USE OF IRRADIATION FOR THERAPY OF RETINOBLASTOMA IN CHILDREN MORE THAN 1 YEAR-OLD - THE ST-JUDE CHILDRENS RESEARCH HOSPITAL EXPERIENCE AND REVIEW OF LITERATURE

Fifteen children (>1 year old at diagnosis) were treated for retinobla stoma (RB) with primary irradiation at St. Jude Children's Research Ho spital between January 1963 and January 1992. Staging of the 19 treate d eyes was as follows: Reese-Ellsworth (R-E) Groups I and II, n = 7; G roup III, n = 3; Group IV, n = 1; Group V, n = 7; information on one g lobe is incomplete. Total dosage ranged from 25 to 45 Gy (median = 40 Gy) in fractions of 170-225 cGy delivered 5 x/week (n = 13) or 225-265 cGy delivered 4x/week (n = 4 eyes) or x 5/week (n = 2 eyes). Treatmen t techniques included anterior field (n = 11) or lens-sparing techniqu e (n = 8). One patient has died of progressive central nervous system (CNS) disease at 13 months; one patient succumbed to second malignant neoplasm within the irradiated field at 194 months; the remaining 13 p atients remain alive from 27 to 301 months (median = 178 months). Loca l control with irradiation alone has been maintained in 12 eyes. Four eyes with local recurrence were salvaged using cryotherapy or reirradi ation. Enucleation was required for three eyes for progressive disease at 4, 7, and 7 months postirradiation. Cataract formation was documen ted in nine eyes treated with anterior fields and in one patient treat ed with lens-sparing technique. At last follow-up, 7 patients had visu al acuity of 20/100 or better. Radiation dose of 40 Gy appears to be a dequate for local control of early stage RB (R-E Groups I-III and VB w hose tumors are R-E Groups I-III) in patients >1 year old. The results of this limited series which has lengthy follow-up is compared with t he results of previously published data in an effort to define the ben efits and disadvantages of the different treatment techniques which ha ve been reported in the treatment of RB in children >1 year old. (C) 1 995 Wiley-Liss, Inc.