The diagnostic efficacy of urinary fractionated metanephrines measured by tandem mass spectrometry in detection of pheochromocytoma.
Clin Endocrinol (Oxf)
; 66(5): 703-8, 2007 May.
Article
in En
| MEDLINE
| ID: mdl-17388796
ABSTRACT
BACKGROUND:
There are limitations to currently available biochemical tests for pheochromocytoma. Our objective was to evaluate the diagnostic efficacy of a novel tandem mass spectrometry assay for the measurement of fractionated urinary metanephrines in patients suspected to have a pheochromocytoma. We also developed clinically based cut-offs for positivity of this measurement.METHODS:
We examined the medical records of 506 patients (including 102 patients with a catecholamine-producing tumour) who underwent measurement of 24-h urinary fractionated metanephrines using tandem mass spectrometry as well as adrenal imaging at Mayo Clinic, Rochester. The cut-offs for positivity were defined as follows total metanephrines (sum of the metanephrine fractions) 5163 nmol/day, normetanephrine fraction 4001 nmol/day, metanephrine fraction 1531 nmol/day. Receiver operating characteristic (ROC) curves were constructed.RESULTS:
The diagnostic efficacy was as follows normetanephrine fraction sensitivity 87.3% [(95% confidence interval (CI) 79.4-92.4%], specificity 95.0% (92.5-96.8); metanephrine fraction sensitivity 56.9% (47.2-66.1), specificity 95.0% (92.5-96.8); elevation of either normetanephrine or metanephrine fraction sensitivity 97.1% (91.7-99.0) and specificity 91.1% (87.9-93.5). Areas under the ROC curves (AUCs) were 0.972 (95% CI 0.955-0.990) for the normetanephrine fraction, 0.800 (0.741-0.858) for the metanephrine fraction, 0.991 (0.985-0.996) for total metanephrines, and 0.991 (0.985-0.996) for a regression-derived ROC curve incorporating both the metanephrine and normetanephrine fractions.CONCLUSION:
Measurement of 24-h urinary fractionated metanephrines by a tandem mass spectrometry assay appears to be an effective biochemical technique in the investigation of pheochromocytoma.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pheochromocytoma
/
Metanephrine
/
Biomarkers, Tumor
/
Adrenal Gland Neoplasms
/
Tandem Mass Spectrometry
Type of study:
Diagnostic_studies
/
Evaluation_studies
/
Observational_studies
/
Prognostic_studies
Limits:
Adolescent
/
Adult
/
Aged
/
Aged80
/
Child
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Clin Endocrinol (Oxf)
Year:
2007
Document type:
Article
Affiliation country: