Clinical Analysis Of Radiotherapy Of Grabes'orbitopathy

IntroductionGraves' orbitopathy is an unpredictable orbitalinflammatory disorder which most frequentlyencountered in adult patients with abnormal thyroidfunction. The mechanism of this disease might be animmunological disturbance consisting of edema of theorbital tissues with lymphocytic infiltration anddeposits of mucopolysaccharides. The aspect of thepatient is usually modified by inflammatory eye andlids, Proptosis, and hypertrophy of oculomotormuscles. At the beginning, these abnormalities areregressive and intermittent. However, in time theycan involve into fat fibrosis and fibrous atrophy ofthe muscles. Optical neuropathy is partly related tocompressive phenomena and to the blockage of thevenous drainage during the edematous phase.The treatment of Graves'orbitopathy usually includescorticosteroids, immunosuppressors, plasmatic exchanges,surgical orbital decomprdssion, and radiotherapy.Radiotherapy introduced during the 1940s involvedboth the orbital region and the pituitary gland, however,since 1973, it has been admitted that orbital radiotherapyalone yielded equivalent results.In the course of this 20-year experience, indications forradiotherapy became clearer: the majority of the patientstreated by radiotherapy have been those with predominantsigns. The aim of this study is to evaluate the response ofGraves' orbitopathy to irradiation, and to specify theprognostic factors allowing one to better define theindications of orbital radiotherapy.ffethodBThe study included l04 patients treated from l979 tol999 in the Radiotherapy Department of General Hospital ofPLA. All patients received bilateral orbital irradiation l500-3500 cGy in 2-4 weeks fOr a progressive Graves' orbitopathy.Follow-up period were between 6 and 2l6 months.BBBM,tB33 patients (32%)had a good or excellent reponse toorbital irradiation. 50(48%)had a partial response.l6(l5%)were stable. 5(5%) had a progression of disease. The signsthat best responded to radiotherapy were the infiltration ofsoft tissues and the corneal involvement. Responses ofproptosis or oculomotor disorders were more completelywhen these signs were stable at the time of treatment. Thebest results were recorded for early or moderately advancedpresentation (p<0.05).Co"cIuBio-Had it s good resu1 t s and to1erance, radiotherapycan be proposed as first--1 ine treatment measurementfor patients with a severe progressive form ofthyroi d ophtha1mopathy. As second--l ine treatment,radi otherapy i s effic ient after fai 1ure orinto1erance t o cort icosteroi d. 0rb ita1 irradi at ionwas efficient in Graves' orbi topathy by stopping theprogression of disease in almost all cases. byimprovi ng the symptoms, by obtai ni ng object iveresponses, and by avoi di ng surgi ca1 treatment spart icular1 y when s igns were moderate.