Undetectable or low (<1 ng/ml) postsurgical thyroglobulin values do not rule out metastases in early stage differentiated thyroid cancer patients

Alfredo Campennì; Luca Giovanella; Salvatore Antonio Pignata; Antonio Vento; Angela Alibrandi; Letterio Sturiale; Riccardo Laudicella; Alessio Danilo Comis; Rossella Filice; Giuseppe Giuffrida; Maria Elena Stipo; Salvatore Giovinazzo; Francesco Trimarchi; Rosaria Maddalena Ruggeri; Sergio Baldari

doi:10.18632/oncotarget.24766

Undetectable or low (<1 ng/ml) postsurgical thyroglobulin values do not rule out metastases in early stage differentiated thyroid cancer patients

Oncotarget. 2018 Apr 3;9(25):17491-17500. doi: 10.18632/oncotarget.24766.

Authors

Alfredo Campennì¹, Luca Giovanella², Salvatore Antonio Pignata¹, Antonio Vento¹, Angela Alibrandi³, Letterio Sturiale¹, Riccardo Laudicella¹, Alessio Danilo Comis¹, Rossella Filice¹, Giuseppe Giuffrida⁴, Maria Elena Stipo¹, Salvatore Giovinazzo⁴, Francesco Trimarchi⁵, Rosaria Maddalena Ruggeri⁴, Sergio Baldari¹

Affiliations

¹ Department of Biomedical and Dental Sciences and Morpho-Functional Imaging, Nuclear Medicine Unit, University of Messina, Messina, Italy.
² Nuclear Medicine and PET/CT Centre, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
³ Department of Economical, Business and Environmental Sciences and Quantitative Methods, University of Messina, Messina, Italy.
⁴ Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Messina, Messina, Italy.
⁵ Accademia Peloritana dei Pericolanti, University of Messina, Messina, Italy.

Abstract

Background: Differentiated thyroid cancer (DTC) work-up is based on (near)total-thyroidectomy plus thyroid remnant ablation (TRA) with 131-radioiodine in many patients, and long-life follow-up. ¹³¹I-post therapy whole body scan (pT-WBS) and serum thyroglobulin (Tg) are used in identifying metastatic patients. Some authors have evaluated the possibility of using post-surgical Tg (ps-Tg) values in deciding for or against TRA. The aim of our study was to verify the diagnostic accuracy of ¹³¹I-pT-WBS and SPECT/CT imaging (post-therapeutic imaging) compared to serum Tg levels in detecting metastases in early stage of DTC patients.

Results: Post-therapeutic imaging revealed metastases in 82 out of 570 (14.4%) patients. Metastases were successively confirmed by other diagnostic tools or by histology (sensitivity and PPV = 100%). Seventy-three out of 82 patients (90.2%) showed ps-Tg levels ≤1 ng/ml. In fifty-four per cent of patients, serum Tg levels at TRA remained ≤1 ng/ml.

Conclusion: In conclusion, ps-Tg levels cannot be used in deciding for or against TRA. In early stage of DTC, post-therapeutic imaging (¹³¹I-pT-WBS and SPECT/CT) is an accurate method of detecting metastases, also in patients with stimulated serum Tg values ≤1 ng/ml.

Methods: We retrospectively reviewed the records of 570 consecutive patients affected by pT1-pT3 DTC (F = 450, M = 120), referred to our Nuclear Medicine Units in the last five years to perform TRA after (near)-total-thyroidectomy.All patients underwent TRA 3-4 months after thyroid surgery either in euthyroid or in hypothyroid state. Serum Tg values evaluated in post-surgical period and at TRA were matched with post-therapeutic imaging results.

Keywords: 131-radioiodine thyroid remnant ablation; 131-radioiodine treatment; differentiated thyroid cancer; post-therapy whole body scintigraphy; thyroglobulin.