ORIGINAL ARTICLES   

The Quarterly Journal of Nuclear Medicine and Molecular Imaging 2004 September;48(3):237-42

Copyright © 2009 EDIZIONI MINERVA MEDICA

language: English

Comparative evaluation of two methods to assay thyroglobulin serum concentrations in patients with differentiated thyroid carcinomas

Ferrari L. ¹, Seregni E. ¹, Aliberti G. ¹, Martinetti A. ¹, Pallotti F. ¹, Villano C. ¹, Lucignani G. ², Bombardieri E. ¹

¹ Nuclear Medicine Division Radioisotope Laboratory Istituto Nazionale per lo Studio e la Cura dei Tumori, Milan, Italy 2 Institute of Radiological Sciences University of Milan, Unit of Molecular Imaging Division of Radiation Therapy European Institute of Oncology, Milan, Italy

Aim. This ­study was ­aimed at the com­par­a­tive assess­ment of the ana­lyt­i­cal and clin­i­cal per­for­manc­es of 2 ­tests for thyroglobulin (Tg) ­assays: the Dynotest Tg-Plus immu­nor­a­di­o­met­ric ­assay (­IRMA), a new meth­od ­that ­might be of inter­est for its ­claimed super­i­or sen­si­tiv­ity com­pared to oth­er meth­ods, and the ­HTGK-2 ­IRMA, one of the ­test cur­rent­ly ­used in clin­i­cal rou­tine.
Methods. The ­study was per­formed in ser­um sam­ples ­from 157 ­patients ­with dif­fer­en­tiat­ed thy­roid car­ci­no­ma (DTC). The clin­i­cal sen­si­tiv­ity of the ­test was eval­u­at­ed in ­patients ­with and with­out thy­roid stim­u­lat­ing hor­mone (TSH) sup­pres­sion.
Results. The low­est detect­able Tg con­cen­tra­tion val­ues and the with­in-­assay coef­fi­cient of vari­a­tion (CV) ­were 0.4 and 0.8 µg/L and 5% and 3% for the Dynotest Tg-Plus ­assay and the ­HTGK-2 ­assay, respec­tive­ly; the ­between-­assay CV was 6% for ­both ­assays. The clin­i­cal ­results of the Dynotest Tg-Plus and ­those of the ­HTGK-2 kit ­were sim­i­lar in ­both DTC ­patient pop­u­la­tions, ­either ­under or off the TSH sup­pres­sive treat­ment. In ­spite of the ­manufacturer’s state­ment ­that the cal­i­bra­tors of ­both ­assays had ­been stan­dard­ized ­against the ­same com­mon ref­er­ence (stan­dard CRM 457 of the Community Bureau of References), the Dynotest Tg-Plus ­test under­rat­ed by a fac­tor of 0.5 the Tg val­ues meas­ured by ­means of ­HTGK-2 ­IRMA.