Brachytherapy

Brachytherapy is one type of radiation therapy used to treat cancer. Radiation therapy is the use of a type of energy, called ionizing radiation, to kill cancer cells and shrink tumors.

Unlike external beam therapy (EBT), in which high-energy x-ray beams generated by a machine are directed at the tumor from outside the body, brachytherapy involves placing a radioactive material directly inside the body.

Brachytherapy, also called internal radiation therapy, allows a physician to use a higher total dose of radiation to treat a smaller area and in a shorter time than is possible with external radiation treatment.

Brachytherapy may be either temporary or permanent :

In temporary brachytherapy, the radioactive material is placed inside or near a tumor for a specific amount of time and then withdrawn. Temporary brachytherapy can be administered at a low-dose rate (LDR) or high-dose rate (HDR). Low-dose rate brachytherapy is also used in the treatment of coronary artery disease to prevent restenosis (The closing or narrowing of an artery that was previously opened by a cardiac procedure such as angioplasty.) after angioplasty.

Permanent brachytherapy, also called seed implantation, involves placing radioactive seeds or pellets (about the size of a grain of rice) in or near the tumor and leaving them there permanently. After several weeks or months, the radioactivity level of the implants eventually diminishes to nothing. The seeds then remain in the body, with no lasting effect on the patient.

Indications

• Cervical cancer
• Ovarian cancer
• Endometrial cancer
• Myometrial cancer
• Cancer of the tongue
• Esophageal cancer
• Colonic cancer
• Lung cancer
• Brain tumor
• Breast cancer

Advantages of Brachytherapy

Experts have found that brachytherapy allows a higher than normal dose of radiation placed in or adjacent to the tumor. This approach reduces the risk of damage to healthy tissue and increases the likelihood of destroying the tumor.

Choices of treatment

1. co-treatment
2. surgery

Preparation for the procedure

Your physician will determine which tests need to be done prior to your brachytherapy procedure. These may include :

• Blood tests
• Electrocardiogram (EKG)
• Chest X-rays

Your physician may also schedule an examination of the tumor with the help of imaging studies and a sophisticated computer program to plan the brachytherapy treatment.

A few days before your procedure, you will be given specific instructions on how to prepare for your brachytherapy procedure.

Procedures

Permanent Brachytherapy : In permanent brachytherapy, also called seed implantation, needles pre-filled with the radioactive seeds are inserted into the tumor, leaving the radioactive seeds behind. Seeds may also be implanted using a device that inserts them individually at regular intervals. X-rays, ultrasound or CT scans may be used to assist the physician in positioning the seeds. Additional imaging tests may be done after the implantation to verify seed placement.

Temporary Brachytherapy : In temporary brachytherapy, a delivery device, such as a catheter, needle, or applicator, is placed into the tumor using fluoroscopy, ultrasound or CT to help position them. The physician may insert the radioactive material at the same time manually through the delivery device and later remove the material and delivery device.

Alternatively, the patient may be moved to a hospital room where the delivery device is connected to a remote-controlled machine, which pushes the radioactive material to the tumor site. This is called an afterloaded implant. After a specified amount of time, the radioactive material is withdrawn back into the machine and disconnected from the delivery device.
The delivery device is then removed from the patient.

High-Dose Rate (HDR) : HDR brachytherapy is usually an outpatient procedure. A specified dose of radiation is delivered via a remote-controlled machine to the tumor in a short burst, lasting only a few minutes. This may be repeated several times in a day before the delivery device is removed and the patient returns home. Patients may receive up to 12 separate HDR brachytherapy treatments over one or more weeks.

Low-Dose Rate (LDR) : With the LDR brachytherapy procedure, the patient is treated with radiation delivered at a continuous rate over several hours or days. This treatment may be delivered using a manually or remotely afterloaded implant. Patients receiving LDR brachytherapy stays overnight at the hospital, so the delivery device can remain in place throughout the treatment period.

During the procedure : Before the brachytherapy procedure begins, an intravenous line may be inserted into your arm or hand to deliver anesthetic medications. Depending on the site of the tumor and your physician’s recommendations, you may receive general anesthesia and/or a sedative. Following the procedure, patients rest in a hospital or recovery room. Most patients can return home the same day; others might require a short stay in the hospital for observation.

Your physician and/or treatment team will give you specific home-care instructions. You might experience tenderness and swelling in the treatment area and/or other symptoms depending on your specific procedure. Most patients are able to resume their normal activities within days of brachytherapy treatment.

As your brachytherapy treatment progresses, you may experience treatment related side effects. Members of your treatment team can advise you on how to manage the anticipated side effects from your brachytherapy treatment.

Patients who have an afterloaded implant for temporary brachytherapy may hear a clicking or humming noise from the treatment machine as the radioactive material is being pushed to the tumor site. Although you will be alone during the procedure, you will be able to speak via a speaker with members of your treatment team, who will be located nearby, where they can see and hear you at all times.

In LDR brachytherapy treatment, which requires a stay in the hospital, you might experience discomfort related to having to lie relatively still for up to 72 hours. Your physician will prescribe medications to help relieve this discomfort.

Following permanent brachytherapy, in which radioactive seeds are implanted permanently in the body, the radioactivity of the seeds decays very quickly. However, you should discuss with your physician any specific recommendations for limiting close contact with others, such as pregnant women or children.

Known risks and side effects

1. radiation effects (please specify)
2. fever
3. abdominal pain
4. nausea, vomiting
5. bleeding (please specify)