A Battle of Technologies: Immunoassay or Mass Spectrometry Testing for Therapeutic Drug Monitoring.

The rise in use of newer generation therapeutic drug monitoring drug candidates is driving an increase in testing demands, leading many institutions currently sending these tests out to reference laboratories to consider bringing this testing volume in-house. In terms of assay performance, many currently available immunoassays are comparable to liquid chromatography-mass spectrometry, which is considered the gold standard. Thus, institutions with capacity for mass spectrometry testing are faced with a more complex laboratory stewardship decision. Achieving the balance among cost, turnaround time, frequency of testing, and clinical utility of test results is a unique process for each institution.