Unilateral retinoblastoma classified as ICRB Group A or ICRB Group B with macular sparing — a small tumor without high-risk features such as extraocular extension or choroidal/optic nerve invasion. This patient has already undergone a first-line focal therapy attempt that did not reach its regression target.
The preceding line applied focal therapy for tumor consolidation: cryotherapy (triple-freeze-thaw technique under indirect ophthalmoscopy) or transpupillary thermotherapy (TTT) via an 810 nm diode laser, with multiple sessions at 4-week intervals. The required endpoint — a flat scar or completely calcified tumor with full regression — was not achieved. That unmet goal is the trigger for escalation.
When focal therapy does not achieve the regression endpoint, globe salvage therapy is the next consideration. The particular pathway selected depends on the nature and location of tumor seeding identified — different seeding patterns direct different treatment strategies. The full structured protocol specifies the decision algorithm and the available options for each seeding scenario.
DOI: 10.4103/ijo.IJO_721_20