Estimated radiation risk of cancer from medical imaging in haemodialysis patients

Background. In recent years the widespread use of medical procedures increased the cumulative effective doses of ionizing radiation. Although many haemodialysis patients undergo multiple examinations with high radiation exposure, no data are available characterizing their attendant potential risks of cancer. Methods. The radiation exposures were obtained from a retrospective study of 159 consecutive haemodialysis patients with a follow-up duration ≥1 year. Effective dose and organ dose were estimated on an individual basis. Radiation risk was expressed as risk of exposure-induced death (REID) (%). Results. The 159 patients (101 males) were followed for a median of 2.7 years (mean 3.0 years). A total of 486 patient-years were available for follow-up. The mean age at study entry was 65.3 years. The mean cumulative organ doses were 103, 102, 100, 99, 77 and 58 mSv for kidneys, lung, stomach, liver, colon and bone marrow, respectively. On average, computed tomography, nuclear medicine and interventional radiology accounted for 90, 4.5 and 5.5% of organ doses, respectively. The average REID was 0.99% (i.e. odds 1 in 100) and the median REID was 0.45%. At univariate analysis, increasing age and presence of diabetes were independent predictors of lower REID, whilst patients eligible for kidney transplantation were exposed to a significantly higher REID. At multivariate analysis, younger age was an independent predictor of higher REID. Conclusions. The excess cancer risk-attributable radiation exposure in haemodialysis patients is not negligible. Particular attention should be paid to younger patients and to patients who will undergo kidney transplantation.