Use of
Gamma Knife technology for a uveal melanoma

Uveal melanomas are tumors that develop in the eye. They originate in the choroid, a highly vascular layer that is rich in melanocytes and located behind the retina. The tumors are extremely rare, affecting just six out of every million people. Although the tumor is similar to a malignant melanoma, there is no correlation between exposure to the sun and tumor frequency.

Growth of the tumor could cause detachment of the retina. This often leads to acute, unilateral impaired vision. Depending on the location of the tumor in the eye (central vision or peripheral field of vision), symptoms may be noticed early on or only much later in the course of the disease. While a small, central uveal melanoma impairs vision early on, peripheral uveal melanomas can grow for years before the patient notices symptoms.

Depending on the size of the tumor, we monitor uveal melanomas on a wait-and-see basis. Where necessary we treat them surgically or using radiation therapy or radiosurgery.

Combination of radiosurgery and surgery

With very large uveal melanomas, often in the past the affected eye had to be removed. This is because uveal melanoma is such a malignant tumor. If the tumor spreads through the body, the patient’s life is at risk. As such, the primary aim of treatment is to prevent the tumor from spreading. This means that large, prominent uveal melanomas are not simply removed surgically. The risk of dragging active tumor cells into the body would be too high. It is at this point that our radiosurgery comes into its own.

As a preparatory measure, we inactivate, i.e. eliminate the tumor radiosurgically by irradiating it. The tumor is then removed surgically. The retina is put back into position. So we not only manage to remove the tumor and cure the patient, but can even restore partial function of the eye in the majority of cases. We will only recommend radiosurgery on an interdisciplinary basis. This will involve physician from various specialties in an ophthalmic center. A combined procedure now provides the best outcome whereby the tumor is first killed using radiosurgery and then removed surgically.

The treatment is very complex. Apart from fixing the head, the eye also needs to be fixed. The ophthalmologist anesthetizes the eye using local anesthetic, which temporarily paralyzes the eye muscles. The eye and, in turn, the tumor thus cannot move during the Gamma Knife treatment. After about 2-3 hours the anesthetic wears off and the eye functions normally again. This specialist therapy is only available in a few centers.

Continued treatment at the eye clinic.

Immediately after radiosurgical inactivation of the tumor, we send the patient to the referring eye clinic. Here the radiosurgically inactivated tumor is removed surgically the next day or the day after at the latest. No more than two days should elapse between radiosurgery and surgery to ensure an optimum outcome.

The eye clinic and the patient’s ophthalmologist are exclusively in charge of the aftercare. This includes regular ophthalmic checkups along with an oncological checkup for a certain period. Regular checkups every three months ensure the tumor has not metastasized in the lungs and liver. Based on our previous experience, the probability of this happening is well below 10% of treated cases. Due to the susceptibility of the eye lens to radiation, a cataract on the affected side may occur as a late consequence. Current opthalmologic surgical procedures can rectify this problem with a short outpatient surgery. Retinal and optic nerve damage may also occur in addition to this side effect. Based on our experience, the side effects of surgical intervention are greater than those of the radiosurgery.