Objective: To evaluate the change in regression pattern following chemoreduction and tumor consolidation therapy (thermotherapy or cryotherapy) for retinoblastoma
Methods: Retrospective medical record analysis was completed for 557 retinoblastomas (239 eyes of 157 patients) that were treated with chemoreduction and showed regression to 1 of 5 patterns (type 0, no visible remnant; type 1, completely calcified remnant; type 2, completely noncalcified remnant; type 3, partially calcified remnant; and type 4, atrophic chorioretinal flat scar). Evolution of these regression patterns was observed over time.
Results: Immediately following 6 cycles of chemoreduction, types 0 (2%), 1 (30%), 2 (3%), 3 (33%), and 4 (32%) regression patterns were found. During a mean follow-up period of 56 months (median, 48 months; range, 18-145 months), there was no change in regression patterns classified as type 0, 1, or 4. However, there was evolution of regression pattern types 2 and 3. Over time, type 2 tumor scars either remained stable (41%) or evolved to type 4 (41%), 3 (9%), or 1 (9%) scars. Type 3 tumor scars remained stable (74%) or evolved to type 1 (26%) scars.
Conclusion: Following chemoreduction and tumor consolidation therapy, retinoblastoma regression patterns types 2 and 3 can slowly evolve over time into a slightly different appearance, even without additional treatment. Ophthalmologists should be familiar with these regression patterns and their evolution.