title: High-sensitive basal serum thyroglobulin 6-12 months after thyroid ablation is strongly associated with early response to therapy and event-free survival in patients with low-to-intermediate risk differentiated thyroid carcinomas.
abstract: OBJECTIVE
  High-sensitive thyroglobulin assays (hsTg) has decreased the need for stimulated Tg measurements in patients with differentiated thyroid carcinoma (DTC). However, multiple assays analyzing the same samples may report different values. Accordingly, appropriate assay-specific cut-off levels should be selected in representative patient series. Here, we evaluate the role of a new hsTg assay in low-to-intermediate risk DTC patients and select appropriate assay-specific clinical cut-off limits.
  
  
  METHODS
  This was a retrospective study. The response to treatment was assessed according to ATA.
  
  
  METHODS
  Patients with low-to-intermediate risk DTC treated and regularly followed-up in our thyroid center. Tg was measured on the Kryptor Compact Plus Instrument (BRAHMS Thermo Fisher Scientific).
  
  
  RESULTS
  The study series comprised 201 DTC patients and excellent response (ER) was demonstrated in 184 (91.5%). Optimized threshold of basal Tg (onT4-Tg) measured 6-12 months after initial treatment was set by ROC curves analysis at 0.28 ng/mL. Having onT4-Tg <0.28 ng/mL at 6-12 months after treatment was associated with longer disease-free survival of Kaplan-Meier (P <0.001), ER at early follow-up (odds ratio (OR): 165,P <0.001) and absence of relapse during follow-up (OR: 328,P= 0.0001).
  
  
  CONCLUSIONS
  Patients with low- and intermediate-risk DTC could be considered cured when they have onT4-Tg levels <0.28 ng/mL coupled with negative imaging at their first post-ablation visit.
authors.affiliation: Department of Nuclear Medicine and Thyroid CentreOncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Trimboli
authors.affiliation: Department of Nuclear MedicineBolzano Regional Hospital, Bolzano, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Zilioli
authors.affiliation: Department of Laboratory MedicineEnte Ospedaliero Cantonale, Bellinzona, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Imperiali
authors.affiliation: Department of Nuclear Medicine and Thyroid CentreOncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Ceriani
authors.affiliation: Department of Nuclear Medicine and Thyroid CentreOncology Institute of Southern Switzerland, Bellinzona, Switzerland.|Department of Laboratory MedicineEnte Ospedaliero Cantonale, Bellinzona, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Giovanella
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D002454:Cell Differentiation / Q000502:physiology; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053685:Laser Therapy / Q000639:trends*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013954:Thyroglobulin / Q000097:blood*; D013964:Thyroid Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D013954:Thyroglobulin