The Role of Periocular Carboplatin in Treatment of Advanced Intraocular Retinoblastoma

Purpose: To evaluate the results of combined chemotherapy and periocular carboplatin injection to control advanced intraocular retinoblastoma (Rb). Methods: In this prospective interventional case-series, we included 8 eyes of 8 patients with advanced intraocular Rb (group C or D in International Intraocular Retinoblastoma Classification, IIRC). In these patients, periocular carboplatin was injected as a primary adjuvant therapy combined with chemotherapy (VEC regimen) or as a secondary treatment in patients who had recurrent disease or did not respond to primary chemotherapy and local modalities. All patients were examined under anesthesia (EUA) and fundus photography was done by Ret–cam before treatment. Fifteen miligrams of carboplatin was injected into subconjunctival or subtenon space in 3-4 weeks interval. Results: Eight eyes of eight patients were enrolled. Five patients were male and three patients were female. Mean age of patients at the time of treatment was 34 months and the mean duration between initial presentation of Rb and beginning of treatment was 7.5 months. Mean injection of periocular carboplatin in each eye was 3.1 times. Past medical history in our patients before starting of this treatment included: External Beam Radiotherapy (EBRT) in 3 eyes, cryotherapy in 4 eyes, transpupillary thermotherapy (TTT) in 4 eyes and brachytherapy in 2 eyes. Four eyes were in group C and four eyes were in group D. In 3 patients carboplatin was injected as primary treatment and in five patients it was injected for tumor recurrence following initial treatment failure or relapse. Three patients had vitreous, one had sub-retinal and remaining four had both vitreous and subretinal seeding. The degree of seeding was low in two patients, moderate in two patients and severe in four patients. At the end of study, tumor was regressed in six eyes (75%), relapsed in one (12.5%) and recurred in another (12.5%). In both eyes with relapsed and recurrent tumors, enucleation was done. Conclusion: Combined chemotherapy and periocular carboplatin injection as well as focal treatment may be an effective method to control advanced intraocular Rb.