Weigh immediate health risks against later risk of radiation-induced cancer
In recent years, information regarding the dangers of radiation exposure from CT scans and other medical sources has been in the media. Often, the focus is on the lifetime risk estimates of radiation-induced cancer from repeat examinations. According to Pari V. Pandharipande, MD, MPH, abdominal and genitourinary imaging specialist at Massachusetts General Hospital and Harvard Medical School in Boston, this approach has limitations, especially when it comes to clinical decision making.
Immediate or near-term risk of death from the patient’s condition should be taken into account when weighing the benefits of an imaging exam against a potential future risk of radiation-induced cancer from the imaging.
“This must be considered when physicians make imaging decisions for their patients, because the timing of risks changes their relevance,” Pandharipande said. “Risks incurred later in life are not the same as those faced in the present. If you had to choose between the chance of incurring a serious risk now or later in life, most people would choose the latter.”
For their study, published online in the journal Radiology, Pandharipande and colleagues utilized CT radiation dose data and mathematical models to better understand the risk-benefit dynamic of medical radiation. Projected outcomes were based upon testicular cancer patients who undergo CT surveillance in the decade after orchiectomy.
“Testicular cancer affects younger men, and patients treated for early-stage cancer receive several CT scans during surveillance,” Pandharipande said. “These patients do very well, but they have a greater risk of radiation-induced cancer later in life.”
Following data analysis, the researchers predicted that 33-year-old men with early-stage cancer who undergo CT surveillance incur a slightly higher lifetime mortality risk from testicular cancer compared with potential radiation-induced cancers. Because the testicular cancer risk was more immediate, life expectancy loss relatable to testicular cancer was more than 3 times greater than life expectancy loss relatable to radiation-induced cancers. Across all scenarios studied, the trends were constant.
“Radiation-induced cancer risks, often discussed at the population level, can be challenging to conceptualize and apply to imaging decisions that have to be made at the patient level,” Pandharipande said. “We as physicians can benefit from dedicated educational efforts to improve decision making and better convey the risks to patients.”
Source: RSNA.