Treatment complications and outcomes from plaque radiotherapy in eye melanoma

The authors analyzed the complications and outcomes of radiation therapy in specific eye melanoma. 

Choroidal melanoma develops in the choroid (the sponge-like membrane at the back of the eye). It is the most common eye cancer in adults. Juxtapapillary choroidal melanoma affects the optic disc. This is the circular area in the back of the eye where the optic nerve connects to the retina. Plaque radiotherapy is a widely used treatment for choroidal melanoma. It delivers a high radiation dose to the tumor, reducing radiation exposure to the surrounding healthy tissues. The plaque (radioactive element) is surgically placed directly into or very close to the cancer site for 4-7 days.

Treatment with plaque radiotherapy can be associated with several eye complications. This includes impaired vision (retinopathy), damage to the macula (maculopathy – specific part of the eye), papillopathy (eye nerve damage), cataract (clouding of the lens in the eye) and glaucoma (group of eye disorders resulting in eye nerve damage) among others.

A better understanding of the side effects related to plaque radiotherapy is needed to understand the challenges of this treatment.

The authors aimed to analyze the side effects in juxtapapillary choroidal melanoma treated with plaque radiotherapy.

In this study, 650 patients received plaque radiotherapy. The median (midpoint) follow-up time was 40 months.

At 5 years, 66% of patients developed non-proliferative (non-spreading) retinopathy. 24% developed proliferative (spreading) retinopathy. 56% developed maculopathy. 61% developed papillopathy. 66% developed cataract. 15% developed glaucoma in new blood vessels. 35% developed bleeding between the lens and retina. Eyeballs were retained in 87% of patients.

Vision was 20/100 or worse in 54% of patients. This meant patients had to be as close as 20 feet to see what a person with normal vision could see at 100 feet. A loss of more than 5 lines in the Snellen chart (eye testing chart that determines visual accuracy) occurred in 45% of patients.

At 10 years, 75% of patients developed non-proliferative retinopathy. 32% developed proliferative retinopathy. 65% developed maculopathy. 77% developed papillopathy. 80% developed cataract. 22% developed glaucoma in new blood vessels. 42% developed bleeding between the lens and retina. Vision was 20/100 or worse in 87% of patients. A loss of more than 5 lines in the Snellen chart occurred in 78% of patients.

The authors concluded that plaque radiotherapy was a suitable treatment option in juxtapapillary melanoma with high eyeball retention rates.