review of literature on clinical pancreatology - The Pancreapedia

MD-CT is suitable for evaluating tumor spread during therapy for nonresectable pancreaticcarcinoma. The IS is useful for assessing the impact on the veins and arteries, i.e. degree <strong>of</strong>change in vessel invasion [433].After neoadjuvant treatmentTo evaluate the effect <strong>of</strong> neoadjuvant combined chemotherapy and radiation therapy (CCRT)on preoperative accuracy <strong>of</strong> multidetector computed tomography (CT) for resectability andtumor staging in patients with pancreatic head cancer from 2002 to 2007,38 patients withpancreatic head adenocarcinoma underwent multidetector CT before surgery. Of these, 12patients received neoadjuvant CCRT. The accuracy in determining resectability was 83percent (10 <strong>of</strong> 12) in patients who had received neoadjuvant CCRT and 81 percent (21 <strong>of</strong> 26)in patients who had not. Of 32 patients who underwent pancreaticoduodenectomy,histopathologic tumor staging was reported for T1 (n=2), T2 (n=1), and T3 (n=9) lesions inpatents with neoadjuvant CCRT (n=12), and for T3 in all patients without neoadjuvant CCRT(n=20). T-staging accuracy was 67 percent (eight <strong>of</strong> 12) with neoadjuvant CCRT and 95percent (19 <strong>of</strong> 20) without it, which is a significant difference. This means that neoadjuvantCCRT reduces the accuracy <strong>of</strong> tumor restaging after treatment <strong>of</strong> pancreatic head cancer,but this effect is not so great as to affect the determination <strong>of</strong> resectability [434].PET-CTThe purpose <strong>of</strong> one study was to evaluate the diagnostic usefulness <strong>of</strong> PET/CT forpancreatic malignancy. It was retrospectively analyzed medical records <strong>of</strong> 115 patients withpathologically diagnosed pancreatic cancer between 2003 to 2008 who underwentabdominal CT and PET/CT examination before histological confirmation. CT and PET/CTimages were <strong>review</strong>ed in single-blinded status and diagnostic ability on primary pancreaticlesion, regional lymph node metastasis, and distant metastasis was evaluated. Ninety-ninepatients (86 %) had malignant diseases including 91 cases <strong>of</strong> adenocarcinoma, and 16patients (14 %) benign diseases. Only CA 19-9 value and SUV were significantly differentbetween PET/CT positive and negative groups. Sensitivity, specificity and positive predictivevalues (PPV) <strong>of</strong> both modality for pancreatic lesion were same (94 %, 62 %, and 95 %,respectively), and negative predictive values (NPV) were 67 percent on CT and 57 percenton PET/CT. PET/CT correctly diagnosed 8 cases (7 %) <strong>of</strong> falsely diagnosed pancreaticlesion on CT. Nine cases (16 %) <strong>of</strong> misdiagnosed lymph node metastasis on CT werecorrectly diagnosed on PET/CT. But, there was no significant difference in the diagnosis <strong>of</strong>regional lymph node metastasis. Three out <strong>of</strong> 29 cases <strong>of</strong> distant metastasis, except 2 cases<strong>of</strong> supraclavicular lymph node metastasis, were additionally diagnosed by PET/CT. But,overall sensitivity <strong>of</strong> distant metastasis was significantly higher in CT (83 % vs 69 %).Although PET/CT provided additional correct diagnoses in many cases, it showed fairdiagnostic power for primary pancreatic lesion and lymph node metastasis, and lowersensitivity for distant metastasis. Therefore, PET/CT should be used as an supplementarymodality <strong>of</strong> CT in diagnosing pancreatic malignancy [435].Magnetic resonance imaging (MRI)To compare diffusion-weighted imaging (DWI) findings and the apparent diffusion coefficient(ADC) values <strong>of</strong> pancreatic cancer, mass-forming focal pancreatitis (FP), and the normalpancreas DWI (b = 0 and 600 seconds/mm 2 ) findings <strong>of</strong> 14 patients with mass-forming FPproven by histopathology and or clinical follow-up, 10 patients with histopathologically-provenpancreatic cancer, and 14 subjects with normal pancreatic exocrine function and normalimaging findings were retrospectively evaluated. ADC values <strong>of</strong> the masses, the remainingpancreas, and the normal pancreas were measured. On b = 600 seconds/mm 2 DWI, massformingFP was visually indistinguishable from the remaining pancreas whereas pancreaticcancer was hyperintense relative to the remaining pancreas. The mean ADC value <strong>of</strong>