Protecting Our Own: A Method for Reducing Breast Radiation Exposure in Healthcare Workers.

ABSTRACT: Standard lead aprons do not protect the female breast adequately from radiation exposure, which has been associated with breast cancer in healthcare workers. A novel lead shield was designed to reduce radiation to the breast, axilla, and thyroid (BAT). A procedure room was simulated with an anthropomorphic phantom representing the operator. Dosimeters were positioned on the outer quadrant of each breast, the chest, the thyroid, and deep inside of a phantom acrylic female torso with neck and head. Standard lead vest plus a thyroid shield was used as control and compared to standard lead vest plus BAT shield. Three operator and two image receptor positions were tested. The reductions in radiation exposure were calculated. The standard vest plus BAT shield provided significant reductions in radiation exposure for all anatomic locations compared to control. When averaging all operator positions, the BAT provided reductions of 91% (p < 0.0001) for near breast. Reductions for far breast, chest, thyroid, and deep tissues were 76% (p = 0.016), 94% (p < 0.0001), 52% (p = 0.026), and 60% (p = 0.004). With operator 90° to the table using a cross-table lateral beam, the BAT provided a 97.7% reduction in radiation to the near breast and significant reduction in radiation to the chest, thyroid, and deep tissues. The BAT shield reduces radiation exposure to the breast, chest, thyroid and deep hematopoietic tissues. Such shields could benefit healthcare workers to reduce the risk of breast cancer and other radiation-associated cancers.

Get the Lead off Our Backs!

Many interventionalists face physical challenges almost daily for years or decades. The burden of assuming awkward positions while carrying extra weight can take its toll on the musculoskeletal system to such an extent that the career is ended or modified to exclude procedural aspects. The proliferation of lighter aprons has unfortunately resulted in reduced protection with poor correlation of protection to labeling due to the inadequacies of testing methods for nonlead materials. The protective quality of the non-leads is not superior to lead-containing composites on a weight basis, and the user no longer knows how well they are protected unless buying aprons containing lead. Various useful methods and shields that may reduce radiation exposure are supported by the floor, ceiling, table, or patient. The suspended personal radiation protection system is a recent development which provides substantially greater radiation protection than conventional lead aprons combined with other shields, while also taking all of the weight off of the operator. It is composed of an expansive and thick (1mm Pb equiv) apron with a large face-shield to protect the neck, head, and eyes, and is suspended overhead to provide motion in the x, y, and z planes. Exposures may also be substantially reduced by leaving the area during acquisition sequences and use of power injectors.

Transjugular intrahepatic portosystemic shunt creation using a three-dimensional fluoroscopy guidance system in patients with the Budd-Chiari syndrome.

When performed for Budd-Chiari syndrome (BCS), transjugular intrahepatic portosystemic shunt (TIPS) creation can be technically difficult due to hepatic congestion and asymmetric hypertrophy. We present three female patients with decompensated BCS in whom TIPS were created using a three-dimensional fluoroscopy guidance system. On a dedicated workstation using three-dimensional volumes of computed tomography imaging, a virtual needle path was created by the operator extending from the needle entry point (hepatic vein stump or inferior vena cava) to the target portal vein. Subsequently, the virtual needle path was overlaid on the fluoroscopy image for guidance of portal venous cannulation. This technology can be used for TIPS procedures in patients with BCS and other complex TIPS cases, as it may help delimit the trajectory of the needle pass and optimally result in more efficient procedures with decreased radiation dose.

Endovascular caudal retraction of the cranial end of a misplaced Viatorr TIPS prior to liver transplantation.

Transjugular intrahepatic portosystemic shunt (TIPS) extension far into the inferior vena cava (IVC) or the right atrium may complicate or preclude orthotopic liver transplantation depending on the space available for placement of a hemostatic clamp in the suprahepatic IVC. Until 2004, most TIPS were performed with bare metal stents, which integrate into the vessel wall, making percutaneous or intraoperative repositioning uncertain. Most TIPS are currently created with stent grafts that have an outer fabric to increase shunt patency and prevent endothelial ingrowth. We describe the first known manipulation of a covered stent graft prior to transplantation. The stent graft, which extended well into the IVC, was snared from a femoral approach and deflected caudally in order to document feasibility and nonadherence to the vein wall prior to definitive surgical planning of liver transplantation. Provisions were made for endovascular retraction during actual transplant surgery 9 weeks later, but this became unnecessary when manual retraction of the exposed liver enabled suprahepatic IVC clamping. Due to the nonadherent nature of the outer graft material, compared with a bare metal stent, extension of a stent graft into the IVC or right atrium may not preclude transplantation, and intraoperative endovascular retraction may be considered.

Determination of minimum effective height of transparent radiation face shielding for fluoroscopy.

During interventional procedures, the vast majority of scatter radiation originates from the patient and table and travels in all directions in straight lines. Because the operator's head is much higher than the patient and at an angle upward and to the side of the patient (not directly above), the scatter received by the operator's head is projected in an upward angle. Thus a face shield could potentially be lower than the object it is shielding, e.g., below the eyes. This principle may be used as an advantage to design the lowest shield that effectively protects the head while providing optimum vision, appearance, acoustics, low weight, and sense of openness. A flat acrylic plate shield, 0.5 mm Pb equivalence, was suspended vertically in front of a 451P dosimeter. A phantom patient created scatter in an interventional suite while the dosimeter was placed at the level of the crowns of different operators' heads. Many different configurations were tested to determine which ones would provide effective shielding. The results confirmed that the top of the shield may reside several centimeters below the vertical height of the dosimeter (operator's crown), allowing line of sight to monitor above the shield, and still provide effective shielding equivalent to when the dosimeter is positioned directly behind the center of the shield. The image receptor functioned as an effective shield against scatter. Factors increasing the minimum height of effective shielding included shorter operator, opposite oblique projection of image receptor, and shield closer to the face (in horizontal direction).

Comparison of a suspended radiation protection system versus standard lead apron for radiation exposure of a simulated interventionalist.

PURPOSE: To evaluate the radiation protective characteristics of a system designed to enhance operator protection while eliminating weight to the body and allowing freedom of motion. MATERIALS AND METHODS: Radiation doses to a mock interventionalist were measured with calibrated dosimeters in a clinical interventional suite. A standard lead apron (SLA; Pb equivalent, 0.5 mm) was compared with a suspended radiation protection system (ZeroGravity; Zgrav) that shields from the top of the head to the calves (except the right arm and left forearm) with a complex overhead motion system that eliminates weight on the operator and allows freedom of motion. Zgrav included a suspended lead apron with increased lead equivalency, greater length, proximal left arm and shoulder coverage, and a wraparound face shield of 0.5 mm Pb equivalency. A 26-cm-thick Lucite stack (ie, mock patient) created scatter during 10 controlled angiography sequences of 120 exposures each. Parameters included a field of view of 40 cm, table height of 94 cm, 124 cm from the tube to image intensifier, 50 cm from the image center to operator, 66 kVp, and 466-470 mA. RESULTS: Under identical conditions, average doses (SLA vs Zgrav) were 264 versus 3.4 (ratio, 78) to left axilla (P < .001), 456 versus 10.2 (ratio, 45) to left eye (P < .001), 379.4 versus 6.6 (ratio, 57) to right eye (P < .005), and 18.8 versus 1.2 (ratio, 16) to gonad (P < .001). CONCLUSIONS: Relative to a conventional lead apron, the Zgrav system provided a 16-78-fold decrease in radiation exposure for a mock interventionalist in a simulated clinical setting.

Left colic artery pseudoaneurysm from pancreatitis presenting as upper gastrointestinal hemorrhage.

Visceral pseudoaneurysms resulting from pancreatitis occur in approximately 10% of cases. The present report describes a left colic artery pseudoaneurysm from pancreatitis presenting with active duodenal bleeding. Based on the clinical and endoscopic demonstration of duodenal bleeding, celiac and superior mesenteric arteriograms were initially obtained, and their findings were negative. Repeat arteriography, including an inferior mesenteric artery injection, demonstrated a left colic pseudoaneurysm with rupture into the pancreatic duct and retrograde flow into the duodenum. Because of inconsistent diagnostic yields for arteriography performed for pancreatitis-related bleeding, the authors recommend disciplined interrogation of all three major mesenteric vessels, unbiased by initial endoscopic findings, to reduce false-negative examination results and empiric embolization.

Transjugular intrahepatic portosystemic shunt creation for recurrent gastrointestinal bleeding during pregnancy.

Treatment of bleeding esophageal varices during pregnancy is a rare clinical dilemma. Primary therapy remains endoscopy and band ligation. Refractory variceal hemorrhage treated with a transjugular intrahepatic portosystemic shunt (TIPS) procedure potentially exposes the fetus to radiation. The present report describes a TIPS procedure performed at 22 weeks gestation with the use of radiation-sparing maneuvers in a patient with recurrent esophageal variceal hemorrhage. The TIPS procedure delivered an estimated fetal dose of 5.49 mSv (0.549 Rad), much less than the dose threshold thought to induce biologic effects and only slightly greater than annual background radiation. The interventional radiologist should not hesitate to perform a TIPS procedure for refractory variceal hemorrhage with use of strategies aimed at minimizing radiation.