Subconjunctival carboplatin in retinoblastoma: impact of tumor burden and dose schedule.
OBJECTIVE
To evaluate the impact of tumor burden and chemotherapy dose scheduling on the response to subconjunctival carboplatin treatment in a murine transgenic retinoblastoma model.


METHODS
Eighty simian virus 40 T antigen-positive mice were treated at age 5 or 10 weeks. Six control animals received placebo treatment. Twenty-four 5-week-old mice received 6 subconjunctival carboplatin injections at doses of 30 to 300 microg delivered at 72-hour intervals. Fifty 10-week-old mice received either 6 or 12 subconjunctival carboplatin injections at doses of 30 to 300 microg delivered at 72-hour intervals. All eyes were obtained at age 16 weeks for histopathologic examination. Eyes were graded as positive if any tumor was present.


RESULTS
All simian virus 40 T antigen-positive control eyes contained large tumor foci throughout the retina. Subconjunctival carboplatin injections controlled tumors in a dose-dependent manner. Tumor control was observed in 50% of treated eyes at 138.3 microg for the 10-week-old 6-injection group, 94.3 microg for the 5-week-old 6-injection group, and 85.9 microg for the 10-week-old 12-injection group.


CONCLUSIONS
Increased tumor burden requires an increase in subconjunctival carboplatin dose scheduling to maintain local tumor control in this murine model of retinoblastoma.


CONCLUSIONS
This study documents the efficacy of subconjunctival carboplatin in the treatment of an animal model of retinoblastoma. These data establish a framework for further human clinical trials. Arch Ophthalmol. 2000;118:1549-1554
Hayden
B H
BH
Bascom Palmer Eye Institute, Department of Opthalmology, University of Mialmi, PO Box 016880, Miami, FL 33101.
Murray
T G
TG
Scott
I U
IU
Cicciarelli
N
N
Hernandez
E
E
Feuer
W
W
Fulton
L
L
O'Brien
J M
JM
D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D016190:Carboplatin / Q000008:administration & dosage*; D003228:Conjunctiva; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D007267:Injections; D051379:Mice; D008822:Mice, Transgenic; D009883:Ophthalmic Solutions; D019572:Retinal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D012175:Retinoblastoma / Q000188:drug therapy* / Q000473:pathology
D000970:Antineoplastic Agents; D009883:Ophthalmic Solutions; D016190:Carboplatin