Supervoltage
radiotherapy was used in 21 orbits of 19 patients with idiopathic inflammatory
orbital pseudotumor. Seventeen orbits (15 patients) were initially treated with systemic
corticosteroids, but recurrence of orbital
inflammation during dosage tapering was the most frequent indication for
radiotherapy. Fifteen orbits (14 patients) responded favorably, as judged by reduced
proptosis, decreased lid
edema and conjunctival injection, improved ocular motility, and increased visual acuity. Six orbits (five patients) did not improve with
radiotherapy. Patients who were successfully treated with
radiotherapy have been free of recurrence for a mean follow-up period of 25.05 months; these patients have not required further
corticosteroid treatment or additional
radiotherapy. Low-dose (1,000 to 2,000 rad) supervoltage
radiotherapy seems to have a definite role in the management of idiopathic
orbital pseudotumor in the following instances: (1) when
corticosteroids fail or systemic complications are unacceptable (2) when signs and symptoms recur during decreasing
corticosteroid dosage, and (3) when systemic
corticosteroids are medically contraindicated.