Topography of the Chimpanzee Corpus Callosum

The corpus callosum (CC) is the largest commissural white matter tract in mammalian brains, connecting homotopic and heterotopic regions of the cerebral cortex. Knowledge of the distribution of callosal fibers projecting into specific cortical regions has important implications for understanding the evolution of lateralized structures and functions of the cerebral cortex. No comparisons of CC topography in humans and great apes have yet been conducted. We investigated the topography of the CC in 21 chimpanzees using high-resolution magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). Tractography was conducted based on fiber assignment by continuous tracking (FACT) algorithm. We expected chimpanzees to display topographical organization similar to humans, especially concerning projections into the frontal cortical regions. Similar to recent studies in humans, tractography identified five clusters of CC fibers projecting into defined cortical regions: prefrontal; premotor and supplementary motor; motor; sensory; parietal, temporal and occipital. Significant differences in fractional anisotropy (FA) were found in callosal regions, with highest FA values in regions projecting to higher-association areas of posterior cortical (including parietal, temporal and occipital cortices) and prefrontal cortical regions (p<0.001). The lowest FA values were seen in regions projecting into motor and sensory cortical areas. Our results indicate chimpanzees display similar topography of the CC as humans, in terms of distribution of callosal projections and microstructure of fibers as determined by anisotropy measures

Cortical Representation of Lateralized Grasping in Chimpanzees (Pan troglodytes): A Combined MRI and PET Study

Functional imaging studies in humans have localized the motor-hand region to a neuroanatomical landmark call the KNOB within the precentral gyrus. It has also been reported that the KNOB is larger in the hemisphere contralateral to an individual's preferred hand, and therefore may represent the neural substrate for handedness. The KNOB has also been neuronatomically described in chimpanzees and other great apes and is similarly associated with handedness. However, whether the chimpanzee KNOB represents the hand region is unclear from the extant literature. Here, we used PET to quantify neural metabolic activity in chimpanzees when engaged in unilateral reach-and-grasping responses and found significantly lateralized activation of the KNOB region in the hemisphere contralateral to the hand used by the chimpanzees. We subsequently constructed a probabilistic map of the KNOB region in chimpanzees in order to assess the overlap in consistency in the anatomical landmarks of the KNOB with the functional maps generated from the PET analysis. We found significant overlap in the anatomical and functional voxels comprising the KNOB region, suggesting that the KNOB does correspond to the hand region in chimpanzees. Lastly, from the probabilistic maps, we compared right- and left-handed chimpanzees on lateralization in grey and white matter within the KNOB region and found that asymmetries in white matter of the KNOB region were larger in the hemisphere contralateral to the preferred hand. These results suggest that neuroanatomical asymmetries in the KNOB likely reflect changes in connectivity in primary motor cortex that are experience dependent in chimpanzees and possibly humans

Consensus guidelines for the definition of time-to-event end points in image-guided tumor ablation: results of the SIO and DATECAN initiative

International audienceThere is currently no consensus regarding preferred clinical outcome measures following image-guided tumor ablation or clear definitions of oncologic end points. This consensus document proposes standardized definitions for a broad range of oncologic outcome measures with recommendations on how to uniformly document, analyze, and report outcomes. The initiative was coordinated by the Society of Interventional Oncology in collaboration with the Definition for the Assessment of Time-to-Event End Points in Cancer Trials, or DATECAN, group. According to predefined criteria, based on experience with clinical trials, an international panel of 62 experts convened. Recommendations were developed using the validated three-step modified Delphi consensus method. Consensus was reached on when to assess outcomes per patient, per session, or per tumor; on starting and ending time and survival time definitions; and on time-to-event end points. Although no consensus was reached on the preferred classification system to report complications, quality of life, and health economics issues, the panel did agree on using the most recent version of a validated patient-reported outcome questionnaire. This article provides a framework of key opinion leader recommendations with the intent to facilitate a clear interpretation of results and standardize worldwide communication. Widespread adoption will improve reproducibility, allow for accurate comparisons, and avoid misinterpretations in the field of interventional oncology research. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Liddell in this issue

Combining Local and Regional Therapeutic Modalities to Treat Hepatic Malignancies

Hepatocellular carcinoma and metastatic colon cancer have proven to be challenging problems in oncology today. Currently multiple treatment options are available for treating patients with these diseases, and for this reason, a multimodality and multidisciplinary approach is needed to optimize the effectiveness of treatment. Local ablation techniques along with intra-arterial therapy may be complementary and therefore increase survival in patients being treated for hepatocellular carcinoma and metastatic colon cancer. With proper patient selection, further improvement in treatment outcomes can be achieved when these techniques are combined with surgical resection and multidrug systemic chemotherapy. Therefore, it is imperative that interventional radiologists work closely with our colleagues in other medical and surgical specialties to provide our patients with the best possible treatment options

Lipiodol transarterial chemoembolization for hepatocellular carcinoma: A systematic review of efficacy and safety data

Transarterial chemoembolization (TACE) using lipiodol-based regimens, including the administration of an anticancer-in-oil emulsion followed by embolic agents, is widely used in the treatment of hepatocellular carcinoma (HCC). This approach has been supported by meta-analyses of randomized, controlled trials (RCTs) performed more than a decade ago. We performed a systematic review to understand current efficacy and safety data of lipiodol TACE in treatment of HCC. A search of the literature published between January 1, 1980 and June 30, 2013 was performed using MEDLINE and EMBASE databases. All potentially relevant publications were reviewed and articles were selected based on predefined inclusion and exclusion criteria. Of a total of 1,564 articles reviewed, 101 articles, including a total of 10,108 patients treated with lipiodol TACE, were selected for the efficacy analysis. Objective response rate was 52.5% (95% confidence interval [CI]: 43.6-61.5). Overall survival (OS) was 70.3% at 1 year, 51.8% at 2 years, 40.4% at 3 years, and 32.4% at 5 years. Median OS was 19.4 months (95% CI: 16.2-22.6). A total of 217 articles presenting precise description on numbers of adverse events (AEs) were selected for the safety review: In these studies, a total of 21,461 AEs were reported in 15,351 patients. Liver enzyme abnormalities were the most commonly observed AE, followed by the symptoms associated with postembolization syndrome. Overall mortality rate was 0.6% and the most common cause of death was related to acute liver insufficiency. Conclusions: In a systematic literature review, survival figures of HCC patients undergoing lipiodol TACE appear to be in line with those reported in previous RCTs, and no new or unexpected safety concerns were identified. (Hepatology 2016;64:106â\u80\u93116)

Preoperative Embolization

Preoperative embolization procedures are constantly evolving and allow the performance of, or improve the outcome of, subsequent surgical interventions. Currently, some of the more frequently performed procedures in this group are portal vein embolization (PVE) in anticipation of extended liver resection, preoperative embolization of hypervascular tumors, and chemoembolization of hepatocellular carcinoma (HCC) as a bridge to liver transplantation. The indications, technique, and results of these procedures will be reviewed

Percutaneous in utero thoracoamniotic shunt creation for fetal thoracic abnormalities leading to nonimmune hydrops

PURPOSE: To describe a transabdominal, transuterine Seldinger-based percutaneous approach to create a shunt for treatment of fetal thoracic abnormalities. MATERIALS AND METHODS: Five fetuses presented with nonimmune fetal hydrops secondary to fetal thoracic abnormalities causing severe mass effect. Under direct ultrasound guidance, an 18-gauge needle was used to access the malformation. Through a peel-away sheath, a customized pediatric transplant 4.5-F double J ureteral stent was advanced; the leading loop was placed in the fetal thorax, and the trailing end was left outside the fetal thorax within the amniotic cavity. RESULTS: Seven thoracoamniotic shunts were successfully placed in five fetuses; one shunt was immediately replaced because of displacement during the procedure, and another shunt was not functioning at follow-up requiring insertion of a second shunt. All fetuses had successful decompression of the thoracic malformation, allowing lung reexpansion and resolution of hydrops. Three of five mothers had meaningful (\u3e 7 d) prolongation of their pregnancies. All pregnancies were maintained to \u3e 30 weeks (range, 30 weeks 1 d-37 weeks 2 d). There were no maternal complications. CONCLUSIONS: A Seldinger-based percutaneous approach to draining fetal thoracic abnormalities is feasible and can allow for prolongation of pregnancy and antenatal lung development and ultimately result in fetal survival

Transarterial Treatment of Colorectal Cancer Liver Metastases with Irinotecan-Loaded Drug-Eluting Beads: Technical Recommendations

Transcatheter hepatic arterial administration of irinotecan-loaded drug-eluting beads (DEBIRI) is used to treat liver-only or liver-dominant metastatic disease from colorectal cancer (CRC). Eligibility for DEBIRI should be established in each individual patient by a multidisciplinary team based on comprehensive clinical, imaging, and laboratory assessment. Standardization of DEBIRI technique and protocols would be expected to lead to improved efficacy and safety. The present article provides a set of technical recommendations for the use of DEBIRI in the treatment of hepatic CRC metastases