Internal radiation is a form of treatment where a source of radiation is put inside your body. This is also called brachytherapy. This allows a higher dose of radiation to directly reach the area where the tumor is, or was prior to surgery. It reduces radiation exposure to the surrounding healthy tissues, such as the bowel and bladder.
Brachytherapy for cervical or endometrial (uterine) cancers is typically done using a "tandem and ovoid" (T&O) applicator or a "tandem and ring" (T&R) applicator, which reaches both the cervix and uterus. The tandem is a long, thin metal tube that is passed through the cervix, into the uterus. The ovoids are circular hollow capsules and the ring is a hollow ring, either are placed in the vagina, pressed against the cervix. Once placed in the vagina, the applicator is connected to a machine that automatically feeds a radiation source into the applicator, where it remains for a predetermined time, known as the dwell time. Once the time is up, the machine removes the source and the applicator is removed from your vagina. The dwell time can be anywhere from 15-25 minutes and during this time you will be alone in a lead lined room. This room is to protect the technicians from receiving radiation, but they can speak to you via a two-way microphone.
Your doctor may recommend brachytherapy in conjunction with traditional external beam radiation (EBT), in which case it is typically given one to two days a week along with 3-4 days a week of EBT (you will not get EBR on the days you receive brachytherapy). Some women will receive brachytherapy after they have completed EBT. You will receive 3 to 6 brachytherapy sessions, depending on the type and extent of the tumor being treated. This article will explain the procedure and what you can expect. Be sure to talk to your doctor or nurse about the procedure at your cancer center and any questions you may have. This procedure can be scary, but knowing what to expect can help to make it a little easier.
In some cases, your doctor may use a "Smitt sleeve", also called a stent, which is a plastic hollow tube that is fitted to your uterine cavity and placed under anesthesia. This is done in a surgical facility and you will be given instructions prior to the procedure on how to prepare. The Smitt sleeve goes though your cervix, into the uterus, and is sutured in place. This remains in place until after the last T&O or T&R procedure to allow for easier, more comfortable placement of the applicator during each treatment. You will likely not feel the Smitt sleeve once it is in place and it does not require anesthesia to be removed.
On the day of a brachytherapy procedure, you will come to the radiation clinic, where you will meet with your nurse and doctor. You will be taken to the treatment room where your doctor and nurse will talk with you and ask about any problems you may be having. You will be asked to lie on a table with your legs in stirrups, similar to a gynecologic exam. Some women will have an IV catheter inserted and be given medications, which may include anti-nausea, relaxation and pain medications. A catheter (called a foley catheter) is placed into the bladder for the duration of the treatment. A contrast dye is put into the catheter, which allows the technicians and physicians to see the location of the bladder when giving the treatment.
The doctor will then insert the tandem and ovoid applicator into your vagina. The applicator is positioned and gauze is inserted around the applicator to prevent it from moving during the treatment. Alternatively, the physician may place 2 balloons (one in front of and one behind the applicator), which are filled with a contrast dye solution that can be seen on the CT scan. These balloons keep the applicator from moving and provide some protection to the surrounding bowel and bladder tissue. The placement of the applicator can take 30-40 minutes.
Once the equipment has been placed, multiple scans will be performed to check placement of the applicator and to plan your radiation dose. These may include x-rays, CT scans and/or MRIs. When the scans are completed you will need to wait while your doctor and physicist plan your radiation treatment. The planning is a complex process and can take several hours. While you wait, you will be able to have a friend or family member sit with you. You may want to bring something to help you relax while waiting for the treatment to be planned; music with headphones, a book, magazines, etc.
Tandem & ovoid applicator
Tandem & ring applicator
The brachytherapy treatment room
Tandem & Ovoid applicator in place (as seen by x-ray)
Once the planning is complete, the applicator is connected with thin wires to the brachytherapy machine, which houses the radiation source. Once everyone has left the room, the brachytherapy machine dispenses the radiation source into the applicator. You will not feel this, but you may hear the noise of the machine. A physicist has determined how much radiation will be used and how long it will need to remain in place, therefore the time the radiation remains in the applicator varies based on your treatment plan, but is typically 20-25 minutes. The doctor or technician can tell you ahead of time how long the radiation will remain in the applicator so you are prepared. You will be alone in the room during this time, but your team can see and hear you from their control room.
Once the time is up, the machine removes the radiation source and returns it to the housing, making it safe for the team to enter the room again. The applicator and foley catheter will then be removed. You will need to remain in the department for a little while to be monitored for bleeding, be sure you can urinate on your own after the catheter is removed and to be sure you can move around safely after any medications you received. You will go home the same day. You will not be able to drive a vehicle or do any strenuous activity, so be sure to have an escort to take you home.
Learn more about the potential side effects of radiation therapy for gynecologic cancers.