The biological damages are mainly produced by direct ionization and excitation of bio-molecular DNA electrons or by indirect chemical reaction of water radiolysis products with DNA. In this work, we restricted our study on the interaction of energetic ion proton beams with liquid water; since the water represents over 80% of the most-soft tissues. The proton collisions with water molecules are ...

The European Directive 96/29/EURATOM and adapted national regulations on radiation protection are claiming new limits of radiation exposure and the introduction of new measuring quantities. Dosimeters for area monitoring of penetrating X-ray and gamma radiation have to measure the ICRU operational quantity ambient dose equivalent, H*(10). In this paper, the development stages of a passive H*(10...

The calculation of absorbed dose from internally incorporated radionuclides is based on the so-called specific absorbed fractions (SAFs) which represent the fraction of energy emitted in a given source region that is absorbed per unit mass in a specific target organ. Until recently, photon SAFs were calculated using MIRD-type mathematical phantoms. For electrons, the energy released was assumed...

Applicators containing metal have been widely used in recent years when applying brachytherapy to patients with cervical cancer. However, the high dose rate (HDR) treatment-planning system (TPS) that is currently used in brachytherapy still assumes that the treatment environment constitutes a homogeneous water medium and does not include a dose correction for the metal material of the applicato...

Automatic tube current modulation (TCM) is used in modern CT devices. This is implemented in the numerical calculation of dose conversion coefficients for CT examinations. For four models of adults, the female and male reference models of ICRP and ICRU and a lighter and a heavier female model, dose conversion coefficients normalized to CTDI(vol) (DCC(CT)) have been computed with a Monte Carlo t...

Microdosimetric distribution/Target theory/Nanometer-size target/Calculation method/60Co ƒÁ rays A calculation method of frequency distributions for the microdosimetric quantity J (number of effec tive primary events produced in a target), hj, is presented. This method is briefly compared with other approaches developed by Kellerer and Chmelevsky, and Wilson and Paretzke for numerical calculati...

A patient dose distribution was calculated by a 3D multi-group S N particle transport code for intracavitary brachytherapy of the cervix uteri and compared to previously published Monte Carlo results. A Cs-137 LDR intracavitary brachytherapy CT data set was chosen from our clinical database. MCNPX version 2.5.c, was used to calculate the dose distribution. A 3D multi-group S N particle transpor...

Background Stereotactic radiotherapy (SRT) should be applied with a biologically effective dose an ?/? of 12 (BED12) ? 40 Gy to reach 1-year local control (LC) 70%. The aims this retrospective study were report series 81 unresected large brain metastases treated Linac-based multifraction SRT according the ICRU 91 and identify predictive factors associated LC. Methods Included in first (BM) cons...