When the PDD (percentage depth dose) in the megavoltage beams is measured in the water phantom using the dosimetry system, the polarity and ion recombination effects of ionization chambers with depth in water are not usually taken into consideration. The polarity and ion recombination effects may vary depending on the radiation type and spectrum, which vary with depth in water [1-4]. If those e...

RESUMO Araujo DR, Braga AFA, Moraes CM, Fraceto LF, Paula E – Mistura com Excesso Enantiomérico de 50% (S75-R25) de Bupivacaína Complexada com Ciclodextrinas e Anestesia por Via Subaracnóidea em Ratos JUSTIFICATIVA E OBJETIVOS: Com a finalidade de prolongar a duração de ação e reduzir a toxicidade sistêmica, têm-se desenvolvido formulações de anestésicos locais (AL) complexados com ciclodextrin...

BACKGROUND Intensity-modulated proton therapy (IMPT), non-coplanar 4π intensity-modulated radiation therapy (IMRT), and volumetric-modulated arc therapy (VMAT) represent the most advanced treatment methods based on heavy ion and X-rays, respectively. Here we compare their performance for prostate cancer treatment. METHODS Ten prostate patients were planned using IMPT with robustness optimizat...

The aim of this study was to evaluate the influence of drying protocols (DP) on the apical sealing (AS) and on the bond strength (BS) of teeth filled with different sealers. The root canals of one hundred and fifty-six roots of maxillary canines were prepared with Reciproc rotary files (R50). The teeth were randomly divided into four groups (n = 39), according to the DP: GI-paper points; GII-70...

While the structure of the DNA-binding domain (DBD) of the vitamin D receptor (VDR) has been determined in great detail, the roles of its domains and how to bind the motif of its target genes are still under debate. The VDR DBD consists of two zinc finger modules and a C-terminal extension (CTE), at the end of the C-terminal of each structure presenting α-helix. For the first zinc finger struct...

Recent dosimetry protocols for clinical high-energy electron beams recommend measurements of absorbed dose-to-water with a plane-parallel or cylindrical ionization chamber. For well-guarded plane-parallel ionization chambers, the ionization chamber perturbation factor in water, p(Q), has a recommended value of unity in all protocols. This assumption was investigated in detail in this study for ...

The electron Monte Carlo (eMC) dose calculation algorithm of the Eclipse treatment planning system is based heavily upon Monte Carlo simulation of the linac head and modeling of the linac beam characteristics with minimal measurement of beam data. Commissioning of the eMC algorithm on multiple identical linacs provided a unique opportunity to systematically evaluate the algorithm with actual me...

introduction: in recent decades, several monte carlo codes have been introduced for research and medical applications. these methods provide both accurate and detailed calculation of particle transport from linear accelerators. the main drawback of monte carlo techniques is the extremely long computing time that is required in order to obtain a dose distribution with good statistical accuracy. ...

The study by Duarte et al. 1 confirmed the theoretical fundaments by which enantiomeric excess bupivacaine or enantiomeric mixture of bupivacaine was developed. When we developed this drug, we geared the pre-clinical phase to study whether handling of the isomers regarding their ability to block the nerve would be possible. For such, the mice sciatic nerve was used. Once confirmed the activity ...

Purpose/Objective(s) The first clinical biology-guided radiation therapy (BgRT) system – RefleXionTM X1 - was installed and commissioned for use at our institution. This study aimed evaluating the treatment plan quality delivery efficiency IMRT/SBRT cases without PET-guidance. Materials/Methods Forty-two patient plans across six cancer sites (conventionally-fraction...