Initial Experience With Staging Rectal Adenocarcinoma Using 7T Magnetic Resonance Imaging.

BACKGROUND: Magnetic resonance imaging (MRI) has become the preferred method for local staging of rectal cancer. Current MRI technology, operating at 1.5-3 T, results in incorrectly reported tumor depth and therefore inaccurate staging in one-third of individuals. Inaccurate staging can result in suboptimal treatment in patients with rectal cancer and can submit them to unnecessary treatments. The Medical College of Wisconsin Center for Imaging Research houses one of approximately twenty experimental 7 T MRIs worldwide capable of imaging the human pelvis. We present our initial experience with this novel imaging technique for the human rectum. METHODS: This was a prospective observational trial conducted at a single institution. Patients diagnosed with rectal cancer and who underwent low anterior resection or abdominoperineal resection between July 2015 and July 2017 were included. Excised rectal specimens were suspended in a saline-filled container and imaged by MRI at 7T. Tumor depth and lymph node status were determined by a single radiologist who was blinded to the pathologic results. These MRI interpretations were then compared with the pathologic stage. RESULTS: Seven of the 10 patients received neoadjuvant chemoradiation. When using the T1-weighted volumetric interpolated breath-hold examination-flex fat-suppressed sequences, radiologic and pathologic interpretation was identical regarding tumor depth in 7 of 10 patients (70%). Nodal status was correctly interpreted by 7T MRI in 8 of 10 patients (80%). Lymph nodes as small as 2 mm were able to be correctly characterized as harboring malignancy. CONCLUSIONS: We have demonstrated that 7T MRI of the rectum ex vivo has a strong correlation with histologic results. With its superior signal-to-noise ratio and spatial resolution, 7T MRI holds promise in more accurately staging rectal cancer and may be useful in correctly categorizing response to neoadjuvant therapy.

Pouch Volvulus in Patients Having Undergone Restorative Proctocolectomy for Ulcerative Colitis: A Case Series.

BACKGROUND: Restorative proctocolectomy with IPAA improves quality of life in patients with medically refractory ulcerative colitis. Although bowel obstruction is common, pouch volvulus is rare and described only in case reports. Diagnosis can be challenging, resulting in delayed care and heightened morbidity. OBJECTIVE: The purpose of this study was to delineate the symptoms and successful management strategies used in patients with IPAA volvulus that result in pouch salvage. DESIGN: This study was a case series. SETTINGS: The study was conducted at a tertiary referral center for ulcerative colitis in Milwaukee, Wisconsin. PATIENTS: Patients included those with volvulus of the IPAA. MAIN OUTCOME MEASURES: Over the study period (2010-2015), 6 patients were diagnosed with IPAA volvulus. The primary outcomes were symptom manifestation, diagnostic practices, and treatment of pouch volvulus. RESULTS: Six patients with ulcerative colitis were identified with pouch volvulus. The majority (n = 4) underwent a laparoscopic pouch creation and had early symptom manifestation after surgery. Complications preceding volvulus included pouch ulceration (n = 5) and pouchitis (n = 4). The most common presenting symptoms of volvulus were abdominal pain (n = 4) and obstipation (n = 4). Multiple imaging modalities were used, but volvulus was most frequently identified by CT scan. Management was primarily operative (n = 5), composed of excision of the pouch (n = 3), pouch-pexy (n = 1), and detorsion with defect closure (n = 1). Both operative and nonoperative treatment with endoscopic detorsion resulted in low morbidity and improved patient symptoms. LIMITATIONS: This single-institution study is limited by its retrospective design and small number of patients. CONCLUSIONS: IPAA volvulus is a rare and challenging cause of bowel obstruction in ulcerative colitis. Heralding signs and symptoms, such as pouch ulceration and acute obstipation, should initiate a workup for a twisting pouch. Diagnosis, which is multimodal, must occur early to avert necrosis and allow for preservation of a well-functioning pouch. See Video Abstract at http://links.lww.com/DCR/A561.

Thoracostomy tube function not trajectory dictates reintervention.

BACKGROUND: Hemothorax and/or pneumothorax can be managed successfully managed with tube thoracostomy (TT) in the majority of cases. Improperly placed tubes are common with rates near 30%. This study aimed to determine whether TT trajectory affects the rate of secondary intervention. METHODS: A retrospective review of all adult trauma patients undergoing TT placement over a 4-y period was performed. TT trajectory was classified as ideal, nonideal, or kinked-based on anterior-posterior chest x-ray. TTs with sentinel port outside the thoracic cavity were excluded. The primary outcome was any secondary intervention. RESULTS: Four-hundred eighty-six patients and a total of 547 hemithoraces underwent placement and met inclusion criteria. The majority of patients were male (76%), with a median age of 41 y, and majority suffered blunt trauma ideal trajectory was identified in 429 (78.4%). Kinked TTs were noted in 33 (6%) hemothoraces with a 45.5% replacement rate. Review with staff demonstrates inherent bias to replace kinked TTs. The overall secondary intervention rate was 27.8%. Kinked TTs were removed from final analysis due to treatment bias. Subsequent analysis demonstrated no significant difference between ideal and nonideal trajectories (25.1% versus 34.1%, P = 0.09). CONCLUSIONS: Intrathoracic trajectory of nonkinked TTs with the sentinel port within the thoracic cavity does not affect secondary intervention rates, including the rate of surgical intervention.

Clinical Conundrum: Killian-Jamieson Diverticulum with Paraesophageal Hernia.

Killian-Jamieson diverticulum is a outpouching of the lateral cervical esophageal wall adjacent to the insertion of the recurrent laryngeal to the larynx and is much less common in clinical practice than Zenkers Diverticulum. Surgical management of Killian-Jamieson diverticulum requires open transcervical diverticulectomy due to the proximity of the recurrent laryngeal nerve to the base of the pouch. We present a case of a Killian-Jamieson diverticulum associated with a concurrent large type III paraesophageal hernia causing significant solid-food dysphagia, post-prandial regurgitation of solid foods, and chronic cough managed with open transcervical diverticulectomy and laparoscopic paraesophageal hernia repair with Nissen fundoplication.

Food safety knowledge and practices of young adults.

The objective of the study described in this article was to ascertain the food safety knowledge and practices of undergraduate students attending a major American university. The study participants were undergraduate college students (mean age 18.9 +/- 1.14 SD) enrolled in a required health course. The students were invited to take a validated food safety knowledge questionnaire as part of a health risk behavior online survey. The 786 respondents indicated their food is most often prepared at on-campus dining facilities and the majority of the students (72%) felt they were "unlikely or "very unlikely" at risk of foodborne disease. The mean food safety knowledge score of the participants was 10.23 (43%) +/- 4.13 SD (25%-60%), indicating the study population overall has poor knowledge of safe food practices. As a result, food safety educational initiatives and awareness campaigns should be developed to better inform young adults about safe food handling practices and habits.

Predicting Treatment Response From Extracellular Volume Fraction for Chemoradiation Therapy of Pancreatic Cancer.

PURPOSE: Dual-energy computed tomography (DECT) data can be used to calculate the extracellular volume fraction (ECVf) in tumors, which has been correlated with treatment outcome. This study sought to find a correlation between ECVf and treatment response as measured by the change in cancer antigen (CA) 19 to 9 during chemoradiation therapy (CRT) for pancreatic cancer. METHODS AND MATERIALS: Dual-energy CT data acquired during the late arterial contrast phase in the standard radiation therapy simulation on a dual-source DECT simulator for 25 patients with pancreatic cancer, along with their CA19-9 and hematocrit data, were analyzed. Each patient underwent preoperative CRT with a prescription of 50.4 Gy in 28 fractions. The patients were chosen based on the presence of a solid tumor in the pancreas that could be clearly delineated. A region of interest (ROI) was placed in the tumor and in the aorta. From the ratio of the iodine density calculated from the DECT in the ROI and the hematocrit taken at the time of simulation, the ECVf was calculated. The ECVf was then compared with the change in CA19-9 before and after the CRT. Distant metastases as the cause of CA19-9 elevation were ruled out on subsequent restaging images before surgery. The DECT-derived iodine ratio was validated using a phantom study. RESULTS: The DECT-derived iodine concentration agreed with the phantom measurements (R2, 1.0). The average hematocrit, ECVf, and change in CA19-9 during the treatment for the 25 patients was 35.6 ± 5.4%, 7.3 ± 4.9%, and -4.6 ± 21.8 respectively. A linear correlation was found between the ECVf and the change in CA19-9, with an R2 of 0.7: ΔCA19-9 = 3.63 × ECVf - 31.1. The correlation was statistically significant (P = .006). CONCLUSIONS: The calculated ECV fraction based on iodine maps from dual-source DECT may be used to predict treatment response after neoadjuvant chemoradiation therapy for pancreatic cancer.

Predicting Neoadjuvant Treatment Response in Rectal Cancer Using Machine Learning: Evaluation of MRI-Based Radiomic and Clinical Models.

BACKGROUND: Radiomics is an approach to medical imaging that quantifies the features normally translated into visual display. While both radiomic and clinical markers have shown promise in predicting response to neoadjuvant chemoradiation therapy (nCRT) for rectal cancer, the interrelationship is not yet clear. METHODS: A retrospective, single-institution study of patients treated with nCRT for locally advanced rectal cancer was performed. Clinical and radiomic features were extracted from electronic medical record and pre-treatment magnetic resonance imaging, respectively. Machine learning models were created and assessed for complete response and positive treatment effect using the area under the receiver operating curves. RESULTS: Of 131 rectal cancer patients evaluated, 68 (51.9%) were identified to have a positive treatment effect and 35 (26.7%) had a complete response. On univariate analysis, clinical T-stage (OR 0.46, p = 0.02), lymphovascular/perineural invasion (OR 0.11, p = 0.03), and statin use (OR 2.45, p = 0.049) were associated with a complete response. Clinical T-stage (OR 0.37, p = 0.01), lymphovascular/perineural invasion (OR 0.16, p = 0.001), and abnormal carcinoembryonic antigen level (OR 0.28, p = 0.002) were significantly associated with a positive treatment effect. The clinical model was the strongest individual predictor of both positive treatment effect (AUC = 0.64) and complete response (AUC = 0.69). The predictive ability of a positive treatment effect increased by adding tumor and mesorectal radiomic features to the clinical model (AUC = 0.73). CONCLUSIONS: The use of a combined model with both clinical and radiomic features resulted in the strongest predictive capability. With the eventual goal of tailoring treatment to the individual, both clinical and radiologic markers offer insight into identifying patients likely to respond favorably to nCRT.

Auto-segmentation of pancreatic tumor in multi-parametric MRI using deep convolutional neural networks.

PURPOSE: The recently introduced MR-Linac enables MRI-guided Online Adaptive Radiation Therapy (MRgOART) of pancreatic cancer, for which fast and accurate segmentation of the gross tumor volume (GTV) is essential. This work aims to develop an algorithm allowing automatic segmentation of the pancreatic GTV based on multi-parametric MRI using deep neural networks. METHODS: We employed a square-window based convolutional neural network (CNN) architecture with three convolutional layer blocks. The model was trained using about 245,000 normal and 230,000 tumor patches extracted from 37 DCE MRI sets acquired in 27 patients with data augmentation. These images were bias corrected, intensity standardized, and resampled to a fixed voxel size of 1 × 1 × 3 mm3. The trained model was tested on 19 DCE MRI sets from another 13 patients, and the model-generated GTVs were compared with the manually segmented GTVs by experienced radiologist and radiation oncologists based on Dice Similarity Coefficient (DSC), Hausdorff Distance (HD), and Mean Surface Distance (MSD). RESULTS: The mean values and standard deviations of the performance metrics on the test set were DSC = 0.73 ± 0.09, HD = 8.11 ± 4.09 mm, and MSD = 1.82 ± 0.84 mm. The interobserver variations were estimated to be DSC = 0.71 ± 0.08, HD = 7.36 ± 2.72 mm, and MSD = 1.78 ± 0.66 mm, which had no significant difference with model performance at p values of 0.6, 0.52, and 0.88, respectively. CONCLUSION: We developed a CNN-based model for auto-segmentation of pancreatic GTV in multi-parametric MRI. Model performance was comparable to expert radiation oncologists. This model provides a framework to incorporate multimodality images and daily MRI for GTV auto-segmentation in MRgOART.

Estimation of changing gross tumor volume from longitudinal CTs during radiation therapy delivery based on a texture analysis with classifier algorithms: a proof-of-concept study.

BACKGROUND: Adaptive radiation therapy (ART) is moving into the clinic rapidly. Capability of delineating the tumor change as a result of treatment response during treatment delivery is essential for ART. During image-guided radiation therapy (IGRT), a CT or cone-beam CT is taken at the time of daily setup and the tumor is not visible by eye in regions of soft tissue due to low contrast. The scope of this paper is to develop a method using a classifier trained on non-contrast CT textures, to estimate the gross tumor volume (GTV) of the day (GTVd) from daily (longitudinal) CTs acquired during the course of IGRT when the tumor is not visible. METHODS: CT textures from daily diagnostic-quality CTs routinely acquired during IGRT using an in-room CT were analyzed. Pretreatment GTV was delineated from pre-RT diagnostic images and populated to the first daily CT. Maps of first-order textures (mean, SD, entropy, skewness and kurtosis) and short-range second-order textures were created from the first daily CT. The classifier was trained to sort voxels into GTV and surrounding tissue on subsequent daily CTs over the course of RT. Optimum combinations of textures was defined by repeating the training process with all possible texture combinations. The trained classifier was used to identify voxels belonging to the GTVd, based on the CT of the day. Posttreatment GTV delineated from the post-RT follow-up images was populated to the last daily CT and used to validate the last GTVd delineated by the classifier. To demonstrate the concept, the method was described using three representative treatment sites, e.g., lung, breast and pancreatic tumors. RESULTS: Comparing the classifier map generated from a new CT to the initial training CT, the dice coefficient (DC) for GTV in lung is 83% on the eighth treatment and 84% on the last. The DC for the breast GTV is 56% mid-treatment and 65% at the last treatment. In the case of the pancreas with the least in organ tissue contrast, the DC for 4 cases ranges from 21% to 77% for the last treatment compared with the post-RT diagnostic CT. The Housdorff distance (HD) ranged from 2.9 to 5.9 mm with the mean GTV RECIST dimension of 22.75 mm long by 14.7 mm short. CONCLUSIONS: It is feasible to estimate the general region of the GTV of the day from the daily CT acquired during RT, based on CT textures, using a trained voxel classifier algorithm. The obtained GTV may be used as a starting point for an accurate GTV delineation in online adaptive replanning. Further study with larger patient datasets is required to improve the robustness of the algorithms.

Appropriate magnetic resonance imaging techniques for gross tumor volume delineation in external beam radiation therapy of locally advanced cervical cancer.

BACKGROUND: Accurate delineation of the gross tumor volumes (GTV) is a prerequisite for precise radiotherapy planning and delivery. Different MRI sequences have different advantages and limitations in their ability to discriminate primary cervical tumor from normal tissue. The purpose of this work is to determine appropriate MRI techniques for GTV delineation for external-beam radiation therapy of locally advanced cervical cancer (LACC). MATERIALS AND METHODS: GTVs were delineated on the MRI, CT, and PET images acquired for 23 LACC patients in treatment positions to obtain GTVs on CT (GTV-CT), on various MRI sequences including T1 (GTV-T1), T2 (GTV-T2), T1 with fat suppression and contrast (GTV-T1F+), DWI-ADC (GTV-ADC) and on PET were generated using the threshold of 40% of maximum SUV (GTV-SUV40%) as well as SUV of 2.5 (GTV-SUV2.5). MRI, CT and PET were registered for comparison. The GTVs defined by MRI were compared using the overlap ratio (OR) and relative volume ratio (RVR). The union of GTV-T2 and GTV-ADC was generated to represent the MRI-based GTV (GTV-MRI). RESULTS: The differences between GTV-T2 and other MRI GTVs are significant (P < 0.05). The average ORs for GTV-T1, GTV-T1F+, and GTV-ADC related to GTV-T2 were 86.3%, 81.6%, and 61.6% with the corresponding average RVRs 113.8%, 112.3% and 77.2%, respectively. There is no significant difference between GTV-T1 and GTV-T1F+. GTV-ADC was generally smaller than GTV-T2, however, encompassed suspicious regions that are uncovered in GTV-T2 (up to 16% of GTV-T2) because of different imaging mechanisms. There was significant difference between GTV-MRI, GTV-SUV2.5, GTV-SUV40%, and GTV-CT. On average, GTV-MRI is 18.4% smaller than GTV-CT. CONCLUSIONS: MRI provides improved visualization of disease over CT or PET for cervical cancer. The GTV from the union of GTV-T2 and GTV-ADC provides a reasonable GTV including tumor region defined anatomically and functionally with MRI and substantially reduces the conventional GTV defined on CT.

Correlation of ADC With Pathological Treatment Response for Radiation Therapy of Pancreatic Cancer.

PURPOSE: To investigate the feasibility of using apparent diffusion coefficient (ADC) to assesspathological treatment response in pancreatic ductal adenocarcinoma (PDAC) following neoadjuvant chemoradiation (nCR). MATERIALS/METHODS: MRI and pathological data collected for 25patients with resectable and borderline resectable PDAC following nCR were retrospectively analyzed. Pre- and post-nCR mean ADC values in the tumors were compared using Wilcoxon matched pairs test. Correlation of pathological treatment response and ADC values was assessed using Pearson's correlation coefficient test and receiver-operating-curve (ROC) analysis. RESULTS: The average mean and standard deviation (SD) of the ADC values for all the patients analyzed were significantly higher in post-nCR (1.667±0.161×10-3) compared with those prior to nCR (1.395±0.136×10-3 mm2/sec), (P<0.05). The mean ADC values after nCR were significantly correlated with the pathological responses (r=-0.5172); P=0.02. The area under the curve (AUC) of the ADC values for differentiating G1, G2 and G3 pathological responses, using ROC analysis, was found to be 0.6310 and P=0.03. CONCLUSION: Changes of pre- and post-treatment ADC values significantly correlated with pathological treatment response for PDAC patients treated with chemoradiation therapy, indicating that the ADC could be used to assesstreatment response for PDAC.

Development of a high risk pancreatic screening clinic using 3.0 T MRI.

Selective screening for pancreatic cancer (PC) has been proposed. We describe the establishment of a comprehensive multidisciplinary screening program using 3.0 T MRI. Criteria for screening included the presence of PC in: ≥ 2 first degree relatives (FDR), 1 FDR and 1 s degree relative (SDR), ≥ 3 any degree relatives (ADR), or any known hereditary cancer syndrome with increased PC risk. Imaging with 3.0 T MRI was performed routinely and endoscopic ultrasound was used selectively. Screening was completed in 75 patients (pts). Hereditary cancer syndromes were present in 42 (56%) of the 75 pts: BRCA2 (18), ATM (8), BRCA1 (6), CDKN2A (4), PALB2 (3), Lynch (2), and Peutz-Jeghers (1). A family history of PC was present in ≥ 2 FDR in 12 (16%) pts, 1 FDR and 1 SDR in 5 (7) pts, and ≥ 3 ADR in 16 (21%) pts. Of the 65 pts who received screening MRI, 28 (43%) pts had pancreatic cystic lesions identified, including 1 (1%) patient in whom a cholangiocarcinoma was diagnosed as well. No patient underwent surgical resection. Using a 3.0 T MRI to screen patients at high risk for developing PC identified radiographic abnormalities in 43% of patients, which were stable on subsequent surveillance. Specific guidelines for the frequency of surveillance and indications for surgery remain areas of active investigation as the global experience with high risk screening continues to mature.

Pancreatic gross tumor volume contouring on computed tomography (CT) compared with magnetic resonance imaging (MRI): Results of an international contouring conference.

PURPOSE: Accurate identification of the gross tumor volume (GTV) in pancreatic adenocarcinoma is challenging. We sought to understand differences in GTV delineation using pancreatic computed tomography (CT) compared with magnetic resonance imaging (MRI). METHODS AND MATERIALS: Twelve attending radiation oncologists were convened for an international contouring symposium. All participants had a clinical and research interest in pancreatic adenocarcinoma. CT and MRI scans from 3 pancreatic cases were used for contouring. CT and MRI GTVs were analyzed and compared. Interobserver variability was compared using Dice's similarity coefficient (DSC), Hausdorff distances, and Jaccard indices. Mann-Whitney tests were used to check for significant differences. Consensus contours on CT and MRI scans and constructed count maps were used to visualize the agreement. Agreement regarding the optimal method to determine GTV definition using MRI was reached. RESULTS: Six contour sets (3 from CT and 3 from MRI) were obtained and compared for each observer, totaling 72 contour sets. The mean volume of contours on CT was significantly larger at 57.48 mL compared with a mean of 45.76 mL on MRI, P = .011. The standard deviation obtained from the CT contours was significantly larger than the standard deviation from the MRI contours (P = .027). The mean DSC was 0.73 for the CT and 0.72 for the MRI (P = .889). The conformity index measurement was similar for CT and MRI (P = .58). Count maps were created to highlight differences in the contours from CT and MRI. CONCLUSIONS: Using MRI as a primary image set to define a pancreatic adenocarcinoma GTV resulted in smaller contours compared with CT. No differences in DSC or the conformity index were seen between MRI and CT. A stepwise method is recommended as an approach to contour a pancreatic GTV using MRI.

Proteomic analysis of bronchoalveolar lavage fluid: effect of acute exposure to diesel exhaust particles in rats.

BACKGROUND: Inhalation of diesel exhaust particles (DEPs) is characterized by lung injury and inflammation, with significant increases in the numbers of polymorphonuclear leukocytes and alveolar macrophages. This influx of cellular infiltrates is associated with the activation of multiple genes, including cytokines and chemokines, and the production of reactive oxygen species. OBJECTIVE: The pathogenesis of the lung injury is not fully understood, but alterations in the presence or abundance of a number of proteins in the lung have been observed. Our objective in this study was to further characterize these changes and to ask whether additional changes could be discerned using modern proteomic techniques. METHODS: The present study investigates global alterations in the proteome of bronchoalveolar lavage fluid taken from rats 1, 7, or 30 days after exposure to 5, 35, or 50 mg/kg of animal weight of DEPs. RESULTS: Analysis by surface-enhanced laser desorption/ionization-time of flight mass spectrometry identified two distinct peaks that appeared as an acute response postexposure at all doses in all animals. We identified these two peaks, with mass to charge ratios (m/z) of 9,100 and 10,100, as anaphylatoxin C3a and calgranulin A by additional mass spectral investigation using liquid chromatography coupled to mass spectrometry. CONCLUSIONS: With this approach, we found a number of inflammatory response proteins that may be associated with the early phases of inflammation in response to DEP exposure. Further studies are warranted to determine whether serum levels of these proteins could be markers of diesel exhaust exposure in workers.

A novel amphibian tier 2 testing protocol: a 30-week exposure of Xenopus tropicalis to the antiandrogen flutamide.

In 1996, the U.S. Congress mandated the development of a screening program for endocrine-disrupting chemicals (EDCs) using validated test systems. Subsequently, the Endocrine Disruptor Screening and Testing Advisory Committee recommended the development of a standardized amphibian assay for tier 2 testing of EDCs. For that reason, a tier 2 testing protocol using Xenopus (Silurana) tropicalis and a 30-week, flow-through exposure to the antiandrogen flutamide from stage 46 tadpoles through sexually mature adult frogs were developed and evaluated in this pilot study. The endpoints for this study included measurements of frog body lengths and weights, liver weights, ovary/egg mass weights, testicular and ovarian histopathology, plasma vitellogenin levels, and notes on any abnormalities observed at necropsy. Increasing exposure concentrations to flutamide caused significant increases in frogs with no recognizable gonadal tissue and increased body and liver weights in male frogs, whereas the body lengths and weights decreased significantly in female frogs. Important issues must be resolved before a tier 2 amphibian assay can be further developed and validated, including the establishment of baseline values in the controls for the parameters under study; the maintenance, measurement, and timing of exposure concentrations; and the development of additional biomolecular markers of effect. This study demonstrated the feasibility of conducting long-term EDC exposure studies using X. tropicalis.

Assessment of treatment response during chemoradiation therapy for pancreatic cancer based on quantitative radiomic analysis of daily CTs: An exploratory study.

PURPOSE: In an effort for early assessment of treatment response, we investigate radiation induced changes in quantitative CT features of tumor during the delivery of chemoradiation therapy (CRT) for pancreatic cancer. METHODS: Diagnostic-quality CT data acquired daily during routine CT-guided CRT using a CT-on-rails for 20 pancreatic head cancer patients were analyzed. On each daily CT, the pancreatic head, the spinal cord and the aorta were delineated and the histograms of CT number (CTN) in these contours were extracted. Eight histogram-based radiomic metrics including the mean CTN (MCTN), peak position, volume, standard deviation (SD), skewness, kurtosis, energy and entropy were calculated for each fraction. Paired t-test was used to check the significance of the change of specific metric at specific time. GEE model was used to test the association between changes of metrics over time for different pathology responses. RESULTS: In general, CTN histogram in the pancreatic head (but not in spinal cord) changed during the CRT delivery. Changes from the 1st to the 26th fraction in MCTN ranged from -15.8 to 3.9 HU with an average of -4.7 HU (p<0.001). Meanwhile the volume decreased, the skewness increased (less skewed), and the kurtosis decreased (less peaked). The changes of MCTN, volume, skewness, and kurtosis became significant after two weeks of treatment. Patient pathological response is associated with the changes of MCTN, SD, and skewness. In cases of good response, patients tend to have large reductions in MCTN and skewness, and large increases in SD and kurtosis. CONCLUSIONS: Significant changes in CT radiomic features, such as the MCTN, skewness, and kurtosis in tumor were observed during the course of CRT for pancreas cancer based on quantitative analysis of daily CTs. These changes may be potentially used for early assessment of treatment response and stratification for therapeutic intensification.

Educating Future Environmental Health Professionals.

Future environmental health problems will require a new generation of educated and trained professionals. Efforts to enhance the environmental public health workforce have been promoted by several organizations. While progress has been measured by these organizations, many environmental health academic programs are experiencing budget reductions and lower enrollments. One of the reasons for this trend is the so-called higher education crisis. We argue that training is not equivalent to education in the environmental health sciences, albeit the two terms are often used interchangeably. Organizations involved with the education, training, and credentialing of environmental health professionals must work together to ensure the viability and effectiveness of environmental health academic programs.

Application of kaizen methodology to foster departmental engagement in quality improvement.

The Toyota Production System, also known as Lean, is a structured approach to continuous quality improvement that has been developed over the past 50 years to transform the automotive manufacturing process. In recent years, these techniques have been successfully applied to quality and safety improvement in the medical field. One of these techniques is kaizen, which is the Japanese word for "good change." The central tenant of kaizen is the quick analysis of the small, manageable components of a problem and the rapid implementation of a solution with ongoing, real-time reassessment. Kaizen adds an additional "human element" that all stakeholders, not just management, must be involved in such change. Because of the small size of the changes involved in a kaizen event and the inherent focus on human factors and change management, a kaizen event can serve as good introduction to continuous quality improvement for a radiology department.

The disruptive physician: a legal perspective.

RATIONALE AND OBJECTIVES: This article addresses the medical and legal implications of disruptive physician behavior. In addition, this article will address the appropriate use of due process in peer review of disruptive physician behavior. CONCLUSIONS: While most hospitals and even national organizations, like the American Medical Association, have definitions for what constitutes disruptive physician behavior, these definitions have been further examined and clarified in court rulings. These court rulings not only further clarify what constitutes disruptive behavior but also establish a threshold for revocation/nonrenewal of a physician's hospital privileges.