Mid-term outcomes of physician-modified endograft therapy for complex aortic aneurysms.

OBJECTIVES: Our goal was to evaluate early and mid-term outcomes of physician-modified endografting for pararenal and thoraco-abdominal aortic aneurysms from 10 Japanese aortic centres. METHODS: From January 2012 to March 2022, a total of 121 consecutive adult patients who underwent physician-modified endografting for pararenal and thoraco-abdominal aortic aneurysms were enrolled. We analysed early and mid-term postoperative outcomes, including postoperative complications and mortality. RESULTS: The pararenal and thoraco-abdominal aortic aneurysm groups included 62 (51.2%) and 59 (48.8%) patients, respectively. The overall in-hospital mortality rate was 5.8% (n = 7), with mortality rates of 3.2% (n = 2) and 8.5% (n = 5) in pararenal and thoraco-abdominal aortic aneurysm groups, respectively (P = 0.225). Type IIIc endoleaks occurred postoperatively in 18 patients (14.9%), with a significantly higher incidence (P = 0.033) in the thoraco-abdominal aortic aneurysm group (22.0%, n = 13) than in the other group (8.1%, n = 5). Major adverse events occurred in 7 (11.3%) and 14 (23.7%) patients in pararenal and thoraco-abdominal aortic aneurysm groups (P = 0.074), respectively. The mean follow-up period was 24.2 months. At the 3-year mark, both groups differed significantly in freedom from all-cause mortality (83.3% and 54.1%, P = 0.004), target aneurysm-related mortality (96.8% and 82.7%, P = 0.013) and any reintervention (89.3% and 65.6%, P = 0.002). Univariate and multivariate regression analyses demonstrated that ruptures, thoraco-abdominal aortic aneurysms and postoperative type IIIc endoleaks were associated with an increased risk of all-cause mortality. CONCLUSIONS: The mid-term outcomes of physician-modified endografting for pararenal and thoraco-abdominal aortic aneurysms were clinically acceptable and comparable with those in other recently published studies. Notably, pararenal and thoraco-abdominal aortic aneurysms represent distinct pathological entities with different postoperative outcomes.

Leiomyosarcoma Presenting as Rupture With a Type II Endoleak After Thoracic Endovascular Aortic Repair.

Endovascular stent-graft therapy is a commonly performed procedure for aortic lesions worldwide and complications unique to stent grafts, such as postoperative endoleaks, are well known. However, as this treatment modality becomes more popular, physicians should carefully monitor for other unexpected complications, which may not always be related to the graft. This study presents a case of leiomyosarcoma of the aorta that developed during follow-up for a type II endoleak (T2EL) after thoracic endovascular aortic repair. The presence of the T2EL hindered the diagnosis of the sarcoma at an early stage. These findings suggest that an apparent aneurysm that grows suddenly during follow-up after stent grafting should raise the index of suspicion for a neoplasm as well as an endoleak.

Extensive Aortic Stent Graft Coverage for Thoracoabdominal Aortic Aneurysm is Associated With Hemorrhagic Complications Induced by Disseminated Intravascular Coagulation.

BACKGROUND: Hybrid endovascular repair for thoracoabdominal aortic aneurysm (TAAA) is a less invasive alternative treatment than conventional open repair. However, disseminated intravascular coagulation (DIC) and hemorrhagic complications can occur postoperatively. We investigated risk factors for hemorrhagic complications after hybrid endovascular TAAA repair. METHODS: Sixty-one patients who underwent elective hybrid endovascular TAAA repair between 2007 and 2020 were included. Laboratory data before and after placing stent graft were collected, and DIC was diagnosed using a scoring system established by the Japanese Association for Acute Medicine. The length of the stent graft used to cover the aorta was defined as the aortic coverage length, which was measured using the first postoperative computed tomography image. Predictors of unexpected hemorrhagic complications were evaluated. RESULTS: Postoperative thrombocytopenia was observed in 57 (93%) patients, and their platelet count decreased significantly after stent graft placement (14.3 [9.5-18.0] vs. 8.2 [5.4-10.9] × 104/µL, P < 0.001). Fifteen (25%) and 45 patients (74%) were diagnosed with DIC before and after stent graft placement, respectively. Hemorrhagic complications were observed in 21 patients (34%). Multivariate logistic regression analysis revealed that aortic coverage length was an independent risk factor for hemorrhagic complications (odds ratio 1.441/50 mm increase; 95% confidence interval, 1.041-1.994, P = 0.027). The cutoff value for aortic coverage length obtained from the receiver operating characteristic curve (area under the curve = 0.72) was 304.4 mm (sensitivity 0.76, specificity 0.70). CONCLUSION: Aortic coverage length is a risk factor for hemorrhagic complications. Patients undergoing extensive aortic coverage greater than 304 mm should be closely monitored.

Evaluation of juxtapapillary duodenal diverticula using multiplanar reformation in MDCT: correlation with ERCP findings.

OBJECTIVE: To determine the ability of multidetector computed tomography (MPR-MDCT) to identify and classify the juxtapapillary duodenal diverticulum (JPDD), with ERCP findings as the gold standard. METHODS: We retrospectively reviewed all ERCP examinations (n: 455) performed between January 2010 to December 2018 and selected 105 patients with JPDD as the inclusion criteria. Of those, 28 patients were excluded because of advanced pancreatic carcinoma, incomplete MDCT examinations and biliary catheter insertion. Finally, MDCT examinations of 77 patients with JPDD were assessed for the presence and type of JPDD. RESULTS: MPR-MDCT was able to identify 71 (92.2%) JPDD in 77 cases with 88.9% accuracy, 83.3% sensitivity, and 91.6% specificity in classifying the type of JPDD. MPR-MDCT performed best in determining type 1 JPDD, with accuracy of 95.4% compared with type 2 (83.3%) and type 3 (87.8%). There was no significant difference between age, gender, incidence of biliary stones and pancreatitis between each type of JPDD. No correlation of sizes with types of JPDD was found. CONCLUSIONS: MPR-MDCT can accurately identify and classify JPDD. This information will be useful in determining the difficulty of ERCP.

Invasive intraductal papillary mucinous neoplasms of the pancreas: relationships between mural nodules detected on thin-section contrast-enhanced MDCT and invasive components.

PURPOSE: To elucidate the relationships between mural nodules (MNs) and invasive components in patients with invasive intraductal papillary mucinous neoplasm (IPMN) on the basis of thin-section contrast-enhanced multidetector CT (CE-MDCT) and pathologic findings. METHODS: This retrospective study included 28 patients with surgically confirmed invasive IPMN. Two radiologists independently evaluated the thin-section (1-mm section thickness, no overlap) triple-phase CE-MDCT images for MNs, invasive components, and the continuity between them using a five-point scale (confidence scores of 1-3 as negative, 4 and 5 as positive). Kappa statistic was used to evaluate interobserver agreement. The CE-MDCT findings were correlated with pathologic findings. RESULTS: Interobserver agreement was good or excellent. MNs consisting of tumor cells were recognized in 12 (42.9%) of 28 patients with no discrepancy between the two radiologists. Invasive components were detected in 85.7% and 82.1% in the pancreatic parenchymal phase for radiologist 1 and 2, respectively, and recognized as hypoattenuating areas. Pathologic continuities between MNs and invasive components were confirmed in five (41.7%) of 12 patients with MNs and these were detected on CE-MDCT. When combined seven patients without continuities between MNs and invasive components and 16 patients without MNs, the invasive components pathologically derived from non-nodular low-height papillary epithelium in 23 (82.1%) of 28 patients. CONCLUSIONS: The invasive components derived more often from low-height papillary epithelium without MN appearance on CE-MDCT than from MN. Careful attention should be paid to the existence of an invasive component even in the absence of an enhancing MN.

Multicenter Analysis of Endovascular Aortic Arch In Situ Stent-Graft Fenestrations for Aortic Arch Pathologies.

BACKGROUND: In situ fenestration of aortic stent grafts for treatment of aortic arch aneurysms is a new option for endovascular aortic arch repair. So far, only few reports have shown perioperative and short-term results of in situ fenestrations for aortic arch diseases. We present the multicenter experience with the aortic arch in situ fenestration technique documented in the AARCHIF registry for treatment of aortic arch aneurysms or localized type A aortic dissections and analyzed perioperative outcome and midterm follow-up. METHODS: Patients with aortic arch pathologies treated by aortic arch in situ fenestration with proximal stent graft landing in aortic arch Ishimura zones 0 and 1 were included in the registry. Stent-graft in situ fenestrations were created using needles or radiofrequency or laser catheters and completed by implantation of covered connecting stent grafts. Single in situ fenestrations for the left subclavian artery (LSA) were excluded. RESULTS: Between 06/2009 and 03/2017, twenty-five patients were treated by in situ stent-graft fenestrations for aortic arch pathologies at 9 institutions in 7 different countries, 3 of them as bailout procedures for stent-graft malplacement. In situ fenestrations were performed for the brachiocephalic trunk (n = 20), the left common carotid artery (n = 21) and the LSA (n = 9). Technical success for intended in situ fenestrations was 94.0% (47/50), with additional supraaortic bypass procedures performed in 14 patients. Perioperative mortality occurred in 1 (4.0%) patient, treated as a bailout procedure and 3 (12.0%) perioperative strokes were observed. One proximal aortic stent-graft nonalignment and 4 type III endoleaks, 2 early and 2 late, required reeintervention. During follow-up (1-118 months), the diameter of aortic arch aneurysms decreased from 61.5 ± 4.1 mm to 48.4 ± 3.2 mm (P = 0.02) and, so far, 6 patients died from diseases unrelated to their aortic arch pathologies with a mean survival time of 79.5 months and 3 endovascular reinterventions for distal aortic expansion were performed. Cerebrovascular event (n = 4) was the most relevant prognostic factor for mortality during midterm follow-up (P = 0.003). CONCLUSIONS: The aortic arch in situ fenestration technique for endovascular aortic arch repair seems to be valuable treatment option for selected patients, although initial consideration of other treatment options is mandatory. Data about long-term durability are required.

Small pancreatic ductal carcinomas on triple-phase contrast-enhanced computed tomography: enhanced rims and the pathologic correlation.

PURPOSE: To reveal the prevalence of small (≤ 20 mm) pancreatic ductal carcinomas with enhanced rims on triple-phase contrast-enhanced CT and correlate the CT images with the pathologic findings. MATERIALS AND METHODS: Between April 2005 and April 2016, 45 patients underwent preoperative triple-phase contrast-enhanced CT and were pathologically diagnosed with small pancreatic ductal carcinoma. CT images were independently reviewed by two radiologists. The attenuation values of the enhanced rims, internal areas of the tumors, and surrounding pancreatic parenchyma were compared using Mann-Whitney U test. These areas were also correlated with the pathologic findings. Tumor invasiveness was compared between the tumors with and without enhanced rims using Fisher's exact test. RESULTS: Enhanced rims were identified in 18 tumors (40%) by consensus between the two reviewers. The enhanced rims showed significantly higher mean attenuation values compared with the internal areas of the tumors (p < 0.001) and surrounding pancreatic parenchyma (p < 0.0086), and were most clearly visualized on equilibrium phase. The enhanced rims pathologically reflected the abundant fibrotic stroma with cancer cells in all tumors. There was no statistically significant difference in tumor invasiveness between the tumors with and without enhanced rims (anterior peripancreatic invasion, p = 0.137; posterior peripancreatic invasion, p = 0.758; portal vein invasion, p = 0.639; and lymph node metastases, p = 0.359). CONCLUSIONS: Enhanced rims were detected at a rate of 40% in small pancreatic ductal carcinomas and could be an important finding for diagnosis on CT images, but did not suggest a less aggressive nature.

Ten-year experience of the thoraco-abdominal aortic aneurysm treatment using a hybrid thoracic endovascular aortic repair.

OBJECTIVES: The treatment of thoraco-abdominal aortic aneurysm continues to have a high mortality and paraplegia rate. In superaging societies, the methods of performing less invasive operations remain a major issue. We reviewed our 10-year experience in the treatment of thoraco-abdominal aortic aneurysm using a hybrid procedure of combined visceral reconstruction and thoracic endovascular aortic repair. METHODS: Sixty patients underwent a hybrid repair for the treatment of the thoraco-abdominal aortic aneurysm between 2007 and 2016. The mean age was 72.7 years. A true aneurysm was found in 43 (72%) patients and a chronic dissection in 17 (28%) patients. The standard operative procedure involved replacing the abdominal aorta with an artificial graft, and the visceral arteries were reconstructed using a quadrifurcated graft. Renovisceral debranching and stent grafting were performed as a 2-stage procedure. RESULTS: The hospital mortality rate was 5%. Two (3%) patients died due to an aneurysmal rupture in the hospital just after renovisceral debranching. The other 2 patients died due to an aneurysmal rupture in the long-term period after preventive renovisceral debranching. Two (3%) patients experienced spinal cord ischaemia after the stenting procedure. Four (7%) patients required additional treatment during the follow-up period. The overall survival was 75.9% at 2 years, 65.2% at 5 years and 43.5% at 8 years. The rates of freedom from aorta-related events were 92.9% at 2 years, 80.5% at 5 years and 72.5% at 8 years. CONCLUSIONS: The hybrid repair is considered to be a good option for elderly and high-risk patients. Further long-term follow-up is necessary to extend the indication in younger patients.

[Transaortic Thoracic Endovascular Aortic Repair Via Right Anterior Mini-thoracotomy;Report of a Case].

An 81-year-old man presented with ruptured thoracic aortic aneurysm under stable condition. He had been suffering from chronic obstructive pulmonary disease, chronic renal failure and rheumatoid arthritis. We performed hybrid thoracic endovascular aortic repair via right anterior mini-thoracotomy inserting a device through a conduit on the ascending aorta. The patient was discharged without aorta-related complications.

MDCT features of strangulated ileus due to an appendix epiploica of the sigmoid colon: four cases and a review of the literature.

PURPOSE: The aim of this study was to investigate the multidetector computed tomography (MDCT) features of strangulated ileus caused by epiploic appendix of the sigmoid colon. METHODS: We retrospectively evaluated MDCT images of four patients who underwent surgery in our hospital between 2011 and 2014. Patients were aged from 66 to 79 years, and two were female. RESULTS: Closed loop obstruction of the small bowel was confirmed in all patients. A fatty peritoneal band around the orifice of the ileus was detected in two patients, but was equivocal in the other two patients. Traction of the sigmoid colon toward the hilum of the closed loop of the small bowel was obvious in three patients. CONCLUSION: When traction of the sigmoid colon is detected in MDCT in a case of closed loop obstruction of the small bowel, strangulated ileus caused by an epiploic appendix should be considered in the differential diagnosis.

Renal Arteriovenous Shunts: Clinical Features, Imaging Appearance, and Transcatheter Embolization Based on Angioarchitecture.

Renal arteriovenous (AV) shunt, a rare pathologic condition, is divided into two categories, traumatic and nontraumatic, and can cause massive hematuria, retroperitoneal hemorrhage, pain, and high-output heart failure. Although transcatheter embolization is a less-invasive and effective treatment option, it has a potential risk of complications, including renal infarction and pulmonary embolism, and a potential risk of recanalization. The successful embolization of renal AV shunt requires a complete occlusion of the shunted vessel while preventing the migration of embolic materials and preserving normal renal arterial branches, which depends on the selection of adequate techniques and embolic materials for individual cases, based on the etiology and imaging angioarchitecture of the renal AV shunts. A classification of AV malformations in the extremities and body trunk could precisely correspond with the angioarchitecture of the nontraumatic renal AV shunts. The selection of techniques and choice of adequate embolic materials such as coils, vascular plugs, and liquid materials are determined on the basis of cause (eg, traumatic vs nontraumatic), the classification, and some other aspects of the angioarchitecture of renal AV shunts, including the flow and size of the fistulas, multiplicity of the feeders, and endovascular accessibility to the target lesions. Computed tomographic angiography and selective digital subtraction angiography can provide precise information about the angioarchitecture of renal AV shunts before treatment. Color Doppler ultrasonography and time-resolved three-dimensional contrast-enhanced magnetic resonance angiography represent useful tools for screening and follow-up examinations of renal AV shunts after embolization. In this article, the classifications, imaging features, and an endovascular treatment strategy based on the angioarchitecture of renal AV shunts are described.

Balloon-Occluded Retrograde Transvenous Obliteration for Isolated Gastric Varices Draining through Pericardiophrenic Vein without Gastrorenal or Gastrocaval Shunts.

Balloon-occluded retrograde transvenous obliteration (BRTO) is an effective and minimally invasive treatment for isolated gastric varices (GVs) that is usually performed through a gastrorenal shunt (GRS) or gastrocaval shunt (GCS). However, there are some cases in which GVs drain mainly into the left pericardiophrenic vein without an accessible GRS or GCS. This brief report presents four cases of GVs without a GRS/GCS treated by BRTO through the pericardiophrenic vein. BRTO was successfully performed with the use of flexible balloon catheters without any complications in all four patients, and the GVs were completely obliterated.

Unenhanced magnetic resonance angiography with time-spatial labeling inversion pulse for evaluating visceral artery aneurysms after endosaccular packing with detachable coils: preliminary results.

The aim of this brief report is to compare unenhanced magnetic resonance (MR) angiography with time-spatial labeling inversion pulse (Time-SLIP) with conventional digital subtraction angiography (DSA) in assessing degree of saccular visceral artery aneurysm (VAA) occlusion after endosaccular packing with detachable coils. Eight patients with VAAs (five renal and three splenic artery aneurysms) were enrolled in this study. VAA occlusion rates based on Time-SLIP MR angiography were complete occlusion in four patients, neck remnants in three patients, and body filling in one patient. These findings corresponded with the DSA findings.

Anatomic features and retrograde transvenous obliteration of duodenal varices associated with mesocaval collateral pathway.

PURPOSE: To evaluate techniques and efficacy of retrograde transvenous obliteration for the treatment of duodenal varices associated with mesocaval collateral pathway. MATERIALS AND METHODS: Six consecutive cases of large/growing or ruptured duodenal varices treated by retrograde transvenous obliteration were retrospectively reviewed. Selective balloon-occluded retrograde transvenous obliteration (B-RTO) with 5% ethanolamine oleate (EO) was performed in all cases. When EO could not be sufficiently stagnated in the varices, additional/alternative techniques were performed, including coil embolization of afferent vein or intravariceal injection of n-butyl-2-cyanoacrylate (NBCA). Clinical findings, anatomic features of duodenal varices, obliteration techniques, complications, posttherapeutic computed tomography (CT) findings, and follow-up endoscopic findings were investigated. RESULTS: All duodenal varices were located at the second/third junction of the duodenum and were fed by single (n = 1) or multiple (n = 5) pancreaticoduodenal veins. One varix fed by a single afferent vein was successfully treated by simple selective B-RTO technique alone. The other five cases required coil embolization of afferent vein (n = 1) or intravariceal injection of NBCA (n = 4) because sclerosant was not sufficiently stagnated in the varices. CT 1 week after the procedure showed complete occlusion of the varices in all cases. A duodenal ulcer at the variceal site developed in one patient and was successfully treated by medication. Follow-up endoscopy showed disappearance of varices in all cases, and no recurrence was observed during follow-up. CONCLUSIONS: Retrograde transvenous obliteration is an effective technique for the treatment of duodenal varices. However, additional/alternative techniques are required for successful treatment because of the complex anatomic features of duodenal varices.

Endovascular aortic arch reconstruction using in situ stent-graft fenestration in the brachiocephalic artery.

A patient who had previously undergone retrosternal gastric tube reconstruction for esophageal cancer presented with an aortic arch aneurysm. The patient was treated with endovascular stent-graft placement without median sternotomy, followed by revascularization of the brachiocephalic trunk using percutaneous in situ graft fenestration. A 9-month follow-up examination revealed marked regression of the aneurysm with patency of the stent-graft, without any complications. This in situ fenestration technique may extend the limits of thoracic endovascular therapy for patients who are unsuitable for sternotomy or aortic side-clamping.

Internal hernias after abdominal surgeries: MDCT features.

As less-invasive treatments for small bowel obstruction, such as laparoscopic surgery or small incision therapy, have become common, there is a growing demand for preoperative assessment of the cause and location of the small bowel obstruction. Thus, the role of computed tomography (CT) in the evaluation of small bowel obstruction is expanding. CT imaging of internal hernias (IHs) has been extensively described and is well established; however, CT imaging of IH after abdominal surgeries is not well recognized because of their anatomical complexity. The aims of this pictorial review are (1) to evaluate the causes of internal IHs in relation to previous abdominal surgery (e.g., IH associated with Roux-en-Y reconstruction, Billroth II reconstruction, peritoneal adhesive band, perineal hernia, and IH after gynecological procedures), (2) to demonstrate the spectrum of imaging findings on multidetector CT (MDCT), and (3) explain the key features for CT diagnosis of IHs related to previous surgical procedures, with emphasis on the multi-planar reformation (MPR) image. We also demonstrate the dynamic changes in the progression of mesenteric strangulation revealed by CT. Understanding the imaging appearance on MDCT can help radiologists guide therapy for patients with a small bowel obstruction after abdominal surgery.

Pancreatic adenocarcinoma versus chronic pancreatitis: differentiation with triple-phase helical CT.

BACKGROUND: Chronic pancreatitis and pancreatic adenocarcinoma often show similar clinical and imaging appearances. This study aims to differentiate chronic pancreatitis from pancreatic adenocarcinoma by defining enhancement patterns in both pathologic conditions during triple-phase helical CT. METHODS: The study included 42 patients with chronic pancreatitis and 85 patients with pancreatic adenocarcinoma. CT images obtained according to protocol A (scan delays, 30, 60, and 150 s; 300 mg I/mL contrast material) or protocol B (scan delays, 40, 70, and 150 s; 370 mg I/mL contrast material) were retrospectively evaluated. RESULTS: Mean contrast enhancement value of normal pancreas peaked in the first phase (early-washout pattern) while that of chronic pancreatitis peaked in the second phase (delayed-washout pattern), and that of pancreatic adenocarcinoma gradually rose (increasing pattern) in both protocols. Diagnostic indices for pancreatic adenocarcinoma were 82.4% and 94.1% for sensitivity, 83% and 83% for specificity, 82.7% and 90.4% for accuracy in protocols A and B, respectively, when differentiation between chronic pancreatitis and pancreatic adenocarcinoma was performed based on time-attenuation curve patterns. CONCLUSION: Our results indicate that time attenuation curves obtained from triple-phase helical CT in protocol B provide useful information in differentiating chronic pancreatitis from pancreatic adenocarcinoma.

Invasive carcinomas originating from intraductal papillary mucinous neoplasms of the pancreas: conspicuity and primary sites of the solid masses on triple-phase dynamic CT imaging.

OBJECTIVE: To assess the conspicuity of invasive carcinomas (solid masses) originating from pancreatic intraductal papillary mucinous neoplasms (invasive IPMNs) and the primary sites of the solid masses on thin-slice dynamic CT. METHODS: Twenty patients with pathologically proven invasive IPMNs underwent triple-phase dynamic CT examinations (arterial, portal, and delayed phases). Qualitative and quantitative analyses of conspicuity of the solid masses were performed for all phases. The primary sites [branch duct and/or main pancreatic duct (MPD)] of the solid masses were evaluated on CT in comparison to the pathologic findings. RESULTS: The qualitative and quantitative analyses of the conspicuity of the solid masses showed that the arterial phase images were superior to those of the portal and delayed phases. The primary sites of the solid mass were histopathologically diagnosed as branch ducts in 6 (30%) patients, MPD in 13 (65%), and both branch ducts and the MPD in one (5%). The sensitivity and specificity of the CT evaluation of the primary sites were 100% for the branch ducts, and for the MPD 93% and 100%, respectively. CONCLUSION: Arterial phase images are useful for the diagnosis of invasive IPMNs, and attention should be paid to pancreatic parenchyma surrounding the MPD when detecting invasive carcinomas.

Fibrous stroma and vascularity of pancreatic carcinoma: correlation with enhancement patterns on CT.

OBJECTIVE: To demonstrate the contrast-enhancement behavior of pancreatic carcinoma on dynamic contrast-enhanced CT (DCE-CT), and the relationship between the degree of contrast-enhancement and the vascularity (vessel density) and amount of fibrous stroma (fibrosis within the tumor) on pathological specimen. METHODS: The contrast-enhancement values were measured by producing the subtracting images for obtaining largest region of interests to reduce measurement errors and variability. Vascularity was determined by immunostaining of the tissue sections with factor 8 and the fibrous stroma was determined by picrosirius staining. Correlation of the findings of DCE-CT with pathological findings was performed in 21 patients with pancreatic carcinoma. RESULTS: All but one patient exhibited a gradually increasing enhancement, but there was considerably wide range in contrast-enhancement values of tumors. Examination of the overall relationship between vascularity and fibrous stroma with contrast-enhancement behavior showed that tumor with more fibrosis and higher vascularity had a higher contrast effect through all phases of dynamic study. Tumors having liver metastases tended to be less fibrotic than tumors without liver metastases. CONCLUSION: The contrast-enhancement behavior of pancreatic carcinoma may be helpful in estimating vascularity and the extent of tumor fibrosis and possibility of liver metastases.

Radioimmunoscintigraphy of pancreatic cancer in tumor-bearing athymic nude mice using (99m)technetium-labeled anti-KL-6/MUC1 antibody.

PURPOSE: KL-6 is an extracellular epitope of MUC1, a membrane-penetrating glycoprotein, and its overexpression has been reported in pancreatic cancer. The aim of this study was to examine whether radiolabeled anti-KL-6/MUC1 antibody could be used for molecular imaging of pancreatic cancer in vivo. MATERIALS AND METHODS: Anti-KL-6/MUC1 antibody was labeled with 99mTC by the stannous reduction method. Immunoreactivity of the 99mTc-labeled anti-KL-6/MUC1 antibody was evaluated by a whole-cell binding study. In vivo experiments were performed by injecting the 99mTc-labeled anti-KL-6/MUC1 antibody into athymic nude mice bearing the KP-1NL pancreatic cancer cell line. RESULTS: A whole-cell binding study showed that the radiolabeled antibody retained its immunoreactivity. On scintigrams, the density of the tumors remained unchanged during the 16-32 h after injection, whereas that of the kidneys decreased time-dependently. The radioactivity levels of the kidneys and tumors were measured densitometrically, and we found that the intensity in the tumors relative to that in the kidneys increased time-dependently. Radioactivity levels were the highest in the blood 32 h after injection, and those in the liver, kidney, lung, and tumor were also rather high. CONCLUSION: 99mTc-labeled anti-KL-6/MUC1 antibody appears to be a promising agent as a tumor-specific radiotracer for pancreatic cancer.