background: radiation-induced lung toxicity is an important dose-limiting toxicity in lung cancer radiotherapy, for which there are no generally accepted predictive factors. this study seeks to identify risk factors associated with the development of severe radiation-induced lung toxicity using clinical and dosimetric parameters. methods: we reviewed the medical records of 54 patients with hist...

Introduction: Nowadays ionizing radiation has a considerable contribution in medical diagnostic and treatment. Using ionizing radiation is increasing rapidly, so biological effects of ionizing radiation should be considered more. X-rays in the range of diagnostic radiology have hazardous effects and risks that are defined as random effects. These effects obey the LNT hypothesis that occur at lo...

Introduction: The purpose of this study was to estimate the secondary cancer risk of thyroid for standard radiotherapy methods which are commonly used for breast cancer patients. Materials and Methods: Sixty-four breast cancer patients (their age range was around 50 years old) who referred to Seyed- Al- Shohada hospital (Isfahan, Iran) were included in this ...

Bystander or non-targeted effect is known to be an interesting phenomenon in radiobiology. The genetic consequences of bystander effect on non-irradiated cells have shown that this phenomenon can be considered as one of the most important factors involved in secondary cancer after exposure to ionizing radiation. Every year, millions of people around the world undergo radiotherapy in order to cu...

This instructional material is intended to provide the user with the best available information concerning what is currently known about the health risks from exposure to ionizing radiation. A question and answer format has been used. The questions were developed by the NRC staff in consultation with workers, union representatives, and licensee representatives experienced in radiation protectio...

Introduction Radioactive materials naturally exist in the world. Indeed, approximately 82% of human-absorbed radiation doses, which are out of human control, arise from natural sources of radiation including cosmic, terrestrial, and exposure through inhalation or ingestion. Thus, the aim of the present study was to estimate health risk, as well as the effective and organ doses from naturally oc...

The public fear of radiation is in part driven by the Linear No Threshold Hypothesis (LNTH), or the concept that each and every ionization increases the risk for cancer. Even if this were true, it is important to recognize that the increased risk is very small at low doses and cannot be detected. This paper demonstrates the large number of assumptions and extrapolations needed when using the LN...

patients and methods we evaluated radiation exposure from initial and downstream testing in a prospectively collected, matched cohort evaluated for cp in the emergency department (ed) with either ccta compared with usual care over a median follow-up of 19.6 months. effective radiation dose was calculated using published conversion factors. results prospective, ecg-triggered acquisition using a ...