Diagnostic 131I whole-body scintigraphy 1 year after thyroablative therapy in patients with differentiated thyroid cancer: correlation of results to the individual risk profile and long-term follow-up
- 163 Downloads
131I whole-body scan (WBS) and serum thyroglobulin (TG) are important in detecting thyroid remnants or recurrent disease in patients with differentiated thyroid cancer. Usually, a diagnostic WBS is carried out 6 months after ablation to exclude residual disease. We retrospectively analysed results of a second routine diagnostic WBS and TG measurements at 1 year after thyroablation and correlated these to the risk profile of patients with long-term follow-up.
A total of 197 patients were followed up after thyroidectomy and ablative 131I therapy. Follow-up included clinical examination, radioiodine WBS and thyroid-stimulating hormone (TSH), free thyroxine and TG measurements at 3–6 months and 1 year after ablation. WBS (+) patients received a therapeutic activity of 131I. The risk profile of patients was defined according to clinical results before the 1-year control. Clinical results at 1 year after ablation were analysed in correlation to the patient risk profile and long-term follow-up data (mean 7.2 years).
One year after thyroablation, 95.8% of low-risk patients had no residual disease when diagnostic WBS was carried out using 370 MBq 131I; 4.2% of low-risk patients had residual disease at this time point. In the high-risk group of this cohort, 54.5% were disease-free 1 year after ablation, but 45.5% demonstrated residual disease. After the 1-year control, 94% of all applied radioiodine therapies were executed in the high-risk group, compared with 6% in the low-risk group (p < 0.01).
A second routine WBS 1 year after thyroablation is not indicated in low-risk patients. Risk stratification according to the early clinical course effectively identified patients with higher likelihood of persistent or recurrent disease in the long-term follow-up.
KeywordsDiagnostic 131I whole-body scintigraphy Thyroablative therapy Differentiated thyroid cancer
The authors thank Professor Dr. K. Tatsch for valuable advice. F.B. would like to thank Professor Dr. Dr. h.c. M. Reiser and Professor Dr. P. Bartenstein for their support, which made realization of such a long-term follow-up study possible.
F.B. and the coauthors dedicate this paper to the memory of the endocrinologist Professor Dr. Klaus Horn († 2003). His knowledge, advice and mentorship, but also his kindness and humour are sorely missed.
Conflicts of interest
- 2.Junginger T. Leitlinien der Deutschen Krebsgesellschaft e.V. zur Therapie maligner Schilddrüsentumoren. Forum Dtsch Krebsgesellschaft 1997;2:14–21.Google Scholar