Simple, rapid, and cost-effective microextraction by the packed sorbent method for quantifying of urinary free catecholamines and metanephrines using liquid chromatography-tandem mass spectrometry and its application in clinical analysis.

Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors arising from adrenal and extra-adrenal chromaffin cells. They produce excessive amounts of catecholamines and their metabolites. A newly analytical procedure based on the semi-automated microextraction by packed sorbent (MEPS) technique, using a digitally controlled syringe (eVol) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS), was developed to quantify free urinary catecholamines and metanephrines. The important parameters affecting MEPS performance, namely the type of sorbent material (porous graphitized carbon (PGC), polar enhanced polymer (PEP), cation-exchange (CX) and C18), number of extraction cycles, and elution solvent system, were evaluated. The optimal experimental conditions involved the loading of sample mixture in seven extraction cycles through a C18 sorbent in a MEPS syringe, followed by using elution solutions (water/acetonitrile/formic acid, 95/4.75/0.25). The entire sample preparation took about 4 min. Chromatographic separation was well achieved with an HSS PFP column using the gradient elution. The linearity range of the method was 0.167-33.4 ng/mL for epinephrine, 0.650-130 ng/mL for norepinephrine, 1.53-306 ng/mL for dopamine, 1.34-268 ng/mL for metanephrine, 3.43-686 ng/mL for normetanephrine, and 1.33-265 ng/mL for 3-methoxytyramine. The intra- and interassay precisions were ≤ 12.8%, and the respective accuracies were 88.4-112.0% and 89.0-109.5%. The carryover and sample stability without acidification were also investigated. Validation using clinical urine specimens showed that the proposed method had higher sensitivity compared with other urinary biochemical tests. The developed MEPS-LC-MS/MS method was simple, fast, and cost-effective; it helped to obtain information about multiple metabolites. It is applicable in routine clinical laboratories for the screening of PPGL. Graphical abstract.

Short-term outcomes and cost of care of treatment of head and neck paragangliomas.

OBJECTIVES/HYPOTHESIS: To characterize contemporary treatment of head and neck paragangliomas and the effect of treatment on postoperative complications, length of stay, and costs. STUDY DESIGN: Retrospective cross-sectional study. METHODS: Discharge data from the Nationwide Inpatient Sample for 7,791 patients who underwent endovascular or surgical treatment of head and neck paragangliomas between 1993 and 2008 were analyzed using cross tabulations and multivariate regression modeling. RESULTS: Surgery only was performed in 91% of cases, embolization alone was performed in 4% of cases, and both embolization and surgery were performed in 5% of cases. Postoperative surgical complications were significantly more likely in patients undergoing embolization and surgery during the same admission (odds ratio [OR], 2.3; P = .031), whereas acute medical complications were more likely in patients undergoing embolization only (OR, 3.9; P = .001). Embolization alone was specifically associated with an increased risk of acute renal failure (OR, 8.2; P = .026) and pneumonia (OR, 3.9; P = .001). Cranial nerve injury was associated with increased odds of dysphagia (OR, 8.5; P = .004), and dysphagia was associated with increased odds of voice disturbance (OR, 5.1; P = .004). Embolization, with or without surgery during the same admission, was associated with significantly increased hospital-related costs, after controlling for all other variables. CONCLUSIONS: Endovascular treatment of head and neck paragangliomas is associated with an increase in complications and hospital-related costs. Although these findings may reflect larger tumor size and comorbidity in patients selected for embolization, these data suggest a need to reexamine the benefits and cost-effectiveness of embolization in surgical patients.

A comprehensive next generation sequencing-based genetic testing strategy to improve diagnosis of inherited pheochromocytoma and paraganglioma.

CONTEXT: Pheochromocytomas and paragangliomas are notable for a high frequency of inherited cases, many of which present as apparently sporadic tumors. OBJECTIVE: The objective of this study was to establish a comprehensive next generation sequencing (NGS)-based strategy for the diagnosis of patients with pheochromocytoma and paraganglioma by testing simultaneously for mutations in MAX, RET, SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, and VHL. DESIGN: After the methodology for the assay was designed and established, it was validated on DNA samples with known genotype and then patients were studied prospectively. SETTING: The study was performed in a diagnostic genetics laboratory. PATIENTS: DNA samples from 205 individuals affected with adrenal or extraadrenal pheochromocytoma/head and neck paraganglioma (PPGL/HNPGL) were analyzed. A proof-of-principle study was performed using 85 samples known to contain a variant in 1 or more of the genes to be tested, followed by prospective analysis of an additional 120 samples. MAIN OUTCOME MEASURES: We assessed the ability to use an NGS-based method to perform comprehensive analysis of genes implicated in inherited PPGL/HNPGL. RESULTS: The proof-of-principle study showed that the NGS assay and analysis gave a sensitivity of 98.7%. A pathogenic mutation was identified in 16.6% of the prospective analysis cohort of 120 patients. CONCLUSIONS: A comprehensive NGS-based strategy for the analysis of genes associated with predisposition to PPGL and HNPGL was established, validated, and introduced into diagnostic service. The new assay provides simultaneous analysis of 9 genes and allows more rapid and cost-effective mutation detection than the previously used conventional Sanger sequencing-based methodology.

Cost-effectiveness analysis of somatostatin receptor scintigraphy.

UNLABELLED: We analyzed the results of conventional imaging and somatostatin receptor scintigraphy in 150 patients with neuroendocrine tumors. METHODS: The outcomes of combinations of imaging modalities were compared in terms of tumor localization, effect on patient management and financial costs. RESULTS: In patients with carcinoids, a combination of somatostatin receptor scintigraphy, chest radiograph and ultrasound of the upper abdomen had a high sensitivity for tumor localization, and detected lesions in patients in whom no tumor was found with conventional imaging, justifying the greater cost. In patients with medullary thyroid carcinoma, somatostatin receptor scintigraphy adds little to the information obtained with conventional imaging and therefore should not be used as a screening method. In patients with paraganglioma, CT scanning of the region where a paraganglioma is suspected, followed by somatostatin receptor scintigraphy to detect multicentricity has the best cost effectiveness ratio. In patients with gastrinomas, the combination of somatostatin receptor scintigraphy and CT scanning of the upper abdomen had the highest sensitivity. The relatively high cost of this process is outweighed by its demonstrating a resectable tumor. In patients with insulinomas, the highest yield against the lowest cost is obtained if somatostatin receptor scintigraphy is only performed if CT scanning fails to demonstrate the tumor. CONCLUSIONS: Somatostatin receptor scintigraphy should be performed in patients with small-cell lung carcinoma because it can lead to a change of stage and may demonstrate otherwise undetected brain metastases. The cost increase is outweighed by the omission of unnecessary treatment for some of the patients and by the possibility of irradiating brain metastases at an early stage, which may lead to a better quality of life.