Uveal melanoma (a type of eye cancer) can be treated with so-called brachytherapy, which involves a radioactive applicator being temporarily sewn to the white of the eye to irradiate the tumour.
The study, which compares the results of various types of treatment, shows that the risk of the eye having to be removed or having to repeat the radiotherapy is two to three times higher when the treatment is performed on tumours near the optic nerve. This is because the optic nerve prevents the applicator from enclosing the tumour in an optimal way. Applicators with a small notch to fit the optic nerve provided higher radiation doses to the tumour. However, the shape of the applicator, the radioisotope used, or whether treatment was supplemented with laser treatment, did not have any significance on neither the risk of repeated treatment, the need to remove the eye at a later stage nor the risk of dying from the disease. “This is important information for patients and doctors,” says Gustav Stålhammar, specialist in eye diseases and clinical pathology at St. Erik Eye Hospital, and associate professor and research group manager at Karolinska Institutet.
“The information about the increased risk may seem worrying. Therefore, it is important to emphasise that the treatment is successful in most cases. It is also important to underline that we did not find any statistically increased risk of the tumour spreading beyond the eye, even in cases where the treatment was not successful. Patients and doctors may very well still choose to try brachytherapy on a tumour close to the optic nerve, as long as they understand and accept the risks,” says Gustav Stålhammar.