JASN: Kidney transplant patients face high rad doses
Hemodialysis patients are exposed to high levels of radiation that contribute to significantly increased risks of cancer, while commonly providing no new information, according to a study published Feb. 24 in the Journal of the American Society of Nephrology.

Commonly presenting with serious comorbidities, patients on hemodialysis require continuous care and often undergo repeated imaging with ionizing radiation, both for diagnostic and therapeutic interventions. The authors sought to quantify cumulative effective doses (CEDs) of radiation for 106 patients (median age 65) undergoing hemodialysis, with a median follow-up of three years, amounting to 281 patient-years.

A total of 1,303 radiation-inducing procedures were performed on the 106 patients, including 848 x-rays, 248 CT scans, 108 nuclear imaging exams and 99 interventional procedures. The median CED was 11.7 mSv (mean CED, 21.9 mSv) per patient-year. CT accounted for 76 percent of all participants’ CED, despite representing only 19 percent of procedures.

Twenty-two patients were considered to be exposed to low doses of radiation (CED below 3 mSv per year), while 51 were in the moderate (3 to 20 mSV per year), 22 in the high (20 to 50 mSv) and 11 in the very high dose (greater than 50 mSv per year) groups.

“The cumulative radiation exposure was significantly higher in relatively younger patients and in those who are transplant-eligible,” explained Andreana De Mauri, MD, of the nephrology department at University Hospital Maggiore della Carita in Novara, Italy. “This is of particular concern given the anticipated life expectancy of these subjects and the ongoing use of immunosuppressive agents in the latter.

"Altogether, these findings emphasize the need to begin tracking at least the CT-related exposure, as recently suggested by the American College of Radiology, to develop and increment alternative strategies to reduce patient-specific radiation burden,” De Mauri continued. “Although the retrospective nature of this study does not allow us to draw conclusive inferences about the percentage of CT studies that could have been avoided, the significant number of examinations that resulted in non-notable findings or in negative results points toward the need of a more stringent process of justification of CT referral.”