Diagnostic Value of Recombinant Human Thyrotropin–Stimulated 123I Whole-Body Scintigraphy in the Follow-Up of Patients With Differentiated Thyroid Cancer

• Published in: Clinical nuclear medicine 2012-03, Vol.37 (3), p.229-234
• Main Authors: Alzahrani, Ali S, AlShaikh, OmAlkhaire, Tuli, Mahmoud, Al-Sugair, Abdulaziz, Alamawi, Reem, Al-Rasheed, Maha M
• Format: Article
• Language: English
• Subjects: Biomarkers, Tumor - blood; Biopsy; Chi-Square Distribution; Female; Follow-Up Studies; Humans; Iodine Radioisotopes; Luminescent Measurements; Male; Middle Aged; Multimodal Imaging; Neoplasm Recurrence, Local - diagnostic imaging; Neoplasm, Residual - diagnostic imaging; Positron-Emission Tomography; Predictive Value of Tests; Recombinant Proteins; Retrospective Studies; Sensitivity and Specificity; Statistics, Nonparametric; Thyroglobulin - blood; Thyroid Neoplasms - blood; Thyroid Neoplasms - diagnostic imaging; Thyroid Neoplasms - pathology; Thyroid Neoplasms - surgery; Thyroidectomy; Thyrotropin; Tomography, X-Ray Computed; Whole Body Imaging
• ISSN: 0363-9762; 1536-0229
• DOI: 10.1097/RLU.0b013e31823ea463

PURPOSE:Published data on recombinant human thyrotropin- (rhTSH-) stimulated iodine-123 (I) diagnostic whole-body scintigraphy (DxWBS) in differentiated thyroid cancer (DTC) surveillance after initial treatment are limited. We sought to evaluate this modalityʼs diagnostic value in this setting. MATERIALS AND METHODS:We retrospectively compared rhTSH-stimulated I DxWBS results with DTC status concurrently determined by stimulated serum thyroglobulin (Tg) measurement, neck ultrasonography, and other imaging studies. Disease was considered present based on stimulated Tg level ≥1 μg/L without interfering Tg autoantibodies with or without positive imaging or biopsy-proven DTC. We also compared scan positivity and disease detection rates of rhTSH-stimulated DxWBS scans obtained with I with those acquired with iodine-131 (I) during the same period. The sample comprised 105 consecutive totally thyroidectomized patients undergoing rhTSH-aided DxWBS with I-123 (n = 67) or with I (n = 38) for diagnostic follow-up. rhTSH, 0.9 mg/d, was injected intramuscularly on 2 consecutive days. Oral diagnostic activities of 5 to 10 mCi (185–370 MBq) I or 3 mCi (111 MBq) I were given on the third day. DxWBS was performed 24 hours (I) or 48 to 72 hours (I) later. RESULTS:rhTSH-aided I DxWBS scans showed 35.3% sensitivity, 98.0% specificity, 85.7% positive predictive value, and 81.6% negative predictive value. rhTSH-stimulated I and I DxWBS did not differ in scan positivity (10.4% vs. 13.2%, P = 0.75) or disease detection rates (35.3% vs. 27.8%, P = 1.00). CONCLUSIONS:In DTC, rhTSH-aided I DxWBS achieves comparable results in diagnostic follow-up with those of rhTSH-aided I DxWBS. Future studies should address the preablation setting and scan activity and timing.