Identification of risk-factors for perioperative morbidity and mortality during different phases in the treatment of esophageal cancer patients

Een chirurgische resectie van een slokdarmcarcinoom is nog steeds de belangrijkste curatieve behandelmodaliteit. Deze gaat echter gepaard met een aanzienlijk risico op complicaties. Het doel van dit proefschrift was om risicofactoren te identificeren die gerelateerd zijn aan morbiditeit en mortaliteit gedurende de behandeling van een patiënt met een slokdarmcarcinoom. Om een correcte inschatting te maken van het individuele perioperatieve risico, zijn verschillende risico-inschattende modellen ontwikkeld. Uit dit proefschrift blijkt dat O-POSSUM een relatief correcte voorspelling geeft, maar nog steeds ongeschikt is voor individuele risico-inschatting in de dagelijkse praktijk. Een mogelijk risicovolle groep wordt gevormd door de oudere patiënten (> 70 jaar). Uit dit proefschrift blijkt echter dat er geen significant verschil bestaat in korte –en lange termijn overleving tussen oudere en jongere patiënten. Wel kwamen enkele complicaties vaker voor bij oudere patiënten. Neoadjuvante chemoradiotherapie (CRT) wordt tegenwoordig standaard toegepast in de behandeling van patiënten met een slokdarmcarcinoom. Ondanks laag gerapporteerde toxiciteit, toont dit proefschrift aan dat neoadjuvante CRT een verhoogd risico geeft op preoperatieve trombo-embolische processen. Tevens werden er meer postoperatieve longontstekingen en hartritmestoornissen geconstateerd na neoadjuvante CRT. Laboratorium waarden zijn een belangrijk hulpmiddel in de vroege identificatie van patiënten met een gecompliceerd postoperatief beloop. Dit proefschrift toont aan dat zowel bekende waarden (C-reactief protein en lactaat dehydrogenase), als minder bekende waarden (intestinal fatty acid binding protein en angiopoietin) een belangrijke rol spelen in de vroege identificatie van postoperatieve complicaties. Daarnaast zijn er aanwijzingen dat cytokinen concentraties gerelateerd zijn aan de mate van pathologische respons na neoadjuvante CRT. Mogelijk spelen ze ook een rol bij geïndividualiseerde behandelingsvormen

Bone marrow edema in sacroiliitis : detection with dual-energy CT

Objectives: To evaluate the feasibility and diagnostic accuracy of dual-energy computed tomography (DECT) for the detection of bone marrow edema (BME) in patients suspected for sacroiliitis. Methods: Patients aged 18-55 years with clinical suspicion for sacroiliitis were enrolled. All patients underwent DECT and 3.0 T MRI of the sacroiliac joints on the same day. Virtual non-calcium (VNCa) images were calculated from DECT images for demonstration of BME. VNCa images were scored by two readers independently using a binary system (0 = normal bone marrow, 1 = BME). Diagnostic performance was assessed with fluid-sensitive MRI as the reference standard. ROIs were placed on VNCa images, and CT numbers were displayed. Cutoff values for BME detection were determined based on ROC curves. Results: Forty patients (16 men, 24 women, mean age 37.1 years +/- 9.6 years) were included. Overall inter-reader agreement for visual image reading of BME on VNCa images was good (kappa = 0.70). The sensitivity and specificity of BME detection by DECT were 65.4% and 94.2% on the quadrant level and 81.3% and 91.7% on the patient level. ROC analyses revealed AUCs of 0.90 and 0.87 for CT numbers in the ilium and sacrum, respectively. Cutoff values of - 44.4 HU (for iliac quadrants) and - 40.8 HU (for sacral quadrants) yielded sensitivities of 76.9% and 76.7% and specificities of 91.5% and 87.5%, respectively. Conclusions: Inflammatory sacroiliac BME can be detected by VNCa images calculated from DECT, with a good interobserver agreement, moderate sensitivity, and high specificity

MRI of the axial skeleton in spondyloarthritis : the many faces of new bone formation

Spondyloarthritis has two hallmark features: active inflammation and structural lesions with new bone formation. MRI is well suited to assess active inflammation, but there is increasing interest in the role of structural lesions at MRI. Recent MRI studies have examined the established features of new bone formation and demonstrated some novel features which show diagnostic value and might even have potential as possible markers of disease progression. Although MRI is not the first imaging modality that comes into mind for assessment of bony changes, these features of new bone formation can be detected on MRI-if one knows how to recognize them. This review illustrates the MRI features of new bone formation and addresses possible pitfalls

Translation-Based Dictionary Alignment for Under-Resourced Bantu Languages

Despite a large number of active speakers, most Bantu languages can be considered as under- or less-resourced languages. This includes especially the current situation of lexicographical data, which is highly unsatisfactory concerning the size, quality and consistency in format and provided information. Unfortunately, this does not only hold for the amount and quality of data for monolingual dictionaries, but also for their lack of interconnection to form a network of dictionaries. Current endeavours to promote the use of Bantu languages in primary and secondary education in countries like South Africa show the urgent need for high-quality digital dictionaries. This contribution describes a prototypical implementation for aligning Xhosa, Zimbabwean Ndebele and Kalanga language dictionaries based on their English translations using simple string matching techniques and via WordNet URIs. The RDF-based representation of the data using the Bantu Language Model (BLM) and - partial - references to the established WordNet dataset supported this process significantly

99mTc-labelled S-HYNIC certolizumab pegol in rheumatoid arthritis and spondyloarthritis patients : a biodistribution and dosimetry study

Background: Biologicals directed against tumour necrosis factor (TNF) have proven their efficacy in the treatment of spondyloarthritis and rheumatoid arthritis. We present a radiolabelling method for certolizumab pegol (CZP), a commercially available humanized Fab'-fragment directed against TNF. A biodistribution and dosimetry study was conducted. Tc-S-HYNIC CZP was synthesized. The in vitro TNF neutralizing activity was tested by exposing L929s-cells to various concentrations 99mTc-S-HYNIC CZP and measuring TNF-induced cytotoxicity. For biodistribution and dosimetry, WB images and blood and urine sampling were performed up to 24 h pi. Cumulative activities were estimated using mono-exponential fitting, and organ doses were estimated using OLINDA/EXM. The effective dose was calculated using the International Commission on Radiological Protection 103 recommendations. The uptake of the tracer in the peripheral joints was assessed visually and semiquantitatively. Results: In vitro tests showed blocking of TNF cytotoxicity by the Tc-99m-S-HYNIC CZP formulation comparable to the effect obtained with the unlabelled CZP with or without the HYNIC linker. We analysed eight patients with rheumatoid arthritis or spondyloarthritis. The highest mean absorbed organ doses were recorded for kidneys, spleen, and liver: 56 (SD 7), 34 (SD 6), and 33 (SD 7) mu Gy/MBq. The effective dose was 6.1 (SD 0.9) mSv for a mean injected activity of 690 (SD 35) MBq. The urinary excretion was 15.1% (SD 8.1) of the IA at 22.5 h. Blood analysis yielded a distribution half-life of 1.2 h (SD 1.5) and an elimination half-life of 26.9 h (SD 2.7). Visual analysis of the scans revealed marked tracer accumulation in the clinically affected peripheral joints. In addition, there was a statistically significant higher uptake of the tracer in the swollen joints (median uptake ratio compared to background of 3.3 in rheumatoid arthritis and 2.4 in peripheral spondyloarthritis) compared to clinically negative joints (respectively 1.3 and 1.6). Conclusions: We present a radiolabelling technique for CZP, a Fab'-fragment directed against TNF and currently used as a therapeutic agent in rheumatology. An effective dose of 6.1 mSv (SD 0.9) was estimated. We confirmed the uptake of this new radiopharmaceutical in clinically affected peripheral joints