Brachytherapy is a type of radiation therapy that involves the implantation of radioactive material inside the body to kill cancer cells and shrink tumours. It is also known as internal radiation and may radiate high or low amounts of radiation. The therapy is used to treat cancers throughout the body, including prostate, cervix, head and neck, breast, gallbladder, uterus, vagina, lung, rectum, eye and skin.
Types of brachytherapy?
There are two types of brachytherapy:
- Temporary brachytherapy: This type of radiotherapy involves implantation of highly radioactive material within the body inside a catheter or slender tube for a specific amount of time and then withdrawn. The therapy can be administered at low-dose rate (LDR) or high-dose rate (HDR) depending upon your treatment plan.
- Low-dose rate is most commonly used for treating prostate cancer. In this procedure, the radioactive seeds stay inside the prostate and radiate small amounts of radiation for a few months. You can resume your normal routine even with the seeds implanted.
- High-dose radiation lasts for 30 minutes and a computerised robot may be used to implant the seeds. The radioactive seeds inside the prostate radiate for the treatment duration and are then removed immediately after the treatment.
- Permanent brachytherapy:In this type of implantation, the radioactive seeds or pellets, which are about the size of a grain of rice, can be implanted permanently in or near the tumour. After a few months these implants lose their radioactivity and the inactive seeds remain in the body, without causing any adverse effects.
The placement of radioactive seeds is performed under the guidance of imaging studies such as CT scan or ultrasound. Implantation of the material may be either inside a body cavity or into body tissue.
- Radiation placed inside a body cavity: In intra cavity brachytherapy, the radioactive material is placed through a body opening. A tube or cylindrical device may be used to carry the radioactive material and to fit in the specific body opening.
- Radiation inserted into body tissue: In this procedure, the radioactive material can be placed within the body tissues of the prostate through a wire or balloon.
To guide and ensure the accurate placement of the device advance imaging techniques such as CT scans or ultrasound may be used.
Temporary brachytherapy: The application of high dose brachytherapy can be performed as an out-patient procedure. After screening, the radiation team inserts the radiation material in the treatment area with the assistance of a computerised monitoring machine. The team leaves the room during the treatment session and monitors you from the outside. Once the treatment session is completed, the radioactive material can be removed from the treatment site. In the case of low dose brachytherapy, you need to be hospitalised for at least one night. The procedure can be performed under anaesthesia or sedation to maintain your position during the procedure. The radiation team implants the radiation seeds to treatment location by hand or machine.
Permanent brachytherapy: This procedure is usually performed under anaesthesia or sedation. Unlike the temporary method, the radioactive seeds can be placed by hand to the treatment site and advanced using imaging such as CT scan or ultrasound to help with the implantation. After surgery, you are instructed to limit contact with others, especially young children and pregnant women as the radiation of the radioactive material can harm them. It may also set off radiation detectors at airports.
Risks and Complications
Like all procedures, brachytherapy has certain risks that may be general or specific. The general risks include allergic reactions or breathing trouble due to anaesthesia, and bleeding or infection at the site of the surgery. Specific risks of brachytherapy include impotency, difficulty with voiding requiring a catheter, rectal urgency (feeling of sudden urge to move bowels), irritation of the skin around the rectum or bleeding from the rectum, and other urinary problems. Rarely, you may develop an ulcer or fistula in the rectum, or narrowing and scarring of the urethra.