Treatment of XXXX by precision megavoltage radiation therapy.

@entity1 @entity231 @entity5 @entity3459 @entity735 @entity221 @entity995
The principal treatment concept in the Utrecht @entity995 Centre is megavoltage irradiation, followed by @entity3459 and/or cryotherapy if there is any doubt as to whether the @entity5 is still active. Radiation therapy is administered by means of a simple but highly accurate temporal beam technique. A standardized dose of 45 Gy is given in 15 fractions of 3 Gy at 3 fractions per week. From 1971 to 1982, 39 @entity1 with @entity995 have been irradiated in at least one eye. Of the 73 affected eyes, 18 were primarily enucleated, one received @entity3459 only, and 54 received radiation therapy. Of the 54 @entity735 , 32 were additionally treated by @entity3459 and/or cryotherapy for suspicious @entity5 (in 29 eyes), recurrent @entity5 (in 3 eyes) and 10 were ultimately enucleated. Two eyes also received @entity221 . The percentages of cure of the @entity735 with a minimum follow-up of 2 years were 100% (14/14), 100% (9/9), 83% (10/12), 79% (11/14) and 0% (0/5) in the Reese-Ellsworth groups I to V-A, respectively. Of the saved eyes 95% achieved useful vision. Eighteen eyes developed a clinically detectable radiation @entity231 ; in five of these the lens was aspirated. Cataracts developed exclusively in those lenses of which a posterior portion of more than 1 mm had to be included in the treatment field. The likelihood and the degree of @entity231 formation was found to be directly related to the dose of radiation to the germinative zone of the lens epithelium. The minimum cataractogenic dose found in this series was 8 Gy.
