Pancreatic cancer

Pancreatic cancer is a highly fatal disease with a 5-year survival rate of approximately 10% in the USA, and it is becoming an increasingly common cause of cancer mortality. Risk factors for developing pancreatic cancer include family history, obesity, type 2 diabetes, and tobacco use. Patients typically present with advanced disease due to lack of or vague symptoms when the cancer is still localised. High quality computed tomography with intravenous contrast using a dual phase pancreatic protocol is typically the best method to detect a pancreatic tumour and to determine surgical resectability. Endoscopic ultrasound is an increasingly used complementary staging modality which also allows for diagnostic confirmation when combined with fine needle aspiration. Patients with pancreatic cancer are often divided into one of four categories based on extent of disease: resectable, borderline resectable, locally advanced, and metastatic; patient condition is also an important consideration. Surgical resection represents the only chance for cure, and advancements in adjuvant chemotherapy have improved long-term outcomes in these patients. Systemic chemotherapy combinations including FOLFIRINOX (5-fluorouracil, folinic acid [leucovorin], irinotecan, and oxaliplatin) and gemcitabine plus nab-paclitaxel remain the mainstay of treatment for patients with advanced disease. Data on the benefit of PARP inhibition as maintenance therapy in patients with germline BRCA1 or BRACA2 mutations might prove to be a harbinger of advancement in targeted therapy. Additional research efforts are focusing on modulating the pancreatic tumour microenvironment to enhance the efficacy of the immunotherapeutic strategies.

Treatment with the radiolabeled somatostatin analog [177 Lu-DOTA 0,Tyr3]octreotate: toxicity, efficacy, and survival

PURPOSE

Despite the fact that most gastroenteropancreatic neuroendocrine tumors (GEPNETs) are slow-growing, median overall survival (OS) in patients with liver metastases is 2 to 4 years. In metastatic disease, cytoreductive therapeutic options are limited. A relatively new therapy is peptide receptor radionuclide therapy with the radiolabeled somatostatin analog [(177)Lu-DOTA(0),Tyr(3)]octreotate. Here we report on the toxicity and efficacy of this treatment, performed in over 500 patients.

PATIENTS AND METHODS

Patients were treated up to a cumulative dose of 750 to 800 mCi (27.8-29.6 GBq), usually in four treatment cycles, with treatment intervals of 6 to 10 weeks. Toxicity analysis was done in 504 patients, and efficacy analysis in 310 patients.

RESULTS

Any hematologic toxicity grade 3 or 4 occurred after 3.6% of administrations. Serious adverse events that were likely attributable to the treatment were myelodysplastic syndrome in three patients, and temporary, nonfatal, liver toxicity in two patients. Complete and partial tumor remissions occurred in 2% and 28% of 310 GEPNET patients, respectively. Minor tumor response (decrease in size > 25% and < 50%) occurred in 16%. Median time to progression was 40 months. Median OS from start of treatment was 46 months, median OS from diagnosis was 128 months. Compared with historical controls, there was a survival benefit of 40 to 72 months from diagnosis.

CONCLUSION

Treatment with [(177)Lu-DOTA(0),Tyr(3)]octreotate has few adverse effects. Tumor response rates and progression-free survival compare favorably to the limited number of alternative treatment modalities. Compared with historical controls, there is a benefit in OS from time of diagnosis of several years.

The clinical utility of endoscopic ultrasound-guided fine-needle aspiration in the diagnosis and staging of pancreatic carcinoma

BACKGROUND

Endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) of pancreatic lesions is being increasingly used. Our aim was to determine the safety, accuracy, and clinical utility of EUS-guided FNA in both the diagnosis and staging of pancreatic cancer.

METHODS

Forty-four patients (24 men/20 women) had EUS-guided FNA of pancreatic lesions (39 head/neck, 5 body, 3 tail) and/or associated lymph nodes. The mean age was 61 (range, 28 to 88 years). The indication for EUS-guided FNA was a pancreatic lesion seen initially on CT (39%), ERCP (43%), or EUS (18%). Follow-up data were collected on all patients for mean of 14.5 months (range 1 to 33 months).

RESULTS

CT detected only 15 of 61 (25%) focal lesions seen by EUS, Adequate specimens were obtained by EUS-guided FNA in 44 of 47 (94%) pancreatic lesions and 14 of 14 (100%) associated lymph nodes (overall adequacy was 95%). Of the 46 lesions in which specimens were adequate and a final diagnosis was available (32 malignant, 14 benign), EUS-guided FNA had a sensitivity of 92%, specificity of 100%, and diagnostic accuracy of 95% for pancreatic lesions and 83%, 100%, and 88% for lymph nodes, respectively. Six percent of pancreatic cases had inadequate specimens and, if included, lowered the sensitivity to 83%, specificity to 80%, and diagnostic accuracy to 88% for pancreatic lesions. In 3 patients with enlarged celiac nodes on EUS, EUS-guided FNA was able to make a tissue diagnosis of metastasis, which changed the preoperative staging and precluded surgery. EUS in combination with EUS-guided FNA precluded surgery in 12 of 44 (27%) and may have precluded surgery in an additional 6 of 44 (14%). EUS-guided FNA avoided the need for further diagnostic tests, thus expediting therapy in a total of 25 (57%) patients and influenced clinical decisions in 30 of 44 (68%) patients. The estimated cost savings based on surgeries avoided was approximately $3300 per patient. There was only one complication (2%), a post-FNA fever.

CONCLUSION

EUS-guided FNA of the pancreas appears to be a safe and effective method that increases both the diagnostic and staging capability of EUS in pancreatic cancer. The clinical impact of EUS-guided FNA includes avoiding surgery and additional imaging studies with a substantial cost savings.

Impact of resection status on pattern of failure and survival after pancreaticoduodenectomy for pancreatic adenocarcinoma

OBJECTIVE

To better understand the impact of a microscopically positive margin (R1) on patterns of disease recurrence and survival after pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma.

SUMMARY BACKGROUND DATA

A positive resection margin after PD is considered to be a poor prognostic factor, and some have proposed that an R1 margin may be a biologic predictor of more aggressive disease. The natural history of patients treated with contemporary multimodality therapy who underwent a positive margin PD has not been described.

METHODS

We analyzed our experience from 1990 to 2004, which included the prospective use of a standardized system for pathologic analysis of all PD specimens. All patients who underwent PD met objective computed tomographic criteria for resection. Standard pathologic evaluation of the PD specimen included permanent section analysis of the final bile duct, pancreatic, and superior mesenteric artery (SMA) margins. First recurrences (all sites) were defined as local, regional, or distant. Survival and follow-up were calculated from the date of initial histologic diagnosis to the dates of first recurrence or death and last contact, respectively.

RESULTS

PD was performed on 360 consecutive patients with pancreatic adenocarcinoma. Minimum follow-up was 12 months (median, 51.9 months). The resection margins were negative (R0) in 300 patients (83.3%) and positive (R1) in 60 (16.7%); no patients had macroscopically positive (R2) margins. By multivariate analysis (MVA), high mean operative blood loss and large tumor size were independent predictors of an R1 resection. Patients who underwent an R1 resection had a median overall survival of 21.5 months compared with 27.8 months in patients who underwent an R0 resection. After controlling for other variables on MVA, resection status did not independently affect survival. By MVA, only lymph node metastases, major perioperative complications, and blood loss adversely affected survival.

CONCLUSIONS

There was no statistically significant difference in patient survival or recurrence based on R status. However, this series is unique in the incorporation of a standardized surgical technique for the SMA dissection, the prospective use of a reproducible system for pathologic evaluation of resection margins, the absence of R2 resections, and the frequent use of multimodality therapy.

Localization of pancreatic endocrine tumors by endoscopic ultrasonography

BACKGROUND

After a pancreatic endocrine tumor has been diagnosed on the basis of clinical signs and the results of laboratory tests, localization of the tumor by the usual imaging procedures fails in as many as 40 to 60 percent of patients. Endoscopic ultrasonography, a sensitive test for small carcinomas of the pancreas, might also be useful in patients with endocrine tumors of the pancreas that cannot be localized by conventional methods.

METHODS

We studied 37 patients later shown to have 39 endocrine tumors of the pancreas who had negative results on transabdominal ultrasonography and CT. All the patients underwent endoscopic ultrasonography, and 22 also underwent selective angiography. All the tumors were confirmed by surgical excision and immunohistologic examination; they consisted of 31 insulinomas, 7 gastrinomas, and 1 glucagonoma, 0.5 to 2.5 cm (mean, 1.4 cm) in diameter. All but one of the patients were cured of their disease, as ascertained by at least six months of clinical and laboratory follow-up.

RESULTS

Using endoscopic ultrasonography, we were able to localize 32 of the 39 tumors (sensitivity, 82 percent); no tumor was incorrectly localized. The size of the tumors was very similar (within 2 mm) to that predicted by endoscopic ultrasonography. Among the 22 patients who underwent both angiography and endoscopic ultrasonography, ultrasonography was significantly more sensitive than angiography for tumor localization (sensitivity, 82 percent vs. 27 percent). Among 19 control patients without pancreatic endocrine tumors, endoscopic ultrasonography was negative in 18 (specificity, 95 percent).

CONCLUSIONS

Endoscopic ultrasonography is a highly sensitive and specific procedure for the localization of pancreatic endocrine tumors. It should be considered for the preoperative localization of such tumors once the clinical and laboratory diagnosis has been established.

Staging of pancreatic and ampullary carcinoma by endoscopic ultrasonography. Comparison with conventional sonography, computed tomography, and angiography

In a prospective study, endoscopic ultrasonography was compared with transabdominal ultrasonography, computed tomography, and angiography in 60 consecutive patients with pancreatic (n = 46) and ampullary (n = 14) cancer considered to be candidates for surgery. The diagnostic value of these imaging procedures in determining local resectability was assessed. The diagnosis of ampullopancreatic malignancy was made by operation (n = 40) or puncture/biopsy (n = 20). In the 40 patients who underwent surgery, endoscopic ultrasonography was significantly superior to abdominal ultrasonography and computed tomography in determining tumor size and extent and lymph node metastases of pancreatic and ampullary cancer. Furthermore, involvement of the portal venous system as judged by histopathology or surgical exploration was correctly assessed by endoscopic ultrasonography in 95%, whereas angiography (85%), computed tomography (75%) and abdominal ultrasonography (55%) were less sensitive. Of 11 cases of portal venous infiltration found at surgery, endoscopic ultrasonography correctly predicted 10, abdominal ultrasonography only 1, computed tomography 4, and angiography 5 (P less than 0.05 for all three comparisons). Twenty patients did not undergo surgery for different reasons: of those, 9 patients were excluded from operation because of portal venous involvement as shown by angiography. Endoscopic ultrasonography detected portal venous invasion in all these cases. In contrast to the venous system, arterial encasement was less reliably detected by endoscopic ultrasonography. In conclusion, endoscopic ultrasonography is the most effective single imaging procedure for local tumor staging in pancreatic and ampullary cancer. Thus, endoscopic ultrasonography will improve the assessment of tumor resectability and further decrease the need for explorative laparotomy.

Localisation of endocrine-related tumours with radioiodinated analogue of somatostatin

Various endocrine-related tumours contain large numbers of high-affinity somatostatin receptors. 123I-labelled tyr-3-octreotide (tyr-3-SMS 201-995, a synthetic derivative of somatostatin) was used to localise such tumours in vivo with a gamma-camera. Positive scans were obtained for two meningiomas, two gastrinomas, and one carcinoid; negative scans were obtained for one insulinoma (in which unlabelled octreotide had no effect on insulin levels), one phaeochromocytoma, one adrenal carcinoma (octreotide had no effect on cortisol levels), and three medullary thyroid carcinomas (octreotide had no effect on calcitonin levels). Thus radioiodinated tyr-3-octreotide can label somatostatin receptors in endocrine-related tumours in vivo and can therefore be used for tumour localisation.

Somatostatin-receptor imaging in the localization of endocrine tumors

BACKGROUND AND METHODS

A number of different tumors have receptors for somatostatin. We evaluated the efficacy of scanning with 123I-labeled Tyr3-octreotide, a somatostatin analogue, for tumor localization in 42 patients with carcinoid tumors, pancreatic endocrine tumors, or paragangliomas. We then evaluated the response to octreotide therapy in some of these patients.

RESULTS

Primary tumors or metastases, often previously unrecognized, were visualized in 12 of 13 patients with carcinoid tumors and in 7 of 9 patients with pancreatic endocrine tumors. The endocrine symptoms of these patients responded well to therapy with octreotide. Among 20 patients with paragangliomas, 8 of whom had more than one tumor, 10 temporal (tympanic or jugular), 9 carotid, and 10 vagal tumors could be visualized. One small tympanic tumor and one small carotid tumor were not seen on the scan.

CONCLUSIONS

The 123I-labeled Tyr3-octreotide scanning technique is a rapid and safe procedure for the visualization of some tumors with somatostatin receptors. A positive scan may predict the ability of octreotide therapy to control symptoms of hormonal hypersecretion.

Endoscopic palliation of malignant gastric outlet obstruction using self-expanding metal stents: experience in 36 patients

OBJECTIVE

Malignant gastric outlet obstruction is seen in the setting of a variety of cancers, most commonly pancreatic. Self-expanding metal stents can be used to palliate these patients and restore the ability to eat.

METHODS

We reviewed the Mayo Clinic experience in the endoscopic treatment of malignant gastric outlet obstruction. Thirty-six patients (26 male, 10 female) were treated between October, 1998 and January, 2001. Data were collected from charts, endoscopy reports, x-rays, and telephone calls. A scoring system was created to grade the ability to eat.

RESULTS

All procedures were successful. Thirty-one of 36 patients (86%) required one stent at initial endoscopy, and 5/36 patients (14%) required two or more stents. Pretreatment, 19/36 patients (53%) were nil per os, 15/36 (42%) drank liquids, and 2/36 were able to eat soft solids. After stent placement, only 1/36 (3%) was still nil per os, 13/36 (36%) drank liquids, 13/36 (36%) ate soft solids, and 9/36 (25%) ate a full diet. The improvement in ability to eat using the scoring system was statistically significant (p < 0.0001). Nine of 36 patients (25%) required reintervention for recurrent symptoms. Sixteen of 36 patients (44%) had concomitant or subsequent development of biliary obstruction, of which 15 were successfully decompressed.

CONCLUSIONS

Self-expanding metal stents are a safe and efficacious method for palliating malignant gastric outlet obstruction. The majority of patients do not require reintervention, and those that do can usually be managed nonoperatively.

Comparison of endoscopic ultrasonography and multidetector computed tomography for detecting and staging pancreatic cancer

BACKGROUND

Accurate preoperative detection and staging of pancreatic cancer may identify patients with locoregional disease that is amenable to surgical resection.

OBJECTIVE

To compare endoscopic ultrasonography and multidetector computed tomography (CT) for the detection, staging, and resectability of known or suspected locoregional pancreatic cancer.

DESIGN

Prospective, observational, cohort study.

SETTING

Single, tertiary referral hospital in Indianapolis, Indiana.

PATIENTS

120 participants with known or suspected locoregional pancreatic cancer.

INTERVENTIONS

Endoscopic ultrasonography followed by multidetector CT was performed in all patients. Patients with known or suspected pancreatic cancer deemed potentially resectable by 1 or both tests were considered for surgery.

MEASUREMENTS

Detection, staging, and resectability of pancreatic cancer. Surgically resected pancreatic cancer with negative microscopic histologic margins was considered resectable.

RESULTS

Of 120 patients enrolled, 104 (87%) underwent endoscopic ultrasonography and CT. Of the 80 patients with pancreatic cancer, 27 (34%) were managed nonoperatively, and 53 (66%) treated surgically had resectable (n = 25) or unresectable (n = 28) cancer. For the 80 patients with cancer, the sensitivity of endoscopic ultrasonography (98% [95% CI, 91% to 100%]) for detecting a pancreatic mass was greater than that of CT (86% [CI, 77% to 93%]; P = 0.012). For the 53 surgical patients, endoscopic ultrasonography was superior to CT for tumor staging accuracy (67% vs. 41%; P < 0.001) but equivalent for nodal staging accuracy (44% vs. 47%; P > 0.2). Of the 25 resectable pancreatic tumors in patients recommended for surgery, endoscopic ultrasonography and CT correctly identified 88% and 92%, respectively, as resectable. Of the 28 unresectable pancreatic tumors in patients recommended for surgery, endoscopic ultrasonography and CT correctly identified 68% and 64%, respectively, as unresectable.

LIMITATIONS

Radiologists who read the scans and endosonographers were not blinded to previous radiographic information. Because of the modest sample size, CIs of the sensitivity estimates were sometimes wide.

CONCLUSION

Compared with multidetector CT, endoscopic ultrasonography is superior for tumor detection and staging but similar for nodal staging and resectability of preoperatively suspected nonmetastatic pancreatic cancer.

Local staging of pancreatic cancer: criteria for unresectability of major vessels as revealed by pancreatic-phase, thin-section helical CT

OBJECTIVE

This study was conducted to determine the criteria for unresectability of major peripancreatic vessels in patients with pancreatic carcinoma as revealed by optimally enhanced, pancreatic-phase thin-section helical CT.

SUBJECTS AND METHODS

Twenty-five patients with pancreatic adenocarcinoma who underwent local dissection during curative or palliative surgery also underwent preoperative pancreatic-phase thin-section helical CT (40- to 70-sec delay, 2.5- to 3-mm collimation). Tumor involvement of the portal and superior mesenteric veins and the celiac, hepatic, and superior mesenteric arteries was prospectively graded on a 0-4 scale based on circumferential contiguity of tumor to vessel. Subsequent surgical results were then correlated with the CT grades.

RESULTS

At surgery, definitive evaluation was possible for 80 vessels. Forty-eight of 48 vessels graded 0 and three of three vessels graded 1 were resectable. Four of seven vessels graded 2, seven of eight vessels graded 3, and 14 of 14 vessels graded 4 were unresectable. A threshold of between grades 2 and 3, which corresponded to tumor involvement of one-half circumference of the vessel, yielded the lowest number of false-negatives and an acceptable number of false-positives for unresectability. Such a threshold would have yielded a sensitivity of 84%, a specificity of 98%, a positive predictive value of 95%, and a negative predictive value of 93% for unresectability of the vessels studied.

CONCLUSION

A grading system for tumor involvement of the major vessels in patients with pancreatic adenocarcinoma can be based on the degree of circumferential contiguity of tumor to vessel. Involvement of vessel to tumor that exceeds one-half circumference of the vessel is highly specific for unresectable tumor.

Screening for pancreatic neoplasia in high-risk individuals: an EUS-based approach

BACKGROUND & AIMS

Relatives of patients with pancreatic cancer and persons with certain inherited syndromes are at increased risk for developing pancreatic cancer. We prospectively evaluated the feasibility of screening for pancreatic neoplasia in high-risk individuals.

METHODS

Individuals from familial pancreatic cancer kindreds and a patient with Peutz-Jeghers syndrome underwent screening endoscopic ultrasound (EUS). If the EUS was abnormal, EUS-guided fine-needle aspiration, endoscopic retrograde cholangiopancreatography (ERCP), and spiral computed tomography (CT) were performed. Patients with abnormalities suggesting neoplasia had surgery.

RESULTS

Thirty-eight patients were studied; 31 (mean age, 58 yr; 42% men) from kindreds with > or =3 affected with pancreatic cancer; 6 from kindreds with 2 affected relatives, 1 was a patient with Peutz-Jeghers syndrome. None had symptoms referable to the pancreas or suggestive of malignancy. Six pancreatic masses were found by EUS: 1 invasive ductal adenocarcinoma, 1 benign intraductal papillary mucinous neoplasm, 2 serous cystadenomas, and 2 nonneoplastic masses. Hence, the diagnostic yield for detecting clinically significant pancreatic neoplasms was 5.3% (2 of 38). The 1 patient with pancreatic cancer was treated and still is alive and disease-free >5 years after surgery. EUS changes similar to those associated with chronic pancreatitis were found, which were more common in patients with a history of regular alcohol intake (P = 0.02), but also occurred in patients who did not consume alcohol. Screening also led to a new diagnosis and treatment of symptomatic upper-gastrointestinal conditions in 18.4% of patients.

CONCLUSIONS

EUS-based screening of asymptomatic high-risk individuals can detect prevalent resectable pancreatic neoplasia but false-positive diagnoses also occur.

Pancreatic tumors: comparison of dual-phase helical CT and endoscopic sonography

OBJECTIVE

The purpose of this study was to compare dual-phase helical CT and endosonography for the diagnosis and staging of pancreatic tumors.

SUBJECTS AND METHODS

Thirty patients with suspected pancreatic tumors underwent endosonography and dual-phase helical CT. A pathologic diagnosis was obtained in all cases with surgery (n = 23) or biopsy (n = 7), resulting in 27 neoplasms. Dual-phase helical CT and endosonographic findings were correlated with surgical and pathologic findings to determine diagnosis and resectability of pancreatic tumors.

RESULTS

Overall diagnostic sensitivity was 92% for dual-phase helical CT and 100% for endosonography (p = .45). Overall accuracy for staging of pancreatic tumors was 93% for both dual-phase helical CT and endosonography. Overall accuracy for predicting resectability was 90% for both dual-phase helical CT and endosonography. Accuracy of predicting unresectability was 100% for dual-phase helical CT and 86% for endosonography (p > .80). Differences were not considered statistically significant.

CONCLUSION

Dual-phase helical CT and endoscopic sonography do not differ significantly for diagnosis and assessment of resectability of pancreatic tumors.

Limited value of fluorine-18 fluorodeoxyglucose positron emission tomography for the imaging of neuroendocrine tumours

Scintigraphy using [111In-DTPA-d-Phe1]-pentetreotide or pentavalent technetium-99m-dimercaptosuccinic acid [99mTc(V)-DMSA] has been shown to localize well-differentiated and slowly growing neuroendocrine tumours, whereas increased fluorodeoxyglucose (FDG) uptake is associated with malignancy. The aim of this study was to compare the value of fluorine-18 FDG positron emission tomography (PET) with that of somatostatin receptor scintigraphy (SS-R) and dual-radionuclide scintigraphy [SS-R and 99mTc(V)-DMSA = DNS] in detecting malignant neuroendocrine tumours. Fifteen patients with metastasizing gastroenteropancreatic tumours (GEP tumours; n = 7), medullary thyroid carcinomas (MTCs; n = 8) and elevated tumour markers [GEP tumours: 5-hydroxyindoleacetic acid, insulin; MTCs: calcitonin, carcinoembryonic antigen (CEA)] were studied. Prior to PET, all patients with GEP tumours underwent SS-R. DNS was performed in all patients with MTC. Patients had been fasting for at least 12 h and normal glucose plasma levels were confirmed. Sixty minutes after intravenous administration of 18F-FDG (mean: 374 MBq) whole-body PET and regional scans were performed. In addition, the resected tissues were prepared for immunocytochemistry examination (cell cycle-associated Ki-67 antigen). In two patients with less-differentiated GEP tumours associated with high proliferative activity and increased FDG uptake, SS-R failed to detect any lesion. In comparison, in four patients with well-differentiated GEP tumours showing low proliferative activity, SS-R localized four primary tumours, 22 lymph node metastases and 18 malignant liver lesions, whereas 18F-FDG PET demonstrated normal distribution. In one patient with a metastasizing carcinoid (medium proliferative activity) SS-R localized multiple metastases, whereas PET demonstrated low FDG uptake in all known metastases. In patients with recurrent MTC and rapidly increasing CEA levels DNS detected only three lesions in two patients, whereas PET demonstrated one pulmonary, three osseous, 20 mediastinal, ten locoregional, and four liver metastases in seven patients. Twenty-nine malignant lesions were confirmed by follow-up and nine lymph node metastases could be surgically removed. In conclusion, PET imaging of gastroenteropancreatic tumours revealed increased glucose metabolism only in less-differentiated GEP tumours with high proliferative activity and metastasizing MTC associated with rapidly increasing CEA levels. Therefore, additional 18F-FDG PET should be performed only if SS-R or DNS is negative.

Are radiogallium-labelled DOTA-conjugated somatostatin analogues superior to those labelled with other radiometals?

PURPOSE

Gallium-68 is a metallic positron emitter with a half-life of 68 min that is ideal for the in vivo use of small molecules, such as [68Ga-DOTA,Tyr3]octreotide, in the diagnostic imaging of somatostatin receptor-positive tumours. In preclinical studies it has shown a striking superiority over its 111In-labelled congener. The purpose of this study was to evaluate whether third-generation somatostatin-based, radiogallium-labelled peptides show the same superiority.

METHODS

Peptides were synthesised on solid phase. The receptor affinity was determined by in vitro receptor autoradiography. The internalisation rate was studied in AR4-2J and hsst-HEK-transfected cell lines. The pharmacokinetics was studied in a rat xenograft tumour model, AR4-2J.

RESULTS

All peptides showed high affinities on hsst2, with the highest affinity for the Ga(III)-complexed peptides. On hsst3 the situation was reversed, with a trend towards lower affinity of the Ga(III) peptides. A significantly increased internalisation rate was found in sst2-expressing cells for all 67Ga-labelled peptides. Internalisation into HEK-sst3 was usually faster for the 111In-labelled peptides. No internalisation was found into sst5. Biodistribution studies employing [67Ga-DOTA,1-Nal3]octreotide in comparison to [111In-DOTA,1-Nal3]octreotide and [67Ga-DOTA,Tyr3]octreotide showed a significantly higher and receptor-mediated uptake of the two 67Ga-labelled peptides in the tumour and somatostatin receptor-positive tissues. A patient study illustrated the potential advantage of a broad receptor subtype profile radiopeptide over a high-affinity sst2-selective radiopeptide.

CONCLUSION

This study demonstrates that 67/68Ga-DOTA-octapeptides show distinctly better preclinical, pharmacological performances than the 111In-labelled peptides, especially on sst2-expressing cells and the corresponding animal models. They may be excellent candidates for further development for clinical studies.

Early experience with laparoscopic resections of islet cell tumors

BACKGROUND

Diagnostic laparoscopy and laparoscopic ultrasonography have been applied recently for diagnosis and localization of islet-cell tumors. A further step was taken by performing resection of these tumors with laparoscopic techniques.

METHODS AND RESULTS

We studied a retrospective series of 12 patients operated on with laparoscopic techniques since January 1992. The seven female and five male patients had a mean age of 43 years. The mean tumor size was 3 cm. Thirty-six percent of the tumor site could not be identified before operation. Eight patients underwent planned laparoscopic distal pancreatectomy (five insulinomas, two gastrinomas, and one unknown origin), and four underwent planned laparoscopic enucleation (one insulinoma and three unknown origin). Of the eight distal procedures, three had conversions (one inability to localize the tumor and two metastatic gastrinomas). Average operating time was 4.5 hours, with an average hospital stay of 5 days. Of the four explorations for possible enucleation, one was performed and one was converted to a Whipple procedure for nesidioblastoma of the head of the pancreas. The other two had negative explorations. The successful enucleation of an insulinoma of the anterior body of the pancreas was performed in 3 hours, and the hospital stay was 4 days. No recurrence was seen in the enucleated or distal pancreatectomy group in follow-up (15 to 38 months).

CONCLUSIONS

Laparoscopic enucleation or resection of benign islet tumors results in a shorter hospital recovery and is a good alternative to open surgery.

Factors predicting the number of EUS-guided fine-needle passes for diagnosis of pancreatic malignancies

BACKGROUND

The factors that affect the number of needle passes needed to diagnose pancreatic malignancies using endoscopic ultrasound (EUS) -guided fine-needle aspiration are unknown.

METHODS

Patient and endosonographic data were prospectively recorded on 121 consecutive patients with pancreatic malignancy. Of these, 110 underwent EUS-guided fine-needle aspiration. A cytopathologist was in attendance for all aspiration procedures.

RESULTS

Initial EUS detected a pancreatic mass in 96% of cases; 23% of these were not seen by computed tomography. EUS-guided fine-needle aspiration was performed in 109 of 110 (99%) patients, including 95 masses, 7 lymph nodes, and 7 hepatic metastases. EUS-guided fine-needle aspiration provided a cytologic diagnosis of malignancy in 104 of 110 (95%). Only tumor differentiation and the site of aspiration affected the number of passes.

CONCLUSIONS

With the participation of a cytopathologist, EUS-guided fine-needle aspiration can diagnose pancreatic malignancies with a high degree of accuracy. Only the aspiration site (mass versus node/liver metastasis) can be used to direct the number of passes if a cytopathologist is not present. Without a cytopathologist in attendance, 5 to 6 passes should be made for pancreatic masses and 2 to 3 for liver metastases or lymph nodes; however, this approach will be associated with a 10% to 15% reduction in definitive cytologic diagnoses, extra procedure time, increased risk and additional needles.

Endosonography-guided fine needle aspiration biopsy in the evaluation of pancreatic masses

OBJECTIVES

Diagnosis of pancreatic tumors can be problematic. This study aimed to determine the performance of endoscopic ultrasound-guided fine needle aspiration biopsy (EUS FNA) in pancreatic malignancy when prior biopsies performed by CT guidance or ERCP were negative.

METHODS

A total of 185 patients with known or suspected pancreatic masses were prospectively evaluated with EUS FNA. Before EUS FNA, all patients were evaluated with abdominal CT (61 with CT-guided biopsy) and 91 with ERCP (41 had brushings or biopsy).

RESULTS

EUS had greater sensitivity than CT in detecting a mass (99% vs 57%, p < 0.0001). In 58 patients with negative CT-guided biopsies, EUS FNA had 90% sensitivity for malignancy, 50% specificity for benign disease and 84% accuracy. Similarly, in 36 patients with negative ERCP tissue sampling, results for EUS FNA were 94%, 67% and 92%, respectively. Complications were mild and infrequent (0.5%).

CONCLUSION

EUS FNA of pancreatic masses safely and accurately diagnoses pancreatic malignancy when prior biopsy techniques have been unsuccessful.

Endoscopic ultrasound is highly accurate and directs management in patients with neuroendocrine tumors of the pancreas

Preoperative localization of pancreatic neuroendocrine tumors with traditional imaging fails in 40-60% of patients. Endoscopic ultrasound (EUS) is highly sensitive in the detection of these tumors. Previous reports included relatively few patients or required the collaboration of multiple centers. We report the results of EUS evaluation of 82 patients with pancreatic neuroendocrine tumors.

METHODS

We prospectively used EUS early in the diagnostic evaluation of patients with biochemical or clinical evidence of neuroendocrine tumors. Patients had surgical confirmation of tumor localization or clinical follow-up of >1 yr.

RESULTS

Eighty-two patients underwent 91 examinations (cases). Thirty patients had multiple endocrine neoplasia syndrome type 1. One hundred pancreatic tumors were visualized by EUS in 54 different patients. The remaining 28 patients had no pancreatic tumor or an extrapancreatic tumor. Surgical/pathological confirmation was obtained in 75 patients. The mean tumor diameter was 1.51 cm and 71% of the tumors were < or =2.0 cm in diameter. Of the 54 explorations with surgical confirmation of a pancreatic tumor, EUS correctly localized the tumor in 50 patients (93%). Twenty-nine insulinomas, 18 gastrinomas, as well as one glucagonoma, one carcinoid tumor, and one somatostatinoma were localized. The most common site for tumor localization was the pancreatic head (46 patients). Most tumors were hypoechoic, homogenous, and had distinct margins. EUS of the pancreas was correctly negative in 20 of 21 patients (specificity, 95%). EUS was more accurate than angiography with or without stimulation testing (secretin for gastrinoma, calcium for insulinoma), transcutaneous ultrasound, and CT in those patients undergoing further imaging procedures. EUS was not reliable in localizing extrapancreatic tumors.

CONCLUSIONS

In this series, the largest single center experience reported to date, EUS had an overall sensitivity and accuracy of 93% for pancreatic neuroendocrine tumors. Our results support the use of EUS as a primary diagnostic modality in the evaluation and management of patients with neuroendocrine tumors of the pancreas.

Yield of endoscopic ultrasound-guided fine-needle aspiration biopsy in patients with suspected pancreatic carcinoma

BACKGROUND

Although atypical or suspicious cytology may support a clinical diagnosis of a malignancy, it is often not sufficient for the implementation of therapy in patients with pancreatic carcinoma. Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) is a relatively new method for obtaining cytology samples, and one that may decrease the number of atypical/suspicious diagnoses. The goals of the current study were to prospectively evaluate the yield of EUS-FNAB in the diagnosis of patients presenting with solid pancreatic lesions and to evaluate the significance of atypical, suspicious, and false-negative aspirates.

METHODS

All patients who presented with a solid pancreatic lesion and underwent EUS-FNAB over a 13-month period were included in the current study. One endoscopist performed all EUS-FNABs. On-site evaluation of specimen adequacy by a cytopathologist was available for each case. Follow-up included histologic correlation (n = 21) and clinical and/or imaging follow-up (n = 80), including 38 patients who died of the disease.

RESULTS

EUS-FNABs were obtained from 101 patients (mean age, 62 +/- 11.8 years; age range, 34-89 years). The male-to-female ratio was 2:1. Sixty-five percent of the lesions were located in the head of the pancreas, 12% were located in the uncinate, 17% were located in the body, and 6% were located in the tail. The mean size of the tumors was 3.3 cm (range, 1.3-7 cm). A median of 4 needle passes were performed (range, 1-11 needle passes). Sixty-two biopsies (61.4%) were interpreted as malignant on cytologic evaluation, 5 (5%) as suspicious for a malignancy, 6 (5.9%) as atypical/indeterminate, and 26 (25.7%) as benign processes. Of the 76 malignant lesions, 71 were adenocarcinomas, 3 were neuroendocrine tumors, 1 was a lymphoma, and 1 was a metastatic renal cell carcinoma. All except one of the suspicious/atypical aspirates were subsequently confirmed to be malignant. Agreement was complete for the atypical cases. Among the suspicious cases, 2 of the 5 were identified as carcinoma by one cytopathologist and as suspicious lesions by the other, yielding a 40% disagreement rate between the 2 cytopathologists. Therefore, for the 10 atypical or suspicious cases that later were confirmed to be malignant, the final diagnosis of malignant disease was not made due to scant cellularity that could be attributed to sampling error in 8 cases and to interpretative disagreement in 2 cases (20%). All four false-negative diagnoses were attributed to sampling error. Two percent of all biopsies were inadequate for interpretation. Of the 99 adequate specimens, 72 yielded true-positive results, 23 yielded true-negative results, and 4 yielded false-negative results. No false-positives were encountered. Therefore, the sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNAB for solid pancreatic masses were 94.7% (95% confidence interval [CI], 89.7-99.8%), 100%, 100%, and 85.2% (95% CI, 71.8-98.6%), respectively.

CONCLUSIONS

EUS-FNAB is a safe and highly accurate method for tissue diagnosis of patients with solid pancreatic lesions. Patients with suspicious and atypical EUS-FNAB aspirates deserve further clinical evaluation.

Assessment of complications of EUS-guided fine-needle aspiration

BACKGROUND

EUS-guided fine-needle aspiration (EUS-FNA) permits both morphologic and cytologic analysis of lesions within or adjacent to the GI tract. Despite increasing use of this technique, the safety and overall complication rates remain poorly defined.

METHODS

During a period of 20 months, 322 consecutive patients underwent EUS-FNA in 2 centers. All procedures were performed with the patients under general anesthesia. All complications (including local complications resulting from endoscopy/aspiration or clinical complications after the procedure) were evaluated. Potential risk factors for the development of complications were also analyzed including site and nature of the lesion, presence of portal hypertension, and number of needle passes.

RESULTS

A total of 345 lesions were aspirated in 322 patients. EUS-FNA involved the pancreas in 248 cases. Pancreatic lesions included solid (134) and cystic (114) types, which required a mean of 2.5 and 1.4 needle passes, respectively. Complications were observed in 4 (1.2%) patients after aspiration of pancreatic cystic lesions (acute pancreatitis, n = 3; aspiration pneumonia, n = 1) and all cases of pancreatitis resulted from FNA of lesions in the head/uncinate process. No complications resulted from FNA of solid pancreatic lesions. Complications were not observed after FNA of lymph nodes (n = 62) and one case of aspiration pneumonia was observed after FNA of a stromal tumor. EUS-FNA was performed without complication in 16 patients (5%) with portal hypertension. The number of needle passes was not predictive of complications.

CONCLUSIONS

Because the overall risk of complications from EUS-FNA was relatively low (1.6%) with no severe or fatal incidents and although the risk appears slightly higher than that for standard EUS alone, the safety of EUS-FNA appears acceptable based on this analysis from an experienced center.

Issues in respiratory motion compensation during external-beam radiotherapy

PURPOSE

To investigate how respiration influences the motion of lung and pancreas tumors and to relate the observations to treatment procedures intended to improve dose alignment by predicting the moving tumor's position from external breathing indicators.

METHODS AND MATERIALS

Breathing characteristics for five healthy subjects were observed by optically tracking the displacement of the chest and abdomen, and by measuring tidal air volume with a spirometer. Fluoroscopic imaging of five radiotherapy patients detected the motion of lung and pancreas tumors synchronously with external breathing indicators.

RESULTS

The external and fluoroscopic data showed a wide range of behavior in the normal breathing pattern and its effects on the position of lung and pancreas tumors. This included transient phase shifts between two different external measures of breathing that diminished to zero over a period of minutes, modulated phase shifts between tumor and chest wall motion, and other complex phenomena.

CONCLUSIONS

Respiratory compensation strategies that infer tumor position from external breathing signals, including methods of beam gating and dynamic beam tracking, require three-dimensional knowledge of the tumor's motion trajectory as well as the ability to detect and adapt to transient and continuously changing characteristics of respiratory motion during treatment.

Endoscopic ultrasound in pancreatic tumor diagnosis

In a prospective study from 1988 to 1990, 132 patients with suspected pancreatic tumor were examined with endoscopic ultrasound (EUS), transabdominal ultrasound (US), computed tomography (CT), and ERCP. The final diagnosis of 102 pancreatic tumors of different origin (76 malignant and 26 inflammatory tumors) and the exclusion of a pancreatic tumor in 30 patients was made by operation (N = 47), puncture (N = 36), autopsy (N = 3), or follow-up of a mean of 51 weeks (N = 46). Sensitivity and specificity in pancreatic tumor diagnosis were significantly higher for EUS (99% and 100%) than for US (67%/40%) and CT (77%/53%) and equal to ERCP (sensitivity 90%). This was even more obvious in small pancreatic tumors of 3 cm and less. However, as with the other imaging procedures, EUS was not able to differentiate reliably malignant from inflammatory pancreatic masses (accuracy 76% for malignancy and 46% for focal inflammation). From analysis of the endosonographic pattern of pancreatic tumors, no consistent morphologic features were identified which could have been specifically attributed to malignant or inflammatory masses. Our results show that EUS is superior to US and CT and equal to ERCP in pancreatic tumor diagnosis. In contrast to the indirect evidence obtained by ERCP, EUS provides direct visualization of tumor size and shape in almost all patients examined. Thus, EUS should be considered early in the evaluation of patients with suspected pancreatic tumors.

Fine-needle aspiration cytology guided by endoscopic ultrasonography: results in 141 patients

BACKGROUND AND STUDY AIMS

Diagnosis of submucosal lesions, pancreatic tumors, and mediastinal or celiac lymph nodes or masses is possible using endoscopic ultrasonography (EUS), but histological confirmation to differentiate between benign and malignant lesions is still required. The aim of this study was to evaluate the efficacy of a new method of EUS-guided fine-needle aspiration biopsy of intramural and paramural lesions.

PATIENTS AND METHODS

From October 1991 to September 1994, EUS-guided fine-needle aspiration biopsy was carried out in 141 patients with findings of mediastinal masses (18 cases), mediastinal lymph nodes (24 cases), submucosal tumors (seven cases), celiac lymph nodes (26 cases), large gastric folds with negative endoscopic biopsy (13 cases), pancreatic tumors (43 cases), a small liver metastasis (five cases), retrorectal tumors (four cases), and an adrenal metastasis (one case). The EUS examination was performed using a Pentax-Hitachi FG 32-UA system.

RESULTS

A malignant tumor was diagnosed in 110 of the 141 patients. EUS-guided fine-needle aspiration was positive in 85 cases. In 15 cases, an adequate specimen could not be obtained (10.6%). The sensitivity and specificity of the diagnosis of malignancy were 77.0% and 100%, respectively. Results were better for mediastinal masses (sensitivity 88%), mediastinal lymph nodes (81%), and celiac lymph nodes (80%) than for pancreatic tumors (75%) or submucosal tumors (60%).

CONCLUSIONS

These results suggest that EUS-guided fine-needle biopsy using a curved-array transducer represents a step forward in the tissue diagnosis of gastrointestinal lesions.