Domenico Albano1, Mark Tulchinsky2, Francesco Dondi3, Angelica Mazzoletti3, Davide Lombardi4, Francesco Bertagna3, Raffaele Giubbini3. 1. Nuclear Medicine, University of Brescia and Spedali Civili Brescia, P.le Spedali Civili 1, 25123, Brescia, Italy. doalba87@libero.it. 2. Section of Nuclear Medicine, Department of Radiology, Milton S. Hershey Medical Center, Penn State Health, Hershey, PA, USA. 3. Nuclear Medicine, University of Brescia and Spedali Civili Brescia, P.le Spedali Civili 1, 25123, Brescia, Italy. 4. Department of Otorhinolaryngology - Head and Neck Surgery, University of Brescia, Brescia, Italy.
Abstract
PURPOSE: To investigate the potential role of serum thyroglobulin doubling time (TgDT) in predicting 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) PET/CT results in patients affected by differentiated thyroid carcinoma (DTC) who demonstrated a combination of positive Tg but a negative [131I] whole-body scan ([131I]-WBS). MATERIALS AND METHODS: Inclusion criteria were (1) prior [131I] treatment for DTC, (2) negative subsequent [131I]-WBS, (3) no interfering anti-Tg antibodies, (4) three consecutive Tg measurements under the thyroid hormone replacement therapy to calculate TgDT before 2-[18F]FDG PET/CT, and (5) at least 6 months of clinical and/or imaging follow-up to ascertain the diagnosis. Receiver operating characteristic (ROC) curve and the area under the curve (AUC) were used to identify the optimal cutoff point for the last stimulated Tg and TgDT prior to [18F]FDG PET/CT. RESULTS: One hundred and thirteen patients were included. Seventy-four (65%) patients had positive [18F]FDG PET/CT for DTC recurrence, while the remaining 39 (35%) negative. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of [18F]FDG PET/CT were 92%, 94%, 97%, 87%, and 93%. Patients with positive [18F]FDG PET/CT had higher Tg and TgDT than those with negative PET/CT. ROC curve analysis revealed an optimal Tg cutoff of 19 ng/mL (sensitivity 78%, specificity 85%, AUC = 0.844) and TgDT of 2.5 years (sensitivity 93%, specificity 87%, AUC = 0.911). TgDT threshold of 2.5 years predicted significantly (p = 0.023) better than Tg level PET/CT results. CONCLUSIONS: The diagnostic performance of [18F]FDG PET/CT could be significantly improved when TgDT is less than or equal to 2.5 years, as compared with using the absolute Tg level.
PURPOSE: To investigate the potential role of serum thyroglobulin doubling time (TgDT) in predicting 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) PET/CT results in patients affected by differentiated thyroid carcinoma (DTC) who demonstrated a combination of positive Tg but a negative [131I] whole-body scan ([131I]-WBS). MATERIALS AND METHODS: Inclusion criteria were (1) prior [131I] treatment for DTC, (2) negative subsequent [131I]-WBS, (3) no interfering anti-Tg antibodies, (4) three consecutive Tg measurements under the thyroid hormone replacement therapy to calculate TgDT before 2-[18F]FDG PET/CT, and (5) at least 6 months of clinical and/or imaging follow-up to ascertain the diagnosis. Receiver operating characteristic (ROC) curve and the area under the curve (AUC) were used to identify the optimal cutoff point for the last stimulated Tg and TgDT prior to [18F]FDG PET/CT. RESULTS: One hundred and thirteen patients were included. Seventy-four (65%) patients had positive [18F]FDG PET/CT for DTC recurrence, while the remaining 39 (35%) negative. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of [18F]FDG PET/CT were 92%, 94%, 97%, 87%, and 93%. Patients with positive [18F]FDG PET/CT had higher Tg and TgDT than those with negative PET/CT. ROC curve analysis revealed an optimal Tg cutoff of 19 ng/mL (sensitivity 78%, specificity 85%, AUC = 0.844) and TgDT of 2.5 years (sensitivity 93%, specificity 87%, AUC = 0.911). TgDT threshold of 2.5 years predicted significantly (p = 0.023) better than Tg level PET/CT results. CONCLUSIONS: The diagnostic performance of [18F]FDG PET/CT could be significantly improved when TgDT is less than or equal to 2.5 years, as compared with using the absolute Tg level.
Authors: Zubair Baloch; Pierre Carayon; Bernard Conte-Devolx; Laurence M Demers; Ulla Feldt-Rasmussen; Jean-François Henry; Virginia A LiVosli; Patricia Niccoli-Sire; Rhys John; Jean Ruf; Peter P A Smyth; Carole A Spencer; Jan R Stockigt Journal: Thyroid Date: 2003-01 Impact factor: 6.568
Authors: Domenico Albano; Francesco Dondi; Angelica Mazzoletti; Pietro Bellini; Carlo Rodella; Francesco Bertagna Journal: Diagnostics (Basel) Date: 2021-11-25