introduction: in this paper, by complete definition of human eye containing the various parts and their materials, the difference between this model and a homogeneous water phantom are compared for two ophthalmic plaques using 125i and 103pd. material and methods: the simulation of the two phantoms were performed in the mcnp-4c code and by using the geometry of a three-dimensional eye, differen...

Introduction: In radiation therapy, accurate dose determination and precise dose delivery to the tumor are directly associated with better treatment outcomes in terms of higher tumor control and lower post radiation therapy complications. The current study aims the development and clinical application of the Patient Specific Quality Assurance (PSQA) procedures for nasopharyngea...

introduction: polymer gels are modern dosimeters providing three dimensional dose distributions. these dosimeters can be used in brachytherapy in which the tumor dimension is relatively small and the dose gradient is high. in this study, the ability of the magica polymer gel was investigated for assessing the absolute dose values as well as the dose distribution of low dose rate (ldr) ir-192 wi...

BACKGROUND The high-dose-rate (HDR) brachytherapy might be an effective tool for palliation of dysphagia. Because of some concerns about adverse effects due to absorbed radiation dose, it is important to estimate absorbed dose in risky organs during this treatment. OBJECTIVES This study aimed to measure the absorbed dose in the parotid, thyroid, and submandibular gland, eye, trachea, spinal c...

This work presents experimental dosimetry results for a new 103Pd brachytherapy seed, in accordance with the AAPM TG-43U1 recommendation that all new low-energy interstitial brachytherapy seeds should undergo one Monte Carlo (MC) and at least one experimental dosimetry characterization. Measurements were performed using TLD-GR200A circular chip dosimeters using standard methods employing thermo...

Introduction: In brachytherapy, as in external radiotherapy, image-guidance plays an important role. For GYN treatments it is standard to acquire at least CT images and preferably MR images prior to each treatment and to calculate the dose of the day on each set of images. Then, the dose to the target and to the organs at risk (OAR) is calculated with worst case scenario from I...

introduction: the purpose of this work was to study the ability of mri normoxic polymer gel dosimetry for evaluating the dose distribution in hdr brachytherapy of esophagial cancer at imam reza brachytherapy center (mashhad, iran). materials and methods: initially, 2liters of normoxic gel (magic) was fabricated and then poured into 12 calibration test tubes and placed in a perspex walled phanto...

Introduction Low dose rate brachytherapy sources have been widely used for interstitial implants in tumor sites, particularly in prostate. Dosimetric characteristics of a new IrSeed 125I brachytherapy source have been determined using the LiF thermoluminescent dosimeter (TLD) chips. Materials and Methods Dose rate constant, radial dose function, and anisotropy function around the IrSeed 125I so...