Reduction of radiation doses to patients and staff during endoscopic retrograde cholangiopancreatography

BACKGROUND/AIM

Endoscopic retrograde cholangiopancreatography (ERCP) is associated with a considerable radiation exposure for patients and staff. While optimization of the radiation dose is recommended, few studies have been published. The purpose of this study has been to measure patient and staff radiation dose, to estimate the effective dose and radiation risk using digital fluoroscopic images. Entrance skin dose (ESD), organ and effective doses were estimated for patients and staff.

MATERIALS AND METHODS

Fifty-seven patients were studied using digital X-ray machine and thermoluminescent dosimeters (TLD) to measure ESD at different body sites. Organ and surface dose to specific radiosensitive organs was carried out. The mean, median, minimum, third quartile and the maximum values are presented due to the asymmetry in data distribution.

RESULTS

The mean ESD, exit and thyroid surface dose were estimated to be 75.6 mGy, 3.22 mGy and 0.80 mGy, respectively. The mean effective dose for both gastroenterologist and assistant is 0.01 mSv. The mean patient effective dose was 4.16 mSv, and the cancer risk per procedure was estimated to be 2 × 10(-5).

CONCLUSION

ERCP with fluoroscopic technique demonstrate improved dose reduction, compared to the conventional radiographic based technique, reducing the surface dose by a factor of 2, without compromising the diagnostic findings. The radiation absorbed doses to the different organs and effective doses are relatively low.

Radiation risk from fluoroscopically-assisted anterior cruciate ligament reconstruction

INTRODUCTION

Precise tunnel positioning is crucial for success in anterior cruciate ligament (ACL) reconstruction. The use of intra-operative fluoroscopy has been shown to improve the accuracy of tunnel placement. Although radiation exposure is a concern, we lack information on the radiation risk to patients undergoing fluoroscopically-assisted ACL reconstruction with a standard C-arm. The aim of our study was to determine the mean radiation doses received by our patients.

PATIENTS AND METHODS

Radiation doses were recorded for 18 months between 1 April 2007 and 30 September 2008 for 58 consecutive patients undergoing ACL reconstruction assisted by intra-operative fluoroscopy. Dose area product (DAP) values were used to calculate the entrance skin dose (ESD), an indicator of potential skin damage and the effective dose (ED), an indicator of long-term cancer risk, for each patient.

RESULTS

The median age of 58 patients included in data analysis was 28 years (range, 14-52 years), of whom 44 were male (76%). The mean ESD during intra-operative fluoroscopy was 0.0015 +/- 0.0029 Gy. The mean ED was 0.001 +/- 0.002 mSv. No results exceeded the threshold of 2 Gy for skin damage, and the life-time risk of developing new cancer due to intra-operative fluoroscopy is less than 0.0001%.

CONCLUSIONS

Radiation doses administered during fluoroscopically-assisted ACL reconstruction were safe and do not represent a contra-indication to the procedure.

Radiation risks from pediatric computed tomography scanning

Although radiological exams are not frequently used to diagnose unsuspected endocrine disease, computed tomography (CT) plays a significant role in today's endocrinology. Despite the known association between radiation exposure during childhood and cancer, the use of pediatric CT, which delivers non-negligible radiation doses to some organs and tissues, continues to rise sharply. The purpose of this review is to describe the current use of pediatric CT, explain basic concepts in ionizing radiation physics and dosimetry, and discuss potential risks from pediatric CT scans. Finally, we will summarize two recent programs for reducing and controlling exposure to ionizing radiation from pediatric CT: the As Low As Reasonably Achievable (ALARA) concept and the Image Gently initiative. Promoting public awareness and particularly educating referring physicians, including endocrinologists, about the potential radiation-associated risks from CT scans, is essential for reducing unnecessary radiation exposure from CT in children.

Radiation dose reduction in computed tomography: techniques and future perspective

Despite universal consensus that computed tomography (CT) overwhelmingly benefits patients when used for appropriate indications, concerns have been raised regarding the potential risk of cancer induction from CT due to the exponentially increased use of CT in medicine. Keeping radiation dose as low as reasonably achievable, consistent with the diagnostic task, remains the most important strategy for decreasing this potential risk. This article summarizes the general technical strategies that are commonly used for radiation dose management in CT. Dose-management strategies for pediatric CT, cardiac CT, dual-energy CT, CT perfusion and interventional CT are specifically discussed, and future perspectives on CT dose reduction are presented.

Expandable self-locking nail in the management of closed diaphyseal fractures of femur and tibia

BACKGROUND

Intramedullary fixation is the treatment of choice for closed diaphyseal fractures of femur and tibia. The axial and rotational stability of conventional interlocking nails depends primarily on locking screws. This method uses increased operating time and increased radiation exposure. An intramedullary implant that can minimize these disadvantages is obviously better. Expandable intramedullary nail does not rely on interlocking screws and achieves axial and rotational stability on hydraulic expansion of the nail. We analyzed 32 simple fractures of shaft of femur and tibia treated by self-locking expandable nail.

MATERIALS AND METHODS

Intramedullary fixation was done by using self-locking, expandable nail in 32 patients of closed diaphyseal fractures of tibia (n = 10) and femur (n = 22). The various modes of injury were road traffic accidents (n = 21), fall from height (n = 8), simple fall (n = 2), and pathological fracture (n = 1). Among femoral diaphyseal fractures 16 were males and six females, average age being 33 yrs (range, 18- 62 yrs). Seventeen patients had AO type A (A1 (n = 3), A2 (n = 4), A3 (n = 10)) and 5 patients had AO type B (B1 (n = 2), B2 (n = 2), B3 (n = 1)) fractures. Eight patients having tibial diaphyseal fractures were males and two were females; average age was 29.2 (range, 18- 55 yrs). Seven were AO type A (A1 (n = 2), A2 (n = 3), A3 (n = 2)) and three were AO type B (B1 (n = 1), B2 (n = 1), and B3 (n = 1)). We performed closed (n = 27) or open reduction (n = 5) and internal fixation with expandable nail to stabilize these fractures. The total radiation exposure during surgery was less as no locking screws were required. Early mobilisation and weight-bearing was started depending on fracture personality and evidences of healing. Absence of localised tenderness and pain on walking was considered clinical criteria for union, radiographic criteria of union being continuity in at least in three cortices in both AP and lateral views. Patients were followed for at least one year.

RESULTS

The average operative time was 90 min (range, 55-125 min) for femoral fractures and 53 min (range, 25-115 min) for tibial fractures. Radiation exposure was minimum, average being 84 seconds (range, 54-132) for femoral fractures and 54 seconds (range, 36-78) for tibial fractures. All fractures healed, but few had complications, such as infection (one case with tibial fracture) bent femoral nail with malunion (n = 1), and delayed union (n = 3; 2 cases in femur and 1 case in tibia). Mean time of union was 5.1 months (range, 4-10(1/2) months) for femoral fractures and 4.8 months (range, 3-9 months) for tibial fractures.

CONCLUSION

We found the nail very easy to use with effective fixation in AO type A and B fractures in our setting. Less surgical time is required with minimum complications. The main advantage of the expandable nail is that if affords. satisfactory axial, rotatory, and bending stability with decreased radiation exposure to operating staff and the patient.

Radiation protection in diagnostic radiology

INTRODUCTION

The use of ionizing radiation is regulated by legislative bodies to limit both individuals' and the population's exposure to radiation. Germany has implemented the European 97/43/EURATOM directive in national law by updating the existing radiation protection regulations. The German Commission on Radiological Protection regularly publishes statements and recommendations on radiation protection in medicine and diagnostic radiology, such as the introduction of diagnostic reference levels and referral guidelines for radiological and nuclear medicine imaging.

METHODS

Review of selected literature, national and international recommendations and legal texts.

RESULTS

From a radiological protection perspective, clear justification for radiological examinations and techniques aimed at minimizing radiation dose while providing the required diagnostic information, are essential.

DISCUSSION

Referring doctors should be sure to use existing guidelines for medical imaging, and liaise with radiologists and nuclear medicine specialists, with whom they share the responsibility for choosing appropriate imaging modalities.

Radiation risk and mammographic screening of women from 40 to 49 years of age: effect on breast cancer rates and years of life

The aim of this study was to evaluate the carcinogenic risks associated with radiation in mass mammographic screening. Assessment was in terms of breast cancer mortality and years of life for a hypothetical cohort of 100 000 women. Data were obtained on incidence, mortality and life expectancy for the female population of Stockholm. With a screening interval of 18 months at ages 40-49 years, a total absorbed dose to the breast of 13 mGy per invited woman; and an annual breast cancer reduction of 25% per year 7 years from screening start, the net number of years gained was at least 2800. However, using the highest absorbed dose reported in routine mammographic screening in Sweden (approximately 3 mGy per view), and the highest reported radiation risk in the literature, a programme entailing annual screening with 2 views would require at least a 20% annual reduction in breast cancer mortality to give a net benefit in both the number of years of life gained and number of breast cancer deaths avoided. This observation supports the conclusion that exposures with low absorbed dose are essential when performing mass screening with mammography among young women.

Childhood exposure due to the Chernobyl accident and thyroid cancer risk in contaminated areas of Belarus and Russia

The thyroid dose due to 131I releases during the Chernobyl accident was reconstructed for children and adolescents in two cities and 2122 settlements in Belarus, and in one city and 607 settlements in the Bryansk district of the Russian Federation. In this area, which covers the two high contamination spots in the two countries following the accident, data on thyroid cancer incidence during the period 1991-1995 were analysed in the light of possible increased thyroid surveillance. Two methods of risk analysis were applied: Poisson regression with results for the single settlements and Monte Carlo (MC) calculations for results in larger areas or sub-populations. Best estimates of both methods agreed well. Poisson regression estimates of 95% confidence intervals (CIs) were considerably smaller than the MC results, which allow for extra-Poisson uncertainties due to reconstructed doses and the background thyroid cancer incidence. The excess absolute risk per unit thyroid dose (EARPD) for the birth cohort 1971-1985 by the MC analysis was 2.1 (95% CI 1.0-4.5) cases per 10(4) person-year Gy. The point estimate is lower by a factor of two than that observed in a pooled study of thyroid cancer risk after external exposures. The excess relative risk per unit thyroid dose was 23 (95% CI 8.6-82) Gy(-1). No significant differences between countries or cities and rural areas were found. In the lowest dose group of the settlements with an average thyroid dose of 0.05 Gy the risk was statistically significantly elevated. Dependencies of risks on age-at-exposure and on gender are consistent with findings after external exposures.