Orbital development in long-term survivors of retinoblastoma.
OBJECTIVE
To determine the effects of enucleation, irradiation, and age at diagnosis on bony orbital growth in long-term survivors of retinoblastoma using measurements based on computed tomographic (CT) imaging.


METHODS
We used CT obtained at a median age of 13 years to measure orbital volume and configuration in 54 patients who had been treated for retinoblastoma a minimum of 5 years previously.


RESULTS
Enucleation and high-dose orbital irradiation (> 35 Gy) both independently adversely affected orbital development (P = .014 and P = .022, respectively). Orbital volume differences for children treated when < or = 1 year old were no greater than those for children treated when older than 1 year of age. In children treated for bilateral retinoblastoma, the impact of enucleation on orbital development was not statistically different from that of irradiation (P = .13). Small implants (12 to 14 mm in diameter) were more commonly associated with smaller orbital volumes. Migration of orbital implants was associated with the smaller orbital sphere size in children < or = 1 year of age (P < .035).


CONCLUSIONS
Treatment for retinoblastoma compromises orbital development. Resulting orbital asymmetry seems to be at least partially related to the size of the implant. Detailed imaging-based measurements of orbital volume and configuration may aid the planning for cosmetic and reconstructive surgery in those who develop orbital asymmetry.
Kaste
S C
SC
Department of Diagnostic Imaging, St Jude Children's Research Hospital, Memphis, TN 38105-2794, USA. sue.kaste@stjude.org
Chen
G
G
Fontanesi
J
J
Crom
D B
DB
Pratt
C B
CB
D000367:Age Factors; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D015353:Eye Enucleation / Q000009:adverse effects*; D005134:Eye Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000628:therapy*; D005137:Eye, Artificial / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009378:Neoplasms, Multiple Primary / Q000473:pathology / Q000532:radiotherapy / Q000628:therapy; D009915:Orbit / Q000000981:diagnostic imaging / Q000254:growth & development* / Q000528:radiation effects; D011879:Radiotherapy Dosage; D012175:Retinoblastoma / Q000473:pathology / Q000532:radiotherapy / Q000628:therapy*; D017741:Survivors; D014057:Tomography, X-Ray Computed