Background: The trabecular bone changes in the tibia of C3H/HeN mice were measured 12 weeks after whole body irradiation with various doses of fast neutrons (0-2.4 Gy) or 137Cs-generated gamma-rays (0-6 Gy). Materials and Methods: Serum calcium, phosphorus, estradiol concentration and alkaline phosphatase activity were measured. Tibiae were anal...

The standard formulation of the fractionation problem with multiple organs-at-risk based on the linear-quadratic dose-response model requires the solution of a nonconvex quadratically constrained quadratic program. Existing literature therefore uses heuristic methods without any analyses about solution quality. There is no known method that is guaranteed to find an optimal solution. We prove th...

Historically it has been shown repeatedly that single high doses of radiation do not allow a therapeutic differential between tumor and critical normal tissues but dose fractionation does. The purpose of conventional dose fractionation is to increase dose to the tumor while preserving normal tissue function. Tumors are generally irradiated with 2Gy dose per fraction delivered daily to a more or...

Background: A new biological dosimeter based on methemoglobin level was developed in this study. Materials and Methods: Methemoglobin level in erythrocytes from mice subjected to &gamma rays from a 60Co source was detected using the methemoglobin kit. The dose range was from 0.5 to 8 Gy and the dose rate was 0.5 Gy/min. Results: The results demonstrate that methemoglobin level increases with in...

The computation of the relative biological effectiveness (RBE) is a fundamental step in planning cancer radiotherapy treatments with accelerated ions. Numerical parameters derived analyzing dose response chosen cell line after irradiation to photons (i.e., α and β, namely linear quadratic terms linear-quadratic model survival) are generally used as input biophysical models predict ion RBE. α/β ...

While radical cystectomy remains the primary treatment of choice for bladder cancer, increased evidence supports use bladder-preservation strategies based on adjuvant radiotherapy. This highlights need a better understanding cancer radiosensitivity to different types deliveries. The purpose this study is analyze effect time, dose and fractionation number sizes grown three-dimensional (3D) spher...

Current inverse treatment planning methods that optimize both catheter positions and dwell times in prostate HDR brachytherapy use surrogate linear or quadratic objective functions that have no direct interpretation in terms of dose-volume histogram (DVH) criteria, do not result in an optimum or have long solution times. We decrease the solution time of the existing linear and quadratic dose-ba...

Whole-body and thoracic ionizing radiation exposure are associated with increased cardiovascular disease (CVD) risk. In atomic bomb survivors, radiation dose is also associated with increased hypertension incidence, suggesting that radiation dose may be associated with chronic renal failure (CRF), thus explaining part of the mechanism for increased CVD. Multivariate Poisson regression was used ...

Li J.-L., Xu Y.-Q., Shi B.-L., Sun D.-S., Yan S.-M., Guo X.-Y. (2017): Dietary chitosan affects metabolism of arachidonic acid in weaned piglets. Czech J. Anim. Sci., 62, 58–66. The effects of chitosan on immune function via arachidonic acid (AA) pathway in weaned piglets were investigated. A total of 180 piglets (Duroc × Yorkshire × Landrace) were randomly assigned to 5 dietary treatments and ...

PURPOSE To develop an in-house software program that is able to calculate and generate the biological dose distribution and biological dose volume histogram by physical dose conversion using the linear-quadratic-linear (LQL) model. MATERIAL AND METHODS The Isobio software was developed using MATLAB version 2014b to calculate and generate the biological dose distribution and biological dose vo...