In this study, researchers compared complication rates arising from primary and secondary intra-arterial chemotherapy (IAC) treatments of retinoblastoma.

Study design

This retrospective study included 196 patients with retinoblastoma who received IAC infusions between 2009 and 2018. Ninety-eight patients received infusions as their primary form of treatment (98 eyes, 328 infusions) and 98 patients underwent IAC as a secondary “salvage” treatment after receiving other therapy (105 eyes, 354 infusions). The chemotherapy treatment included melphalan alone, with topotecan or carboplatin, or a combination of all 3. Vascular events were noted.

Outcomes

Ophthalmic vascular events occurred in approximately 5% of all IAC treatments. After an average of 3 infusions per eye, rates of complications arising from primary or secondary IAC were similar between groups (18% vs 15%; P=0.57). Reported events included vascular attenuation, peripheral retinal pruning, branch retinal artery occlusion, central retinal artery occlusion, macular ischemia, vitreous hemorrhage, subretinal hemorrhage, retinal pigment epithelium atrophy, choroidal atrophy, optic disc pallor, and ophthalmic artery occlusion.

Most complications in both cohorts occurred after the third infusion. Although enucleation rates were similar between groups, ophthalmic vascular events increased risk of enucleation in eyes undergoing secondary IAC (P=0.043)

Limitations

One shortcoming of this study was its retrospective design. Treatment regimens were not standardized, but instead determined by the treating physician. Although additional adjuvant treatments were used in this study, they unlikely had an effect on the treatment regimens or their complications.

Clinical significance

IAC has been shifting from a secondary "salvage therapy" to becoming a primary treatment for retinoblastoma. The complication rate is low and should not preclude clinicians from treating patients with IAC when clinically warranted.