Comparison of endoscopic ultrasound, computed tomography and magnetic resonance imaging in assessment of detailed structures of pancreatic cystic neoplasms

AIM To evaluate the advantages of endoscopic ultrasound(EUS) in the assessment of detailed structures of pancreatic cystic neoplasms(PCNs) compared to computed tomography(CT) and magnetic resonance imaging(MRI).METHODS All patients with indeterminate PCNs underwent CT, MRI, and EUS. The detailed information, including size, number, the presence of a papilla/nodule, the presence of a septum, and the morphology of the pancreatic duct of PCNs were compared among the three imaging modalities. The size of each PCN was determined using the largest diameter measured. A cyst consisting of several small cysts was referred to as a motherdaughter cyst. Disagreement among the three imaging modalities regarding the total number of mother cysts resulted in the assumption that the correct number was the one in which the majority of imaging modalities indicated.RESULTS A total of 52 females and 16 males were evaluated. The median size of the cysts was 42.5 mm by EUS, 42.0 mm by CT and 38.0 mm by MRI; there was no significant difference in size as assessed among the three imaging techniques. The diagnostic sensitivity and ability of EUS to classify PCNs were 98.5%(67/68) and 92.6%(63/68), respectively. These percentages were higher than those of CT(73.1%, P < 0.001; 17.1%, P < 0.001) and MRI(81.3%, P = 0.001; 20.3%, P < 0.001). EUS was also able to better assess the number of daughter cysts in mother cysts than CT(P = 0.003); however, there was no significant difference between EUS and MRI in assessing mother-daughter cysts(P = 0.254). The papilla/nodule detection rate by EUS was 35.3%(24/68), much higher than those by CT(5.8%, 3/52) and MRI(6.3%, 4/64). The detection rate of the septum by EUS was 60.3%(41/68), which was higher than those by CT(34.6%, 18/52) and by MRI(46.9%, 30/64); the difference between EUS and CT was significant(P = 0.02). The rate of visualizing the pancreatic duct using EUS was 100%, whereas using CT and MRI it was less than 10%.CONCLUSION EUS helps visualize the detailed structures of PCNs and has many advantages over CT and MRI. EUS is valuable in the diagnosis and assessment of PCNs.

Endoscopy-guided ablation of pancreatic lesions:Technical possibilities and clinical outlook

Endoscopic ultrasound(EUS) and endoscopic retrograde cholangiopancreatography(ERCP)-guided ablation procedures are emerging as a minimally invasive therapeutic alternative to radiological and surgical treatments for locally advanced pancreatic cancer(LAPC), pancreatic neuroendocrine tumours(PNETs), and pancreatic cystic lesions(PCLs). The advantages of treatment under endoscopic control are the real-time imaging guidance and the possibility to reach a deep target like the pancreas. Currently, radiofrequency probes specifically designed for ERCP or EUS ablation are available as wel as hybrid cryotherm probe combining radiofrequency with cryotechnology. To date, many reports and case series have confirmed the safety and feasibility of that kind of ablation technique in the pancreatic setting.Moreover, EUS-guided fine-needle injection is emerging as a method to deliver ablative and anti-tumoral agents inside the tumuor. Ethanol injection has been proposed mostly for the treatment of PCLs and for symptomatic functioning PNETs, and the use of gemcitabine and paclitaxel is also interesting in this setting. EUS-guided injection of chemical or biological agents including mixed lymphocyte culture, oncolytic viruses, and immature dendritic cells has been investigated for the treatment of LAPC. Data on the long-term efficacy of these approaches,and large prospective randomized studies are needed to confirm the real clinical benefits of these techniques for the management of pancreatic lesions.

In vivo and ex vivo confocal endomicroscopy of pancreatic cystic lesions: A prospective study

AIM To investigate the reproducibility of the in vivo endoscopic ultrasound(EUS)-guided needle based confocal endomicroscopy(n CLE) image patterns in an ex vivo setting and compare these to surgical histopathology for characterizing pancreatic cystic lesions(PCLs). METHODS In a prospective study evaluating EUS-nC LE for evaluation of PCLs, 10 subjects underwent an in vivo nC LE(AQFlex nC LE miniprobe; Cellvizio, MaunaK ea, Paris, France) during EUS and ex vivo probe based CLE(pC LE) of the PCL(Gastroflex ultrahigh definition probe, Cellvizio) after surgical resection. Biopsies were obtained from ex vivo CLE-imaged areas for comparative histopathology. All subjects received intravenous fluorescein prior to EUS and pancreatic surgery for in vivo and ex vivo CLE imaging respectively. RESULTS A total of 10 subjects(mean age 53 ± 12 years; 5 female) with a mean PCL size of 34.8 ± 14.3 mm were enrolled. Surgical histopathology confirmed 2 intraductal papillary mucinous neoplasms(IPMNs), 3 mucinous cystic neoplasms(MCNs), 2 cystic neuroendocrine tumors(cystic-NETs), 1 serous cystadenoma(SCA), and 2 squamous lined PCLs. Characteristic in vivo nC LE image patterns included papillary projections for IPMNs, horizon-type epithelial bands for MCNs, nests and trabeculae of cells for cystic-NETs, and a "fern pattern" of vascularity for SCA. Identical image patterns were observed during ex vivo pC LE imaging of the surgically resected PCLs. Both in vivo and ex vivo CLE imaging findings correlated with surgical histopathology.CONCLUSION In vivo n CLE patterns are reproducible in ex vivo p CLE for all major neoplastic PCLs. These findings add further support the application of EUS-nC LE as an imaging biomarker in the diagnosis of PCLs.