Purpose: Fiber carbon is the most common material used in treating couch as it causes less beam attenuation than other materials. Beam attenuation replaces build-up region, reduces skin-sparing effect and causes target volume under dosage. In this study, we aimed to evaluate beam attenuation and variation of build-up region in 550 TxT radiotherapy couch.Materials and Methods: In this study, we ...

Heterogeneous nucleation of a liquid droplet on a solid surface was simulated with the molecular dynamics method. Argon vapor was represented by 5,760 Lennard-Jones molecules and the solid surface was represented by one layer of 4,464 harmonic molecules with the constant temperature heat bath model using the phantom molecules. The potential parameter between a solid molecule and a vapor molecul...

Background: Placing a self-expandable metallic stent (SEMS) is safe and effective for the palliative treatment of malignant gastroduodenal (GD) strictures. SEMS abutment in the duodenal wall is associated with increased food impaction, resulting in higher stent malfunction and shorter stent patency. The desire to evaluate the mechanism and significance of stent abutment led us to design an in v...

The heterogeneous nucleation of liquid droplet on a solid surface was simulated with the molecular dynamics method. Argon vapor was represented by 5760 Lennard-Jones molecules and the solid surface was represented by one layer of 1020 harmonic molecules with the constant temperature heat bath model using the phantom molecules. The potential parameter between solid molecule and vapor molecule wa...

The water equivalency of five "water-equivalent" solid phantom materials was evaluated in terms of output calibration and energy characterization over a range of energies for both photon (Co-60 to 24 MV) and electron (6-20 MeV) beams. Evaluations compared absorbed doses calculated from ionization measurements using the same dosimeter in the solid phantom materials and in natural water (H2O). Io...

UNLABELLED This study described and validated a new solid-state single-photon gamma-camera and compared it with a conventional-SPECT Anger camera. The compact new camera uses a unique method for localizing gamma-photon information with a bank of 9 solid-state detector columns with tungsten collimators that rotate independently. METHODS Several phantom studies were performed comparing the new ...

introduction dosimetric accuracy is a major issue in the quality assurance (qa) program for treatment planning systems (tps). an important contribution to this process has been a proper dosimetry method to guarantee the accuracy of delivered dose to the tumor. in brachytherapy (bt) of gynecological (gyn) cancer it is usual to insert a combination of tandem and ovoid applicators with a complicat...

Introduction Dosimetric accuracy is a major issue in the quality assurance (QA) program for treatment planning systems (TPS). An important contribution to this process has been a proper dosimetry method to guarantee the accuracy of delivered dose to the tumor. In brachytherapy (BT) of gynecological (Gyn) cancer it is usual to insert a combination of tandem and ovoid applicators with a complicat...

In treatment planning of brachytherapy, absorbed dose is calculated by superposing predetermined distributions of absorbed dose to water in water for the single source according to the irradiation pattern ͓i.e., placement of the source͑s͒ or dwelling position͑s͔͒. Single-source reference water data are derived from Monte Carlo ͑MC͒ simulations and/or experiments. For reasons of positional accuracy, exp...

A standard protocol of dosimetric measurements is used by the organizations responsible for verifying that the doses delivered in radiation-therapy institutions are within authorized limits. This study evaluated a self-designed simple auditing phantom for use in verifying the dose of radiation therapy; the phantom design, dose audit system, and clinical tests are described. Thermoluminescent do...