Evaluation of contrast-enhanced ultrasound of the pancreas combined with concurrent hormone stimulation.

PURPOSE: To evaluate the potential of combined administration of the gastrointestinal hormones secretin (Secrelux) and c-terminal cholecystokinin (CCK-8 s) together with contrast-enhanced ultrasound (CE-US) to generate an extended contrast enhancement of healthy pancreatic tissue. MATERIALS AND METHODS: 14 anaesthetised pigs weighing 30-35 kg were studied. After laparotomy, the pancreas was located and a B-mode examination followed by a CE-US examination of the gland was made using SonoVue 1.5 ml. After an injection of Secrelux 1 U/kg and CCK-8 s 100 pmol/kg, a second CE-US examination was conducted. The hormones and the contrast agent were administered through a catheter in the superior vena cava. The sonographic images were stored for later evaluation. RESULTS: The study showed that CE-US increased the echogenicity of the pancreas by an average of 15.6 decibel (dB) (confidence intervals [CI]: 13.72, 17.42) p < 0.0001, an increase of 24%. The administration of Secrelux and CCK-8 s in combination with CE-US further increased the echogenicity of the pancreas by an average of 3% (CI: 0.36, 5.36) p = 0.028. A new sequence of hormones and CE-US 20 min after the previous injection did not induce further enhancement. The area under the curve (AUC) was significantly larger using both hormones and CE-US compared with CE-US alone by an average of 66 dBx sec (CI: 28,103) p = 0.002. CONCLUSION: It is possible to generate an extended contrast enhancement of healthy pancreatic tissue using CE-US combined with the administration of the gastrointestinal hormones secretin (Secrelux) and c-terminal cholecystokinin (CCK-8 s). Our results may improve the ability to discriminate between healthy pancreatic tissue and areas with a changed blood flow due to either neoplasm or other pathological lesions.

Radiation exposure to surgical staff during F-18-FDG-guided cancer surgery.

PURPOSE: High-energy gamma probes have recently become commercially available, developed for (18)F-FDG probe-guided surgery. The radiation received by the staff in the operating room might limit the use of it, but has never been determined. We therefore wanted to measure the absorbed staff doses at operations where patients had received a preoperative injection of (18)F-FDG. METHODS: Thirty-four patients with different cancers (breast cancer, melanoma, gastrointestinal cancers, respectively) were operated. At every operation the surgeon was monitored with a TLD tablet on his finger of the operating hand and a TLD tablet on the abdomen. The surgeon and anaesthesiologist were also monitored using electronic dosimeters placed in the trousers lining at 25 operations. RESULTS: The dose rate to the surgeon's abdominal wall varied between 7.5-13.2 microSv/h, depending on tumour location. The doses to the anaesthesiologists and the finger doses to the surgeon were much lower. About 350-400 MBq, i.e. ca. eight times higher activities than those used in the present study are supposed to be necessary for guiding surgery. It can be calculated from the body doses measured that a surgeon can perform between 150-260 h of surgery without exceeding permissible limits for professional workers. CONCLUSIONS: The radiation load to the operating staff will generally be so small that it does not present any limitation for FDG-guided surgery. However, it is recommended to monitor the surgical staff considering that the surgeon may be exposed to other radiation sources, and since the staff often includes women of child-bearing age.