Keywords:
Thyroid / Parathyroids, Eyes, CT, Radiation therapy / Oncology, Endocrine disorders
Authors:
E. Isdale, Z. Thotathil; Hamilton/NZ
DOI:
10.26044/ranzcr2019/R-0112
Purpose
To assess the effectiveness of orbital radiotherapy for Thyroid eye disease at Waikato Hospital.
Thyroid eye disease (TED) is a well-known side effect of Graves’ disease. Signs and symptoms may include proptosis, gritty eyes, tearing, orbital pain, blurred vision, diplopia, periorbital edema, change in colour vision and in more severe cases loss of vision conjunctival inflammation and ulceration. [1, 8]
TED is primarily a disease of the eye orbit caused by the response of retroocular tissues to autoantibodies to the thyroid stimulating hormone receptor (TSHR) [1, 3, 4]. The increase in the volume of the extraocular muscle and retroocular connective tissue as well as fluid accumulation and inflammation results in increased pressure within the confined environment of the orbit [1, 3].
Management the disease is based around management of the underlying disease, smoking cessation, reduction in ocular surface irritation and treatment of inflammation and swelling [6]. In moderate to severe disease immunomodulatory therapy such as oral or IV glucocorticoids would be utilised and in sight threatening event, orbital decompression surgery [3].
In the case of severe and steroid resistant disease external orbital radiation with concurrent IV steroid is another option [2, 5]. The technique is that 20Gy is delivered in 10 fractions with the theoretical goal of targeting the retroorbital T-cells, studies have shown that this is best delivered in the active or inflammatory stage of the disease that can last between 6-24 months before the development of the fibrotic or stabilised symptoms [1, 6].