On the design of an image compression scheme based upon a priori knowledge about imaging system and image statistics

This contribution is about the design of an image compression scheme for near loss-less image compression of a restricted class of images and a specific application. The images are digital diagnostic X-ray images of the coronary vessels of the human heart. This paper proposes a novel compression scheme with a compression ratio of 8-10 with preservation of the diagnostic image quality. Central in our approach is the amount of information a trained and highly skilled observer i.e. the cardiologist is able discern at a given exposure and thus quantum noise level. The physics of the image detection process together with the a priori knowledge of the imaging system are the basis of the image statistics. Relevant elements of the human visual system complete the stochastic characterization of imaging process whereon the compression scheme is based. 1

Optimal timing of harvest of two fish species with multiple gear types

In this paper a bioeconomic model is developed for a commercial fishery with multiple gear types in the case of two independent fish species. Where most bioeconomic fishery models focus on either multiple gear types or multiple species (mostly predator-prey relationships) this model combines both aspects for four gear types and two independent fish species. The objective of the paper is to find the optimal allocation of four gear types per period to obtain the highest net benefits while harvesting at a sustainable rate. This is done by developing a discrete time LP-model for a sole owner fishery, given a Total Allowable Catch for the two fish species. The model is applied to the Chippewas of Nawash First Nation commercial fishery in Lake Huron and Georgian Bay (Ontario, Canada). Sensitivity analyses are performed on price changes as well as on the average harvest levels per boat

Recurrent hemorrhagic pericardial effusion in a child due to diffuse lymphangiohemangiomatosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Recurrent hemorrhagic pericardial effusion in children with no identifiable cause is a rare presentation.</p> <p>Case presentation</p> <p>We report the case of a 4-year-old Indian girl who presented with recurrent hemorrhagic pericardial effusion. Diffuse lymphangiomatosis was suspected when associated pulmonary involvement, soft tissue mediastinal mass, and lytic bone lesions were found. Pericardiectomy and lung biopsy confirmed the diagnosis of diffuse lymphangiohemangiomatosis. Partial clinical improvement occurred with thalidomide and low-dose radiotherapy, but our patient died from progressive respiratory failure.</p> <p>Conclusion</p> <p>Diffuse lymphangiohemangiomatosis should be considered in the differential diagnosis of hemorrhagic pericardial effusion of unclear cause.</p

Advances in adjuvant therapy of biliary tract cancer: an overview of current clinical evidence based on phase II and III trials

Patients with biliary tract cancer (BTC) have a high recurrence rate after complete surgical resection. To reduce the risk of recurrence and to improve survival, several chemotherapeutic agents that have shown to be active in locally advanced and metastatic BTC have been investigated in the adjuvant setting in prospective clinical trials. Based on the results of the BILCAP phase III trial, capecitabine was adapted as the standard of care by the ASCO clinical practice guideline. Ongoing randomized controlled trials mainly compare capecitabine with gemcitabine-based chemotherapy or chemoradiotherapy. This review provides an update of adjuvant therapy in BTC based on published data of phase II and III trials and ongoing randomized controlled trials (RCTs)

Risk factors for complications after surgery for pancreatic neuroendocrine tumors

BACKGROUND: Surgical resection is the only potentially curative treatment for pancreatic neuroendocrine tumors. The choice for the type of procedure is influenced by the expected oncological benefit and the anticipated risk of procedure-specific complications. Few studies have focused on complications in these patients. This cohort study aimed to assess complications and risk factors after resections of pancreatic neuroendocrine tumors. METHODS: Patients undergoing resection of a pancreatic neuroendocrine tumor were identified within 2 centers of excellence. Complications were assessed according to the Clavien-Dindo classification and the comprehensive complication index. Logistic regression was performed to compare surgical procedures with adjustment for potential confounders (Clavien-Dindo ≥3). RESULTS: The cohort comprised 123 patients, including 12 enucleations, 50 distal pancreatectomies, 51 pancreatoduodenectomies, and 10 total/combined pancreatectomies. Mortality was 0.8%, a severe complication occurred in 41.5%, and the failure-to-rescue rate was 2.0%. The median comprehensive complication index was 22.6 (0-100); the comprehensive complication index increased after more extensive resections. After adjustment, a pancreatoduodenectomy, as compared to a distal pancreatectomy, increased the risk for a severe complication (odds ratio 3.13 [95% confidence interval 1.32-7.41]). Of the patients with multiple endocrine neoplasia type 1 or von Hippel-Lindau, 51.9% developed a severe complication vs 38.5% with sporadic disease. After major resections, morbidity was significantly higher in patients with multiple endocrine neoplasia type 1/von Hippel-Lindau (comprehensive complication index 45.1 vs 28.9, P = .029). CONCLUSION: Surgery for pancreatic neuroendocrine tumors is associated with a high rate of complications but low failure-to-rescue in centers of excellence. Complications are procedure-specific. Major resections in patients with multiple endocrine neoplasia type 1/von Hippel-Lindau appear to increase the risk of complications

Minimally invasive versus open pancreatoduodenectomy (LEOPARD-2): Study protocol for a randomized controlled trial

Background: Data from observational studies suggest that minimally invasive pancreatoduodenectomy (MIPD) is superior to open pancreatoduodenectomy regarding intraoperative blood loss, postoperative morbidity, and length of hospital stay, without increasing total costs. However, several case-matched studies failed to demonstrate superiority of MIPD, and large registry studies from the USA even suggested increased mortality for MIPDs performed in low-volume (< 10 MIPDs annually) centers. Randomized controlled multicenter trials are lacking but clearly required. We hypothesize that time to functional recovery is shorter after MIPD compared with open pancreatoduodenectomy, even in an enhanced recovery setting. Methods/design: LEOPARD-2 is a randomized controlled, parallel-group, patient-blinded, multicenter, phase 2/3, superiority trial in centers that completed the Dutch Pancreatic Cancer Group LAELAPS-2 training program for laparoscopic pancreatoduodenectomy or LAELAPS-3 training program for robot-assisted pancreatoduodenectomy and have performed ≥ 20 MIPDs. A total of 136 patients with symptomatic benign, premalignant, or malignant disease will be randomly assigned to undergo minimally invasive or open pancreatoduodenectomy in an enhan

National consensus on a new resectability classification for perihilar cholangiocarcinoma - A modified Delphi method

Background: Currently, no practical definition of potentially resectable, borderline or unresectable perihilar cholangiocarcinoma (pCCA) is available. Aim of this study was to define criteria to categorize patients for use in a future neoadjuvant or induction therapy study. Method: Using the modified DELPHI method, hepatobiliary surgeons from all tertiary referral centers in the Netherlands were invited to participate in this study. During five online meetings, predefined factors determining resectability and additional factors regarding surgical resectability and operability were discussed. Results: The five online meetings resulted in 52 statements. After two surveys, consensus was reached in 63% of the questions. The main consensus included a definition regarding potential resectability. 1) Clearly resectable: no vascular involvement (≤90°) of the future liver remnant (FLR) and expected feasibility of radical biliary resection. 2) Clearly unresectable: non-reconstructable venous and/or arterial involvement of the FLR or no feasible radical biliary resection. 3) Borderline resectable: all patients between clearly resectable and clearly unresectable disease. Conclusion: This DELPHI study resulted in a practical and applicable resectability, or more accurate, an explorability classification, which can be used to categorize patients for use in future neoadjuvant therapy studies.</p

Chronic recurrent Gorham-Stout syndrome with cutaneous involvement

Type IV osteolysis or Gorham-Stout syndrome is a rare condition characterized by recurrent vascular tumors that disrupt normal anatomical architecture. Gorham-Stout syndrome is most commonly associated with the skeletal system with resulting replacement of bone with scar tissue following tumor regression. The loss of entire bones has given Gorham-Stout syndrome the moniker vanishing bone disease. Natural progression of Gorham-Stout syndrome is characterized by spontaneous disease resolution. However, rare variants of recurrent, progressive, and/or systemic disease have been reported. We present a patient with a history of recurrent Gorham- Stout disease refractory to all treatment options considered. In addition to skeletal disease, our patient had soft tissue and cutaneous involvement, thus reflecting the more aggressive disease variant. Previous surgical attempts to control disease had been ineffective and the patient was referred to us for radiation therapy. Treatment with external beam radiation therapy resulted in good local control and symptom palliation, but full disease resolution was never accomplished. In addition to presentation of this patient, a review of the literature on etiological hypotheses and past/future treatment options was conducted and is included

Should jaundice preclude resection in patients with gallbladder cancer? Results from a nation-wide cohort study

Background: It is controversial whether patients with gallbladder cancer (GBC) presenting with jaundice benefit from resection. This study re-evaluates the impact of jaundice on resectability and survival. Methods: Data was collected on surgically explored GBC patients in all Dutch academic hospitals from 2000 to 2018. Survival and prognostic factors were assessed. Results: In total 202 patients underwent exploration and 148 were resected; 124 non-jaundiced patients (104 resected) and 75 jaundiced patients (44 resected). Jaundiced patients had significantly (P < 0.05) more pT3/T4 tumors, extended (≥3 segments) liver- and organ resections, major post-operative complications and margin-positive resection. 90-day mortality was higher in jaundiced patients (14% vs. 0%, P < 0.001). Median overall survival (OS) was 7.7 months in jaundiced patients (2-year survival 17%) vs. 26.1 months in non-jaundiced patients (2-year survival 39%, P < 0.001). In multivariate analysis, jaundice (HR1.89) was a poor prognostic factor for OS in surgically explored but not in resected patients. Six jaundiced patients did not develop a recurrence; none had liver- or common bile duct (CBD) invasion on imaging. Conclusion: Jaundice is associated with poor survival. However, jaundice is not an independent adverse prognostic factor in resected patients. Surgery should be considered in patients with limited disease and no CBD invasion on imaging