Assessment of effective dose and radiation-induced cancer risk in CT-KUB

Abstract

Background and objectivesAmong the various imaging techniques employed for disorders related to the renal and urinary tract systems, computed tomography of kidneys, ureters, and bladder (CT-KUB) is considered the gold standard. The study evaluated effective dose and organ equivalent dose and estimated cancer risk for patients undergoing CT-KUB scans. MethodsScans of 110 patients (76 males, 31 females; mean age 45 years) were completed using a calibrated GE Light Speed 64-slice multi-slice CT (MSCT) scanner. CT exposure parameters were recorded, including tube current, pitch factor tube potential, volume CT dose index (CTDIvol) and dose-length product (DLP), and the National Cancer Institute dosimetry system for computed tomography (NCICT) was used to calculate the effective dose for each patient. Patient organ doses for colon, breast, stomach, bladder, prostate, and ovaries were calculated and converted to estimate cancer risk, based on the Biological Effects of Ionizing Radiation (BEIR) VII report. ResultsCTDIvol, DLP, and effective dose reported mean values of 9.9 mGy, 483.57 mGy cm, and 5.8 mSv, respectively. Lifetime cancer risk ranged from 0.01% to 0.08%, with a mean of 0.03% per 100,000 CT-KUB procedures. For younger individuals, the level of risk was higher for females than for males. While male patients are at higher risk than females for colon cancer, with close risk for both genders regarding stomach and bladder cancers. A statistically significant positive correlation was observed between effective dose and body mass index (p < 0.011, r > 0.4), AP diameter (p < 0.01, r > 0.4), and transfer diameter (p < 0.01, r > 0.5). ConclusionsAlthough the reported effective doses fall within the standard limits, there is significant potential to reduce the radiation dose for patients undergoing CT-KUB. Possible options include low dose protocols and ultrasonography, depending on patient characteristics and clinical condition. Appropriate education and training of radiologic technologists can help to ensure radiation dose optimization.