURPOSE:To investigate magnetic resonance (MR) volumetry of endometrial tumors and its association with deep myometrial invasion, tumor grade, and lymphovascular invasion and to assess the value of apparent diffusion coefficient (ADC) histographic analysis of the whole tumor volume for prediction of tumor grade and lymphovascular invasion.MATERIALS AND METHODS:The institutional review board approved this retrospective study; patient consent was not required. Between May 2010 and May 2012, 70 women (mean age, 64 years; range, 24-91 years) with endometrial cancer underwent preoperative MR imaging, including axial oblique and sagittal T2-weighted, dynamic contrast material-enhanced, and diffusion-weighted imaging. Volumetry of the tumor and uterus was performed during the six sequences, with manual tracing of each section, and the tumor volume ratio (TVR) was calculated. ADC histograms were generated from pixel ADCs from the whole tumor volume. The threshold of TVR associated with myometrial invasion was assessed by using receiver operating characteristic curves. An independent sample Mann Whitney U test was used to compare differences in ADCs, skewness, and kurtosis between tumor grade and the presence of lymphovascular invasion.RESULTS:No significant difference in tumor volume and TVR was found among the six MR imaging sequences (P = .95 and .86, respectively). A TVR greater than or equal to 25% allowed prediction of deep myometrial invasion with sensitivity of 100% and specificity of 93% (area under the curve, 0.96; 95% confidence interval: 0.86, 0.99) at axial oblique diffusion-weighted imaging. A TVR of greater than or equal to 25% was associated with grade 3 tumors (P = .0007) and with lymphovascular invasion (P .05). The minimum, 10th, 25th, 50th, 75th, and 90th percentile ADCs were significantly lower in grade 3 tumors than in grades 1 and 2 tumors (P < .02).CONCLUSION:The combination of whole tumor volume and ADC can be used for prediction of tumor grade, lymphovascular invasion, and depth of myometrial invasion