The procedure
guideline for radioiodine therapy of differentiated thyroid cancer (version 4) was developed in the
consensus of a representative expert group. This fulfils the level S1 (first step) within the AWMF classification of Clinical Practice
Guidelines (AWMF, Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, Germany). This procedure
guideline completed the
guideline for surgical management of thyroid cancer (level S2) with the aspects from nuclear medicine. Controversies over ablative radioiodine therapy in small papillary thyroid cancers and in minimally invasive follicular cancer without angioinvasion, over empirical standard doses for ablative radioiodine therapy, and over the kind of TSH-stimulation were described and the
guideline formulated a corridor of good clinical practice. The text has included the recent results from the National Cancer database and the SEER database (both from the USA), indicating that the ablative radioiodine therapy has improved the survival rate even in low risk patients. Such a statistically significant benefit can be detected only by a national cancer registry with long-term follow-up data.