Patient dose reference levels for interventional radiology: a national approach.

A set of patient dose reference levels (RLs) for fluoroscopically guided interventional procedures was obtained in a survey launched by the National Society of Interventional Radiology (IR), involving 10 public hospitals, as recommended by the European Medical Exposures Directive. A sample of 1391 dose values (kerma area product [KAP]) was collected randomly during clinical procedures for seven of the most frequent procedures. Third quartiles of the KAP distributions were used to set the RLs. A regular quality control of the X-ray systems and a calibration of the dose meters were performed during the survey. The fluoroscopy time and total number of digital subtraction angiography images per procedure were also analyzed. The RL values proposed were 12 Gy cm(2) for fistulography (hemodialysis access; sample of 180 cases), 73 Gy cm(2) for lower limb arteriography (685 cases), 89 Gy cm(2) for renal arteriography (55 cases), 80 Gy cm(2) for biliary drainage (205 cases), 289 Gy cm(2) for hepatic chemoembolization (151 cases), 94 Gy cm(2) for iliac stent (70 cases), and 236 Gy cm(2) for uterine embolization (45 cases). The provisional national RL values are lower than those obtained in a similar survey carried out in the United States from 2002 to 2004. These new values could be used to improve the practice of centers consistently working with doses higher than the RLs. This national survey also had a positive impact, as it helped increase the awareness of the members of the National Society of IR on a topic as crucial as patient dose values and programs on radiation protection.

A pilot experience launching a national dose protocol for vascular and interventional radiology.

The design of a national dose protocol for interventional radiology has been one of the tasks during the European SENTINEL Coordination Action. The present paper describes the pilot experience carried out in cooperation with the Spanish Society on Vascular and Interventional Radiology (SERVEI). A prospective sample of procedures was initially agreed. A common quality control of the X-ray systems was carried out, including calibration of the air kerma area product (KAP) meters. Occupational doses of the radiologists involved in the survey were also included in the survey. A total of 10 Spanish hospitals with interventional X-ray units were involved. Six hundred and sixty-four patient dose data were collected from 397 diagnostic and 267 therapeutic procedures. Occupational doses were evaluated in a sample of 635 values. The obtained KAP median/mean values (Gy.cm2) for the gathered procedures were: biliary drainage (30.6/68.9), fistulography (4.5/9.8), lower limb arteriography (52.2/60.7), hepatic chemoembolisation (175.8/218.3), iliac stent (45.9/73.2) and renal arteriography (39.1/59.8). Occupational doses (mean monthly values, in mSv) were 1.9 (over apron); 0.3 (under apron) and 4.5 (on hands). With this National experience, a protocol was agreed among the SENTINEL partners to conduct future similar surveys in other European countries.

Effectiveness and safety of balloon dilation of the papilla and the use of an occlusion balloon for clearance of bile duct calculi.

OBJECTIVE: The purpose of this study was to describe a technique for percutaneous bile duct stone clearance by pushing the stones into the small bowel after balloon dilation of the papilla. SUBJECTS AND METHODS: During a 2-year period, 38 patients were treated percutaneously for stones in the biliary tree. Twenty-one patients were treated through a T tube or transcystic tract. Seventeen patients were treated through a transhepatic tract. Twenty-three patients had one stone each. Eight patients had two stones, and seven patients had three or more calculi. Stone size ranged from 3 to 16 mm in diameter (mean size, 6.7 nm). Balloon diameter based on the transverse diameter of the stones ranged from 7 to 18 mm (mean, 6.7 mm). An 11.5-mm occlusion balloon was used for pushing the stones through a 7- to 9-French vascular introducer. A catheter was left in the common bile duct from 1 to 6 days for external drainage. RESULTS: The technique was successfully used for clearance of stones in 36 (94.7%) of the 38 patients. With 29 patients, the procedure was performed with only one attempt. Two attempts were necessary for five patients, and three attempts were necessary for four patients. Two major complications were cholangitis and biliary pleural effusion. No deaths were related to the procedure. CONCLUSION: Percutaneous bile duct stone clearance by dilation of the papilla and evacuation of the stones in an antegrade fashion with an occlusion balloon is a safe and effective technique. It can be an alternative to basketing stones in selected patients.