Severe XXXX following external beam irradiation.

@entity1 @entity135 @entity2194 @entity227 @entity1066 @entity936 @entity130
PURPOSE: There are limited data in the literature on the probability of @entity2194 according to radiotherapy dose. This study investigates the risk of radiation-induced severe @entity936 in @entity1 in whom an entire orbit was exposed to fractionated external beam irradiation. METHODS AND MATERIALS: Between October 1964 and May 1989, 33 @entity1 with @entity135 received irradiation of an entire orbit. Most @entity1 were treated with 60Co. The dose to the lacrimal apparatus was calculated at a depth of 1 cm from the anterior skin surface, the approximate depth of the major lacrimal gland. The end point of the study was severe @entity936 sufficient to produce @entity227 secondary to corneal opacification, @entity1066 , or vascularization. RESULTS: Twenty @entity1 developed severe @entity936 . All 17 @entity1 who received doses > or = 57 Gy developed severe @entity936 . Three (19%) of 16 @entity1 who received doses < or = 45 Gy developed severe @entity936 ; @entity130 in the latter group were much slower to develop (4 to 11 years) than in the higher dose group, in whom corneal vascularization and opacification were usually pronounced within 9-10 months. There were no data for the range of doses between 45.01 and 56.99 Gy. The data did not suggest an increased risk of severe @entity936 with increasing age. CONCLUSION: Data from the current series and the literature are combined to construct a sigmoid dose response curve. The incidence of injury increases from 0% reported after doses < or = 30 Gy to 100% after doses > or = 57 Gy.
