Diffusion-weighted and gadolinium-enhanced dynamic MRI in parotid gland tumors.

PURPOSE: To evaluate the value of diffusion-weighted imaging and dynamic contrast-enhanced MRI for the diagnosis of parotid gland tumors. METHODS: Retrospective review of patients with surgically treated parotid tumors between January 2009 and June 2020, who underwent a preoperative parotid gland MRI including standard morphological sequences, diffusion-weighted echoplanar imaging with apparent diffusion coefficient measurement and T1-weighted gadolinium-enhanced dynamic MRI sequences with Fat Saturation. The lesion was classified between malignant vs benign and precisions regarding its histological type were given when possible. Imaging findings were compared with pathology results. RESULTS: Inclusion of 133 patients (mean age: 53 years). Multiparametric MRI had a sensitivity of 90.3%, a specificity of 77.5%, an overall accuracy of 80.5%, a positive predictive value of 54.9% and a negative predictive value of 96.3% to differentiate benign parotid tumor from malignant ones. Specificity (85.5%) and positive predictive value (67.6%) were improved for cases, where anatomical and functional MRI characteristics were conclusive and consistent with clinical findings. CONCLUSIONS: Combining diffusion-weighted and gadolinium-enhanced dynamic sequences, in addition to morphological ones enables high (> 90%) sensitivity to detect malignant parotid gland tumors. It also gives the possibility to characterize pleomorphic adenomas and Warthin tumors and to avoid fine-needle aspiration in cases of typical imaging presentation and reassuring clinical findings.

Robotically assisted augmented reality system for identification of targeted lymph nodes in laparoscopic gynecological surgery: a first step toward the identification of sentinel node : Augmented reality in gynecological surgery.

BACKGROUND: To prove feasibility of multimodal and temporal fusion of laparoscopic images with preoperative computed tomography scans for a real-time in vivo-targeted lymph node (TLN) detection during minimally invasive pelvic lymphadenectomy and to validate and enable such guidance for safe and accurate sentinel lymph node dissection, including anatomical landmarks in an experimental model. METHODS: A measurement campaign determined the most accurate tracking system (UR5-Cobot versus NDI Polaris). The subsequent interventions on two pigs consisted of an identification of artificial TLN and anatomical landmarks without and with augmented reality (AR) assistance. The AR overlay on target structures was quantitatively evaluated. The clinical relevance of our system was assessed via a questionnaire completed by experienced and trainee surgeons. RESULTS: An AR-based robotic assistance system that performed real-time multimodal and temporal fusion of laparoscopic images with preoperative medical images was developed and tested. It enabled the detection of TLN and their surrounding anatomical structures during pelvic lymphadenectomy. Accuracy of the CT overlay was > 90%, with overflow rates < 6%. When comparing AR to direct vision, we found that scores were significatively higher in AR for all target structures. AR aided both experienced surgeons and trainees, whether it was for TLN, ureter, or vessel identification. CONCLUSION: This computer-assisted system was reliable, safe, and accurate, and the present achievements represent a first step toward a clinical study.

How to Prevent Sarcopenia Occurrence during Neoadjuvant Chemotherapy for Oesogastric Adenocarcinoma?

The aim of this study was to evaluate the impact of a preoperative feeding jejunostomy (FJ) on the occurrence of sarcopenia before and after preoperative chemotherapy for patients with an oesogastric adenocarcinoma (OGA). Forty-six patients with potentially resectable OGA were enrolled in a perioperative chemotherapy protocol. Sarcopenia was evaluated by measuring muscle surfaces (psoas, paraspinal and abdominal wall muscles) on abdominal CT images at the level of the 3rd lumbar vertebra. A FJ was placed in 31 patients (67.4%) before the neoadjuvant treatment (FJ group), while 15 patients (32.6%) started neoadjuvant treatments without FJ (control group). After preoperative chemotherapy, there were significantly more sarcopenic patients in the control group, compared to the FJ group. In the FJ group, 13% of the patients (n = 4) were sarcopenic before treatment and 22.6% of them (n = 7) became sarcopenic after preoperative chemotherapy (p = 0.3). In the control group, if initially only 6.7% (n = 1) of patients were sarcopenic, the majority of the patients (60%, n = 9) became sarcopenic after chemotherapy (p = 0.012). The FJ was an independent risk factor of sarcopenia after neoadjuvant chemotherapy. FJ with enteral nutritional support during the preoperative management of OGA seemed to efficiently counteract sarcopenia occurrence during preoperative chemotherapy.

Vestibular schwannomas with spontaneous shrinkage: about 35 cases.

PURPOSES: The first aim is to describe the epidemiological, clinical, and radiological characteristics of regressive vestibular schwannomas (VS), based on volumetric measurements on MRI to define which regressions are significant. The secondary aim is to look for a correlation between a shrinkage of the tumor and the medical history, and the presence of clinical symptoms. METHODS: We first selected all patients presenting with a VS who underwent two or more MRI of the internal auditory canal on the same 3 T MRI machine retrospectively between January 2013 and June 2018. All MRI images were evaluated independently by two radiologists. The volumetric analysis was performed contrast-enhanced 2D spin-echo T1-weighted sequence and expressed in cubic centimeters. RESULTS: Thirty-five patients presented with a regressive VS on MRI (14%). The annual mean shrinkage rate was 0.08 cm3/year. Eighty percent of the patients present both a shrinkage by more than 0.01 cm3/year and a decrease of the initial tumor volume by more than 20%. The majority of patients are asymptomatic or presented moderate balance disorders, which remained stable or improved over time. Tinnitus was observed in 47% and was stable or improved in the majority of cases and the mean annual mean hearing loss was by < or = 4 dB/year. CONCLUSION: Out of 247 VS, 14% decreased using follow-up (by > or = 2 MRI), and a spontaneous shrinkage greater than 0.01 cm3/year and greater than 20% could be considered significant.

An image-guided (CT) assessment of a new asymmetric balloon for the treatment of epistaxis.

PURPOSE: The main objective was to perform an image-guided (CT) assessment of the efficacy of the CAVI-T™ balloon to compress the sphenopalatine artery (SPA) on cadaver heads, for the management of epistaxis. The secondary objectives were to analyse the deployment and stability of this balloon according to the volume injected into the nasal cavity, to optimise its use. METHODS: A descriptive anatomical study was performed. The catheterization of the SPA was performed on four fresh-frozen heads with a SPA approach through the maxillary sinus, leaving the nasal cavity unscathed. Computed Tomography images were acquired without and with the balloon, inflated by injections of progressive volumes of diluted iodine, for optimal contrast with the surrounding tissues. We evaluated the positioning of the balloon according to two predetermined markers on the device. RESULTS: Out of 68 image-guided acquisitions, the CAVI-T™ balloon compressed the SPA in 88% of cases. The other nasal cavity structures were compressed in 86% to 100% of the cases, depending on the positioning of the CAVI-T™ balloon, therefore allowing a complete obstruction of the nasal cavity. The device remained stable upon inflation and did not obstruct the nasopharynx. CONCLUSION: The CAVI-T™ balloon provided effective compression of the SPA and the different structures of the nasal cavity.

Imaging of facial neuritis using T2-weighted gradient-echo fast imaging employing steady-state acquisition after gadolinium injection.

BACKGROUND: MRI is the modality of choice for the imaging of facial neuritis. Previously, gadolinium-enhanced T1-weighted imaging of the petrous bone, then FLAIR sequences were thought to be most informative for acute facial neuritis imaging. The aim of this study is to evaluate the value of contrast-enhanced T2-weighted sequence for the diagnosis of acute facial neuritis and compare it to contrast-enhanced T1-weighted and FLAIR sequences. METHODS: We included 50 patients with an acute unilateral idiopathic peripheral facial neuritis. An MRI (3 T) with three sequences was performed (T1-weighted, T2-weighted and FLAIR), all acquired after intravenous contrast-media injection. RESULTS: The contrast-enhanced T2-weighted sequence appeared to be the most accurate one for the diagnosis of acute facial neuritis (Se 94%, Sp 100%, accuracy 98.2%, p < 0.001), with a pathological facial nerve strongly (grade 2-3) enhancing and a homogenous enhancement along the course of the entire facial nerve. Contrast-enhanced T1-weighted (Se 80%, Sp 100%, accuracy 94.1%) and FLAIR sequences (92%, Sp 88%, accuracy 90%, p < 0.001) showed lower accuracy. On T1-weighted sequence, a strong enhancement (blurred margins) of the canalicular segment was observed in 80% of the cases when it was never observed in normal nerves. CONCLUSION: A strong (= iso to hyperintense to the petrous fat signal) and diffuse (all segments) enhancement of the facial nerve on T2-weighted steady-state free precession sequence is a sensitive and specific sign for the diagnosis of acute idiopathic facial neuritis, and appears superior to T1WI and FLAIR sequences.

MRI of endolymphatic hydrops in patients with intralabyrinthine schwannomas: a case-controlled study using non-enhanced T2-weighted images at 3 T.

OBJECTIVE: Like other vestibular schwannomas developing in the internal auditory canal, intralabyrinthine schwannomas (ILS) may present with similar symptoms as in endolymphatic hydrops. Two different studies have described MR saccular hydrops in ~ 30% of internal auditory canal vestibular schwannomas, but this association has never been studied in ILS before. The aim of this work is to study the prevalence of a saccular dilation in ILS, on a T2-weigthed sequence at 3 T, compared to a control group. MATERIAL AND METHODS: All patients presenting with typical ILS between January 2008 and October 2018 were included (n = 28, two patients with bilateral tumors) and compared to a control group (n = 53). All underwent a high-resolution T2-weighted 3D sequence (FIESTA-C). The height and width of the saccule were measured on a coronal plane by two radiologists. RESULTS: The saccule was dilated on the side of the schwannoma in 47% of the cases (p = 0.0006 for the height, p = 0.0487 for the width). Bilateral saccular dilation was observed in 37% of the cases. There was a statistically significant correlation between the presence of a saccular hydrops and balance disorders (p = 0.02) as 50% of the patients with an intralabyrinthine schwannoma who presented with such symptoms had a saccular dilation. CONCLUSION: Forty-seven percent of ILS are associated with homolateral saccular dilation, which is an MR sign of endolymphatic hydrops (bilateral in 37%) and it appears related to the presence of balance disorders. This opens new therapeutic potentialities with the possible use of anti-vertiginous drugs, which could have a beneficial effect on their clinical symptomatology.

Bypassing the Resistance Mechanisms of the Tumor Ecosystem by Targeting the Endoplasmic Reticulum Stress Pathway Using Ruthenium- and Osmium-Based Organometallic Compounds: An Exciting Long-Term Collaboration with Dr. Michel Pfeffer.

Metal complexes have been used to treat cancer since the discovery of cisplatin and its interaction with DNA in the 1960's. Facing the resistance mechanisms against platinum salts and their side effects, safer therapeutic approaches have been sought through other metals, including ruthenium. In the early 2000s, Michel Pfeffer and his collaborators started to investigate the biological activity of organo-ruthenium/osmium complexes, demonstrating their ability to interfere with the activity of purified redox enzymes. Then, they discovered that these organo-ruthenium/osmium complexes could act independently of DNA damage and bypass the requirement for the tumor suppressor gene TP53 to induce the endoplasmic reticulum (ER) stress pathway, which is an original cell death pathway. They showed that other types of ruthenium complexes-as well complexes with other metals (osmium, iron, platinum)-can induce this pathway as well. They also demonstrated that ruthenium complexes accumulate in the ER after entering the cell using passive and active mechanisms. These particular physico-chemical properties of the organometallic complexes designed by Dr. Pfeffer contribute to their ability to reduce tumor growth and angiogenesis. Taken together, the pioneering work of Dr. Michel Pfeffer over his career provides us with a legacy that we have yet to fully embrace.

Importance of signal intensity on T1-weighted spin-echo sequence for the diagnosis of chronic cholesteatomatous otitis.

OBJECTIVE: The aim of our study was to evaluate the importance of a non-injected T1-weighted spin-echo sequence (T1WSE) combined with a non-echo-planar diffusion-weighted (non-EPDW) sequence for the pre-operative detection of cholesteatoma by the radiologist on MRI, compared to surgery. MATERIALS AND METHODS: In this retrospective case review, 113 patients with chronic otitis underwent surgery (gold standard) for a clinical suspicion of cholesteatoma. Our primary outcome was to compare non-EPDW images + a contrast-free T1WSE sequence for cholesteatoma detection. Our secondary outcome was to quantify the signal intensity value of the suspected lesions, relative to the signal intensity of the cerebellum (Sic) to calculate Signal Intensity Ratios (SIR = SI/Sic). The SIR values of cholesteatomatous and non-cholesteatomatous tissue were compared to surgical findings. Receiver-operating characteristic curve analysis determined an optimum SIR cut-off value for the prediction of cholesteatoma. RESULTS: The sensitivity (96.9%) of non-EPDW for the diagnosis of cholesteatoma was high, with good specificity (74.2%), and increased to 85.5% when combined to a T1WSE sequence. Additionally, the mean SIR values (on T1WSE) of cholesteatoma were significantly lower than non-cholesteatomatous tissue (p < 0.05). When nonEPDW and T1WSE were combined, a cut-off SIR value < 1.04, diagnosed cholesteatoma pre-operatively with very high specificity and sensibility (92.7% and 90.3% respectively). CONCLUSION: Our study showed that combining a nonEPDW sequence with the quantitative analysis of contrast-free T1W SE sequence in pre-operative patients enables the correct diagnosis of cholesteatoma with good sensitivity and specificity (> 90%) and reduces risks of false-positive cases for surgeons.

CT and MRI for the diagnosis of perilymphatic fistula: a study of 17 surgically confirmed patients.

BACKGROUND: We evaluated the usefulness of CT and MRI for the diagnosis of perilymphatic fistula (PLF) of the round (RW) and/or oval (OW) windows, with surgery as gold standard. METHODS: We retrospectively enrolled 17 patients who presented a surgically confirmed PLF of the round (RW) or oval (OW) windows. All patients were imaged by CT + MRI (T2W SSFP without contrast) prior to surgery (= gold standard). Two radiologists, analyzed the RW and OW on the side of the clinical symptoms and sensitivity (Se) + Specificity (Sp) were calculated. RESULTS: Round window fistula was the most frequent (71%). The best sign of PLF on imaging was a fluid filling of the window niches, which had good Se (83-100% for RW, 66-83% for OW) and Sp (60% for RW, 91-100% for OW). Disorientation of the footplate and pneumolabyrinth were also only observed in 50% of OW PLF. CONCLUSION: The combination of CT and MRI is a reliable tool for a fast and accurate diagnosis of round and oval window perilymphatic fistula, with good sensitivity (> 80%). The most common sign of PLF on imaging is the presence of a fluid-filling in the RW (especially if > 2/3 of the RW niche) or in the OW niches on both CT and MRI. A disorientation of the footplate or the presence of a pneumolabyrinth are clearly in favor of an oval window perilymphatic fistula.

Pharmacological Inhibition of mTORC2 Reduces Migration and Metastasis in Melanoma.

Despite recent advances in therapy, liver metastasis from melanoma is still associated with poor prognosis. Although targeting the mTOR signaling pathway exerts potent anti-tumor activity, little is known about specific mTORC2 inhibition regarding liver metastasis. Using the novel mTORC2 specific inhibitor JR-AB2-011, we show significantly reduced migration and invasion capacity by impaired activation of MMP2 in melanoma cells. In addition, blockade of mTORC2 induces cell death by non-apoptotic pathways and reduces tumor cell proliferation rate dose-dependently. Furthermore, a significant reduction of liver metastasis was detected in a syngeneic murine metastasis model upon therapy with JR-AB2-011 as determined by in vivo imaging and necropsy. Hence, our study for the first time highlights the impact of the pharmacological blockade of mTORC2 as a potent novel anti-cancer approach for liver metastasis from melanoma.

Extension patterns of vestibular schwannomas towards the middle ear: three new cases and review of the literature.

OBJECTIVE: Middle ear extension of vestibular schwannomas is not a common occurrence, and only a few cases have been described so far in past publications. We report three new cases of vestibular schwannomas extending to the middle ear and reviewed the literature to specify the patterns of such an extension. MATERIALS AND METHODS: We analysed databases of previously published articles to search for additional cases of middle ear extension of vestibular schwannomas and compared them to the cases we have documented. Extension patterns of the tumours were analysed, especially focusing on the extension through the round and oval windows. RESULTS AND CONCLUSION: Middle ear vestibular schwannomas are uncommon tumours and only 13 cases have been published so far. The vestibular schwannoma (internal auditory canal or intralabyrinthine) has to invade the labyrinth first (complete invasion in 88% of the cases, n = 14), before reaching the middle ear. In the majority of cases (69%, n = 11/16), internal auditory canal vestibular schwannomas or intralabyrinthine schwannomas extended in the middle ear though the round window.

Malformations of the lateral semicircular canal correlated with data from the audiogram.

OBJECTIVES: Lateral semicircular canal (LSCC) malformations  are one of the most common inner ear malformations. The purpose of this study is to analyze the prevalence and type of hearing losses associated with LSCC malformations, compared to a control group. MATERIALS AND METHODS: We retrospectively included 109 patients (166 ears) presenting with a CT-confirmed LSCC malformation, compared to a control group (24 patients). The bony island surface and the width of the inner portion of the LSCC were measured to confirm the malformation. There results were correlated to audiogram data: sensorineural (SHNL), mixed (MHL) or conductive hearing loss (CHL) by an otologist. RESULTS: In the LSCC group, 60.9% of patients presented with an audiogram-confirmed hearing loss, especially SNHL (39.2%, n = 65) and MHL (12.7%, n = 21). Hearing was normal in 39.2% (n = 65) of the cases. Bilateral LSCC malformations (n = 57) were frequently associated with hearing loss (80.7%), SNHL in most of the cases (33.3%). Unilateral LSCC malformations were associated with hearing alterations (51.9%, n = 27), but we also observed a high rate (81%, n = 42) of contralateral abnormalities of the audiogram. CONCLUSION: LSCC malformations are commonly associated with hearing loss (61%), especially SHNL (39%). The high rate (81%) of contralateral hearing disturbances in unilateral LSCC malformations should be taken into account in the patient's daily life to avoid triggering or exacerbating any hearing loss. Otologists and radiologists must cooperate to ensure that all malformations are correctly described on CT, especially to improve the patient's education regarding hearing preservation.

Superior vestibular neuritis: improved detection using FLAIR sequence with delayed enhancement (1 h).

INTRODUCTION: Vestibular neuritis is the second cause of vertigo and new imaging protocols using delayed FLAIR with double-dose of gadolinium are proposed for its diagnosis. Our aim is to demonstrate that a single dose of gadolinium is sufficient. METHODS: Thirty-three patients with a unilateral vestibular neuritis are compared to a control group. All patients underwent a FLAIR sequence, 1 hour after intravenous injection of a single dose of gadolinium, on a 1.5 Tesla MRI. Two radiologists analyzed the enhancement intensity of the superior (sup VN) and inferior vestibular nerve (inf VN) and ratios to the signal of the cerebellum were calculated (supVN/C). The statistics were performed using Bayesian analysis. RESULTS: A strong enhancement of the sup VN was observed on the pathological side in 85% of patients with vestibular neuritis. The average signal intensity of the pathological sup VN (139 units ± 44) was more than two times the average intensity in the control group (58.5 units ± 5). The average ratios supVN/C were significantly different between the pathological side in vestibular neuritis (2.43 units ± 0.63) and the control group [1.16 ± 0.14 (Pr(diff > 0) = 1)]. A delayed enhancement > 71.5 units had a sensitivity of 96% and a specificity of 100% for the diagnosis of superior vestibular neuritis. CONCLUSION: A delayed FLAIR sequence, acquired 1 hour after a single dose of gadolinium injection, is a useful method for the diagnosis of vestibular neuritis. An enhancement of the sup VN > 71.5 units was in favor of the diagnosis.

MRI of endolymphatic hydrops in patients with vestibular schwannomas: a case-controlled study using non-enhanced T2-weighted images at 3 Teslas.

OBJECTIVE: Vestibular schwannomas (VS) may present with similar symptoms endolymphatic hydrops. Association between hydrops and internal auditory canal VS has been described by Naganawa et al. (Neuroradiology 53:1009-1015, 2011), but has never been confirmed since. The aim of this work was to study the prevalence of a saccular dilation on a T2-weighted sequence at 3 T MRI in VS compared to a control group. MATERIALS AND METHODS: All patients presenting with typical VS between May 2009 and July 2018 were included (n = 183) and compared to a control group (n = 53). All underwent a high-resolution T2-weighted 3D sequence (FIESTA-C). The height and width of the saccule were measured on a coronal plane by two radiologists. RESULTS: The saccule was dilated on the side of the schwannoma in 28% of the cases (p = 2.81 × 10- 5), with 15.7% of bilateral dilation. Saccular dilation was correlated to sensorineural hearing loss (OR 3.26, p = 0.02). There was also a significant correlation between saccular hydrops on the normal contralateral side of patients with VS and vertigo (p = 0.049), and between saccular hydrops on the side of the tumour and tinnitus (p = 0.006). CONCLUSION: A third (29%) of VS are associated with a saccular dilation on the side of the tumour, which is an MR sign of endolymphatic hydrops (bilateral in 15.7% of the cases) and it appears related to sensorineural hearing loss and tinnitus, as well as vertigo if a contralateral dilation is present. This opens new therapeutic potentialities with the use of anti-vertiginous drugs, which could have a beneficial effect on the clinical symptoms.

Could a Feeding Jejunostomy be Integrated into a Standardized Preoperative Management of Oeso-gastric Junction Adenocarcinoma?

PURPOSE: To evaluate the impact of a feeding jejunostomy (FJ) on the preoperative management of patients with an oesogastric adenocarcinoma (OGA). METHODS: From January 2007 to December 2014, patients with potentially resectable OGA were enrolled in a perioperative chemotherapy protocol. FJ was performed before starting perioperative treatments in patients presenting with dysphagia or with a nutritional risk index (NRI) <97.5. The patients who did not require a FJ served as a control group. RESULTS: Among the 114 patients with OGA consecutively admitted in our surgical department, 88 (77.2%) were enrolled for neoadjuvant treatment. A FJ was placed in 50 patients (56.8%) before the neoadjuvant treatment (FJ group), whereas 38 patients (43.2%) started neoadjuvant treatments without FJ (control group). Ninety-six percent of patients (n = 48) in the FJ group successfully completed the neoadjuvant treatment but only 81.6% of patients without FJ (n = 31; p = 0.004). The FJ group was divided between responders: 37 patients with a weight response (74%), and nonresponders: 13 patients without weight response (26%). In the FJ group, the nutritional response during preoperative chemotherapy was a significant predictive factor for the achievement of second stage oesogastric resection (p = 0.002). CONCLUSIONS: FJ with enteral nutritional support during the preoperative management of OGA is a safe and effective support for the completion of the preoperative chemotherapy. The weight response to the enteral support is a predictor factor for a completion of the preoperative chemotherapy and could identify a group of patients who would have a better chance of reaching radical surgery.

Dual-energy CT in vertebral compression fractures: performance of visual and quantitative analysis for bone marrow edema demonstration with comparison to MRI.

OBJECTIVE: To prospectively evaluate the performance of virtual non-calcium (VNC) dual-energy CT (DECT) images for the demonstration of trauma-related abnormal marrow attenuation in collapsed and non-collapsed vertebral compression fractures (VCF) with MRI as a reference standard. MATERIALS AND METHODS: Twenty patients presenting with non-tumoral VCF were consecutively and prospectively included in this IRB-approved study, and underwent MRI and DECT of the spine. MR examination served as a reference standard. Two independent readers visually evaluated all vertebrae for abnormal marrow attenuation ("CT edema") on VNC DECT images; specificity, sensitivity, predictive values, intra and inter-observer agreements were calculated. A last reader performed a quantitative evaluation of CT numbers; cut-off values were calculated using ROC analysis. RESULTS: In the visual analysis, VNC DECT images had an overall sensitivity of 84%, specificity of 97%, and accuracy of 95%, intra- and inter-observer agreements ranged from k = 0.74 to k = 0.90. CT numbers were significantly different between vertebrae with edema on MR and those without (p < 0.0001). Cut-off values provided sensitivity of 85% (77%) and specificity of 82% (74%) for "CT edema" on thoracic (lumbar) vertebrae. CONCLUSIONS: VNC DECT images allowed an accurate demonstration of trauma-related abnormal attenuation in VCF, revealing the acute nature of the fracture, on both visual and quantitative evaluation.