Ruthenium-106 (106Ru) plaque brachytherapy as salvage treatment for retinoblastoma following intravenous chemotherapy

Abstract

PURPOSE

To describe the clinical presentation and treatment outcomes of patients undergoing Ruthenium-106 (¹⁰⁶Ru) plaque brachytherapy as salvage treatment for retinoblastoma (RB) following intravenous chemotherapy (IVC).

METHODS

Retrospective chart review of 44 eyes of 42 patients. The indications for plaque brachytherapy included solid tumor recurrence (n=20; 45%), solid tumor residual (n=16; 36%), new subretinal seeds (n=5; 12%), and new solid tumor (n=3; 7%).

RESULTS

The median age at the presentation was 12 months (range, 3–72 months). Based on ICRB classification, 8 (18%), 8 (18%), 16 (36%), and 5 (12%) tumors belonged to Groups B, C, D, and E, respectively. A median interval of 5 months (range 3–21 months) was noted between the last IVC cycle and plaque brachytherapy. The mean tumor height was four mm (range, 1.5–6 mm). All patients were treated with ¹⁰⁶Ru plaque (round or notch) with a median total dose of 45 Gy (range, 40–55 Gy) delivered to the tumor apex. At a mean post plaque follow-up period of 28 months (median, 23 months; range, 3–132 months), tumor completely regressed in 25 eyes (56%). Tumor recurrence within the plaque site was noted in eight eyes (18%) associated with a type 2 regression pattern (75%). At the last follow-up, the globe salvage rate was 24 eyes (55%), while 2 patients (5%) died due to metastasis.

CONCLUSION

¹⁰⁶RU plaque brachytherapy can be a useful salvage treatment for focal tumors (new or recurrent) following systemic IVC.