English | Español

Urology

Radiation Protection in Urology

External Beam Radiotherapy

X-rays have been used to diagnose diseases in the kidney and urinary tract for about a century to visualize urinary tract to highlight a kidney stone or tumour that could block the flow of urine. It was only couple of decades ago that urologists started using X-ray fluoroscopy in their operating rooms. Then came lithotripsy and now it is computed tomography (CT) that is increasingly being used. CT is currently the most sensitive and specific imaging test for urolithiasis. The improved diagnostic accuracy of newer generation of CT scanners coupled with speed and patient friendliness is making CT a useful tool in follow-up of cancer patients (such as testicular) and there are situations when a patient is subjected to more than 10 CT scans in a follow up period of 5 years. Urological procedures like intravenous pylography (IVP) or intravenous urography (IVU) are generally performed using radiography machines. These investigations may or may not have a direct involvement of the urologist. However, active involvement of the urologist with the use of radiological facilities is in cystography, retrograde pyelography, voiding cystourethrogram (VCUG) procedures where there is a need to administer contrast agents directly into the urinary system. A number of procedures like percutaneous nephrolithotomy (PCNL), nephrostomy, stent placement, stone extraction and tumor ablation require fluoroscopy machine in the operating room.

Due to the increased use of radiation during urological procedures, protection of patients from ionizing radiation is becoming increasingly important. With such usage, there is a need for adopting dose management techniques in every radiological examination without compromising on image quality and clinical purpose. Further, there is need to reduce the number of CT scans for surveillance. There is possibility of staff getting high exposure in fluoroscopy room if protection principles and tools are not employed.

There are sections on this website that pertain to more specific aspects of protection in fluoroscopy, computed tomography and radiation units and dose quantities.

Patient protection

Staff protection

1. 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.

Page Top

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

Typical values in terms of effective dose are presented in Table 1 below:

Table 1. Typical radiation doses in urological procedures

Procedure Mean effective dose (mSv) values
Abdomen radiography (AP) 0.7 [1]
Intravenous Urogram (6 films) 2.5 [1]
Micturating cysto urethrogram 1.2 [2]
Cystography 1.8 [2]
Lithotripsy 1.3 [2]
Nephrostomy 3.4 [2]
Percutaneous nephrolithotomy (PCNL) 4.5 [3]
Ureteric stenting 4.7 [2]
CT abdomen 10 [1]
Renal angiogram 2 to 30 [4,5]
Kidney stent insertion 12.7 [2]


Page Top

3. 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.

Page Top

4. 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. Read more »

Page Top

5. 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.

Page Top

6. 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 [Table 1]

Page Top

Staff protection

Fluoroscopy in Urology

7. What is the major cause of radiation exposure to personnel during urology procedures utilizing fluoroscopy and what protection measures can help?

The major source of radiation exposure to personnel in fluoroscopy procedures is exposure to scattered radiation from the patient. The exposure comes mainly from the entry surface of the beam into the patient. The main protection for the personnel is lead apron and leaded screens and flaps wherever feasible. Additionally, distance as much as practicable, shortest time of radiation use (intermittent fluoroscopy rather than keeping foot on pedal continuously) is advised. Read more »

Page Top

8. Can one effectively reduce radiation exposure to urology personnel in fluoroscopic examinations?

Yes, there are numerous ways to minimize scatter exposure of fluoroscopy personnel

  • Properly utilize radiation shielding provided with the fluoroscopy equipment, such as sliding lead vinyl shields, protective lead aprons, thyroid shields, leaded eyeglasses. Be sure that these are positioned between the patient and the person being protected.
  • Minimize the area of the fluoroscopy x-ray field
  • Stand as far from the patient as possible.
  • Limit the beam on time to a minimum
  • Use modern equipment with technical innovations such as last image hold and pulsed fluoroscopy beams.
  • Position the image intensifier as close to the patient as possible and the x-ray tube as far from the patient as possible. These steps will also minimize dose to the patient.

http://rpop.iaea.org/RPOP/RPoP/Content/InformationFor/HealthProfessionals/1_Radiology/Fluoroscopy.htm#FluorFAQ06

Read more »

Page Top

9. What are some typical doses to urology personnel from fluoroscopy?

Hellawell et al. has estimated that for a typical uretheral fluoroscopy procedure, utilizing 70 kV and 2 – 3 mA that a surgeon receives about 12 µGy to the lower leg, about 6 µGy to the foot, 2 µGy to the eyes and 3 µGy to the hands. An annual caseload of 50 cases would limit the dose received to a few tenths percent of the annual personnel exposure limits. Radiation exposure during percutaneous nephrolithotomy (PNCL) would be somewhat higher, but would still be expected to be less than a few percent of permissible annual limits. [HELLAWELL, G.O., et al., 2005].

Page Top

References
  1. WALL, B.F., HART, D., Revised radiation doses for typical x-ray examinations, Br. J. Radiol. 70 (1997) 437-439.
  2. HART, D., WALL, B.F., Radiation exposure of the UK population from medical and dental x-ray examinations, NRPB-W4 (2002).
  3. 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.
  4. 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.
  5. 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.
  6. 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.


Social Media

Related Links

 
Copyright © 2013 International Atomic Energy Agency, Vienna International Centre, PO Box 100, 1400 Vienna, Austria