2026 · Analytical and bioanalytical chemistry · paywalled
Development and validation of an LC-MS/MS method for the comprehensive quantification of tamoxifen and its metabolites in volumetric absorptive microsampling: clinical application in breast cancer patients
Kuo et al.
The finding, in our words
An LC-MS/MS method for tamoxifen and six metabolites in VAMS was developed and validated, with water prerinsing improving recoveries and poor room temperature stability but stability for at least 100 days at minus 80 degrees Celsius. Plasma to blood ratios were used to estimate plasma equivalent concentrations, and paired VAMS and plasma samples from ten breast cancer patients showed strong correlations and good agreement on Bland-Altman analysis, supporting reliable decentralised TDM.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
Microsampling with Mitra® devices correlated strongly with venous plasma for capecitabine therapeutic drug monitoring (r=0.97), but yielded consistently lower concentrations. Patients preferred this method and reported minimal pain, suggesting it is suitable for patient-centric oncology drug monitoring in decentralised settings.
Capillary blood collected with the Mitra® device showed correlation with venous samples for paclitaxel therapeutic drug monitoring, but wide confidence intervals suggest the methods may not be interchangeable. While plasma and whole blood concentrations were more closely aligned, the variability raises questions about using self-collected capillary samples for dose individualisation without further validation.
The authors validated an LC-MS and LC-MS/MS method for quantifying axitinib from 10 microlitre capillary blood collected by VAMS, demonstrating within- and between-run precision within 14% CV and accuracy between 81 and 116% against plasma as the gold standard, making the approach suitable for therapeutic drug monitoring in ambulatory and clinical care.
The study validated an LC-MS/MS method for measuring eight tyrosine kinase inhibitors in dried blood samples collected via VAMS, showing good accuracy, precision and haematocrit independence. It demonstrated agreement with venous sampling, supporting the use of decentralised, patient-centric microsampling for oncology drug monitoring.
Volumetric absorptive microsampling (VAMS) using the Neoteryx Mitra device was validated for mitotane therapeutic drug monitoring across 1–50 mg/L, with acceptable haematocrit bias and one-week stability at room temperature. However, comparison with venous plasma showed poor correlation, suggesting home-based VAMS is of limited clinical value for mitotane unless a method-specific target range is established.