Study: Low-Dose Radiation is Not Harmful

A recent study disavowed a 70-year-old linear no threshold hypothesis (LNTH) which claimed that any dose of radiation increased the risk for cancer. The study asserted that radiologic imaging does not cause cancer, and would most likely benefit the prevention of cancer.

Researchers found no credible evidence that supported the risk for cancer related to low-dose imaging. They stated that the LNTH and as-low-as-reasonably-achievable (ALARA) dosage doctrine are flawed because they focused on molecular damage while ignoring protective, organismal biologic responses, and resulted in radiophobia in both health care providers and patients.
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“The LNTH is an invalidated hypothesis, and its use, in the form of ALARA dosing, is responsible for misguided concerns promoting radiophobia, leading to actual risks far greater than the hypothetical carcinogenic risk purportedly avoided,” the researchers stated.

According to their findings, low-dose radiation imaging did not cause harm or increased the risks for cancer in patients. Findings from the Life Span Study of atom-bomb survivors showed that LNTH-predicted, low-dose carcinogenicity was invalid below approximately 200 mGv. The current and effective dosage for a computed tomography scan is 10 mSv, a PET/CT brain scan 5 to 7 mSv, and a routine whole-body F-18 FDG PET/CT scan is 12-15 mSv. Evidence suggests that imaging reduced cancer risks, indicating low-dose radiation imaging might be beneficial for cancer prevention.

“The present work calls for ending the radiophobia caused by those asserting the need for dose optimization in imaging: the low-dose radiation of medical imaging has no documented pathway to harm, whereas the LNTH and ALARA most assuredly do,” the researchers concluded.

—Melissa Weiss

Reference:

Siegel JA, Pennington CW, and Sacks B. Subjecting radiologic imaging to the linear no-threshold hypothesis: a non sequitur of non-trivial proportion [published online before print August 4, 2016]. The Journal of Nuclear Medicine. doi:10.2967/jnumed.116.180182.