Use of an ultrasound imaging device within the applicator to evaluate placement and support treatment planning for breast brachytherapy and intraoperative radiation therapy.

PURPOSE: We evaluated the use of ultrasound imaging within a brachytherapy applicator as a method for applicator positioning, evaluation, and treatment planning in a series of in vitro, cadaver, and human studies. METHODS AND MATERIALS: We evaluated the performance of a prototype system comprising a small ultrasound imaging catheter inserted within the lumen of a balloon brachytherapy catheter. We tested the device in an ultrasound phantom, in human breast tissue, and in an endoscopic ultrasound catheter in cadaveric breast tissue. We evaluated the visualization of adjacent tissue to consider future development of a similar system for use in brachytherapy and intraoperative radiation therapy. RESULTS: Based on the ultrasound images obtained in an ultrasound phantom, cadaveric breast, and human participants, we observed that an ultrasound imaging catheter placed within the lumen of a brachytherapy applicator can effectively image adjacent tissue, ribs, and air voids, with appropriate quality to support clinical use. We observed high correlation in clinically useful information detected on ultrasound and comparative CT, with ultrasound spatial resolution near 1 mm (spatially variant). CONCLUSIONS: The findings from our pilot work suggest that real-time ultrasound imaging, operated from within the applicator, is a promising technique for image guidance and treatment planning during brachytherapy and intraoperative radiation therapy. Further expansion of this technology for clinical use will require development of a cohesive system of components to suit specific clinical applications.

Interventional endoscopic ultrasound-guided cholangiography: long-term experience of an emerging alternative to percutaneous transhepatic cholangiography.

BACKGROUND AND STUDY AIMS: Endoscopic retrograde cholangiography (ERC) with stenting is the procedure of choice for biliary decompression in patients with obstructive jaundice. In cases where biliary access cannot be achieved, interventional endoscopic ultrasound-guided cholangiography (IEUC) has become an alternative to percutaneous transhepatic cholangiography (PTC). PATIENTS AND METHODS: We report on 5 years of experience in patients who underwent IEUC after failed endoscopic retrograde cholangiopancreatography (ERCP). Endoscopic ultrasound-guided access to the targeted biliary duct was attempted with one of two approaches: transgastric-transhepatic (intrahepatic) or transenteric-transcholedochal (extrahepatic). A stent was then advanced over the wire and into the biliary tree. RESULTS: A total of 49 patients underwent IEUC: 35 had biliary obstruction due to malignancy and 14 had a benign etiology. The overall success rate of IEUC was 84% (41/49), with an overall complication rate of 16%. Of the 35 patients who underwent the intrahepatic approach, 23 had a stent placed across the major papilla, one had a stent placed intraductally in the common bile duct, and three patients underwent placement of a gastrohepatic stent. Resolution of obstruction was achieved in 29 patients, with a success rate of 83%. In all, 14 patients underwent an extrahepatic approach. In 8/14 (57%), stent placement across the major papilla was achieved. A transenteric stent was placed in four patients. Biliary decompression was achieved in 12/14 cases (86%). Based on intention-to-treat analysis, the intrahepatic approach achieved success in 29 of 40 cases (73%), and the extrahepatic approach was successful in seven of nine cases (78%). There were no procedure-related deaths. CONCLUSION: IEUC offers a feasible alternative to PTC in patients with obstructive jaundice in whom ERC has failed.

Covered self-expandable metal stents in pancreatic malignancy regardless of resectability: a new concept validated by a decision analysis.

BACKGROUND AND STUDY AIMS: The current treatment model for the management of malignant biliary obstruction is to place a plastic stent for unstaged pancreatic cancer. In patients with unresectable disease but a life expectancy of more than 6 months, self-expandable metal stents (SEMS) are favored because of their more prolonged patency. We analyzed the efficacy and cost-effectiveness of covered SEMS (CSEMS) in patients with pancreatic cancer and distal biliary obstruction without regard to surgical resectability. PATIENTS AND METHODS: Between March 2001 and March 2005, 101 consecutive patients with obstructive jaundice secondary to pancreatic cancer underwent placement of a CSEMS. Patients with resectable tumor were offered pancreaticoduodenectomy. A model was developed to compare the costs of CSEMS and polyethylene and DoubleLayer stents. RESULTS: A total of 21 patients underwent staging laparoscopy, of whom 16 had a resection (76%). The 85 patients who did not have a resection had a mean survival of 5.9 months (range 1-25 months) and a mean CSEMS patency duration of 5.5 months (range 1-16 months). Life-table analysis demonstrated CSEMS patency rates of 97% at 3 months, 85% at 6 months, and 68% at 12 months. In a cost model that accounted for polyethylene and DoubleLayer stent malfunction and surgical resections, initial CSEMS placement (3177 euros per patient) was a less costly intervention than either DoubleLayer stent placement (3224 euros per patient) or polyethylene stent placement with revision (3570 euros per patient). CONCLUSIONS: Covered SEMS are an effective treatment for distal biliary obstructions caused by pancreatic carcinoma. Their prolonged patency and removability makes them an attractive option for biliary decompression, regardless of resectability. The strategy of initial covered SEMS placement might be the most cost-effective strategy in these patients.

Endoscopic ultrasound drainage of pancreatic pseudocyst: a prospective comparison with conventional endoscopic drainage.

BACKGROUND AND STUDY AIMS: Pancreatic pseudocysts are a complication in up to 20% of patients with pancreatitis. Endoscopic management of pseudocysts by a conventional transenteric technique, i. e. conventional transmural drainage (CTD), or by endoscopic ultrasound-guided drainage (EUD), is well described. Our aim was to prospectively compare the short-term and long-term results of CTD and EUD in the management of pseudocysts. PATIENTS AND METHODS: A total of 99 consecutive patients underwent endoscopic management of pancreatic pseudocysts according to this predetermined treatment algorithm: patients with bulging lesions without obvious portal hypertension underwent CTD; all remaining patients underwent EUD. Patients were followed prospectively, with cross-sectional imaging during clinic visits. We compared short-term and long-term results (effectiveness and complications) at 1 and 6 months post procedure. RESULTS: 46 patients (37 men) underwent EUD and 53 patients (39 men) had CTD. The mean age of the entire group was 50 +/- 13 years. There were no significant differences between the two groups regarding short-term success (93% vs. 94%) or long-term success (84% vs. 91%); 68 of the 99 patients completed 6 months of follow-up. Complications occurred in 19% of EUD vs. 18% of CTD patients, and consisted of bleeding in three, infection of the collection in eight, stent migration into the pseudocyst in three, and pneumoperitoneum in five. All complications but one could be managed conservatively. CONCLUSIONS: No clear differences in efficacy or safety were observed between conventional and EUS-guided cystenterostomy. The choice of technique is likely best predicated by individual patient presentation and local expertise.

Clinical impact of conventional endosonography and endoscopic ultrasound-guided fine-needle aspiration in the assessment of patients with Barrett's esophagus and high-grade dysplasia or intramucosal carcinoma who have been referred for endoscopic ablation therapy.

BACKGROUND AND STUDY AIMS: Endoscopic mucosal resection and photodynamic therapy are exciting, minimally invasive curative techniques that represent an alternative to surgery in patients with Barrett's esophagus and high-grade dysplasia or intramucosal adenocarcinoma. However, there is lack of uniformity regarding which staging method should be used prior to therapy, and some investigators even question whether staging is required prior to ablation. We report our experience with a protocol of conventional endoscopic ultrasound staging prior to endoscopic therapy. PATIENTS AND METHODS: A total of 25 consecutive patients with a diagnosis of high-grade dysplasia or intramucosal adenocarcinoma in Barrett's esophagus who had been referred to the University of Chicago for staging in preparation for endoscopic therapy between March 2002 and November 2004 were included in the study. All 25 patients underwent repeat diagnostic endoscopy and conventional endosonography with a radial echo endoscope. Any suspicious lymph nodes that were detected were sampled using endoscopic ultrasound-guided fine-needle aspiration. RESULTS: Baseline pathology in the 25 patients (mean age 70, range 49-85) revealed high-grade dysplasia in 12 patients and intramucosal carcinoma in 13 patients. Five patients were found to have submucosal invasion on conventional endosonography. Seven patients had suspicious adenopathy, six regional (N1) and one metastatic to the celiac axis (M1a). Fine-needle aspiration confirmed malignancy in five of these seven patients. Based on these results, five patients (20%) were deemed to be unsuitable candidates for endoscopic therapy. CONCLUSIONS: By detecting unsuspected malignant lymphadenopathy, conventional endosonography and endoscopic ultrasound with fine-needle aspiration dramatically changed the course of management in 20% of patients referred for endoscopic therapy of Barrett's esophagus with high-grade dysplasia or intramucosal carcinoma. Based on our results, we believe that conventional endosonography and endoscopic ultrasound with fine-needle aspiration when nodal disease is present should be performed routinely in all patients referred for endoscopic therapy in this setting.

Drainage of gallbladder fossa fluid collections with endoprosthesis placement under endoscopic ultrasound guidance: a preliminary report of two cases.

Collections of fluid in the gallbladder fossa can be detected by ultrasound in as many as 29% of patients following cholecystectomy. Traditionally, persistent collections are treated by percutaneous drainage and bile duct decompression. We present two cases of persistent gallbladder fossa fluid collections which were refractory to bile duct decompression but which were successfully drained by endoscopic ultrasound-guided endoprosthesis placement. Under endoscopic ultrasound (EUS) control, a 19-gauge needle was inserted through the duodenal wall into the gallbladder fossa fluid collection. A guide wire was coiled within the collection, and an endoprosthesis was placed over the wire. Endoprosthesis insertion was successful in both cases, resulting in rapid symptomatic and radiographic improvement. EUS-guided drainage offers a minimally invasive alternative to percutaneous treatment of persistent gallbladder fossa fluid collections following cholecystectomy.

Endoscopic ultrasound-guided fine needle aspiration in esophageal cancer.

Esophageal cancer has a poor prognosis since it is often diagnosed in the symptomatic and incurable state. Accurate staging at initial diagnosis is imperative as it determines prognosis and influences treatment. Computed tomography (CT) scan is sensitive for identifying metastatic disease but is insensitive for detecting the extent of wall involvement or nodal disease. Endoscopic ultrasound (EUS) has emerged as a powerful tool in staging esophageal cancer with an impressive accuracy. Use of endoscopic ultrasound-guided fine needle aspiration as an adjunct further improves accuracy in nodal staging and allows for histologic confirmation. The impact of this invaluable staging modality in the management of esophageal cancer continues to grow.