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| PRACTICE CHANGING CONTINUING EDUCATION: OCCUPATIONAL SAFETY AND HEALTH |
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| Year : 2015 | Volume
: 2
| Issue : 2 | Page : 77-82 |
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Radiation risks in urologic practice
Manas Babu
Department of Urology, Lourdes Hospital, Ernakulam, Kerala, India
| Date of Web Publication | 28-Dec-2015 |
Correspondence Address:
Manas Babu
MBBS MS (Gen Surgery), DNB-Urology Resident, Department of Urology, Lourdes Hospital, Ernakulum - 682 012, Kerala
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/2349-0977.172682
X-rays have been used to diagnose diseases in the kidney and urinary tract for about a century. With the advent and advancement of endourology, fluoroscopy has become an integral part of urologic practice. Percutaneous nephrolithotomy, ureterorenoscopy, and extracorporeal shock wave lithotripsy now form the first line treatment modality for urinary calculi. The increased use of fluoroscopy has led to enhanced risk of occupational exposure of the urologist and assisting staff to radiation, leading to health hazards. Therefore, there is an urgent need for protection of both patient and staff from ionizing radiations during urological procedures. There is also a need for adopting dose management techniques in every radiological examination without compromising on the image quality, clinical purpose, to reduce the number of computed tomography scans, and other radiological evaluations for surveillance of various urological illnesses. This article provides a review on the risks of radiation, radiation doses in common urological procedures, current recommendations and regulations for radiation exposure, and methods of radiation protection to be adopted by health personnel. Keywords: Protection, radiation, urology
How to cite this article:
Babu M. Radiation risks in urologic practice. Astrocyte 2015;2:77-82 |
| Introduction | |  |
Though Roentgen discovered X-rays in 1865, the new technology got widely applied for medical imaging purposes only by 1896. With the continuing advancements in the field of Engineering and Radiology, medical practitioners all over the world have become increasingly dependent on use of X-rays for diagnostic purposes. Unfortunately, in the last few decades the X-rays and other radiation modalities are detected to be associated with significant health risks not only to the patients, but also to the medical personnel. A couple of decades ago, Urologists started using X-ray fluoroscopy in their operating rooms and later lithotripsy and computed tomography (CT) came into use. The new generation CT scanners with speed and patient friendliness are making it a useful tool in evaluation and follow-up of cancer and urolithiasis patients. Percutaneous nephrolithotomy (PCNL), ureterorenoscopy, and extracorporeal shock wave lithotripsy (ESWL) now form the first line treatment modality for urinary calculi.
In this paper, we have reviewed the literature on the risks of radiation, radiation doses in common urological procedures, current recommendations and regulations for radiation exposure, and methods of radiation protection to be adopted by health personnel.
| Terminologies Used in Radiation Exposure | | |
- Exposure: Charge per unit mass:[1]
- Traditionally expressed as Roentgen (R)
- SI unit: Coulomb/kg.
- Absorbed dose: Energy absorbed by tissue:[1]
- Traditionally expressed as Rad
- SI unit: Gray (Gy).
- Equivalent dose: Absorbed energy based on tissue type:[1]
- Traditionally expressed as Rem
- SI unit: Sievert (Sv).
- Effective dose: Biologic risk associated with absorbed energy:[1]
- Traditionally expressed as Rem
- SI unit: Sievert (Sv)
- 1 Sievert = 100 rem
- 1 Gray = 100 rad.
| Biologic Effects of Radiation | | |
Ionizing radiation is an established carcinogen, based on animal studies and studies of early radiologists; radium watch dial workers, uranium miners, the atomic bomb survivors, patients treated with radiotherapy, and those undergoing repeated fluoroscopic or radiographic diagnostic examinations.[2],[3],[4],[5] Biologic effects of radiation can be grouped as stochastic or deterministic effects.
Stochastic effect
This represents the probability of effect, rather than its severity. The stochastic effect increases with dose, leading to radiation induced cancer and genetic effects. These stochastic effects lack the threshold dose since injury to few cells or even a single cell could theoretically result in production of the effects. Stochastic effects include cancer and genetic effects, but the scientific evidence for cancer in humans is stronger than for genetic effects.[2],[3]
Deterministic effect
This represents the probability of causing harm based on the dose of radiation, which will be zero at small radiation doses, and damage become apparent when the dose rises above the threshold level, which are typically quite high [Table 1].[6] These thresholds are not normally reached when adequate and proper radiation protection principles are used.[2],[3] After radiotherapy or fluoroscopically guided interventional procedures, generalized erythema may occur within hours then fade within hours to days, followed by a second phase of sustained erythema manifest 10–14 days after the exposure. The early erythema is considered to be an acute inflammatory reaction with an increase in vascular permeability, while the more sustained erythema, without other epidermal changes, is thought to be mediated by cytokines.[7] Radiation cataractogenesis, particularly occurrence of posterior subcapsular opacities has been considered to be another classic example of a deterministic late effect.[6] While epidemiologic studies have shown minimum latency periods of 2–5 years between radiation exposure and the onset of leukemias. The latency periods are reported to be longer for solid tumors, ranging from 10 years to many years after the initial radiation exposure. Risks for most solid tumors continue to increase throughout the radiation-exposed person's lifetime.[8],[9]
| Radiation Limits | | |
It is essential for all the Urologist to have an idea regarding the safety limits in Radiology. For occupational exposure, International Commission on Radiation Protection (ICRP) recommended that the limit should be expressed as an effective dose of 20 mSv/year, averaged over 5 years period (100 mSv in 5 years), with the further provision that the effective dose should not exceed 50 mSv (30 mSv in India) in a single year. ICRP has also given organ-specific permissible limits for radiation exposure. These values can be used in those only specific organs are exposed to radiation rather than the whole body, these dose limits are summarized in [Table 2].[6],[10]
| Radiation Risks during Urology Procedures | | |
Evaluation of a patient with urinary stone disease involve on an average 1–2 ray kidney ureter bladder (KUB), 1–2 abdomen CT examinations and at least one intravenous pyelogram during the 1st year of follow-up. Thus effective dose from such studies may be in the range of 20–50 mSv annually in these patients.[11] CT has replaced other radiological investigations in urinary tract evaluations in most of the centers worldwide, even though it is associated with higher doses of radiation exposures.[6],[12] Studies showed higher effective dose radiation for CT urograms when compared with conventional urography, even after dose reduction strategies in CT are applied.[13],[14] Hence, the patient dose estimates should be taken into account when imaging studies are chosen.[6],[13],[15] Several studies have shown that unenhanced CT is more accurate than excretory urography for the examination of patients with renal colic and is the preferred technique.[15],[16] In the past decade due to advancements in technology and studies focussing on low dose kidney CT protocols have concluded that its radiation dose is comparable to that associated with conventional excretory urography.[16],[17] Dahlman et al.[14] reported a decrease of the effective dose to patients undergoing CT urography by 60% in 1997–11.7 and 8.8 mSv in 2008, for female and male patients, respectively. All these studies have concluded that considerable dose reduction can be achieved without affecting the quality of the image. However, it is evident that the health risks of CT scans is still a considerable fact for patients and health workers. In a study to determine the effective radiation dose associated with an acute stone episode and short-term follow-up of these patients, Ferrandin et al.[11] concluded that the median total effective radiation dose per patient was 29.7 mSv. There were 20% patients who received >50 mSv. Analysis of stone location, number of stones, stone composition, patient age, sex, and surgical intervention indicated no statistically significant difference in the probability of receiving a total radiation dose >50 mSv.
In ESWL, the effective radiation dose to the patient through fluoroscopy and radiography is normally <1–2 mSv, with nearly 50–78% through fluoroscopy,[2],[18],[19],[20] but the dose from ESWL is always added to the dose from pre- and post-treatment KUB and IVU procedures.[19] Mean radiation doses encountered in various other urological procedures are given in [Table 3].[9],[21],[22],[23],[24],[25] Maximum radiation doses are encountered in renal angiograms, whereas minimum in X-ray KUB. | Table 3: The Typical Radiation Dose Levels to the Patient from Various Urological Procedures
Click here to view |
PCNL is a standard procedure for renal calculi >2 cm. This procedure involves exhaustive use of fluoroscopy. The range of fluoroscopy time for PCNL is found to be 1–28 min with a mean of 14.5 min in various studies.[23],[26],[27],[28],[29],[30],[31] This time is showing a gradual decline as the advancements occurred in fluoroscopes and the knowledge of the radiation hazards improved. Though previously PCNL could be completed only in more than 20 min, advances in technology and skills have reduced the mean duration currently to 4–6 min.[23],[26],[27],[28],[29],[30],[31]
Typical effective dose from nephrostomy procedures is 7.7 mSv, with an associated range of 3.4–15 mSv.[2],[18],[19],[32] The documented mean doses per procedure for the urologist were 12–24 µSv.[33] There are various studies calculated the mean dosage exposure to various body parts of personnel performing PCNL. In a study by Majidpour,[27] the highest radiation exposure dose was found to be the legs of the operating surgeon and assistant with 4.1 μGy and 0.1 μGy, respectively. Hellawell et al.[23] had also shown that the surgeon received the highest radiation exposure with leg (11.6 ± 2.7 μGy) and the foot (6.4 ± 1.8 μGy) receiving more radiation than the eyes (1.9 ± 0.5 μGy) and the hands (2.7 ± 0.7 μGy). The radiation exposure to the fingers of Urologists reported in various studies were 0.28 mSv (Kumari [30]), 0.34 mSV (Law et al.[34]), 0.58 mSV (Rao et al.[28]), 0.28 mSV (Kumar [26]), 0.2 mSV (Majidpour [27]), and 0.3 mSV (Bush et al.[29]). Rao et al.[28] documented a mean total radiation dose of 5.2 mSv to the hands, and 1.6 mSv to the eyes, with the mean fluoroscopy time of 21.9 min, which was very high in comparison to that cited in literature. Mancini et al.[35] concluded in their study that high body mass index, higher stone burden, stone nonbranched stone configuration, and a greater number of percutaneous access tracts were significantly associated with higher risks of radiation doses during PCNL.
Objectives of Radiation Protection
The various regulatory bodies like the ICRP, the National Commission for Radiation Protection (NCRP) in America, and the Atomic Energy Regulatory Board in India recommend and lay down norms for radiation protection in various countries around the globe.[36] The ICRP in 1991 stated that “the overall objective of radiation protection is to provide an appropriate standard of protection for a man without unduly limiting the beneficial practices giving rise to radiation exposure.” The NCRP in 1993, issued a similar statement that “the goal of radiation protection is to prevent the occurrence of serious radiation induced conditions (acute and chronic deterministic effects) in exposed persons and to reduce stochastic effects in exposed persons to a degree that is acceptable in relation to the benefits to the individual and to the society from the activities that generate such exposure.” ICRP also suggested that “current standards of protection are meant to prevent occurrence of deterministic effects by keeping doses below relevant thresholds and ensure that all reasonable steps are taken to reduce induction of stochastic effects.”[9],[36],[37],[38]
| General Principles of Radiation Protection | | |
ICRP advocates the principle of “as low as reasonably achievable” which accepts that some amount of radiation exposure may be inevitable. ICRP also recommends that radiation exposure should be based on the principles of time, distance, shielding, justification, optimization, and dose limitation.[6],[39],[40],[41],[42],[43],[44],[45]
Time
Minimizing the duration of radiation can reduce the radiation dose by a factor of 2–20 or more.
Distance
Increasing the distance from the X-ray source as much as is practical, can reduce the radiation dose by a factor of 2–20 or more.
Shielding
Is the most effective as a tool for staff protection. However, shielding has a limited role in patient protection.
Justification
The referring medical practitioner is responsible for ensuring that a diagnostic procedure involving ionizing radiation is necessary for a patient's care and that the radiation dose from the procedure is expected to do more good than harm. In the case of the individual patient, justification normally involves both the referring medical practitioner and the radiologist.
Optimization
Once examinations are justified, they must be optimized, that is, should be done at a lower dose while maintaining efficacy and accuracy. Optimization of the examination should be both generic for the examination type and all the equipment and procedures involved. It should also be specific for the individual, and include review of whether or not it can be effectively done in a way that reduces dose for the particular patient.[6] In addition, the imaging equipment must be properly set and maintained. To achieve good optimization, radiological medical practitioners and radiologic technologists, with substantial input from manufacturers, must work closely with medical physicists to ensure rigorous oversight of radiation-producing imaging units. This includes accuracy of settings, safeguards, calibration, and maintenance, as highlighted in reports of excess radiation during CT brain perfusion scans.[46]
Blair et al.[47] concluded in their study that implementing a decreased fluoroscopy protocol during PCNL resulted in an 80.9% reduction in fluoroscopy time while maintaining success rates, operative times and complications similar to those of the conventional technique. Adopting this reduced fluoroscopy protocol safely decreased radiation exposure to patients, surgeons, and operating room staff during PCNL.
Ngo et al.[48] in their study concluded that mean fluoroscopy times for unilateral ureteroscopy can be decreased by 24% after giving the adequate feedback to surgeons on their fluoroscopy usage time. Other factors like female sex, stones in the distal ureter are independently associated with decreased fluoroscopy times. Whereas factors like hydronephrosis, use of a ureteral access sheath, ureteral balloon dilation and placement of a postoperative stent are associated with increased fluoroscopy times. Weld et al.[49] in their study concluded that safety, minimization and awareness radiation training reduces fluoroscopy time of unilateral uncomplicated ureteroscopy for urolithiasis performed by urology residents by 56%. Greene et al.[50] showed in their study that the reduced fluoroscopy protocol resulted in an 82% reduction in fluoroscopy time without altering patient outcomes. These simple radiation-reducing protocol, included several measures like use of a laser-guided C-arm, use of a designated fluoroscopy technician and substitution of visual for fluoroscopic cues during ureteroscopy, add no technical difficulty and improve safety for the patient, surgeon, and operating room staff by lowering radiation exposure.
Parker et al.[51] showed in their study that operating urologist had a significant impact on a patient's perioperative radiation exposure. Consultant's operating technique, the communication methods used with the radiographer or the consultant's own awareness about the risks of radiation exposure, conscious awareness of how to reduce the perioperative exposure does produced significant results and reduced the risks to the patient and potential harm. Friedman et al.[52] concluded in their study that protective equipment usage and occupational radiation monitoring for the training urologist were insufficient. Despite frequent exposure, resident education in radiation safety was found lacking. They also recommended that efforts should be made to address these deficiencies on a local and national level.
Cohen et al.[53] in their study followed an endourologist for consecutive nine months and estimated the cumulative radiation exposure, which concluded that total radiation exposures were well below annual accepted limits when the necessary precautionary measures are taken. Söylemez et al.[54] highlighted the lack of knowledge and awareness about the importance of ionizing radiation protection among urology residents in Europe. Elkoushy and Andonian [55] concluded in their study that there was good compliance with chest and pelvic shields with 97% of endourologists reported wearing these. Whereas compliance with thyroid shields was only 68%. Furthermore, only 34.3%, 17.2%, and 9.7% of endourologists reported using dosimeters, lead-impregnated glasses, and gloves, respectively. Overall, 64.2% respondents complained of orthopedic problems, like back ache in 38.1%, 27.6% with neck problems, 17.2% with hand problems and 14.2% complained of hip and knee problems. The prevalence of orthopedic complaints was significantly higher among older endourologists (>40 years), longer duration of practice (>10 years) and those with high annual caseload of URS and PCNL.
| Recommendations for Reducing Radiation Risks for Urologists | | |
The following precautionary measures to be followed by urologists and staff have been suggested, which could help in reducing the risk of radiation exposure:[9],[33],[37],[39],[43],[44],[46],[53]
- Position the X-ray tube under the patient not above the patient. The largest amount of scatter radiation is produced where the X-ray bean enters the patient. By positioning the X-ray tube below the patient, we can decrease the amount of scatter radiation that reaches the upper body can be reduced
- Observers should stand on the image intensifier side of the c arm whenever possible, to avoid the leakage radiation from the X-ray tube
- The beam should be collimated tightly to the area of interest. This reduces the patients total entrance skin exposure and improves image contrast. Scatter radiation to the operator will also be decreased
- Viewing prior radiographs helps to reduce the number of exposures and thereby minimizes the time of exposure
- All workers in the operating/X-ray room during studies must wear lead aprons. Lead gloves are required if hands are in the primary beam. Thyroid shields are also needed for fluoroscopy. After use aprons and shields should be hung on racks
- Health personnel should step back from the patient as much as possible. Stepping even one foot further back can significantly reduce one's dose of radiation
- Wear the badge flat against the body at neck. Pregnant ladies should also use waist badge. Turn in the badge for processing at the end of monitoring period
- Medical personnel involved in radiation should be screened monthly or quarterly to quantify the radiation exposure, and the total exposure should not be allowed to exceed the annual permissible limits.
| Conclusion | | |
The review of literature has shown definite radiation risks in diagnostic and therapeutic uroradiological procedures particularly for urologists. The physician and personnel involved in patient care should be well aware of the permissible doses and precautionary measures that can reduce radiation effects for them. The diagnostic imaging modalities and follow up protocols should be tailored taking care so that the patients also receive only permissible doses of radiation exposure.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
| 1. | Fulgham PF, Bishoff JT. Urinary tract imaging: Basic principles. In: Wein AJ, Kavoussi LR, Partin AW, Novick AC, Peters CA, editors. Campbell – Walsh Urology. 10th ed. Philadelphia: Elsevier Saunders; 2012. p. 99-100.  |
| 2. | Medical Exposure to Ionizing Radiation. Annex A, Sources and Effects of Ionizing Radiation, UNSCEAR 2008 Report to General Assembly. New York: United Nations Publications; 2010. p. 22-36. |
| 3. | Miller DL, Balter S, Noonan PT, Georgia JD. Minimizing radiation-induced skin injury in interventional radiology procedures. Radiology 2002;225:329-36. |
| 4. | Boice JD Jr. Ionizing radiation. In: Schottenfeld D, Fraumeni JF Jr, editors. Cancer Epidemiology and Prevention. 3rd ed. New York: Oxford University Press; 2006. p. 259-93. |
| 5. | United Nations Scientific Committee on the Effects of Atomic Radiation. Sources and Effects of Ionizing Radiation. Annex An Epidemiological Studies of Radiation Carcinogenesis. New York: United Nations Scientific Committee on the Effects of Atomic Radiation; 1994. p. 11-183. |
| 6. | The 2007 Recommendations of the International Commission on Radiological Protection. ICRP publication 103. Ann ICRP 2007;37:1-332. |
| 7. | Balter S, Hopewell JW, Miller DL, Wagner LK, Zelefsky MJ. Fluoroscopically guided interventional procedures: A review of radiation effects on patients' skin and hair. Radiology 2010;254:326-41. |
| 8. | Preston DL, Ron E, Tokuoka S, Funamoto S, Nishi N, Soda M, et al. Solid cancer incidence in atomic bomb survivors: 1958-1998. Radiat Res 2007;168:1-64. |
| 9. | Bury RF. Radiation hazards in urological practice. BJU Int 2002;89:505-9. |
| 10. | Wagner LK, Hayman LA. Pregnancy and women radiologists. Radiology 1982;145:559-62. [ PUBMED] |
| 11. | Ferrandino MN, Bagrodia A, Pierre SA, Scales CD Jr, Rampersaud E, Pearle MS, et al. Radiation exposure in the acute and short-term management of urolithiasis at 2 academic centers. J Urol 2009;181:668-72. |
| 12. | Mancini JG, Ferrandino MN. The impact of new methods of imaging on radiation dosage delivered to patients. Curr Opin Urol 2010;20:163-8. |
| 13. | Nawfel RD, Judy PF, Schleipman AR, Silverman SG. Patient radiation dose at CT urography and conventional urography. Radiology 2004;232:126-32. |
| 14. | Dahlman P, Jangland L, Segelsjö M, Magnusson A. Optimization of computed tomography urography protocol, 1997 to 2008: Effects on radiation dose. Acta Radiol 2009;50:446-54. |
| 15. | Eikefjord EN, Thorsen F, Rørvik J. Comparison of effective radiation doses in patients undergoing unenhanced MDCT and excretory urography for acute flank pain. AJR Am J Roentgenol 2007;188:934-9. |
| 16. | Tack D, Sourtzis S, Delpierre I, de Maertelaer V, Gevenois PA. Low-dose unenhanced multidetector CT of patients with suspected renal colic. AJR Am J Roentgenol 2003;180:305-11. |
| 17. | Larsen AS, Pedersen R, Sandbaek G. Computed tomography of the urinary tract: Optimalization of low-dose stone protocol in a clinical setting. Acta Radiol 2005;46:764-8. |
| 18. | Perisinakis K, Damilakis J, Anezinis P, Tzagaraki I, Varveris H, Cranidis A, et al. Assessment of patient effective radiation dose and associated radiogenic risk from extracorporeal shock-wave lithotripsy. Health Phys 2002;83:847-53. |
| 19. | Sandilos P, Tsalafoutas I, Koutsokalis G, Karaiskos P, Georgiou E, Yakoumakis E, et al. Radiation doses to patients from extracorporeal shockwave lithotripsy. Health Phys 2009;90:583-7. |
| 20. | Baldock C, Greener AG, Batchelor S. Radiation dose to patients and staff from Storz Modulith SL20 lithotripter. J Stone Dis 1992;4:216-9. |
| 21. | Wall BF, Hart D. Revised radiation doses for typical X-ray examinations. Report on a recent review of doses to patients from medical X-ray examinations in the UK by NRPB. National Radiological Protection Board. Br J Radiol 1997;70:437-9. |
| 22. | Hart D, Wall BF. UK population dose from medical X-ray examinations. Eur J Radiol 2004;50:285-91. |
| 23. | Hellawell GO, Cowan NC, Holt SJ, Mutch SJ. A radiation perspective for treating loin pain in pregnancy by double-pigtail stents. BJU Int 2002;90:801-8. |
| 24. | Bor D, Sancak T, Olgar T, Elcim Y, Adanali A, Sanlidilek U, et al. Comparison of effective doses obtained from dose-area product and air kerma measurements in interventional radiology. Br J Radiol 2004;77:315-22. |
| 25. | Livingstone R, Kumar N, Raj D. Radiation dose to voluntary kidney donors during renal angiography procedures. J Radiol Prot 2001;21:371-6. |
| 26. | Kumar P. Radiation safety issues in fluoroscopy during percutaneous nephrolithotomy. Urol J 2008;5:15-23. |
| 27. | Majidpour HS. Risk of radiation exposure during PCNL. Urol J 2010;7:87-9. |
| 28. | Rao PN, Faulkner K, Sweeney JK, Asbury DL, Sambrook P, Blacklock NJ. Radiation dose to patient and staff during percutaneous nephrostolithotomy. Br J Urol 1987;59:508-12. |
| 29. | Bush WH, Jones D, Brannen GE. Radiation dose to personnel during percutaneous renal calculus removal. AJR Am J Roentgenol 1985;145:1261-4. [ PUBMED] |
| 30. | Kumari G, Kumar P, Wadhwa P, Aron M, Gupta NP, Dogra PN. Radiation exposure to the patient and operating room personnel during percutaneous nephrolithotomy. Int Urol Nephrol 2006;38:207-10. |
| 31. | Lowe FC, Auster M, Beck TJ, Chang R, Marshall FF. Monitoring radiation exposure to medical personnel during percutaneous nephrolithotomy. Urology 1986;28:221-6. [ PUBMED] |
| 32. | Rehani MM, Ciraj-Bjelac O, Vañó E, Miller DL, Walsh S, Giordano BD, et al. ICRP Publication 117. Radiological protection in fluoroscopically guided procedures performed outside the imaging department. Ann ICRP 2010;40:1-102. |
| 33. | Safak M, Olgar T, Bor D, Berkmen G, Gogus C. Radiation doses of patients and urologists during percutaneous nephrolithotomy. J Radiol Prot 2009;29:409-15. |
| 34. | Law J, Inglis JA, Tolley DA. Radiation dose to urological surgeons during X-ray fluoroscopy for percutaneous stone extraction. Br J Radiol 1989;62:185-7. |
| 35. | Mancini JG, Raymundo EM, Lipkin M, Zilberman D, Yong D, Bañez LL, et al. Factors affecting patient radiation exposure during percutaneous nephrolithotomy. J Urol 2010;184:2373-7. |
| 36. | Gover SB, Kumar J, Gupta A, Khanna L. Protection against radiation hazards; Regulatory bodies, safety norms, does limits and protection devices. Indian J Radiol Imaging 2002;12:157-67. |
| 37. | Shymko MJ. Minimizing occupational exposure. Radiol Technol 1998;70:89-90. |
| 38. | Quality improvement guidelines for recording patient radiation dose in the medical record. Miller DL et al. J Vasc Interv Radiol 2004;15:423-9. [ PUBMED] |
| 39. | Rehani MM, Ciraj-Bjelac O, V1añó E, Miller DL, Walsh S, Giordano BD, et al. ICRP Publication 117. Radiological protection in fluoroscopically guided procedures performed outside the imaging department. Ann ICRP 2010;40:1-102. |
| 40. | Miller DL, Balter S, Wagner LK, Cardella J, Clark TW, Neithamer CD Jr. Quality improvement guidelines for recording patient radiation dose in medical record. J Vasc Interv Radiol 2004;15:423-9. |
| 41. | 1990 Recommendations of the international commission on radiological protection. ICRP publication 60. Ann ICRP 1990;21:119-90. |
| 42. | Wrixon AD. New ICRP recommendations. J Radiol Prot 2008;28:161-8. |
| 43. | Tse V, Lising J, Khadra M, Chiam Q, Nugent R, Yeaman L, et al. Radiation exposure during fluoroscopy: Should we be protecting our thyroids? Aust N Z J Surg 1999;69:847-8. |
| 44. | Giblin JG, Rubenstein J, Taylor A, Pahira J. Radiation risk to the urologist during endourologic procedures, and a new shield that reduces exposure. Urology 1996;48:624-7. |
| 45. | Simpkin DJ, Dixon RL. Secondary shielding barriers for diagnostic X-ray facilities: Scatter and leakage revisited. Health Phys 1998;74:350-65. |
| 46. | Linet MS, Slovis TL, Miller DL, Kleinerman R, Lee C, Rajaraman P, et al. Cancer risks associated with external radiation from diagnostic imaging procedures. CA Cancer J Clin 2012;62:75-100. |
| 47. | Blair B, Huang G, Arnold D, Li R, Schlaifer A, Anderson K, et al. Reduced fluoroscopy protocol for percutaneous nephrostolithotomy: Feasibility, outcomes and effects on fluoroscopy time. J Urol 2013;190:2112-6. |
| 48. | Ngo TC, Macleod LC, Rosenstein DI, Reese JH, Shinghal R. Tracking intraoperative fluoroscopy utilization reduces radiation exposure during ureteroscopy. J Endourol 2011;25:763-7. |
| 49. | Weld LR, Nwoye UO, Knight RB, Baumgartner TS, Ebertowski JS, Stringer MT, et al. Safety, minimization, and awareness radiation training reduces fluoroscopy time during unilateral ureteroscopy. Urology 2014;84:520-5. |
| 50. | Greene DJ, Tenggadjaja CF, Bowman RJ, Agarwal G, Ebrahimi KY, Baldwin DD. Comparison of a reduced radiation fluoroscopy protocol to conventional fluoroscopy during uncomplicated ureteroscopy. Urology 2011;78:286-90. |
| 51. | Parker SG, Kommu SS, Ahmed M. Variables affecting radiation exposure in patients undergoing endo-urological procedures. J Nucl Med Radiat Ther 2013;4:2155-9619. |
| 52. | Friedman AA, Ghani KR, Peabody JO, Jackson A, Trinh QD, Elder JS. Radiation safety knowledge and practices among urology residents and fellows: Results of a nationwide survey. J Surg Educ 2013;70:224-31. |
| 53. | Cohen SA, Rangarajan SS, Chen T, Palazzi KL, Langford JS, Sur RL. Occupational hazard: Radiation exposure for the urologist – Developing a reference standard. Int Braz J Urol 2013;39:209-13. |
| 54. | Söylemez H, Sancaktutar AA, Silay MS, Penbegül N, Bozkurt Y, Atar M, et al. Knowledge and attitude of European urology residents about ionizing radiation. Urology 2013;81:30-5. |
| 55. | Elkoushy MA, Andonian S. Prevalence of orthopedic complaints among endourologists and their compliance with radiation safety measures. J Endourol 2011;25:1609-13. |
[Table 1], [Table 2], [Table 3]
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