Cancer risks attributable to low doses of ionizing radiation: Assessing what we really know

Abstract

High doses of ionizing radiation clearly produce deleterious consequences in humans, including, but not exclusively, cancer induction. At very low radiation doses the situation is much less clear, but the risks of low-dose radiation are of societal importance in relation to issues as varied as screening tests for cancer, the future of nuclear power, occupational radiation exposure, frequent-flyer risks, manned space exploration, and radiological terrorism. We review the difficulties involved in quantifying the risks of low-dose radiation and address two specific questions. First, what is the lowest dose of x-or ␥-radiation for which good evidence exists of increased cancer risks in humans? The epidemiological data suggest that it is Ϸ10 -50 mSv for an acute exposure and Ϸ50 -100 mSv for a protracted exposure. Second, what is the most appropriate way to extrapolate such cancer risk estimates to still lower doses? Given that it is supported by experimentally grounded, quantifiable, biophysical arguments, a linear extrapolation of cancer risks from intermediate to very low doses currently appears to be the most appropriate methodology. This linearity assumption is not necessarily the most conservative approach, and it is likely that it will result in an underestimate of some radiation-induced cancer risks and an overestimate of others.

Use of point-of-care ultrasound in long bone fractures: a systematic review and meta-analysis

“…However, this technique can be impractical because of cost, size of the equipment, the training necessary for the use of this technology, the need for lead protectors on health care providers, as well as the harmful effects to patients of ionizing radiation. 6 The benefits of PoCUS may be even greater for the reduction of displaced fractures, where localized swelling and significant pain may lead to inadequate reduction and repeated attempts, which are known to increase the likelihood of developing compartment syndrome. 7 Moreover, repeated attempts may also put the patient through the risky process of sedation and/or analgesia multiple times, and could possibly lead to increased rates of operative management.…”

CT exposure in adult and paediatric patients: a review of the mechanisms of damage, relative dose and consequent possible risks

“…Following Brenner's publication [31,32] some papers calculated the effective cancer risk with a simple arithmetical calculation (number of CT examinations multiplied by mean exposure in mSv of the population) resulting in impressive and overestimated rates of cancer related to medical exposures in the general population [29]. Valid evidence against this approach was described by Meer in the US, who considered a population of 10 million (Medicare) patients exposed to CT examinations (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005) and found a cancer risk between 0.02 and 0.04 % against the expected 1.5-2.0 %, applying the simple Brenner derived arithmetical calculation [33].…”

Imaging strategies to reduce the risk of radiation in CT studies, including selective substitution with MRI

“…Organ doses associated with routine diagnostic and elective CT scans are similar to the low-dose range of radiation received by atomic-bomb survivors, who have manifested significant increases in cancer incidence and mortality (15)(16)(17). The individuals in the lowest dose group of atomic-bomb survivors who showed a significant rise in cancer incidence and mortality received organ equivalent doses 1 in the range of 5-100 mSv (mean equivalent dose ϭ 29 mSv) and 5-125 mSv (mean equivalent dose ϭ 34 mSv), respectively (15,16).…”

“…The individuals in the lowest dose group of atomic-bomb survivors who showed a significant rise in cancer incidence and mortality received organ equivalent doses 1 in the range of 5-100 mSv (mean equivalent dose ϭ 29 mSv) and 5-125 mSv (mean equivalent dose ϭ 34 mSv), respectively (15,16). Typical equivalent doses in directly irradiated organs are in the range of 20 -30 mSv for a single routine adult CT examination (18,19).…”