ORIGINAL ARTICLE APPLICATION OF POST-SURGICAL STIMULATED THYROGLOBULIN FOR RADIOIODINE REMNANT ABLATION SELECTION IN LOW-RISK PAPILLARY THYROID CARCINOMA Alon Vaisman, HBSc, 1 Steven Orlov, BSc, 1 Jonathan Yip, HBSc, 1 Cindy Hu, HBSc, 1 Terence Lim, HBSc, 1 Mark Dowar, HBSc, 1 Jeremy L. Freeman, MD, FRCS(C), 2 Paul G. Walfish, MD, FRCP(C) 1,2 1 Department of Medicine, Endocrine Division, Mount Sinai Hospital and University of Toronto Medical School, Toronto, Ontario, Canada. E-mail: walfish@mshri.on.ca 2 Department of Otolaryngology, Head and Neck Surgery, Mount Sinai Hospital and University of Toronto Medical School, Toronto, Ontario, Canada Accepted 18 December 2009 Published online 24 February 2010 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/hed.21371 Abstract: Background. We present our ongoing experience in the use of postsurgical stimulated serum thyroglobulin (Stim-Tg) to assist in radioiodine remnant ablation (RRA) decision-making. Methods. Patients with low-risk well-differentiated thyroid carcinoma (WDTC) with undetectable anti-Tg antibodies were prospectively followed after total thyroidectomy and therapeu- tic central compartment neck dissection, when indicated. Stim- Tg was performed 3 months postoperatively and used to base RRA selection. Results. Of 104 patients, 59 patients (56.7%) had an unde- tectable Stim-Tg after thyroidectomy, 35 (33.7%) had Stim-Tg values of 1–5 lg/L, and 10 (9.6%) had Stim-Tg values >5 lg/ L. RRA was administered to 1 patient (1.7%) with undetectable Stim-Tg, 6 patients (17.1%) with Stim-Tg1–5 lg/L, and 9 patients (90%) with Stim-Tg >5 lg/L, for a total of 16 patients (15.4%) receiving RRA. When compared to current RRA selec- tion guidelines, the proposed protocol achieved a significantly lower RRA administration rate. Conclusion. Stim-Tg measurement performed several months after total thyroidectomy is a useful objective parame- ter in assisting RRA decision-making for patients with low-risk WDTC. V V C 2010 Wiley Periodicals, Inc. Head Neck 32: 689– 698, 2010 Keywords: radiology-radiation treatment; thyroid cancer– clinical; thyroglobulin; clinical research; TSH Well-differentiated papillary carcinoma ac- counts for approximately 88% of detected thy- roid carcinomas. 1 The combination of current clinical practice guidelines and physician-held beliefs regarding the utility of radioiodine Correspondence to: P. G. Walfish This work was presented in part at the scientific program of the 79th American Thyroid Association Meeting, Chicago, IL, 2008 (Abstract Number 79); the First World Thyroid Congress, Toronto, Canada, 2009 (Abstract Number 2231); and the 80th American Thyroid Association Meeting, Palm Beach, FL, 2009 (Abstract Number 130). Dr. Paul G. Walfish reports receiving consulting fees from Genzyme Canada Inc. This project was supported in part by unrestricted educational grants from: The Joseph and Mildred Sonshine Family Centre for Head and Neck Diseases at Mount Sinai Hospital; the Temmy Latner/Dynacare Family Foundation; the Julius Kuhl Family Foundation; the Department of Medicine Research Fund, Mount Sinai Hospital; the Mount Sinai Hos- pital Foundation of Toronto; and the Alex and Simona Shnaider Research Chair in Thyroid Oncology. V V C 2010 Wiley Periodicals, Inc. Selective Radioiodine Remnant Ablation HEAD & NECK—DOI 10.1002/hed June 2010 689