Radioactive plaque treatment (also known as brachytherapy) is the most common form of treatment of small and medium sized choroidal melanomas.
The day prior to surgery you will meet with your surgeon. The purpose of this meeting is to review what to expect the day of surgery, and how to manage medication, food and fluid intake the 24 hours prior to surgery. There will also be a chance to answer any remaining questions, and you will be asked to sign a consent form that describes the surgery and any possible complications.
Day of surgery
On the day of surgery report to the 6th Floor of the Casey Eye institute, 3375 SW Terwilliger Blvd. It is important that you have someone that can take you home following surgery. Even if you are returning home by taxicab, you must have someone that can accompany you as the sedation from surgery can leave you groggy. A preoperative nurse will start an intravenous fluid line and dilate your pupil. Any family members or companions may stay with you until you leave the preoperative area to go to the operating room.
The surgery is typically done under local anesthesia. Local anesthesia around the eye is very similar to that used in dentistry. You will be given some strong sedation through the IV so that you generally do not remember the injection of the local anesthetic. The anesthetic is given as an injection behind the eye, and the effects of the anesthetic generally last for 12 hours. Following the injection, the level of IV sedation is lessened but will be maintained at a level so that you are not anxious during surgery.
The surgery itself consists of making a slit like opening in the conjunctiva so that the radioactive plaque can be slid along the surface of the eye so that it overlies the tumor inside the eye. The radiation from the plaque extends through the sclera to deliver a carefully calculated dose of radiation to the tumor. The plaque is anchored in place using sutures. Once the plaque is placed, the position of the plaque is checked using ultrasound to confirm that the plaque covers the entire tumor. Frequently, one of the muscles that moves the eye must be temporarily disinserted so that the plaque can be placed in the ideal location. If the muscle is disinserted, it will be reattached at the time that the plaque is removed.
Following surgery you will have a moderate amount of discomfort that can be controlled with pain medication. Generally, it is best to see if sufficient pain control can be maintained with ibuprofen 400 mg three times a day. If this does not provide sufficient pain relief you will be given a stronger pain medication for use. The stronger medications are more likely to be associated with nausea. Because of the bulk of the plaque and the possible disinsertion of a muscle, you will have double vision when the eye is not patched.
The plaque will remain in place for 5-7 days, depending on the dose of radiation needed. You do not need to remain in the hospital during this time, but we advise you to stay at home, and have minimal contact with other people to avoid exposing them to radiation. You will have a metal shield to wear when around other people to minimize any exposure. You will have an ointment to put in your eye two to three times per day. This ointment reduces inflammation and contains an antibiotic to reduce the risk of infection.
The procedure for removing the plaque is similar to that for inserting the plaque. Following removal of the plaque, any misalignment of the eyes and the associated double vision will usually resolve 1-2 weeks following surgery. Once the plaque is removed, there is no radioactive material remaining in the eye.
Long term management
Treating the tumor with radiation does not result in immediate visible changes in the tumor. Once the eye and surrounding tissues have healed completely, you will need to return at 6 month intervals for evaluation of the response of the tumor to the radiation. These follow up visits will also include photographs of the tumor and echographic measurement of the tumor thickness. Typically, the tumor will gradually diminish in thickness, but the tumor itself will always be visible. As long as there is no recurrent growth of the tumor, we know the radiation has had the desired effect on the tumor. However, recurrent growth of the tumor can appear even 10 years following treatment, so follow up of the tumor for recurrent growth must be carried on indefinitely. Similarly, it is important that you see your primary care physician or oncologist at intervals for screening for any sign of spread of the tumor to other locations. This screening generally consists of blood tests to evaluate the liver, chest x-ray, and imaging of the liver (ultrasound, CT scan, or MRI scan).