Radiotherapie der endokrinen orbitopathie

Graves' ophthalmopathy (GO) is the most frequent extrathyroidal manifestation of Graves' disease, an autoimmune disorder of the thyroid, whereas the precise pathogenesis still remains unclear. In Hashimoto's thyroiditis the occurrence of proptosis is an extremely rare event. The therapy for middle and severe courses of GO shows in partly disappointing results, although several therapy modalities are possible (glucocorticoid therapy, radiotherapy, antithyroid drug treatment, surgery). All these therapies lead in only 40-70% to an improvement of the pathogenic symptoms. An intensive interdisciplinary cooperation is necessary to satisfy the requirements for the treatment of Graves' ophthalmopathy. As a consequence of the very different results of the few of clinical studies that were accomplished with reference to this topic, treatment by radiotherapy in the management of the disease is presently controversially discussed. In the German-speaking countries the radiotherapy is, however, firmly established as a therapy option in the treatment of the moderate disease classes (class 2-5 according to NO SPECS), especially if diplopia is present. This article describes the sequences, dosages and fractionation schemes as well as the risks and side effects of the radiotherapy. Altogether, radiotherapy is assessed as an effective and sure method. The administration of glucocorticoids can take place before the beginning of or during the radiotherapy. For the success of treatment the correct selection of patients who may possibly profit from a radiotherapy is absolutely essential. By realising that GO proceeds normally over a period of 2-5 years, which is followed by a period of fibrotic alteration, the application of the radiotherapy in the early, active phase is indispensable. A precise explanation for the effects of radiotherapy in treatment of the GO does not exist at present. The determination of the most effective irradiation doses was made from retrospectively evaluated collectives. Recently the results of a national survey of all German RT departments were published, initiated by the working group of the DEGRO (German Society of Radiooncology). In the most of the German radiooncology departments irradiation with 8 to 10 × 1.8 - 2.0 Gy 5 × weekly to 16 or 20 Gy is standard. Two recently published prospective German studies pointed out the equivalence of the effectiveness of a short therapy in low dose ranges up to 2.4 Gy as well as of a low proportioned irradiation during a longer period in relation to a standard therapy with 20 Gy. That is why at the moment it is not possible to give a definite recommendation with reference to dosages or the fractionation schemes. In 2003 the first European group (European Group on Graves' Orbitopathy Experience - EUGOGO) was founded for pursuing investigations of GO in multi-centric studies, mainly to improve therapy results.