For single-fraction stereotactic radiosurgery (SRS) using linac in brain metastases, more accurate treatment delivery with higher tumor absorbed doses and lower absorbed doses to normal tissues remains an enormous challenge. The purpose of this study was to investigate the dosimetric superiority in flattening filter free beams (FFF) for volumetric modulated arc therapy (VMAT) in single brain me...

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 γ 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 increas...

Background: The presence of small intestine in the radiation field during pelvic cancers treatment causes an interruption in radiotherapy. A non-invasive method was developed to exclude small intestine during conventional radiotherapy. Materials and Methods: The incidence of the radiation therapy interruption is highly dependent upon the area of the small intestine included in the portals and i...

Introduction: Clinical application of encapsulated radioactive brachytherapy sources has a major role in cancer treatment. In the present research, the effects of different tissue densities on the dose distribution of a 103Pd brachytherapy source in a spherical phantom of 50 cm radius have been studied. Material and Methods: As is well known, absorbed dose in tissue depends to its density, but ...

Introduction Gallium-67 (67Ga) has been used as a radionuclide for imaging a variety of solid tumors since 1969. Since then use of various gallium-based radiotracers has been reported. Recently, 67Ga-labeled acetylacetate bis(thiosemicarbazones) (67Ga-AATS) complex with significant tumor accumulation and fast blood clearance has been employed. Materials and Methods In this study, the absorbed d...

the aim of this study was the investigation of absorbed dose to the kidneys, spleen, and liver during technetium-99 m ethylene dicysteine and technetium-99 m diethylenetriaminepentaacetic acid (99mtc-ec and 99mtc-dtpa) kidney scan. patients who had been prepared for the kidney scan, were divided into two groups (groups 1 and 2). the first group (group 1) and the second group (group 2) received ...

⁹⁰Y PET/CT can be acquired after ⁹⁰Y-microsphere selective radiation internal therapy (SIRT) to describe radioactivity distribution. We performed dosimetry using ⁹⁰Y-microsphere PET/CT data to evaluate treatment efficacy and appropriateness of activity planning from (99m)Tc-MAA scan and SPECT/CT. Twenty-three patients with liver malignancy were included in the study. (99m)Tc-MAA was injected du...

conclusions there was no statistically significant difference in the parotid absorbed dose between spiral tomography and a panoramic radiograph (p value = 0.18). the overall results of this study were similar to other studies. results for the tube side parotid, the average absorbed doses in spiral tomography of the anterior and posterior parts of the maxilla and mandible, with the 2 mm slice th...