Orbital growth retardation in retinoblastoma survivors: Work in progress

Background, Orbital growth retardation, after enucleation and/or external b eam radiation for retinoblastoma (RB), is a serious late effect. We measure d orbital volumes of RB survivors treated at Hadassah University Hospital, Jerusalem, between 1980-1998. Procedure. Forty-five orbits of 28 children w ith RB (17 bilateral, 11 unilateral) were examined. Thirty-six orbits were irradiated, 19 enucleated, and 10 both enucleated and irradiated. The orbit al volumes were calculated from a three-dimensional orbital CT reconstructi on. The orbits of RB survivors were compared to age-matched controls. Resul ts. The mean age at diagnosis was 13 months, mean follow-up time was 56 mon ths. The mean volume of RB orbits (14.4 cc) was statistically significantly smaller than control orbits (17.8 cc). There was no difference between the mean volume of orbits treated with enucleation, irradiation or both. The o rbital volume of children treated before the age of 12 months was statistic ally significantly smaller than those treated later. There was no differenc e between mean volume of fellow orbits in unilateral RB and controls. The m ean orbital asymmetry index in control children (2.6%) was statistically si gnificantly smaller than in RB survivors (14%). Conclusions. There was a si gnificant orbital growth retardation after enucleation and/or irradiation f or RB. There was no difference between mean orbital volumes after enucleati on, radiation or both. Orbital growth retardation was most prominent in chi ldren treated in the first year of life. Although small in number, our stud y suggests that deferring enucleation and/or irradiation until after the ag e of 12 months may reduce long-term complications. (C) 2001 Wiley-Liss, Inc .