Using a sterile disposable protective surgical drape for reduction of radiation exposure to interventionalists

ICRP Publication 117. Radiological protection in fluoroscopically guided procedures performed outside the imaging department

An increasing number of medical specialists are using fluoroscopy outside imaging departments, but there has been general neglect of radiological protection coverage of fluoroscopy machines used outside imaging departments. Lack of radiological protection training of those working with fluoroscopy outside imaging departments can increase the radiation risk to workers and patients. Procedures such as endovascular aneurysm repair, renal angioplasty, iliac angioplasty, ureteric stent placement, therapeutic endoscopic retrograde cholangio-pancreatography,and bile duct stenting and drainage have the potential to impart skin doses exceeding Gy. Although tissue reactions among patients and workers from fluoroscopy procedures have, to date, only been reported in interventional radiology and cardiology,the level of fluoroscopy use outside imaging departments creates potential for such injuries.A brief account of the health effects of ionising radiation and protection principles is presented in Section 2. Section 3 deals with general aspects of the protection of workers and patients that are common to all, whereas specific aspects are covered in Section 4 for vascular surgery, urology, orthopaedic surgery, obstetrics and gynaecology,gastroenterology and hepatobiliary system, and anaesthetics and pain management.Although sentinel lymph node biopsy involves the use of radio-isotopic methods rather than fluoroscopy, performance of this procedure in operating theatres is covered in this report as it is unlikely that this topic will be addressed in another ICRP publication in coming years. Information on radiation dose levels to patients and workers, and dose management is presented for each speciality.

Radiation exposure--do urologists take it seriously in Turkey?

PURPOSE

A questionnaire was administered to urologists to evaluate attitudes and behaviors about protection from radiation exposure during fluoroscopy guided endourological procedures.

MATERIALS AND METHODS

The questionnaire was e-mailed to 1,482 urologists, including urology residents, specialists and urologists holding all levels of academic degrees, between May and June 2011. The questionnaire administered to study participants was composed of demographic questions, and questions on radiation exposure frequency, and the use of dosimeters and flexible protective clothes. If a respondent reported not using dosimeters or protective clothes, additional questions asked for the reason.

RESULTS

Of the 1,482 questionnaires 394 (26.58%) were returned, of which 363 had completed answers. A total of 307 physicians (84.58%) were exposed to ionizing radiation, of whom 79.61% stated that they perform percutaneous nephrolithotomy at the clinic. Fluoroscopy guidance was the initial choice of 96.19% of urologists during percutaneous nephrolithotomy. Despite the common use of lead aprons (75.24%) most urologists did not use dosimeters (73.94%), eyeglasses (76.95%) or gloves (66.67%) while 46.44% always used thyroid shields during fluoroscopy. When asked why they did not use protective clothing, the most common answers were that protective clothes are not ergonomic and not practical.

CONCLUSIONS

Results clearly highlight the lack of use of ionizing radiation protection devices and dosimeters during commonly performed fluoroscopy guided endourological procedures among urologists in Turkey.

[Vertebroplasty and kyphoplasty under dual guidance (CT and fluoroscopy): radiation dose to radiologist. A comparative study]

OBJECTIVES

The goals of this study is to evaluate and compare the irradiation received by the practitioner when performing percutaneous vertebroplasty or kyphoplasty guided by CT and fluoroscopy, for precise anatomical sites.

METHODS

For each intervention, radiothermoluminescent dosimeters were carefully positioned on both orbitals, both hands, and both ankles of the practitioner.

RESULTS

Twenty-four vertebroplasties were performed in 18 patients and nine kyphoplasties on seven patients. The anatomical site that is most exposed to radiation is the right hand. The two other sites subjected to irradiation are the left hand and the left orbital. This study demonstrates a significant correlation between the irradiation dose and fluoroscopy duration, reflecting both the quantity of primary-beam radiation and backscattered radiation.

CONCLUSION

The radiation dose to radiologist is more important for kyphoplasty procedures than vertebroplasty.

Overview of patient dosimetry in diagnostic radiology in the USA for the past 50 years

This review covers the role of medical physics in addressing issues directly related to patient dosimetry in radiography, fluoroscopy, mammography, and CT. The sections on radiography and fluoroscopy radiation doses review the changes that have occurred during the last 50 to 60 years. A number of technological improvements have contributed to both a significant reduction in patient and staff radiation doses and improvements to the image quality during this period of time. There has been a transition from film-screen radiography with hand dip film processing to electronic digital imaging utilizing CR and DR. Similarly, fluoroscopy has progressed by directly viewing image intensifiers in darkened rooms to modern flat panel image receptor systems utilizing pulsed radiation, automated variable filtration, and digitally processed images. Mammography is one of the most highly optimized imaging procedures performed, because it is a repetitive screening procedure that results in annual radiation exposure. Mammography is also the only imaging procedure in the United States in which the radiation dose is regulated by the federal government. Consequently, many medical physicists have studied the dosimetry associated with screen-film and digital mammography. In this review, a brief history of mammography dose assessment by medical physicists is discussed. CT was introduced into clinical practice in the early 1970s, and has grown into one of the most important modalities available for diagnostic imaging. CT dose quantities and measurement techniques are described, and values of radiation dose for different types of scanner are presented. Organ and effective doses to adult patients are surveyed from the earliest single slice scanners, to the latest versions that include up to two x-ray tubes and can incorporate as many as 256 detector channels. An overview is provided of doses received by pediatric patients undergoing CT examinations, as well as methods, and results, of studies performed to assess the radiation absorbed by the conceptus of pregnant patients.

Facts and controversies about radiation exposure, part 1: controlling unnecessary radiation exposures

In this 2-part article, the authors address the need to put in perspective the risks of radiation exposure in the rapidly changing field of radiology, considering the current state of knowledge of effects at low levels. The article is based on the content of the refresher course RC 516 presented at the Radiological Society of North America's 2005 annual meeting. After a brief review of epidemiologic studies, part 1 contains a discussion of typical radiation doses experienced in medicine, by both patients and professionals, and it concludes with a description of practical approaches to reduce unnecessary exposures. Part 2 of the article addresses a special concern for the unborn and discusses advisory and regulatory cancer risk estimates based mainly on epidemiologic studies. The limitations of epidemiologic studies at low-level exposures and recent new findings in radiobiology, some of which are summarized, challenge the notion that any amount of radiation causes adverse effects.

Radiation hand exposure during restoration of flow to the thrombosed dialysis access graft

PURPOSE

To determine radiation dose to the hands of interventional radiologists during restoration of flow to thrombosed dialysis access grafts.

MATERIALS AND METHODS

Sixty-two procedures were performed in 54 patients with thrombosed synthetic arteriovenous hemodialysis access grafts. For each procedure, five staff interventional radiologists wore thermoluminescent ring dosimeters on each hand. Overall hand doses were obtained, and patient and graft factors as well as technical factors were analyzed to determine the effects on hand exposure.

RESULTS

The mean right hand and left hand exposures were 0.78 mSv and 0.55 mSv (78 and 55 mrem), respectively, and there was a significant difference between the two (P = .01). There was a significant difference among the interventionalists, mostly based on the lower doses associated with a single operator (P < .01). Not unexpectedly, fluoroscopy times (P < .01) and, to a lesser degree, the number of angiographic runs (P = .05) were significant factors influencing hand radiation dose. Patient sex, age and location of the graft, previous thrombosis, the number of previous interventions, and success or failure of the procedure were not significant factors in hand dose.

CONCLUSIONS

Hand exposure during the restoration of flow to thrombosed dialysis access grafts is relatively high and is greater for the right hand than for the left. The exposures are dependent on technical factors, most notably fluoroscopy times, not on patient- or graft-related factors.

Heavy metal pad shielding during fluoroscopic interventions

Significant direct and scatter radiation doses to patient and physician may result from routine interventional radiology practice. A lead-free disposable tungsten antimony shielding pad was tested in phantom patients during simulated diagnostic angiography procedures. Although the exact risk of low doses of ionizing radiation is unknown, dramatic dose reductions can be seen with routine use of this simple, sterile pad made from lightweight tungsten antimony material.

Practice of ALARA in the pediatric interventional suite

As interventional procedures have become progressively more sophisticated and lengthy, the potential for high patient radiation dose has increased. Staff exposure arises from patient scatter, so steps to minimize patient dose will in turn reduce operator and staff dose. The practice of ALARA in an interventional radiology (IR) suite, therefore, requires careful attention to technical detail in order to reduce patient dose. The choice of imaging modality should minimize radiation when and where possible. In this paper practical steps are outlined to reduce patient dose. Further details are included that specifically reduce operator exposure. Challenges unique to pediatric intervention are reviewed. Reference is made to experience from modern pediatric interventional suites. Given the potential for high exposures, the practice of ALARA is a team responsibility. Various measures are outlined for consideration when implementing a quality assurance (QA) program for an IR service.

Radiation Safety during Spine Interventions

Image-guided spine interventions are being performed by radiologists and other physicians with increased frequency. This article assesses the use of several techniques and devices that can mitigate radiation exposure during interventional procedures. Measurements were obtained on a humanoid phantom with use of various shielding methods. Significant radiation dose reductions as great as 98.7% can be achieved with use of a combination of stationary and mobile lead barriers and operator position. The application of basic radiation physics in combination with prudent radiographic technique can significantly reduce radiation exposure to the operator and other personnel during spine interventions.

Occupational radiation exposure to the surgeon

Increased use of intraoperative fluoroscopy exposes the surgeon to significant amounts of radiation. The average yearly exposure of the public to ionizing radiation is 360 millirems (mrem), of which 300 mrem is from background radiation and 60 mrem from diagnostic radiographs. A chest radiograph exposes the patient to approximately 25 mrem and a hip radiograph to 500 mrem. A regular C-arm exposes the patient to approximately 1,200 to 4,000 mrem/min. The surgeon may receive exposure to the hands from the primary beam and to the rest of the body from scatter. Recommended yearly limits of radiation are 5,000 mrem to the torso and 50,000 mrem to the hands. Exposure to the hands may be higher than previously estimated, even from the mini C-arm. Potential decreases in radiation exposure can be accomplished by reduced exposure time; increased distance from the beam; increased shielding with gown, thyroid gland cover, gloves, and glasses; beam collimation; using the low-dose option; inverting the C-arm; and surgeon control of the C-arm.

Use of a Sterile, Disposable, Radiation-Absorbing Shield Reduces Occupational Exposure to Scatter Radiation During Pectoral Device Implantation

The aim of this study was to demonstrate the effectiveness of a radiation-absorbing shield in reducing physicians' occupational radiation exposure during pectoral device implantation. A sterile, disposable, lead-free radiation-absorbing surgical drape containing x-ray attenuation material was evaluated. Twenty procedures used the radiation absorbing drape, and 20 were performed without the shielding. Radiation exposure was measured using thermoluminescent dosimetry collar badges. Use of the protective shield was associated with a time adjusted 80% reduction in radiation dose (0.009 mrem/s with shielding vs 0.047 mrem/s without shielding, P < 0.05) to the physician performing the procedures. The radiation-absorbing surgical drape did not interfere with technical performance nor add procedural time, and all procedures were successfully completed. This study demonstrates that a sterile, disposable, radiation-absorbing drape provides a convenient means of augmenting conventional radiation shielding. Use of this protective shielding greatly reduces operators' occupational exposure to scatter radiation during pectoral device implantation without compromising sterility or procedural technique.