Usefulness of technetium-99m hexamethylpropylene amine oxime-labeled leukocyte scintigraphy to detect pancreatic necrosis in patients with acute pancreatitis. Prospective comparison with Ranson, Glasgow and APACHE-II scores and serum C-reactive protein.

BACKGROUND: In acute pancreatitis (AP), pancreatic necrosis (PN) is an important local complication that can be identified by means of contrast-enhanced computed tomography (CECT). Pancreatic leukocyte infiltration is a significant pathogenic event in the development of PN that can be detected by labeled leukocyte scintigraphy (LLS). The aim of this study was to evaluate the utility of LLS with technetium-99m hexamethylpropylene amine oxime ((99m)Tc-HMPAO) to detect the presence of PN in patients with AP. METHODS: Prospective cohort study of 84 patients with AP. Patients underwent LLS and the activity of images was scored on a 0-3 scale. CETC was performed to assess PN. Ranson, Glasgow and APACHE-II scores were calculated. Serum C-reactive protein (CRP) was measured. Sensitivity (Sn), specificity (Sp), positive predictive values (PPV), negative predictive values (NPV), areas under receiver operating characteristic (ROC) curves, likelihood ratios, odds ratios, analysis of variances between groups and correlation coefficients between tests were calculated. RESULTS: PN was present in 11 (13%) patients. Pancreatic labeled leukocyte uptake was present in 38 patients (45%). Sn, Sp, PPV and NPV of LLS grade 2-3 for PN diagnosis were the highest (91, 88, 53 and 98%, respectively) of all tests. Patients with LLS grade 2-3 were 71 times more likely to be at risk of PN compared to those with LLS grade 0-1. The area under ROC curve of the LLS was the largest. A significant correlation was obtained between LLS and CRP (p < 0.001). CONCLUSION: In patients with AP, LLS with (99m)Tc-HMPAO detects PN with an acceptable level of confidence and therefore could be considered an alternative technique to CECT in detecting PN.

99mTc-hexamethylpropylene amineoxime leukocyte scintigraphy in acute pancreatitis: an alternative to contrast-enhanced computed tomography?

OBJECTIVE: Contrast-enhanced computed tomography (CECT) is the most efficient imaging technique for the diagnosis and staging of acute pancreatitis (AP); its use, however, may be unfeasible in some patients as a consequence of the drawbacks of intravenous (IV) contrast material. The aim of this study was to test the utility of labeled leukocyte scintigraphy (LLS) as an alternative imaging technique to CECT for the staging of AP. METHODS: Sixty-six patients with AP were prospectively studied. All patients underwent CECT and pancreatic LLS using (99m)Tc-hexamethylpropylene amineoxime as leukocyte label within a time interval of 2 days, in the early phase of AP. In addition, all patients had their serum C-reactive protein (CRP) concentration measured within 48-72 h after admission. CECT images were analyzed for Balthazar's grade of pancreatitis and for the presence or absence of pancreatic necrosis. Scintigraphic activity of 3-4 h planar images was scored on a 0-2 scale in relation to physiological liver uptake. RESULTS: LLS score was significantly related (p < 0.001) to both components of CECT (grade of pancreatitis and pancreatic necrosis). LLS and serum CRP showed similar results for detecting the most severe pancreatic damage as showed by their respective receiver operating characteristic (ROC) curves. Sensitivities and specificities of LLS score of 2 were, respectively, 62% and 96% for the detection of grade D-E pancreatitis and 90% and 89% for the detection of pancreatic necrosis. Scintigraphic score of 2 increased the likelihood of grade D-E pancreatitis from 32% (pretest probability) to 87% (posttest probability) (likelihood ratio: 13.9) and that of pancreatic necrosis from 16% to 60% (likelihood ratio: 8.4). CONCLUSIONS: Our results show that leukocytes are related to the severity of local pancreatic damage in AP. Thus, LLS is a potential alternative technique to CECT for staging AP.