Diagnostic and prognostic value of preoperative 18F-fluorodeoxyglucose positron emission tomography/computed tomography for colorectal cancer: comparison with conventional computed tomography.

BACKGROUND/AIMS: 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has been used for preoperative staging of colorectal cancer (CRC). However, the diagnostic accuracy of FDG-PET/CT for detection of lymph node or distant metastasis and its prognostic role have not been well established. We therefore evaluated the diagnostic and prognostic value of FDG-PET/CT in comparison with conventional CT for CRC. METHODS: We investigated 220 patients who underwent preoperative FDG-PET/CT and CT, followed by curative surgery for CRC. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG-PET/CT and CT for detection of lymph node metastasis and distant metastasis were evaluated. In addition, we assessed the findings of FDG-PET/CT and CT according to outcomes, including cancer recurrence and cancer-related death, for evaluation of prognostic value. RESULTS: For detection of lymph node metastasis, FDG-PET/CT had a sensitivity of 44%, a specificity of 84%, and an accuracy of 67%, compared with 59%, 65%, and 62%, respectively, for CT (P=0.029, P=0.000, and P=0.022). For distant metastasis, FDG-PET/CT had a sensitivity of 79%, a specificity of 94%, and an accuracy of 93%, compared with 79%, 87%, and 86%, respectively, for CT (P=1.000, P=0.004, and P=0.037). In addition, positive findings of lymph node metastasis and distant metastasis on FDG-PET/CT were associated significantly with cancer recurrence or cancer-related death (P=0.009, P=0.001, respectively). CONCLUSIONS: Preoperative FDG-PET/CT had a higher specificity and accuracy compared to CT for detection of lymph node metastasis and distant metastasis of CRC. In addition, FDG-PET/CT could be a valuable prognostic tool for CRC.

The Usefulness of Early Endoscopic Ultrasonography in Acute Biliary Pancreatitis with Undetectable Choledocholithiasis on Multidetector Computed Tomography.

BACKGROUND/AIMS: EUS can detect bile duct stones (BDS) that are undetectable on multidetector computed tomography (MDCT). BDS associated with acute biliary pancreatitis (ABP) are small and tend to be excreted spontaneously. This study evaluated the usefulness of early EUS in patients with ABP and undetectable BDS on MDCT. METHODS: Forty-one patients with ABP and undetectable BDS on MDCT underwent EUS within 24 hours of admission and were diagnosed with BDS, sludge, dilated common bile duct (CBD), or normal CBD. ERCP was performed in patients with BDS, sludge, or clinical deterioration. The diagnostic yield and the effects of early EUS on morbidity, mortality, and the length of hospitalization were evaluated. RESULTS: EUS detected BDS or sludge in 48.8% of patients examined. BDS was the diagnosis in 13 patients, sludge in seven, and neither for 21 patients. ERCP was performed in 20 patients with BDS or sludge, in two patients with coexisting cholangitis, and in one patient with worsening liver function tests. ERCP identified BDS in 12 patients and sludge in seven. No lesions were diagnosed in four patients by ERCP. All patients improved, and the length of hospitalization in patients with ERCP was 9.0 days, without ERCP 7.1 days. Two patients with major complications by ERCP were hospitalized for a prolonged time. CONCLUSIONS: Early EUS may be useful to select patients for therapeutic ERCP in cases of suspected ABP with undetectable BDS on MDCT.

Diagnostic Accuracy of the Initial Endoscopy for Ampullary Tumors.

BACKGROUND/AIMS: Ampullary tumors come in a wide variety of malignant forms. We evaluated the diagnostic accuracy of endoscopy for ampullary tumors, and analyzed the causes of misdiagnosis. METHODS: We compared endoscopic imaging and biopsy results to final diagnoses. Types of endoscope, numbers of biopsy specimens taken, and final diagnoses were evaluated as possible factors influencing diagnostic accuracy. RESULTS: Final diagnoses were 19 adenocarcinomas, 18 normal or papillitis, 11 adenomas, two adenomyomas, one paraganglioma, and one neuroendocrine tumor. The diagnostic accuracy of endoscopic imaging or the initial biopsy was identical (67.3%). At least one test was concordant with the final diagnosis in all except two cases. Compared with the final diagnosis, endoscopic imaging tended to show more advanced tumors, whereas the initial biopsy revealed less advanced lesions. The diagnostic accuracy of the initial biopsy was influenced by the type of endoscope used and the final diagnosis, but not by the number of biopsies taken. CONCLUSIONS: Endoscopy has limited accuracy in the diagnosis of ampullary tumors. However, most cases with concordant endoscopic imaging and biopsy results are identical to the final diagnosis. Therefore, in cases where both of these tests disagree, re-evaluation with a side-viewing endoscope after resolution of papillitis is required.

Development of a biodegradable sirolimus-eluting stent coated by ultrasonic atomizing spray.

In this study, poly(D,L lactic-co-glycolic acid) (PLGA) was used as a drug carrier to generate two types of stents loaded with different concentrations of sirolimus. These stents were prepared by ultrasonic atomizing spray coating. Ultrasonic atomizing spray nozzle uses a low-pressure air/gas to produce a soft, highly focused beam of small spray drops. An isolated hypotube delivers liquid to the nozzle's atomizing surface while air/gas, delivered through the nozzle orifice at a fixed low pressure, shapes the atomized drops into a very precise, targeted spray. The stent was moved both in the traverse direction and rotated during the spraying process. The morphology of the sirolimus-eluting stents was examined by scanning electron microscopy (SEM) which indicated that the coating was very smooth and uniform. The coating was found to have the ability to withstand the compressive and tensile strains imparted without cracking during the stent inflation process. Release profile of sirolimus was measured by high performance liquid chromatography (HPLC). The release behavior of sirolimus from the stent surface had a two phase release profile with a burst release period of about 2 days, followed by a sustained and slow release phase. The mass loss behavior of PLGA appeared linear throughout most of the degradation period. At 28 days, neointimal formation was found to be significantly decreased for both sirolimus-eluting stents as compared to bare-metal stents (BMS). Assessment of vascular healing revealed an absence of increased inflammation in both sirolimus-eluting stents. Inflammation is commonly observed in drug-eluting stents (DES) with nonbiodegradable polymeric coatings. Taking these results into account, these novel sirolimus-eluting stents may be good candidates to resolve in-stent restenosis.