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Background: In the last two decades, there has been tremendous financial support, political will, and commitment to global malaria elimination focusing on endemic areas. This commitment and support have enabled a few countries to eliminate malaria, while others are making remarkable progress towards elimination. Nevertheless, in the Democratic Republic of the Congo (DRC), the status of Roll Back Malaria (RBM) impact indicators is unclear even though the country is one of the high burden malaria countries in the world. The study aimed to determine malaria morbidity and mortality at Kinshasa Referral General Hospital (KRGH) or the status of RBM impact indicators and factors associated with it.Methods: The study recruited 870 patients admitted at the KRGH in 2017 and 2018. Patient distribution by cause of admission was analysed. Malaria morbidity, mortality, and case-fatality-rates were estimated. A logistic regression model using malaria morbidity/mortality as the dependent variable was developed.Results: The morbidity rate was higher in 2018 than in 2017. Mortality and case-fatality-rates were comparable for the two years. Inpatients with low socioeconomic status (SES) were more than twice at risk of malaria morbidity/mortality than inpatients with high SES. The same results were found among city outskirts dwellers vis-a-vis city residents, with city residents faring better. Conclusion: Malaria morbidity and mortality in DRC were still high at the time of the study, affecting mostly people with low SES. Funding policies in the health sector need to be adjusted for DRC to address the current situation. Access to malaria health care services including drugs for low SES communities should be given priority.

The aim of the study was to analyze whether the fixation of the stereotactic frame is stable and whether the location of the treated target coincides with its anatomical location during Gamma Knife® surgery (GKS). Stereotactic MR examinations using the same high-resolution MRI protocol were performed before and after GKS in 18 consecutive patients. The stereotactic (x,y,z) coordinates for three different anatomical landmarks were independently defined three times in each study for each landmark of the images taken before and after GKS by two of the authors, resulting in a total of 648 coordinate definitions. The uncertainty in the readings of the coordinates for the anatomical landmarks was of the same magnitude as the difference in the coordinates before and after GKS in all but one patient. The differences in this one case were due to MR distortion and not to repositioning of the frame. The difference in the coordinates before and after treatment was not affected by the removal of one of the frontal fixation screws in one of the patients. The stereotactic frame position is stable and does not move.

Purpose : Microdosimetric expectations of Boron contents are extracted from a CRAY-Monte Carlo stimulation of the nuclear reaction 10B(n, α)7Li as it occurs on a boronated membrane of a model cell and as the reaction fragments (α and Li) traverse into the cellular nucleus. Methods and Materials : The present microdosimetry calculation is based upon the assumption that the therapeutic advantage of boron neutron capture therapy (BNCT), while depending upon the RBE and LET of the reaction particles, is equally dependent on the boron carrier preferential localization to tumor tissue, and the boron selectivity to cancerous cells and its specificity within the subcellular compartments. In particular, boron fixes to cell membrane as it ought to, using monoclonal antibodies. The present Monte Carlo simulation computes stochastic expectations of α/Li energy depositions to the nucleus in a uniformly boronated membrane shell of a spherical cell. Differential energy gain was deduced from the stochastic energy depositions in events of neutron reactions with membrane boron compared against those with natural elements (O, H, N) in the cell. Results : Microdosimetry data are presented in terms of specific energy ( z keV μ 3 ) and lineal energy (keV/μ) functions of the nucleus-to-cell volume rations (NCVR). When folded with the geometric boron content and accounting for background reaction energies, the distributions yield effective energy gain to the cell nucleus per neutron capture event. Boron amount required to yield these energy gains found to be of the order of picograms of boron per gram of cell mass. Conclusions : The boron content as inferred by the present Monte Carlo microdosimetry compares well with that deliverable by present pharmacokinetic means, but are orders of magnitude (μ-grams) less than those deduced previously from anthropomorphic macrodosimetry.

Purpose/Objective: In IMRT of tumors abutting critical structures, the PTV substantially overlaps with normal tissue volumes (NTV). Standard IMRT optimization techniques impose constraints only on the PTV and NTV and thus fail to modulate predictably the dose gradient in these overlapping regions. The purpose of this paper is to present the Transitional Boolean Dose Constraints Conjugation, or the TBDCC, optimization technique. This IMRT optimization technique uses constraints conjugation to achieve predictable IMRT dose gradients across overlapping tissue volumes. We report on the TBDCC technique and its effectiveness in more than 150 IMRT patients’ plans otherwise difficult to optimize by standard techniques. Patients presented include post-prostatectomy with iliac nodes, cervix with para-aortic nodes, large meningioma abutting optic nerves and chiasm, and mesothelioma invading the heart and lung pleura. Their comparative IMRT plans, with and without constraints conjugation, are presented.

We propose a mathematical model with the potential capability of predicting the probability of cure and of normal tissue damage in a cancer patient treated with radiation. The basic assumption of the model is that complications occur when small volumes of tissue are totally depleted of the stem cells that are necessary for the repair of radiation damage. We apply this model to the specific problem of radiation injury to the spinal cord (radiation myelitis) and derive a relation between the probability of this complication and the survival probability of individual stem cells. We will perform computer calculations of the complication probability as a function of the dose, fraction size and other parameters of the model and show that good agreement with experimental animal data for this complication can be obtained. Our main objective is to develop mathematical models that would predict the dependence of the probability of cure and of complications on the parameters of the radiation therapy treatment. Such models, together with modern computerized treatment planning techniques could aid the radiotherapist in choosing the optimum treatment strategy. Our approach is a generalization of the model of Munro and Gilbert (Munro, 1961) relating the probability of tumor control to the survival probability of individual tumor cells. We assume that complications arise from the local depletion of clonogenic stem cells and are thus able to relate the complication probability directly to the cell survival probability.