Radiation protection of patients in urology

Frequently asked questions by the health professionals

» What are the sources of radiation exposure to patients in imaging procedures in urology? 
» What are the typical radiation doses associated with some urological procedures? 
» How much radiation dose is received by the patient in follow-up of acute kidney stone episode? 
» Can patient doses be reduced in urology? 
» Are there specific protocols for children? 
» Do fluoroscopy guided urological procedures impart high dose to patients?

» What are the sources of radiation exposure to patients in imaging procedures in urology?

Urological imaging procedures may include abdomino-pelvic CT, fluoroscopy for viewing and positioning for urological problems, radiographs of the kidney, ureters and bladder (KUB), excretory urograms (intravenous pyelogram-IVP) and retrograde urethrograms (micturating cysto urethrogram - MCU). These procedures involve exposure to ionizing radiations (X-rays) whereas ultrasound waves and magnetic resonance imaging (MRI) involve non-ionizing radiations. This website is concerned with exposure to ionizing radiations.

» What are the typical radiation doses associated with some urological procedures?

Typical values in terms of effective dose are presented in the Table below:

Table: Typical radiation doses in urological procedures

» How much radiation dose is received by the patient in follow-up of acute kidney stone episode?

Studies for an acute kidney stone episode may, in some situations, involve a range of radiological procedures which may include 1 or 2 plain Kidney Ureter Bladder (KUB) radiographs, 1 or 2 abdominopelvic CT exams, and an IVP during the first year of follow up. The total effective dose from such studies may be in the range of 20 to 40 mSv.

» Can patient doses be reduced in urology?

Yes.

There are several methods recommended for reduction of patient doses for radiological procedures in urology. Specific methods are available for optimization in radiography, fluoroscopy and computed tomography. The experience shows that with the use of optimization techniques it is possible to achieve significant dose reduction, in some cases to the tune of 50%, without compromising on image quality. Avoiding unnecessary CT or fluoroscopy examinations can contribute to further reduction.

» Are there specific protocols for children?

Yes.

If children or young adults are subjected to CT scanning, paediatric protocols or optimised protocols (reduced exposure parameters compared to adult protocol) are recommended. It is important that children get as little radiation exposure as possible because they are more sensitive to radiation than adults and they have a longer life expectancy.

» Do fluoroscopy guided urological procedures impart high dose to patients?

This depends upon the complexity of the procedure that will determine fluoroscopy time and number of images taken. Typically the radiation dose may lie in the range of 1 to 5 mSv, but procedures such as angiography and stent insertion may involve higher radiation doses in the range of 2 to 30 mSv.

References:

• WALL, B.F., HART, D., Revised radiation doses for typical x-ray examinations, Br. J. Radiol. 70 (1997) 437-439. 
• HART, D., WALL, B.F., Radiation exposure of the UK population from medical and dental x-ray examinations, NRPB-W4 (2002). 
• HELLAWELL, G.O., COWAN, N.C., HOLT, S.J., MUTCH, S.J., A radiation perspective for treating loin pain in pregnancy by double-pigtail stents, BJU International 90 (2002) 801–808. 
• BOR, D., SANCAK, T., OLGAR, T., ELCIM, Y., ADANALI, A., SANLDILEK, U., AKYAR, S., Comparison of effective doses obtained from dose-area product and air kerma measurements in interventional radiology, Br. J. Radiol. 77 (2004) 315-322. 
• LIVINGSTONE, R.S., SHYAMKUMAR, N.K., RAJ, V.D., Radiation dose to voluntary kidney donors during renal angiography procedures, J. Radiol. Prot. 21 (2001) 371–376. 
• HELLAWELL, G.O., MUTCH, S.J., THEVENDRAN, G., WELLS, E., MORGAN, R.J., Radiation exposure and the urologist: what are the risks? J. Urol. 174 (2005) 948-952.