Orbital radiotherapy in the treatment of endocrine ophthalmopathy: when and why?

Radiotherapy for the treatment of thyroid eye disease-a prospective comparison: Is orbital radiotherapy a suitable alternative to steroids?

BACKGROUND AND AIMS

To evaluate the efficacy of orbital radiotherapy (OR) for the treatment of thyroid eye disease (TED).

METHODS

Thirty-five consecutive patients with active TED with contraindications to steroid therapy received a course of OR. Bilateral retrobulbar irradiation was performed with a total dose of 20 Gy. 7-points clinical activity score (7-CAS), ocular motility, visual acuity (VA), exophthalmos and eyelid retraction were prospectively evaluated at 3, 6 and 12 months and compared with baseline data.

RESULTS

There was a statistically significant improvement in 7-CAS at 3, 6 and 12 months post-treatment (p < 0.05). Ocular motility disturbances improved at 6 and 12 months (p < 0.05). Visual acuity remained stable; there was no significant change in exophthalmos (mean 24 mm, SD 3 mm) or eyelid retraction (marginal reflex distance mean 6 mm, SD 1.5 mm) during the follow-up period. No side effects were registered.

CONCLUSIONS

This study suggests that OR might be effective in reducing 7-CAS and ocular motility disturbances. No significant improvement in proptosis or eyelid retraction should be expected from this treatment. OR might be considered a suitable alternative treatment in TED for patients who cannot tolerate steroids.

Radiotherapy in the treatment of Graves ophthalmopathy-to do it or not?

To the objective of this study is to evaluate the role and toxicity of radiotherapy in the treatment of Graves ophthalmopathy. In the years 2000-2003, 121 patients with malignant exophthalmos were treated with radiotherapy of the retrobulbar area to the total dose of 20 Gy in ten fractions with a 6 MeV photon beam. The treatment was performed by the team of the Clinic of Oncology of the Jagiellonian University Medical College in Cracow. The radiotherapy was preceded by intravenous steroid therapy: methylprednisolone acetate administered at the dose of 2 g/week for four consecutive weeks. The highest efficacy, expressed as improvement of all ocular symptoms, was observed for the combined treatment. Female and non-diabetic patients responded positively to the combined treatment. Radiotherapy combined with steroid therapy in the treatment of Graves ophthalmopathy seems to be an effective treatment for strictly defined indications. In the treatment of Graves-Basedow disease, radiotherapy is a well-tolerated treatment modality. Diabetes is a factor that worsens prognosis in Graves ophthalmopathy and female sex is a favourable factor for this condition.

A prospective, randomized, double-blind, placebo-controlled study of orbital radiotherapy for Graves' ophthalmopathy

CONTEXT

Although widely used for more than 85 years, the efficacy of radiotherapy for Graves' ophthalmopathy (GO) has not been established convincingly.

OBJECTIVE

To evaluate the efficacy of radiotherapy for GO.

DESIGN

Prospective, randomized, internally controlled, double-blind clinical trial in a tertiary care academic medical center.

PARTICIPANTS

The patients were ethnically diverse males and females over age 30 seen in a referral practice. The patients had moderate, symptomatic Graves' ophthalmopathy (mean clinical activity score, 6.2) but no optic neuropathy, diabetes, recent steroid treatment, previous decompression, or muscle surgery. Forty-two of 53 consecutive patients were enrolled after giving informed consent and fulfilling study entry criteria. Eleven eligible patients declined to participate because of inconvenience, desire for alternative therapy, or concern about radiation.

INTERVENTION

One randomly selected orbit was treated with 20 Gy of external beam therapy; sham therapy was given to the other side. Six months later, the therapies were reversed.

MAIN OUTCOME MEASURES

Every 3 months for 1 year, we measured the volume of extraocular muscle and fat, proptosis, range of extraocular muscle motion, area of diplopia fields, and lid fissure width. Effective treatment for GO will modify one or more of these parameters.

RESULTS

No clinically or statistically significant difference between the treated and untreated orbit was observed in any of the main outcome measures at 6 months. At 12 months, muscle volume and proptosis improved slightly more in the orbit that was treated first.

CONCLUSIONS

In this group of patients, representative of those for whom radiotherapy is frequently recommended, we were unable to demonstrate any beneficial therapeutic effect. The slight improvement noted in both orbits at 12 months may be the result of natural remission or of radiotherapy, but the changes are of marginal clinical significance.

Thyroid-associated ophthalmopathy: pathogenesis and clinical management

The pathogenesis of thyroid-associated ophthalmopathy is autoimmune. The questions to which answers are eagerly awaited are the identification of the autoantigen(s) and the definition of the autoimmune processes (cellular or humoral) responsible. Cellular and humoral immune responses and modulation by cytokines, against orbital tissues have been described. A link between the thyroid and the orbit seems inevitable, possibly in the form of a cross-reactive antigen, and top of the list of candidate antigens is the TSH receptor. Optimal treatment of TAO necessitates careful assessment. Thoughtful planning and timing and choice of intervention with conventional therapies, can lead to satisfactory results in the majority of cases. In addition to treating the severe complications, such as optic neuropathy, corneal exposure and muscle misalignment, corrective surgery to reconstruct the appearance of the patient's eyes should be made available.