Unilateral Retinoblastoma: Audit of Outcomes of Children treated with Curative Treatment Protocol

Objectives

To evaluate treatment outcome of children diagnosed with unilateral retinoblastoma.

Methods

Retrospective study of children diagnosed with unilateral retinoblastoma registered at our institute from January 2013 to December 2018 and completed the curative treatment protocol.

Results

For the 98 cases analyzed the median age was 24 months. At the time of presentation, 72 had intraocular and 26 had orbital. On imaging extra-scleral spread was observed in 16 patients whereas 18 patients had optic nerve (ON) involvement, 11 patients had both extra-scleral invasion and ON involvement. Majority we ICRB group E (71), and group D=21, group C= 2, group B=4. Majority were IRSS Stage 1(stage0=14, stage1=52, stage2=10, stage3a=21 and stage3b=1). High-risk features on surgical specimen histopathology were ON margin positivity in 6, ON involvement in 21, extra-scleral spread in 3, choroidal invasion in 38 and iris involvement in 10 patients.

Eneucleation was offered to 78 (Primary=52, secondary=26). Chemotherapy was offered to 68 (chemoreduction=17, adjuvant chemotherapy=51). Intra-arterial chemotherapy was offered to 27 patients as a primary treatment or in conjugation with focal therapy (n=11). Definitive radiotherapy was offered to only 2 patients and 22 patients received adjuvant radiotherapy.

At a median follow-up of 62 months, 2 patients had local relapse, which was salvaged by focal therapy in one and enucleation in the other. Ten patients who had leptomeningeal relapse had died. The 5-year local control (LC) is 97.6%, event-free survival (EFS) is 88% and overall survival (OS) is 89.5%. Globe was salvaged in only 16 cases. On univariate analysis, orbital disease, extra-scleral spread, ON involvement (imaging), and ON margin positivity, higher ICRB Group and IRSS stage had poor impact on OS.

Conclusion

Retinoblastoma is curable with optimal globe salvage rates if detected early. Orbital disease, high risk features on surgical specimen histopathology and leptomeningeal relapse are associated with inferior outcomes.