Patient radiation dose associated with uterine artery embolization

Retrospective case-control study on radiation dose for uterine artery embolization procedures

INTRODUCTION

Uterine artery embolization is performed in pre-menopausal women. Understanding the contribution of radiation dose at each stage of the procedure is important for potential dose reduction. The aim was to retrospectively analyse radiation dose on a per-procedural-stage basis, comparing digital subtraction angiography (DSA) and conventional roadmap (CRM).

METHODS

Group A consisted of 50 patients where DSA was used for road mapping at all stages: (I) Aortogram, (II) Left internal iliac artery (IIA) DSA, (III) Left uterine artery (UA) DSA, (IV) Right IIA DSA and (V) Right UA DSA. Group B included 50 patients, where CRM was used for road mapping at stages (II) and (IV).

RESULTS

For Group A, mean total dose-area product (DAP) was 39.7 Gy·cm2; mean DAP for each stage were (I) Aortogram = 3.4 Gy·cm2, (II) Left IIA DSA = 5.9 Gy·cm2, (III) Left UA DSA = 3.2 Gy·cm2, (IV) Right IIA DSA = 5.5 Gy·cm2 and (V) Right UA DSA = 3.0 Gy·cm2. For Group B, mean total DAP was 33.6 Gy·cm2, mean DAP for each stage were (I) Aortogram = 3.3 Gy·cm2, (II) Left IIA CRM = 1.5 Gy·cm2, (III) Left UA DSA = 3.3 Gy·cm2, (IV) Right IIA CRM = 1.5 Gy·cm2 and (V) Right UA DSA = 3.3 Gy·cm2. Fluoroscopy time was 10 and 9.4 min for Groups A and B, respectively.

CONCLUSION

The highest road-mapping radiation dose contribution was from bilateral IIA DSA. The use of CRM, intermittent fluoroscopy and elimination of the aortogram is recommended to further reduce procedural radiation dose.

Unilateral versus Bilateral Femoral Arterial Access for Uterine Artery Embolization

Background: Uterine fibroids are the most common benign tumors in women. Their clinical presentation includes menorrhagia, metrorrhagia, lower abdominal pain and infertility. Treatment of uterine fibroids includes medical management, surgical resection known as myomectomy as well as minimally invasive options like uterine artery embolization. Uterine artery embolization can be done via unilateral or bilateral femoral arterial access. We aim to define the differences between unilateral and bilateral femoral access in concern to radiation dose, procedure time , fluoroscopy time as well as the number of angiographic images. Methods: A total of 48 patients were divided into two groups equally; one with a unilateral femoral access and the other group with a bilateral femoral arterial access. Results: The age of the patients ranged between 25 to 40 years, embolization was done with calibrated spheres. Bilateral procedures compared to the unilateral ones had less fluoroscopy times (8.6 minutes vs 24.3 mins) , less total procedure time (28.4 minutes vs 54.4 minutes) and less dose area product (155 Gy cm2 vs 340.5 Gy cm2) as well as less mean number of angiographic images (93.8 vs 176.5) with no significant difference in puncture site complications. Conclusion: Fluoroscopy times, procedure times, number of angiographic images as well as radiation dose were significantly lower in the bilateral approach with no significant difference in the rates of puncture site complications between the two approaches. Keywords: Uterine Artery Embolization, uterine fibroids, unilateral versus bilateral access.

Identifying predictors of patient radiation dose during uterine artery embolisation

INTRODUCTION

Uterine artery embolisation (UAE) is regarded as a safe and effective treatment for symptomatic uterine fibroids and/or adenomyosis. Dose reduction during UAE is critical for this reproductive-age patient population to minimise the risks of radiation-induced effects. The aim of this study was to identify the predictors of radiation dose which can be controlled and optimised for patients during UAE.

METHODS

A total of 150 patients between June 2018 and August 2019 were included in this study. Demographic and clinical information such as age, body mass index (BMI), total number of fibroids, total fibroid volume, total uterus volume and dosimetric measurements on Dose Area Product (DAP), Air Kerma (AK) and fluoroscopy time were recorded. Total digital subtraction angiography (DSA), total conventional roadmap (CRM), total last-image hold (LIH) and total fluoroscopy were calculated from the dose report. Multiple linear regression analysis was used to identify the independent predictor variables of total dose (DAP) using a regression model.

RESULTS

Total DSA, total CRM and total LIH were identified as the determinants of dose for UAE (P < 0.05) and together accounted for 95.2% of the variance.

CONCLUSIONS

This study identified the key imaging predictors of dose for UAE. Total DSA, total CRM and total LIH were shown to have a greater impact on the outcome DAP compared to other demographic or dosimetric measurements. Optimisation of these predictors during future UAE procedures can facilitate radiation dose reduction to the pelvis and reproductive organs.

MRI of placenta accreta: diagnostic accuracy and impact of interventional radiology on foetal-maternal delivery outcomes in high-risk women

OBJECTIVE

To assess accuracy and reproducibility of MRI diagnosis of invasive placentation (IP) in high-risk patients and to evaluate reliability of MRI features. Secondary aim was to evaluate impact of interventional radiology (IR) on delivery outcomes in patients with IP at MRI.

METHODS

26 patients (mean age 36.24 y/o,SD 6.16) with clinical risk-factors and echographic suspicion of IP underwent 1.5 T-MRI. Two readers reviewed images. Gold-standard was histology in hysterectomised patients and obstetric evaluation at delivery for patients with preserved uterus. Accuracy and reproducibility of MRI findings were calculated.

RESULTS

Incidence of IP was 50% (13/26) and of PP was 11.54% (3/26). MRI showed 100% sensitivity (95% CI = 75.3-100%) and 92.3% specificity (95% CI = 64.0-100%) in the diagnosis of IP. Gold-standard was histology in 10 cases and obstetric evaluation in 16. MRI findings with higher sensitivity were placental heterogeneity, uterine bulging and black intraplacental bands. Uterine scarring, placental heterogeneity, myometrial interruption and tenting of the bladder showed better specificity. MRI inter-rater agreement with Cohen's K was 1. 11 patients among 14 with MRI diagnosis of IP received IR assistance with positive impact on delivery outcomes in terms of blood loss, red cells count, intense care unit length of stay, days of hospitalisation and risk of being transfused.

CONCLUSION

MRI is an accurate and reproducible technique in prenatal diagnosis of IP. MRI helps planning a safe and appropriate delivery eventually assisted by IR, which positively affects foetal and maternal outcomes.

ADVANCES IN KNOWLEDGE

The adoption of MRI evaluation in patients with high risk of invasive placentation allows a more accurate diagnosis in terms of both presence of the disease and its extension to or through or even beyond the myometrium. This led to a better dedicated delivery management with eventual adoption of interventional radiology with a global positive effect on foetal and maternal outcomes.

Pregnancy success and outcomes after uterine fibroid embolization: updated review of published literature

Females with symptomatic leiomyomas (fibroids) wishing to maintain fertility are faced with difficult treatment choices. These include uterine fibroid embolization (UFE), myomectomy, hormonal therapy, MRI high intensity focused ultrasound, and myolysis. This review focuses on UFE, one of the most commonly accepted minimally invasive procedural choices among patients with symptomatic fibroids wishing to retain the option of becoming pregnant in the future, and makes comparisons to myomectomy which has historically been the surgical choice for fertility-preserving fibroid treatment. Pubmed and Google Scholar searches using keywords such as: uterine artery embolization, uterine fibroid embolization, pregnancy, complications, infertility were performed between Jan 1, 2019 and May 10, 2019. Publications were chosen based on their inclusion of information pertaining to fertility or pregnancy after UFE without being limited to single case reports.Randomized controlled trials comparing myomectomy and UFE are limited due to study size and confounding variables, but through registry data and familiarity with referring clinicians, UFE has gained wide acceptance. Healthy pregnancies following UFE have been sporadically reported but the actual fertility rate after UFE remains uncertain. Conversely, low birth weight, miscarriage and prematurity have been associated with UFE. Despite inherent risks of possible fertility issues after UFE, the procedure remains an option for females with clinically symptomatic fibroids who desire pregnancy. However, additional research regarding rates of conception and obstetrical risks of infertility following UFE is necessary.

Impact of Patient and Procedure-Related Factors on Radiation Exposure from Uterine Artery Embolization

PURPOSE

To determine the range of radiation dose metrics for uterine artery embolization and the impact of patient and procedure factors on those measures.

MATERIALS AND METHODS

Procedure records of 515 uterine embolization procedures were reviewed and various metrics recorded, including patient demographics, body mass index (BMI), radiation exposure measures and procedure-related details. Descriptive statistics were used to summarize the measures, and appropriate parametric and nonparametric tests were used to compare and assess the correlation between the measures and the cumulative dose (CD), dose area product and fluoroscopy time (FT). Multivariable regression analysis was used to assess the impact of individual factors on the measures of radiation dose.

RESULTS

The strongest correlation among the measures compared were between CD and BMI (r = 0.70), while the correlation between BMI and FT was weak (r = 0.23). Dose was higher for those procedures done with aortography and those who had TAGM as the embolic agent. Multivariable analysis demonstrated an increase of 7.4% in CD for each increase in BMI, 5.9% for each increase in cm uterine length. FT was impacted to a lesser extent, with an increase of 2.8% per unit BMI. Increasing procedure time had a greater impact on FT (r = 0.56) than on CD (r = 0.33).

CONCLUSION

Among the measured variables, BMI had the greatest impact on CD and has a substantial impact on the risk of radiation-induced skin injury, even without prolonged FT.

The factors contributing to the total radiation exposure of patients during uterine artery embolisation

Uterine artery embolisation (UAE) is an interventional angiography procedure for the treatment of symptomatic fibroids and/or adenomyosis in women. UAE is a less invasive and non-surgical alternative to hysterectomy or myomectomy. However, ionising radiation is used for both fluoroscopic and angiographic image guidance to visualise and access the uterine arteries for embolisation and treatment of these benign conditions. Identifying the contributors and implementing dose reduction techniques are particularly important as UAE patients are usually of child-bearing age. The purpose of this review was to examine the progression of literature on radiation exposure measurements and identifying the factors contributing to the total radiation exposure of female patients undergoing UAE. A Medline, ProQuest Central, ScienceDirect and Scopus database search from 2000 to 2018 was performed and forty articles were deemed acceptable for review following the inclusion and exclusion criteria set. UAE is a viable alternative to hysterectomy and myomectomy, as the reviewed literature demonstrated that the reported radiation exposure doses appear to be below the threshold for any deterministic radiation risks. The total radiation exposure of UAE patients is affected independently by multiple patient, operator expertise and technique, angiographic imaging and x-ray unit variables. Uterus preservation can be attained post-UAE with dose reduction and optimisation, however, a longitudinal study on UAE patients and their risk of radiation-induced deterministic and/or stochastic effects is recommended.

Uterine fibroid embolization efficacy and safety: 15 years experience in an elevated turnout rate center

OBJECTIVE

To evaluate effectiveness and safety of UFE as alternative to surgery, in treatment of uterine fibromatosis.

METHODS/MATERIALS

255 patients (aged 26-55) with symptomatic UF, indication for surgery, followed in our center (2000-2014), single or multiple fibroids, pain and/or functional/compressive disorders, underwent embolization: injection of PVA particles (150-900 μm) from distal portion of uterine arteries (ascending section). Primary end-point: flow-stop distally to injection site, disappearance of lesion design, preservation of flow in main trunk of UA. Secondary end-point: control of pain and functional/compressive disorders during follow-up (2-7 years).

RESULTS

Procedure was performed bilaterally in 250 patients (98%). Mean duration: 47 min (average fluoroscopy: 10:50 min). Post-embolization pelvic pain (according with VAS score) was on average 2.2 at discharge (24 h). Follow-up at 2 years: resolution of menstrual disorders in 78% of patients and improvement in 14%; pain disappeared in 66%; significant improvement of menstrual flow and HCT/HB levels, decrease in total uterine (57.7%)/dominant fibroid (76.1%) volume. Recurrence in 18 patients.

CONCLUSIONS

UFE represents an excellent alternative to surgical treatment: it is safe, tolerable and effective both in short and long term, with evident advantages in economic and social terms.

Impact of Allura Clarity Technology on Radiation Dose Exposure During Left Atrial Appendage Closure

BACKGROUND

To evaluate the impact of the Clarity IQ technology on reducing radiation risk in patients undergoing cardiac interventional radiology (IR) procedures.

MATERIAL/METHODS

Phantom studies were performed with two angiographic systems, FD10 Allura Xper and FD10 Allura Clarity. In the study, we performed left atrial appendage closure. Dosimetric measurements were performed with thermoluminescent dosimeters (TLD) placed inside a CIRS anthropomorphic phantom. Radiation risk was estimated based on the TLD readings and expressed as the dose absorbed by particular organs. The Mann-Whitney U test was carried out to test for significance of differences in the absorbed radiation doses between the techniques.

RESULTS

During left atrial appendage closure, the estimated dose absorbed by particular organs was lower in the case of the FD10 Allura Clarity system in comparison to the Allura Xper. In this procedure, dose reduction for particular organs ranged between 49-86%.

CONCLUSIONS

Application of the FD10 Allura Clarity system resulted in a significant dose reduction, thereby leading to a significant decrease in radiation risk for patients undergoing IR procedures.

Management of Uterine Fibroids: A Focus on Uterine-sparing Interventional Techniques

Uterine fibroids occur in approximately 50% of women over the age of 40 years, and an estimated 50% of those are symptomatic. Menorrhagia is the most common symptom and the primary indication for treatment, although bulk symptoms often occur and can be treated. Pharmacotherapy is typically inadequate unless it can be expected to successfully bridge to menopause or allow for a less-invasive intervention. However, hormonal therapies have risks. Hysterectomy is still the most commonly performed procedure for symptomatic fibroids and has the lowest rate of reintervention (compared with myomectomy or uterine artery embolization [UAE]), but rates of more serious complications are higher and patient satisfaction and ability to return to normal activities may also be less favorable. Myomectomy is not necessarily less morbid than hysterectomy and may have a greater failure rate than UAE. Techniques and devices vary with little standardization, and operator experience is crucial to success. The largest studies of UAE show very low rates of serious complications and rapid recovery. UAE significantly improves symptoms related to uterine fibroids in 85%-90% of patients. Herein, this article will discuss the nature of fibroids and their diagnosis, pharmacotherapy, surgical treatment, and nonsurgical interventional treatment, including UAE and magnetic resonance-guided focused ultrasound. (©) RSNA, 2016.

Randomized comparison of long and short vascular sheaths in reduction of the operator radiation exposure during uterine artery embolization

OBJECTIVE

To introduce a method in which a long sheath is used instead of the traditional short sheath, to reduce the radiation exposure of operators in uterine artery embolization (UAE).

METHODS

52 patients undergoing UAE were randomly divided into two groups before the procedure: an 11-cm short sheath was used in Group A (n = 25), and a 45-cm-long sheath was used in Group B (n = 27); the 45-cm-long sheath was only partly inserted such that the hub of the sheath was approximately 34 cm caudal to the groin puncture site. All the procedures were standard bilateral UAE operations through unilateral approach. The other parameters of the two groups were kept the same, including the fluoroscopy conditions and the pelvic radiation field size. The thermoluminescent personal dosemeters were attached to the left wrist and left outer side of the thyroid collar of the operator during each operation. The radiation exposure of the operator, procedure duration and fluoroscopy time of each procedure were recorded. Statistical analysis was performed using independent samples t-test.

RESULTS

The radiation exposure of both the left hand and thyroid of the operator was significantly reduced with the long sheath compared with the short sheath (89.5 ± 7.2 μGy vs 186.7 ± 12.6 μGy, p < 0.001, and 54.1 ± 5.5 μGy vs 63.9 ± 7.4 μGy, p < 0.001, respectively). No significant differences were found in the procedure duration and fluoroscopy time between the two groups (p > 0.1).

CONCLUSION

Using a long sheath in UAE could significantly reduce the radiation exposure to the interventionists without extending the procedure duration or fluoroscopy time.

ADVANCES IN KNOWLEDGE

For the first time, we introduce a simple and convenient method to reduce the radiation exposure of the operator in the UAE procedure.

Angiographic embolization for intractable obstetrical bleeding

AIMS AND OBJECTIVES

The objective of this study is to review the clinical profile and outcome in patients requiring the angiographic embolization in obstetrics.

METHODS

The retrospective data of patients requiring uterine artery embolization for control of obstetrical hemorrhage was studied during the period from August, 2005 to August, 2010.

RESULTS

A total of 35 patients with obstetrical hemorrhage (seven post lower segment caesarean section, 13 post vaginal delivery, 13 postabortal, one with cervical pregnancy and one patient post laparotomy for abdominal pregnancy) underwent angiographic embolization for control of bleeding. In all patients, hemorrhage was successfully controlled; none required post procedure hysterectomy and one patient subsequently became pregnant with in a year.

CONCLUSION

Our clinical experience suggests that embolization is superior first-line alternatives to surgery for control of obstetric hemorrhage including postpartum, post-cesarean and postabortal bleeding and prevents hysterectomy.

Retrospective study of the impact of fellowship training on two quality and safety measures in uterine artery embolization

RATIONALE AND OBJECTIVES

To measure the impact of 1-year interventional fellowship training on fluoroscopic time and contrast media utilization in uterine artery embolization (UAE).

MATERIALS AND METHODS

Retrospective single institution analysis of 323 consecutive UAEs performed by 12 interventional fellows using a standardized protocol. Fluoroscopy time and contrast media volume were recorded for each patient and correlated with stage of fellowship training. Preprocedure uterine volume (using MRI or ultrasound) was used as a measure of procedural complexity. Regression analysis was conducted per trainee factoring in duration of training, procedure number, supervising radiologist, uterine volume, and outcome variables of fluoroscopy time and contrast media volume.

RESULTS

Median number of patients treated per trainee was 27 (range, 16-43) with mean fluoroscopic time 24.5 minutes (range, 4-90 min) and mean contrast volume 190 mL (range, 50-320 mL). Increasing uterine volume had no significant effect (P > .05) on fluoroscopic time but significantly increased (P < .001) contrast media volume. Significant training effect was identified with decrease in fluoroscopic time (P < .001) and decrease in contrast volume (P = .02) over training. Over the course of a 1-year fellowship, these summed to a decrease of 12 minutes in UAE fluoroscopy time and 17 mL less contrast.

CONCLUSION

A significant (P < .05) training effect that is clinically relevant was demonstrated over the course of a yearlong interventional radiology fellowship program in performance of a standardized protocol for UAE. This data supports fellowship training as a basis for UAE credentialing and privileging.

2D versus 3D roadmap for uterine artery catheterization: impact on several angiographic parameters

BACKGROUND

Three-dimensional (3D) roadmap is a recently developed imaging technique used to guide diagnostic and interventional catheter-directed procedures and mainly evaluated for neurovascular procedures. Few data with regard to efficacy and radiation dose are currently available in literature.

PURPOSE

To evaluate the use of 3D roadmap technique as compared with the conventional two-dimensional (2D) roadmap for uterine artery catheterization and embolization during uterine fibroid embolization and assess the potential impact on radiation dose, contrast load, and total procedure time.

MATERIAL AND METHODS

In this prospective study, 40 patients were randomly assigned to the 2D or 3D roadmap technique for uterine artery catheterization. Demographic data, specifically the patient's age, weight, height, pelvic circumference, and total uterine and fibroid volume were recorded. Exposure parameters, contrast load, and procedure time were recorded and organ doses for ovaries and uterus were calculated.

RESULTS

Demographic data did not differ between the groups. Catheterization and embolization of both uterine arteries were feasible in all patients, although in one patient in the 3D group, a focal dissection of the proximal uterine artery occurred. No significant difference in estimated ovarian dose was found in the 3D versus 2D group (P = 0.07). Total procedure time was shorter in the 2D group (P = 0.01) and no difference in total contrast load was seen (P = 0.17).

CONCLUSION

Both roadmap techniques are effective imaging-guided tools for uterine artery catheterization, without difference in terms of radiation exposure or contrast load. The total procedure time is shorter in the 2D group.

Patient radiation doses in uterine artery embolisation using Monte Carlo simulation

This study aims at quantification of ovarian dose in uterine artery embolisation to study the level of optimisation of this dose. Individual anatomical data and all relevant exposure parameters of individual beam projections were recorded in 52 patients who underwent uterine artery embolisation in two angiography units. The recorded information was used to calculate the individual ovarian doses by Monte Carlo simulation. The mean dose-area product was 196 Gy cm(2). The corresponding mean ovarian dose was 149 mGy. The performance of the two angiography units was analysed starting from these data. Dose-area product and ovarian doses obtained in this study were compared with data from other uterine artery embolisation patient dose studies. It was concluded that although the mean dose-area product and ovarian dose are acceptable, it is possible to optimise the procedure by improving the performance of the units.

Uterine artery embolization for treatment of symptomatic fibroids: a review of the evidence

Fibroids are the most common benign tumors of the uterus during female reproductive age. Uterine artery embolization (UAE) using embolic particles (PVA, Gelfoam) to occlude the uterine arteries, have been reported as a relatively safe, effective, and durable nonsurgical alternative to hysterectomy in diminishing fibroid-related symptoms. To block the arterial blood supply to the fibroid completely, UAE is typically performed in both uterine arteries by an experienced interventional radiologist. Reduction in menorrhagia has been reported as 80-93 percent and the mean decrease in fibroid size varies from 50-78% in the literature. In our center improvement in menstrual bleeding after 6 months was 80.3%, and uterine fibroids underwent shrinkage of 63.7±33.7% after12 months. Complication rate including amenorrhea ranges from 1% - 7% in the literature. UAE may be followed by menopause in 1% of cases. Nevertheless, it is usually encountered in women in their late 40s. It seems that the future of UAE depends on optimal selection of patients according to volume-shrinkage prediction and fertility outcome. Although pregnancy is possible after embolization, however neither fertility preservation nor improvement can be guaranteed following UAE. Indeed, Women who desire to become pregnant should be cautioned about potential complications during pregnancy. The aim of this review is to discuss about the efficacy, safety, technique, and choice of embolic agent. Also we present the effects of this technique on fertility and pregnancy outcome and also methods for dose reduction during this procedure.

Comparing ovarian radiation doses in flat-panel and conventional angiography during uterine artery embolization: a randomized clinical trial

Background

Uterine artery embolization (UAE) is a minimally invasive procedure performed under fluoroscopy for the treatment of uterine fibroids and accompanied by radiation exposure.

Objectives

To compare ovarian radiation doses during uterine artery embolization (UAE) in patients using conventional digital subtraction angiography (DSA) with those using digital flat-panel technology.

Patients and Methods

Thirty women who were candidates for UAE were randomly enrolled for one of the two angiographic systems. Ovarian doses were calculated according to in-vitro phantom study results using entrance and exit doses and were compared between the two groups.

Results

The mean right entrance dose was 1586±1221 mGy in the conventional and 522.3±400.1 mGy in the flat panel group (P=0.005). These figures were 1470±1170 mGy and 456±396 mGy, respectively for the left side (P=0.006). The mean right exit dose was 18.8±12.3 for the conventional and 9.4±6.4 mGy for the flat panel group (P=0.013). These figures were 16.7±11.3 and 10.2±7.2 mGy, respectively for the left side (P=0.06). The mean right ovarian dose was 139.9±92 in the conventional and 23.6±16.2 mGy in the flat panel group (P<0.0001). These figures were 101.7±77.6 and 24.6±16.9 mGy, respectively for the left side (P=0.002).

Conclusion

Flat panel system can significantly reduce the ovarian radiation dose during UAE compared with conventional DSA.

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.

Investigation into scatter radiation dose levels received by a restrainer in small animal radiography

OBJECTIVES

To measure the intensity and distribution of scatter radiation received by a restrainer in veterinary radiography including the intensity of scatter radiation passing through lead protective devices at pre-defined positions.

METHODS

Anthropomorphic phantoms and a Labrador dog cadaver were used to simulate a restrainer and patient. Scatter dose measurements were recorded at the position of the restraining hands, thyroid, breast and gonads with and without appropriate lead protection. This was repeated for the eight most common projections as identified in an initial retrospective survey.

RESULTS

Manual restraint of an animal for a radiographic procedure will result in a scatter radiation dose to the restrainer. The level of radiation dose varies between body regions and between projections. The use of appropriate lead protection resulted in statistically significant dose reductions to all body regions with maximum scatter dose reductions between 93 and 100%.

CLINICAL SIGNIFICANCE

While the doses recorded were small (μGy) in terms of associated risk, they are nonetheless cumulative which can result in a more significant dose. Therefore manual restraint should be avoided and forms of immobilisation should be used such as mechanical means, sedation or general anaesthesia. However, if completely necessary both principles of distance and adequate lead protection should be employed.

Uterine sepsis with uterine artery embolisation in the management of obstetric bleeding

This paper reports three complicated clinical cases of uterine artery embolisation (UAE) in the management of massive obstetric haemorrhage (MPPH), and the consequences of impaired uterine perfusion.

Uterine Artery Embolization in the Management of Symptomatic Uterine Fibroids: An Overview of Complications and Follow-up

Uterine artery embolization (UAE) evolved as a treatment for symptomatic uterine fibroids in the early 1990s, after initially being used as a temporizing measure prior to hysterectomy or myomectomy. Since that time, over 100,000 UAEs have been performed. Technical success rates have been quoted ranging from 94 to 99%. The overall incidence of major complications associated with the procedure is low, the majority of which can be prevented. Knowledge of the potential complications and the measures that can be taken to avoid these complications is essential. Furthermore, because UAE is a relatively new procedure, no standardized recommendations for patient follow-up exist. Common practice for patient follow-up includes both clinic visits at increasing time intervals postprocedure, as well as telephone follow-up, and imaging follow-up when necessary. As symptomatic improvement is subjective, some institutions have developed standardized questionnaires to better assess patient improvement postprocedure. Aggressive pain control is a crucial component of follow-up, as uncontrolled pain can result in readmission and patient dissatisfaction.

Management of post-partum haemorrhage

Management of post-partum haemorrhage (PPH) involves the treatment of uterine atony, evacuation of retained placenta or placental fragments, surgery due to uterine or birth canal trauma, balloon tamponade, effective volume replacement and transfusion therapy, and occasionally, selective arterial embolization. This article aims at introducing pregnancy- and haemorrhage-induced changes in coagulation and fibrinolysis and their relevant compensatory mechanisms, volume replacement therapy, optimal transfusion of blood products, and coagulation factor concentrates, and briefly cell salvage, management of uterine atony, surgical interventions, and selective arterial embolization. Special attention, respective management, and follow-up are required in women with bleeding disorders, such as von Willebrand disease, carriers of haemophilia A or B, and rare coagulation factor deficiencies. We also provide a proposal for practical instructions in the treatment of PPH.

The role of interventional radiology in obstetric hemorrhage

Obstetric hemorrhage remains a major cause of maternal morbidity and mortality worldwide. Traditionally, in cases of obstetric hemorrhage refractory to conservative treatment, obstetricians have resorted to major surgery with the associated risks of general anesthesia, laparotomy, and, in the case of hysterectomy, loss of fertility. Over the past two decades, the role of pelvic arterial embolization has evolved from a novel treatment option to playing a key role in the management of obstetric hemorrhage. To date, interventional radiology offers a minimally invasive, fertility-preserving alternative to conventional surgical treatment. We review current literature regarding the role of interventional radiology in postpartum hemorrhage, abnormal placentation, abortion, and cervical ectopic pregnancy. We discuss techniques, success rates, and complications.

Bilateral versus unilateral femoral access for uterine artery embolization: results of a randomized comparative trial

PURPOSE

To determine if uterine embolization via bilateral femoral puncture reduces fluoroscopy time with a similar frequency of puncture site complications compared with unilateral puncture.

MATERIALS AND METHODS

Patients presenting for uterine artery embolization (UAE) for leiomyomata at a single institution were randomly assigned to receive unilateral or bilateral femoral punctures. Procedures were performed in a standardized fashion. Patients were blinded to the puncture site with an opaque dressing. Outcome measures included fluoroscopy time, dose-area product (DAP), procedure time, and puncture site pain after treatment. Baseline characteristics of the two groups and outcome measures were compared with the use of t tests, analyses of variance, Pearson chi(2) tests, and nonparametric tests.

RESULTS

Fifty-seven patients consented to participate: 22 received bilateral punctures and 35 received unilateral puncture. Bilateral puncture procedures had less fluoroscopy time (13 minutes vs 16.6 minutes; P = .0033), less procedure time (54.9 min vs 62.9 min; P = .026), and fewer angiographic images (46.5 vs 68.3; P < .001). There was no difference in DAP (12,986 muGy/cm(2)for bilateral vs 16,237 muGy/cm(2)for unilateral; P = .35). Groins that were punctured had greater-although still minor-pain than unpunctured groins at 24 hours (visual analog pain scores, 1.45 for punctured groins vs 0 for unpunctured groins; P = .039) and 48 hours (scores of 1 vs 0; P = .018). There were no complications in either group.

CONCLUSIONS

Bilateral femoral puncture during UAE was associated with reduced fluoroscopy time and procedure time, minor puncture site pain, and no increase in complications.

Controlled clinical trial assessing the effect of laparoscopic uterine arterial occlusion on ovarian reserve

STUDY OBJECTIVE

To assess the effect on ovarian reserve function after laparoscopic uterine artery occlusion (LUAO) compared with laparoscopic surgery supracervical hysterectomy (LSH) and laparoscopic myomectomy (LM).

DESIGN

Prospective cohort study (Canadian Task Force classification II-1).

SETTING

Hospital with experience in gynecologic minimal access surgery.

PATIENTS

Ninety patients with uterine myomas operated on from August through December 2007.

INTERVENTION

Ninety patients were divided into 3 groups of 30 patients each: the study group underwent LUAO and myomectomy (LUAO-M), control group 1 underwent LSH, and control group 2 underwent LM only.

MEASUREMENTS AND MAIN RESULTS

Blood samples were collected before surgery and at 1, 3, and 6 months postoperatively. Concentrations of follicle-stimulating hormone (FSH), leuteinizing hormone (LH), and estradiol (EZ) were determined using an immunoassay, and serum inhibin B (INHB) concentration was evaluated using an enzyme-linked immunosorbent assay. No significant differences in preoperative hormone concentrations between the 3 groups were found (p>.05). In the LSH group, FSH, LH, and E2 concentrations were significantly increased, whereas the INHB concentration was significantly decreased at 1 month postoperatively (p<.05); after 3 months, only the INHB concentration was significantly decreased (p<.05). However, in the LOUA-M and LM groups, there were no significant differences between preoperative and postoperative hormone concentrations (p>.05). Serum concentrations of FSH, LH, and INHB in the LSH group were significantly different from those in the study group at 1 and 3 months postoperatively (p<.05); however, the differences in postoperative hormone concentrations between the study group and the LM group were not significant (p>.05).

CONCLUSION

At short-term follow-up, no significant effect on ovarian reserve in patients with myoma who underwent LUAO was found.

Uterine artery embolization for leiomyomata: optimization of the radiation dose to the patient using a flat-panel detector angiographic suite

The purpose of this study was to assess the ability of low-dose/low-frame fluoroscopy/angiography with a flat-panel detector angiographic suite to reduce the dose delivered to patients during uterine fibroid embolization (UFE). A two-step prospective dosimetric study was conducted, with a flat-panel detector angiography suite (Siemens Axiom Artis) integrating automatic exposure control (AEC), during 20 consecutive UFEs. Patient dosimetry was performed using calibrated thermoluminescent dosimeters placed on the lower posterior pelvis skin. The first step (10 patients; group A) consisted in UFE (bilateral embolization, calibrated microspheres) performed using the following parameters: standard fluoroscopy (15 pulses/s) and angiography (3 frames/s). The second step (next consecutive 10 patients; group B) used low-dose/low-frame fluoroscopy (7.5 pulses/s for catheterization and 3 pulses/s for embolization) and angiography (1 frame/s). We also recorded the total dose-area product (DAP) delivered to the patient and the fluoroscopy time as reported by the manufacturer's dosimetry report. The mean peak skin dose decreased from 2.4 +/- 1.3 to 0.4 +/- 0.3 Gy (P = 0.001) for groups A and B, respectively. The DAP values decreased from 43,113 +/- 27,207 microGy m(2) for group A to 9,515 +/- 4,520 microGy m(2) for group B (P = 0.003). The dose to ovaries and uterus decreased from 378 +/- 238 mGy (group A) to 83 +/- 41 mGy (group B) and from 388 +/- 246 mGy (group A) to 85 +/- 39 mGy (group B), respectively. Effective doses decreased from 112 +/- 71 mSv (group A) to 24 +/- 12 mSv (group B) (P = 0.003). In conclusion, the use of low-dose/low-frame fluoroscopy/angiography, based on a good understanding of the AEC system and also on the technique during uterine fibroid embolization, allows a significant decrease in the dose exposure to the patient.

Overview of contemporary interventional fluoroscopy procedures

Interventional fluoroscopy procedures are increasingly important in medical practice. As new procedures are introduced and validated, they tend to replace the equivalent surgical procedure. There is wide variation in patient dose, both among procedures and for a specific procedure. Stochastic risk is present, but interventional fluoroscopy procedures may also present deterministic risk. Radiation risk/benefit analyses are different for interventional fluoroscopy procedures than they are for diagnostic imaging procedures. The radiation risk component of an interventional fluoroscopy procedure is substantially less than the other procedural risks, and there is always clear and measurable benefit to the patient from a successful procedure. Optimizing patient dose will require both improvements in equipment technology and greater attention from regulators, accrediting bodies and medical organizations. Ensuring adequate operator training is essential.

Effective doses in radiology and diagnostic nuclear medicine: a catalog

Medical uses of radiation have grown very rapidly over the past decade, and, as of 2007, medical uses represent the largest source of exposure to the U.S. population. Most physicians have difficulty assessing the magnitude of exposure or potential risk. Effective dose provides an approximate indicator of potential detriment from ionizing radiation and should be used as one parameter in evaluating the appropriateness of examinations involving ionizing radiation. The purpose of this review is to provide a compilation of effective doses for radiologic and nuclear medicine procedures. Standard radiographic examinations have average effective doses that vary by over a factor of 1000 (0.01-10 mSv). Computed tomographic examinations tend to be in a more narrow range but have relatively high average effective doses (approximately 2-20 mSv), and average effective doses for interventional procedures usually range from 5-70 mSv. Average effective dose for most nuclear medicine procedures varies between 0.3 and 20 mSv. These doses can be compared with the average annual effective dose from background radiation of about 3 mSv.

Safety and utility of uterine artery embolization with CO2 and a gadolinium-based contrast medium

The authors evaluated the safety and clinical outcomes of uterine artery embolization (UAE) without the use of conventional iodinated contrast media for symptomatic uterine leiomyomata. Patients underwent UAE with use of CO(2) gas and a gadolinium-based contrast medium. The safety and feasibility of the technique were assessed. Patients were followed up at 24 hours, 1 month, and 6 months after UAE and yearly thereafter. UAE without iodinated contrast medium was attempted in eight patients (mean age, 42.7 years +/- 4.1), and bilateral UAE was successful in all patients. The mean fluoroscopy time was 14.9 minutes. The mean amount of gadolinium-based contrast medium used was 30.6 mL or 0.181 mmol/kg. No major complications were noted. The mean improvement in the symptom severity score was 53.8. The mean reduction in leiomyoma volume was 42%. To date, no repeat interventions have been performed. UAE with CO(2) and a gadolinium-based contrast medium is a viable treatment option for patients with a severe allergy to iodinated contrast media or renal insufficiency.

Laparoscopic uterine artery occlusion combined with myomectomy for uterine myomas

We sought to evaluate the clinical feasibility and mid- to long-term effects of laparoscopic uterine artery occlusion before myomectomy in the treatment of uterine myomas. A total of 566 patients with uterine myoma were treated by laparoscopic uterine artery occlusion before myomectomy from October 2001 through July 2007. Mean blood loss was 88.2 +/- 52.7 mL (95% CI 82.7-93.8). The highest postoperative temperature was 37.8 +/- 0.3 degrees C, and the postoperative morbidity was 5.7% (32/566). Number of days to the return of bowel movement was 1.9 +/- 0.5d and in hospital stay after surgery was 7.7 +/- 2.5d. Complications included 2 instances of subcutaneous emphysema, 1 of vaginal bleeding, and 3 of mild intestinal obstruction. At a median of 26.3 months (range 6-69 months) of follow-up, the rate of myoma recurrence was 3.0% (15/517), uterus volume reduction was 48.9%, and correction of menstruation abnormality was 97.1% (502/517). Laparoscopic uterine artery occlusion before myomectomy can expand myomectomy indications with better results.

Patient Radiation Exposure during Uterine Fibroid Embolization and the Dose Attributable to Aortography

The techniques used for uterine fibroid embolization (UFE) have rapidly evolved during the past decade. One source of uncertainty in the UFE technique has been the importance of the contribution of the ovarian artery to the blood supply of the uterus and fibroids. Although conventional aortography is often used after embolization to assess for collateral arterial supply, few patients are identified with sufficient collateral vessels to warrant supplemental embolization. One potential downside of routine aortography is the additional radiation dose. In this study, the radiation dose associated with UFE and the contribution of each component of the procedure to this dose were evaluated, with the specific goal of identifying the contribution from aortography. Although the overall radiation dose associated with UFE is moderate, aortography contributes a substantial amount of additional radiation, more than 20% of the total, which, coupled with its low clinical utility, suggests that the routine use of aortography at the conclusion of UFE should be reconsidered.