Conservative therapy in intraocular retinoblastoma: response/recurrence rate

Purpose: To evaluate the response/recurrence rate and the outcome in intraocular retinoblastoma treated with chemoreduction and focal therapy, the authors performed a retrospective review of their patients. Methods: The series included 46 newly diagnosed patients with unilateral or bilateral intraocular retinoblastoma (58 eyes) receiving carboplatin/etoposide chemotherapy associated with focal therapy (laser or cryotherapy). The mean follow-up was 53 months (range 11-125). Results: Fifty-one eyes (88%) presented with complete response after four to eight courses of chemotherapy combined with focal treatment. The response rate was 100% in group 1, 94% in group 2, 100% in group 3, 83% in group 4, and 70% in group 5 (5 vs. 1-4, P < 0.03; 5-4 vs. 1-3, P < 0.025). Twenty-nine eyes (57%) relapsed after a mean of 7 months (range 2-36). The relapse rate was 30% in group 1, 27.% in group 2, 67% in group 3, 80% in group 4, and 100% in group 5 (5 vs. 1-4, P < 0.001; 4-5 vs. 1-3, P < 0.001). Seven of 18 cases achieved a second complete response with further conservative treatment (total courses 8-14). Twenty-nine eyes (50%) were treated without external-beam radiotherapy or enucleation: 90% in group 1, 69% in group 2, 67% in group 3, 33% in group 4, and 6% in group 5 (5 vs. 1-4, P < 0.01; 5-4 vs. 1-3, P < 0.001). Ten eyes (17%) required external-beam radiotherapy and 21 eyes (36%) enucleation. The ocular salvage rate was 67%. Conclusions: Although all groups of patients with intraocular retinoblastoma responded to carboplatin/etoposide chemotherapy associated with focal therapy, all the cases in group 5 relapsed. This approach is questionable in group 5, in which could be justified to delay aggressive treatment in a very young child.