790 likes | 2.89k Views
Pancreatic Cancer. Pancreatic Cancer. Pancreatic adenocarcinoma is the fourth leading cause of cancer death in the Western hemisphere.
E N D
Pancreatic Cancer Pancreatic adenocarcinoma is the fourth leading cause of cancer death in the Western hemisphere. Worldwide, pancreatic cancer is the eighth most common cause of death from cancer in both sexes combined, a relative position higher than for incidence (thirteenth) because of the very poor prognosis. Fewer than 5% of all patients are still alive 5 years after initial diagnosis. The collective median survival time of all patients is 4-6 months. Despite the poor prognosis of patients with pancreatic cancer, surgical resection is still the only potentially curative treatment for the disease.
Pancreatic Cancer Pancreatic cancers can arise from both the exocrine and endocrine portions of the pancreas. Of pancreatic tumors, 95% develop from the exocrine portion of the pancreas and adenocarcinomas account for 75% of all pancreas cancers. Normal Pancreas pancreatic carcinoma: the pancreas is bisected along its longitudinal axis revealing a large adenocarcinoma of the head
Pancreatic Cancer Approximately 75% of all pancreatic carcinomas occur within the head or neck of the pancreas, 15-20% occur in the body of the pancreas, and 5-10% occur in the tail. Typically, pancreatic cancer first metastasizes to regional lymph nodes, then to the liver, and less commonly, to the lungs. It can also directly invade surrounding visceral organs such as the duodenum, stomach, and colon. TNM staging of pancreatic carcinoma. T1-T4=local tumor extension; N=lymph node; M=metastasis.
Pancreatic Cancer Preferred Examination: • US is often the initial test in symptomatic patients. • Multisection CT is generally accepted to be the first line of investigation in a patient with suspected pancreatic cancer. • If the patient is clinically jaundiced and when biliary ductal dilatation is demonstrated on ultrasonographic examination, endoscopic retrograde cholangiopancreatography (ERCP) is the next investigation of choice with a view to a drainage procedure. • MRI could be used to evaluate the pancreas in obstructive jaundice if the mass is not demonstrable with CT and US. • In the detection and staging of small tumors, endoscopic US (EUS) can be reliable.
Pancreatic Cancer Ultrasound US is often the initial test in symptomatic patients. US is used for diagnosis rather than staging, although liver metastasis and ascites may be seen. normal anatomy
Pancreatic Cancer Ultrasound On US, pancreatic tumors are seen as hypoechoic mass lesions that become more heterogenous in echotexture with increasing size.
Pancreatic Cancer Endoscopic US Recent evidence suggests that EUS is similar to CT in diagnosis and staging of pancreatic cancer. EUS requires special endoscopic skills and expertise, and it is less readily available worldwide. Invasion of the dilated CBD by a large irregular hypoechoic tumor located in the head of pancreas. A 2.5cm round, hypoechoic tumor is identified in the the region of the genu. The superior mesenteric vein can be seen separate from the tumor. A large hypoechoic tumor is seen to invade the portal vein (arrow), with loss of tumor-vessel interface and tumor extension into vessel lumen. The dilated CBD contains echogenic sludge.
Pancreatic Cancer Endoscopic US Pancreatic Cancer, T4, vascular invasion Pancreatic head tumor mass visualized by EUS as a 3 cm hypoechoic mass at the level of the pancreatic head, with dilatation of the common bile duct and posterior invasion of the portal vein.
Pancreatic Cancer At present, CT is the most widely used and most sensitive test for an evaluation of the pancreas for pancreatic carcinoma. Dynamic CT has a detection rate of approximately 99%. Multisection CT should be the first-line study for detecting this tumor and for evaluating its resectability. • Features suggestive of underlying pancreatic cancer include the following: • alterations in morphology of the gland with abnormalities of CT attenuation values, • obliteration of peripancreatic fat, • loss of sharp margins with surrounding structures, • involvement of adjacent vessels and regional lymph nodes, • pancreatic ductal dilatation, • pancreatic atrophy, • obstruction of the common bile duct (CBD).
Pancreatic Cancer CT Findings Drawing shows T1 tumor, which is defined as being equal to or smaller than 2 cm in maximum diameter and confined to pancreas, and T2 tumor, larger than 2 cm and confined to pancreas Axial CT image shows stage T1 pancreatic ductal adenocarcinoma From: Diagnosis, Staging, and Surveillance of Pancreatic CancerEric P. Tamm et al. AJR 2003; 180:1311-1323
Pancreatic Cancer CT Findings Drawing shows T3 tumor, defined as tumor that may extend beyond pancreas but without involvement of celiac axis or superior mesenteric artery. Contrast-enhanced axial CT image shows T3 tumor that has involved common bile duct, requiring a stent, and that extends medially beyond confines of pancreatic head. Tumor is separated from superior mesenteric vein (long arrow) and superior mesenteric artery (short arrow) by fat plane (type A relationship). Note that tumor involves duodenum (arrowhead). From: Diagnosis, Staging, and Surveillance of Pancreatic CancerEric P. Tamm et al. AJR 2003; 180:1311-1323
Pancreatic Cancer CT Findings Drawing shows T4 tumor, defined as primary tumor involving either superior mesenteric artery or celiac axis. Contrast-enhanced axial CT image shows pancreatic tumor (white arrows) engulfing celiac axis. Short black arrow = splenic artery, long black arrow = common hepatic artery. From: Diagnosis, Staging, and Surveillance of Pancreatic CancerEric P. Tamm et al. AJR 2003; 180:1311-1323
Pancreatic Cancer Preferred Examination: • US is often the initial test in symptomatic patients. • Multisection CT is generally accepted to be the first line of investigation in a patient with suspected pancreatic cancer. • If the patient is clinically jaundiced and when biliary ductal dilatation is demonstrated on ultrasonographic examination, endoscopic retrograde cholangiopancreatography (ERCP) is the next investigation of choice with a view to a drainage procedure. • MRI could be used to evaluate the pancreas in obstructive jaundice if the mass is not demonstrable with CT and US. • In the detection and staging of small tumors, endoscopic US (EUS) can be reliable.
Pancreatic Cancer Endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC) • Before the widespread availability of ERCP, PTC was often used to delineate the biliary anatomy preoperatively. • ERCP has largely replaced PTC as it has several major advantages. • The advantages of ERCP over PTCare that it avoids liver puncture with the accompanying risk of bile leakage and haemorrhage and allows exclusion of other gastroduodenal disease, diagnosis of periampullary tumours, and imaging of the pancreatic duct. Brushing and biopsy specimens can also obtained for cytological and histological examination. • Both endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography allow the insertion of biliary stents
Pancreatic Cancer Endoscopic retrograde cholangiopancreatography (ERCP) ERCP has a sensitivity of 95% and a specificity of 85% for pancreatic malignancy. Most pancreatic carcinomas arise from the ductal epithelium and produce complete or partial ductal obstruction. ERCP image shows dilated biliary tree and obstruction of common bile duct associated with tumor in pancreatic head.
Pancreatic Cancer Percutaneous transhepatic biliary drainage (PTBD) Obstructive jaundice warrants palliation if the patient has pruritus or right upper quadrant pain or has developed cholangitis. Biliary obstruction from pancreatic cancer is usually best palliated by the endoscopic placement of plastic or metal stents. When endoscopic biliary drainage is unsuccessful or is contraindicated, percutaneous transhepatic biliary drainage (PTBD) is recommended. Percutaneous transhepatic cholangiogram showing a catheter in a dilated common bile duct with an abrupt, irregular stricture at the lower end, indicative of a pancreatic cancer
Pancreatic Cancer MRI Findings The role of MRI in pancreatic cancer has been less well studied than the role of CT scanning. It does not appear to be superior to spiral CT scanning. The ability of MRI to demonstrate pancreatic adenocarcinoma largely depends on the demonstration of deformity of the gland, as reflected in its size, shape, contour, and signal intensity characteristics. T1 T1 cont Thin-section helical CT image obtained during pancreatic phase reveals large pancreatic tumor with tumor surrounding celiac trunk and hepatic artery. Extent of vascular encasement is better depicted by CT scan than by MR images. From:Diagnosis and Staging of Pancreatic Cancer … Schima W et al. AJR 2002; 179:717-724
Pancreatic Cancer MRI Findings The normal pancreas is of low signal intensity on T1-weighted images and of intermediate signal on T2-weighted images, with a variable amount of fat in the gland parenchyma. Transverse T1-weighted fat-suppressed image shows verified adenocarcinoma of the pancreatic head Adenocarcinoma was visible as a low-signal-intensity tumor. From: Prospective Evaluation of Pancreatic Tumors … E. L. Hänninen et al. Radiology 2002;224:34-41.
Pancreatic Cancer Compared with other modalities, MRI appears to be more valuable for staging the extent and spread of pancreatic carcinoma than for tumor detection of lesions smaller than 2 cm. ERCP image shows slight narrowing of pancreatic duct and ductal dilatation. Sphincterotomy was performed, and pancreatic stent was placed. Contrast-enhanced CT scan fails to depict tumor (arrow) around stent in dilated common bile duct. Unenhanced T1-weighted MR image shows inhomogeneity of pancreatic head, but does not show tumor. From:Diagnosis and Staging of Pancreatic Cancer … Schima W et al. AJR 2002; 179:717-724
Pancreatic Cancer Magnetic resonance cholangiopancreatography (MRCP) MRCP is as sensitive as ERCP and may prevent inappropriate explorations of the pancreatic and bile ducts in patients with suspected pancreatic carcinoma in whom interventional endoscopic therapy is unlikely Coronal image from MRCP shows double-duct sign caused by obstruction by tumor. Dilated common bile duct and dilated pancreatic duct are seen proximal to abrupt cutoff. From: Diagnosis, Staging, and Surveillance of Pancreatic CancerEric P. Tamm et al. AJR 2003; 180:1311-1323
Pancreatic Cancer Magnetic resonance cholangiopancreatography (MRCP) MR pancreatogram reveals a dilated pancreatic duct proximal to the obstructing pancreatic head mass. ERCP helps confirm the dilatation of the pancreatic duct in the body and the distal stricture. From: MR Pancreatography: A Useful Tool for Evaluating Pancreatic Disorders Ann S. Fulcher et al. Radiographics. 1999;19:5-24.
Pancreatic Cancer MRI Findings Coronal oblique MRCP demonstrates pancreatic duct obstruction in the head with proximal dilatation of both pancreatic duct (PD) and common bile duct (CBD), which is referred to as the double duct sign. Coronal MR angiogram in the venous phase shows vascular infiltration of the portal vein and venous confluens. Note the consecutive mesenteric collateral formation. From: Prospective Evaluation of Pancreatic Tumors … E. L. Hänninen et al. Radiology 2002;224:34-41.
Pancreatic Cancer Upper GI barium studies may reveal an extrinsic impression of the mass on the posteroinferior aspect of the antrum of the stomach. This is known as antral „pad sign”.
Pancreatic Cancer The medial margin of the descending duodenum may be pulled medially at the level of the ampulla, forming a reversed-3 appearance. This is known as Frostberg 3 sign. Duodenal invasion at the level of papilla major demonstrated by upper GI endoscopy
Pancreatic Islet Tumors These tumors are far less common than the non-endocrine tumors listed above. They account for about 1% of pancreatic cancers. It is very important that endocrine tumors be distinguished from non-endocrine because the treatments for the two types are very different. The endocrine tumors may produce highly active hormones and therefore have very dramatic symptoms
Pancreatic Cancer • Pancreatic cancer screening • No reliable screening tests are available for detecting early pancreatic cancer in asymptomatic patients. • Imaging techniques are not suitable as screening tests because of many factors, including cost and/or their invasive nature. • Tumor markers are nonspecific. • Screening for pancreatic cancer is not recommended at this time.