Using internal fiducial markers and electronic portal imaging (EPID) to realign patients has been shown to significantly reduce positioning uncertainties in prostate radiation treatment. This creates the possibility of decreasing the planning target volume (PTV) margin added on the clinical target volume (CTV), which in turn may allow for dose escalation. We compared the outcome of two plans: 7...

Aims. To compare the effective and eye lens radiation dose in helical MDCT brain examinations using automatic tube current modulation in conjunction with either standard filtered back projection (FBP) technique or iterative reconstruction in image space (IRIS). Methods. Of 400 adult brain MDCT examinations, 200 were performed using FBP and 200 using IRIS with the following parameters: tube volt...

introduction: radioactive materials deliver internal radiation dose to patients in nuclear medicine. manual internal radiation dose assessment is a complicated method. introduction of a simple dose calculation software is the main goal of the present study. methods: using the best current data in internal dose calculation (s-factors) recommended by icrp and by considering other technical metho...

background: in radiation therapy, peripheral dose or the dose outside the radiotherapy field, is important when anatomical structures with very low dose tolerances are involved. one of these critical organs in pelvic irradiation is testis. the amount of radiation delivered to the testes in radiotherapy must be kept as small as possible, consistent with the limit dose of this organ. the threshol...

background: breast is one of the main radiological sensitive organs, hence it is important to evaluate absorbed dose to this organ especially to the glandular parts. it is the aim of this study to measure mean glandular dose and image contrast in terms of different mammographic parameters. materials and methods: in this study two mammography machines located at said-al shohada (giotto) and shah...

UNLABELLED Preclinical evaluation of new radiopharmaceuticals is performed in animal systems before testing is started in humans. These studies, often performed in murine or other rodent models, are important in understanding the relationship between absorbed dose and response, which can be translated to preclinical results for humans. In performing such calculations, either electrons are assum...

Cervical cancer radiotherapy on the Linac aircraft uses a 6 MV energy photon beam with 3 Dimension Conformal Radiotherapy (3DCRT) and Intensity Modulation Radiation Therapy (IMRT) techniques. planning 3DCRT IMRT techniques is then compared by analyzing dose distribution or target volume (PTV) coverage through Conformity Index (CI) Homogeneity (HI) Organ At Risk (OAR) where risk organ that consi...

There is a clear dose response for localized prostate cancer radiotherapy and there probably is a radiobiological rationale for hypo-fractionation. Combining the two should maximize tumor control and increase the therapeutic ratio. This study examines the rationale and technical feasibility of CyberKnife radiotherapy (a robotic arm-driven linear accelerator) for localized prostate cancer. Its a...

PURPOSE Lung cancer screening with CT has been recently recommended for decreasing lung cancer mortality. The radiation dose of CT, however, must be kept as low as reasonably achievable for reducing potential stochastic risks from ionizing radiation. The purpose of this study was to calculate individual patients' lung doses and to estimate cancer risks in low-dose CT (LDCT) in comparison with a...