Feasibility of assessing pulmonary blood volume using C-arm CT during transpulmonary chemoperfusion and chemoembolization in primary and secondary lung tumours.

OBJECTIVE: Assessment of parenchymal blood volume (PBV) of primary and secondary pulmonary malignancies by using a C-arm CT, regarding its role in detecting early functional response to transpulmonary chemoembolization (TPCE) and clinical practicability. METHODS: 21 patients with a mean age of 56.77 years, who were assigned to TPCE during their palliative treatment, were included. PBV and the diameter of tumours were analyzed. PBV maps were calculated from three-dimensional CT-angiographic (3D-CTA) data sets. Imaging was performed on a flat detector, C-arm CT. Groups of response were classified according to the criteria of the response evaluation criteria in solid tumours. Statistically significant differences were determined and Pearson's regression analysis correlated PBV and diameter as parameters of response to treatment. RESULTS: During 4.91 sessions, median diameter increased 18.18% (p > 0.05) and PBV reduced 39.62% (p > 0.05). Functional and imaging response per tumour was statistical significantly different (p ≤ 0.05). Correlation coefficient was r = 0.058. 2/41 tumours showed partial response; 31/41 tumours showed stable disease; and 8/41 tumours showed progressive disease. The highest pre-treatment PBV values were measured in decreasing tumours (206.93 ml l(-1)), and the lowest values were measured in increasing tumours (60.17 ml l(-1); p > 0.05). The lowest values were also measured in lung cancer (53.02 ml l(-1)) that was significantly different to uterine leiomyosarcoma (103.31 ml l(-1)) and renal cell cancer (113.14 ml l(-1); p ≤ 0.05). CONCLUSION: Assessment of PBV maps by using 3D-CTA image data is feasible in the clinical routine. PBV shows a stronger response to TPCE treatment than measurement in diameter and should be considered as a response parameter for early detection. ADVANCES IN KNOWLEDGE: Assessment of PBV using C-arm CT during TPCE is a feasible technique. Assessment of PBV might be useful in assessing response to treatment.

Endpoints and cutpoints in head and neck oncology trials: methodical background, challenges, current practice and perspectives.

This article reviews the methodical and statistical basics of designing a trial, with a special focus on the process of defining and choosing endpoints and cutpoints as the foundations of clinical research, and ultimately that of evidence-based medicine. There has been a significant progress in the treatment of head and neck cancer in the past few decades. Currently available treatment options can have a variety of different goals, depending e.g. on tumor stage, among other factors. The outcome of a specific treatment in clinical trials is measured using endpoints. Besides classical endpoints, such as overall survival or organ preservation, other endpoints like quality of life are becoming increasingly important in designing and conducting a trial. The present work is based on electronic research and focuses on the solid methodical and statistical basics of a clinical trial, on the structure of study designs and on the presentation of various endpoints.

Propidium iodide staining: a new application in fluorescence microscopy for analysis of cytoarchitecture in adult and developing rodent brain.

Immunohistochemical visualization of antigens in specimen has evolved to an indispensable technique in biomedical research for investigations of cell morphology and pathology both in bright field and fluorescence microscopy. While there are couple of staining methods that reveal entire cytoarchitecture in bright field microscopy such as Nissl or hemalaun-eosin, there are still limitations in visualizations of cytoarchitecture in fluorescence microscopy. The present study reports a simple staining method that provides the required illustration of cell allocations and cellular composition in fluorescence microscopy in adult and in developing rodent central nervous system using the fluorophore propidium iodide (PI, 5µg/mL). PI is a well-accepted marker for degenerating cells when applied prior to fixation (pre-fixation PI staining). Here, PI was added to the sections after the fixation (post-fixation PI staining). This revised labeling procedure led to similar cytoarchitectural staining patterns in fluorescence microscopy as observed with hemalaun in bright field microscopy. This finding was proven in organotypic hippocampal slice cultures (OHSC) and brain sections obtained from different postnatal developmental stages. Excitotoxically lesioned OHSC subjected to pre-fixation PI staining merely showed brightly labeled condensed nuclei of degenerating neurons. In contrast, post-fixation PI staining additionally revealed extensive labeling of neuronal cell bodies and glial cells within the OHSC, thus allowing visualization of stratification of neuronal layers and cell morphology. Furthermore, post-fixation PI staining was combined with NeuN, calbindin, calretinin, glial fibrillary acidic protein or Griffonia simplicifolia isolectin B4 (IB(4)) in post natal (p1 and p9) and adult rats. In early post-natal brain sections almost all mentioned cellular markers led to an incomplete staining of the native cell organization and resulted in an inaccurate estimation of cell morphology when compared to adult brains. In contrast, post-fixation PI staining allowed investigation of the whole cytoarchitecture independent of the developmental stage. Taken together, post-fixation PI staining provides a detailed insight in the morphology of both developing and adult brain tissues in fluorescence microscopy.

Analyses of neuronal damage in excitotoxically lesioned organotypic hippocampal slice cultures.

Organotypic hippocampal slice cultures (OHSCs) are widely used to study the mechanisms of neurodegeneration and neuroprotection. However, there are still controversies about the most appropriate method for quantification of neuronal damage. The response to excitotoxic lesions can be determined by propidium iodide (PI) staining, which labels nuclei of degenerating cells. Semiquantitative measurements of PI staining are based on (1) recording of the propidium iodide (PI) fluorescence intensity or (2) counting of PI positive neuronal nuclei. Here, we investigated OHSCs lesioned by the application of increasing NMDA concentrations (10microM, 50microM and 500microM) at 6 days in vitro (div) for 4h or left untreated, respectively. After 9 div, PI staining was performed and the staining determined in the dentate gyrus and cornu ammonis (CA1) by measurement of PI-fluorescence intensity or by counting PI(+)-nuclei with a confocal laser scanning microscope. The fluorescence intensity of lesioned OHSCs did not show a NMDA concentration dependent difference. In contrast, confocal laser scanning microscopy revealed a significant and dose-dependent increase in the number of PI(+)-nuclei. Linear regression analysis showed a high correlation between NMDA concentration and the number of PI(+)-nuclei. A high correlation was also found between the mean number of PI(+)-nuclei determined in every third optical section and that determined in a single mid-stag optical section. The results show that proper analysis of neuronal damage requires counting of PI(+)-nuclei by confocal laser scanning microscopy.