Defining the Functional Sensitivity for The Siemens Atellica Calcitonin Assay: Insight from A Single-center Study.

BACKGROUND

Detectable, and especially rising post-thyroidectomy serum calcitonin and Carcinoembryonic Antigen (CEA) levels, as per American Thyroid Association (ATA) guidelines, indicate potential disease presence, requiring frequent calcitonin measurement or imaging for early detection of persistent or recurrent Medullary Thyroid Carcinoma (MTC). Thus, defining the clinical cutoff value of detection of calcitonin assays relative to imaging and clinical status is crucial for patient care. This study aimed to evaluate postoperative calcitonin levels using the new Siemens Atellica assay system to determine the most appropriate levels for clinical decision-making.

METHODS

A retrospective analysis was conducted using Siemens Atellica for calcitonin testing on 56 samples from 40 patients between 09/27/2022 and 08/11/2023. Only calcitonin results performed at least 3 months post-total thyroidectomy were included. Imaging studies, within 6 months of the calcitonin report, were assessed. CEA results were also reviewed.

RESULTS

Precision analysis at 2.94 and 5.24 pg/mL revealed coefficients of variation (CVs) at 16.49% and 8.87%, respectively. For the evidence of post-total thyroidectomy persistent or recurrent MTC confirmed by imaging, using a 1.89 pg/mL cutoff for calcitonin yielded 43% sensitivity and 67% specificity. Using a 5.00 pg/mL cutoff resulted in 0% sensitivity and 100% specificity.

CONCLUSIONS

Our findings indicate the potential suitability of a 5 pg/mL calcitonin cutoff on the Siemens Atellica platform for evaluating tumor persistence or recurrence in post-thyroidectomy patients in our institution. However, individual laboratories should establish their own clinical cutoff value when evaluating calcitonin levels for monitoring tumor recurrence post-thyroidectomy.

Informations de copyright

Copyright © 2024. Published by Elsevier Inc.