A technique for calibrating a high dose rate ¹9²Ir brachytherapy source.

The reference air kerma rate of an ¹9²Ir high dose rate brachytherapy source is determined based broadly on the International Atomic Energy Agency (IAEA) TECDOC 1274 code of practice. Since the primary standards dosimetry laboratory at the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) does not maintain a standard at ¹9²Ir quality, the air kerma calibration coefficient of an IBA FC65-G Farmer type ionisation chamber is calculated using coefficients determined at 300 kV and 6°Co qualities. The methodology proposed by Mainegra-Hing and Rogers [1] at 250 kV and ¹³7Cs qualities is used. The validity of this approach is tested by performing Monte Carlo simulations to determine the chamber's air kerma calibration coefficient at ¹9²Ir quality. Very good agreement is obtained between values using these two methods. The reference air kerma rate is measured using the Farmer chamber in an in air jig. In addition the necessary correction factors are applied to the measured value. The reference air kerma rate determined in this way is compared to the value stated by the vendor of the ¹9²Ir source on the source calibration certificate. Differences are with one exception less than 1%. It is concluded that because of the agreement between the values from the methodology used in this study and the source calibration certificate values this methodology can be used clinically.

Laparoscopic surgery in a mobile army surgical hospital deployed to the former Yugoslavia.

The 212th Mobile Army Surgical Hospital was deployed from a United States military base in Germany to the former Yugoslavia to provide medical support for more than 25,000 United Nations soldiers. This medical unit was the first mobile hospital ever to deploy with a capability for laparoscopic surgery. During a 2-month trial period, seven laparoscopic procedures were performed for various abdominal emergencies. There were no complications, and all patients returned to full duty within 1 week. No equipment problems or other logistical obstacles were identified. This preliminary report suggests that laparoscopic surgery is quite feasible in a forward-deployed field hospital, allowing combat soldiers to return to full duty in a much shorter time than after conventional surgery.

Hepatic ischemia, caused by celiac axis compression, complicating pancreaticoduodenectomy.

OBJECTIVE: In the course of pancreaticoduodenectomy, profound hepatic ischemia developed in two patients (one with ampullary carcinoma, the other with chronic pancreatitis). This article addresses the diagnosis and correction of the celiac axis compression responsible in this complication. SUMMARY BACKGROUND DATA: Since hepatic ischemia appeared immediately after division of the gastroduodenal--pancreaticoduodenal arcade, which provides mesenteric to celiac collateral circulation, celiac axis narrowing or occlusion was suspected. Previous reports have indicated that celiac axis disease may be present in about 10% of such patients. METHODS: Doppler flow studies, and in the second patient, intraoperative angiography were performed. The celiac axis was exposed and mobilized in both. RESULTS: Initially, no flow could be detected in the celiac axis. Dense fibrous tissue was found encasing it. Division of the entrapping tissue restored flow to the upper abdominal viscera. CONCLUSIONS: The anatomic deformation of the celiac axis predisposing to this complication is detectable on the lateral projection of a preoperative celiac angiogram. If, however, an angiogram has not been done, an initial test occlusion of the gastroduodenal artery before its division permits anticipation of the complication, correction of the celiac impingement, and hence, avoidance of hepatic ischemia.