Background: Recently, multileaf collimators (MLC) have become an important part of any LINAC collimation system because they reduce the treatment planning time and improve the conformity. Important factors that affect MLCs collimation performance are leaves material composition and their thickness.Objective: In this study, we investigate main dosimetric parameters of a typical MLC includi...

conclusions according to the results, the old dosimetry formalisms, overestimate the dose especially towards the applicator’s tip. while the tg-43u1 based software perform the calculations more accurately. results for a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator ...

BACKGROUND The purpose of this study was to investigate the differences in the dosimetric advantage of using intraoperatively built custom-linked (IBCL) seeds between permanent iodine-125 (I-125) seed implantation (PI) alone and PI followed by external-beam radiation therapy (EBRT) for prostate cancer. METHODS We reviewed the records of 62 patients with localized prostate cancer who received ...

Background: Recently we have upgraded our Varian Clinac 2100CD with a 6MV FFF beam, this upgrade being the first of its kind in our country. Even though the dosimetric characteristics of FFF beams have been reported both in experimental and Monte Carlo studies, application in planning and delivery is complex. The aim of this study was to validate the commissioning of upgraded FFF beams dosimetr...

We describe a fast, PC-based optimization planning system for a planar permanent-seed implant. Sites where this system is applicable include brain, lung, and head and neck. The system described here allows placing ribbons of different strengths and of different lengths along and across the implant plane. The program takes full advantage of the availability of different source strengths in inven...

Since the publication of AAPM Task Group 60 report in 1999, a considerable amount of dosimetry data for the three coronary brachytherapy systems in use in the United States has been reported. A subgroup, Task Group 149, of the AAPM working group on Special Brachytherapy Modalities (Bruce Thomadsen, Chair) was charged to develop recommendations for dose calculation formalisms and the related con...

A robust model to directly represent output from contemporary brachytherapy calculation had been proposed and developed to make clinical implementation practicable. The model was used to minimize inherent uncertainties associated with the AAMP TG-43 formalism, with consolidation of the TG-43 parameters into new parameter to speed up computational time. Analytical computations were performed to ...

In prostate cancer treatment, there is an increasing interest in the permanent radioactive seeds implant technique. Currently, in Brazil, the seeds are imported with high prices, which prohibit their use in public hospitals. A ceramic matrix that can be used as a radioisotope carrier and radiographic marker was developed at our institution. The ceramic matrix is distinguished by the characteris...

OBJECTIVE In addition to improve glucose intolerance, recent studies suggest that glucagon-like peptide-1 (GLP-1) receptor agonism also decreases triglyceride (TG) levels. The aim of this study was to evaluate the effect of GLP-1 receptor agonism on very-low-density lipoprotein (VLDL)-TG production and liver TG metabolism. EXPERIMENTAL APPROACH The GLP-1 peptide analogues CNTO3649 and exendin...