History
47-year-old male with a history of pancreatic cancer and liver lesions on CT. The study is being done to evaluate extent of disease.
Findings
The breath hold CT chest images show some concave focal posterior pleural thicken- ing on the right. No pleural fluid is apparent. No pathologic mediastinal adenopathy is evident. In the abdomen, there is increased metabolism in the body and tail of the pancreas (Figure 25.1.1), consistent with primary carcinoma of the body/tail of the pancreas (Figure 25.1.2). There are numerous hypermetabolic lesions within the hepatic parenchyma, panlobar (Figure 25.1.3). A disproportionate number of these small liver lesions are surface lesions. This is seen in conjunction with some moderate hyperactivity in the omentum. These features suggest that there is also peritoneal carcinomatosis.
Impression
Primary carcinoma of the body and tail of the pancreas with panlobar liver metastases and probable peritoneal carcinomatosis.
Pearls and Pitfalls
• The role of PET imaging is to distinguish benign pancreatic masses from cancer, stage nodal involvement and liver metastasis, and assess patient response to chemotherapy.1,2,3,5
• It is estimated that PET can alter patient management in 50% of the patients with pancreatic carcinoma.1,2,3,5
Discussion
Pancreatic cancer is the third most common gastrointestinal malignancy in the United States. It is the fifth leading cause of cancer-related mortality. Black, male, and age over
25 Pancreatic Cancer
Heidi R. Wassef
Case 25.1
258
25 Pancreatic Cancer 259
45 are predispositing factors. Patients are asymptomatic. By the time symptomology surfaces, most patients are incurable. Midepigastric abdominal tenderness and weight loss are the most common symptoms. Smoking, alcohol, diabetes, chronic pancreatitis, and family history are all risk factors. Seventy-five percent of the cancers involve the head or neck of the pancreas. Approximately 95% of the pancreatic cancer arises from the exocrine portion. The tumor first spread to regional lymph nodes, then to the liver, and then to the lungs. CEA will be elevated in 40% to 45% and CA 19-9 will elevated in 75% to 85%. CT is useful, with 70% to 80% of lesions detected. Percutaneous ultrasound will detect 60% to 70% of the cancers. Endoscopic ultrasound and ERCP will detect 99% to 100% and 90% to 95% of the cases, respectively.
FIGURE25.1.1.
FIGURE25.1.2. FIGURE25.1.3.
History
82-year-old male who has a history of pancreatic cancer. His recent CT demonstrates fullness in the pancreatic head with bilateral suspicious cavitary pulmonary nodules.
Evaluation for metastasis in the lung is requested.
Findings
There is a hypermetabolic focus on PET which corresponds to the fullness in the pan- creatic head (Figures 25.2.1 and 25.2.2) previously described on CT. This appears to
Case 25.2
FIGURE25.2.1.
FIGURE25.2.2.
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extend into the tail of the pancreas. The nonrandom clusters and smooth wall pul- monary nodules on CT are metabolically negative on PET and are probably inflam- matory rather than neoplastic. The weakly positive activity in the right perihilar node, or medial midlung parenchyma, is probably inflammatory. The retention in the upper pole of the collecting system is due to urinary stasis. The curvilinear activity in the bowel is physiologic.
Impression
1. Hypermetabolic focus in the region of the pancreatic head consistent with history of pancreatic malignancy.
2. The nodules in the lung are not FDG avid and therefore are considered non- neoplastic.
Pearls and Pitfalls
• Pancreatic cancer displays a higher expression of glucose transporter 1 (Glut-1) vs.
glucose transporter 4 (Glut-4) in comparison to chronic mass-forming pancreatitis.4
• The overall sensitivity and specificity for pancreatic cancer by SUV analysis is 94%
and 88%, respectively.1,2,3,5
• When using the SUV cutoff criteria of 1.53, PET has a better sensitivity and specificity than CT for detecting cancer, 93% PET sensitivity as opposed to 80% CT sensitivity, and 93% PET specificity as opposed to 74% CT specificity.1,2,3,5
• Chronic active pancreatitis and serous cystadenoma are common causes for false- positive PET results.
• PET helps accurately stage the disease, making it helpful in planning the appropriate therapy.1,2,3,5
Discussion
Histologically, 80% of the pancreatic cancers are adenocarcinomas. Staging is based on a TNM staging system. At initial presentation, 20% of the patients are in stage I, 40% are in stage II, and 40% are in stage III and IV. Whipple pancreaticoduodenec- tomy is usually performed. 5FU and gemcitabine may improve overall survival.
Palliative therapy is usually employed for analgesia. The overall 5-year survival rate is less than 5%. In patients who are fortunate enough to have a successful curative resection, the 5-year survival rate is 15% to 20%.
History
64-year-old female with a history of pancreatic cancer ten years ago, status post Whipple procedure. There is a history of thyroidectomy for thyroid cancer eight years ago. The current study is being done to evaluate for recurrence.
Findings
There is focal hypermetabolism in the neck (Figure 25.3.1). The focal hypermetabo- lism is midline and retrotracheal in location (Figure 25.3.2), centered 2 cm below the
Case 25.3
FIGURE25.3.2. FIGURE25.3.3.
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vocal cord and centered at the level of the only surgical clip right of midline.
This may represent metastatic disease or recurrent thyroid carcinoma. An elevated thyroglobulin would favor the latter.
There is intense focal hypermetabolism of the 3-cm mass at the root of the mesen- tery (Figures 25.3.3 and 25.3.4), which was shown to be heterogeneously enhancing on prior CT.This is consistent with recurrent pancreatic carcinoma by location but unusual in time frame from diagnosis. It is potentially approachable by percutaneous biopsy.
No abnormal hypermetabolism is evident in the chest. There is no increase in activity related to the fibrotic changes in the pulmonary apices.
Impression
1. Single midline, approximately 1-cm retrotracheal cervical focus, corresponding to increased retrotracheal soft tissues, centered at the level of the only rightsided surgical clip. This could be due to recurrent thyroid carcinoma or metastatic disease.
2. Intensely hypermetabolic 3-cm mesenteric root mass consistent with recurrent pancreatic cancer.
Pearls and Pitfalls
• FDG PET cannot be used to differentiate types of cancer although the level of uptake may correlate with tumor grade in certain types of malignancies.
Discussion
FDG PET is useful in staging and determination of resectability of pancreatic masses at the time of initial diagnosis as well as in reevaluation of patients after therapy and differentiating malignancy from chronic pancreatitis.
FIGURE25.3.4.
