Localized whole eye radiotherapy for retinoblastoma using a (125)I applicator, "claws".
OBJECTIVE
To treat children with retinoblastoma, who require whole eye radiotherapy, with a specially designed (125)I applicator that irradiates the eye while sparing the surrounding tissues.


METHODS
Under general anesthesia, a pericorneal ring is attached to the 4 extraocular muscles, and 4 appendages, each loaded with (125)I seeds, are inserted beneath the conjunctiva in-between each pair of muscles and attached anteriorly to the ring. Twenty-nine eyes were treated. Eighteen received a median dose of 28 Gy during 91 hours and 11 received 40 Gy during 122 hours, when the relative biologic effectiveness was taken as 1 instead of 1.5. Six had received prior chemotherapy.


RESULTS
Twenty-four eyes were followed up for 2-157 months (median 29). Although 22 eyes responded, local control was achieved in 13 patients, 3 of whom required additional treatment for new tumors; a further 3 required additional treatment for tumor recurrence as well as new tumors. One of these eyes was enucleated for neovascular glaucoma. All 6 Group I-III eyes and 6 of 18 Group V eyes were retained for 2-157 months (median 39), with good vision in 10 eyes. Three developed cataracts 7, 8, and 12 years later, 1 of which has been removed.


CONCLUSIONS
This is a new way of irradiating the whole eye with a minimal dose to the surrounding tissues. The treatment time is only 5 days. It is effective in Groups I-III, but only 33% of Group V eyes retained vision. No late cosmetic defects occurred.
Stannard
C
C
Department of Radiation Oncology, Groote Schuur Hospital and University of Cape Town, Cape Town, South Africa. clare@curie.uct.ac.za
Sealy
R
R
Hering
E
E
Korrubel
J
J
Hill
J
J
Barron
A
A
Knowles
R
R
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001918:Brachytherapy / Q000295:instrumentation* / Q000379:methods; D002648:Child; D002675:Child, Preschool; D004867:Equipment Design; D015353:Eye Enucleation; D005260:Female; D006801:Humans; D007223:Infant; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D011879:Radiotherapy Dosage; D012175:Retinoblastoma / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery
D007457:Iodine Radioisotopes