Contrast-enhanced endoscopic ultrasound versus CT scan in the evaluation of focal pancreatic lesions.

Cancer of the exocrine pancreas is the fourth leading cause of cancer-related
death in the United States and is the fifth leading cause of death among all
malignancies, leading to approximately 40,000 deaths each year in Europe.
Surgical resection is the only potentially curative treatment. The operation is
considered major with high morbidity and mortalitiy risk.
Focal pancreatic lesions can be benign in nature, potentially malignant, or
malignant. Therefore it is essential to characterize the nature of focal
pancreatic lesions and select patients accordingly for operation.
Imaging techniques such as CT scans are widely used for the evaluation of these
lesions. Endoscopic ultrasound (EUS) may be useful for diagnosis of small
tumors (eg, less than 2 to 3 cm in diameter) and helpful for evaluating the
possibility of nodal and major vascular involvement. It has been reported that
the sensitivity of EUS is equal or even superior to that of multidetector-row
CT.
Ultrasound contrast agents are a new class of agents used during ultrasound
examinations that can be used to improving the diagnostic capability of US to
detect or characterize focal lesions and to obtain better visualization of the
blood vessels and perfusion.
The basis of these contrast agents is gas microbubbles, small enough to cross
the lung bed to produce systemic enhancement after an intravenous injection.
Among fluoro-gas*containing agents that use phospholipids as the membrane, the
most experience in contrast enhanced-EUS in clinical practice has been made
with Sonovue (Bracco, Milan).

The study is designed to assess the diagnostic value of contrast agents on
endosonographic images during the evaluation of focal pancreatic lesions.

100 individuals will be requested to participate in the study over an inclusion
period of 1 year. During EUS procedure, a 5 ml of contrast agent Sonovue will
be administered. EUS images will be examined for the presence of enhancement.
The final diagnosis will be based on clinical presentation plus
1. the results of serum and fluid analysis (obtained by aspirating cystic
lesions) for lipase, albumin, and tumor markers
2. the results of radiological and endoscopic examinations
3. the results of cytological examination of samples obtained by fine needle
aspiration
4. the results of histological examination of specimens removed surgically
The contrast enhanced EUS findings will be analysed to investigate its value in
diagnosis of focal pancreatic lesions and compare this value with that of CT
scan.

A contrast agent will be administred intravenously

Adverse events that can arise after administration of ultrasound contrast
agents secondary to toxicity, generation of biologic effects, embolism, and
anaphylasis. An assessment by the European Committee for Medical Ultrasound
Safety concluded that the toxic and embolic potential of a ultrasound contrast
agents is of no clinical significance.
There is a risk of allergic reactions, mostly mild, e.g. transient rashes or a
sensation of warmth, but they may be very sever, e.g. dyspnea, bradycardia, or
hypotension.
Premature ventricular ectopic beats can be elicited. There have been reported
cardiac deaths in patients with ischemic heart disease when undergoing contrast
enhanced stress echo studies. The regulatory authorities have issued a
recommendation that the agents implicated (e.g. Sonovue) not be used in
patients with unstable ischemic heart disease.