Intravitreal Melphalan for Vitreous Seeds: Initial Experience in China

Area of Science:

• Ophthalmology
• Pediatric Oncology
• Cancer Treatment

Background:

• Retinoblastoma is the most common primary intraocular malignancy in children.
• Vitreous seeds are a common and challenging manifestation of retinoblastoma, often associated with a poorer prognosis.
• Intravitreal chemotherapy is an emerging treatment modality for localized retinoblastoma, aiming to reduce systemic toxicity.

Purpose of the Study:

• To assess the efficacy and safety of intravitreal melphalan injections for treating vitreous seeds in Chinese patients with retinoblastoma.
• To evaluate the local control rate and globe salvage achieved with this treatment approach.

Main Methods:

• A retrospective review was conducted on 17 consecutive Chinese patients (19 eyes) diagnosed with retinoblastoma and viable vitreous seeds.
• Patients received multiple intravitreal injections of 20 µg melphalan at 2-4 week intervals.
• Data on treatment response, globe retention, complications, and follow-up duration were collected and analyzed.

Main Results:

• Successful control of vitreous seeds was achieved in 16 out of 19 eyes (84.21%).
• Globe retention was successful in 14 out of 19 eyes (73.68%).
• A significant difference in treatment response was observed based on seed morphology (cloud, spheres, dust), with varying numbers of injections required (P = 0.003).
• Common complications included vitreous hemorrhage, cataract, and retinopathy; however, no cases of extraocular extension or systemic metastasis were reported.

Conclusions:

• Intravitreal melphalan is a highly effective treatment for controlling retinoblastoma vitreous seeds in Chinese patients.
• The procedure demonstrates a high rate of local tumor control and globe salvage with acceptable toxicity.
• This approach offers a promising alternative to enucleation or systemic chemotherapy for managing vitreous seeding in retinoblastoma.