History of Brachytherapy
Brachytherapyis a form of internal radiation treatment where radioactive sources are placed on or into cancer tissues. Sometimes the radiation is put in place through a larger metal or plastic tube called an applicator.
During the treatment, implants are placed in the body through the applicators. Some implants are permanent, while others are left in for a short period. The applicator may be removed at the same time as the implant, or it may be left in place until all the treatments are finished. Applicators can be placed either during surgery or by your physician using an imaging test to view the intended location. If the applicators need to be held in place, stitches may be used.
This is not a new technique. It has actually been around for over 100 years as can be seen in the below timeline:
Specific implants are selected based on the location of the tumor, the extent of the tumor, and several other factors. These types are:
- Intracavitary Implant: an applicator is inserted into a body cavity to reach the tumor. Intracavitary implants are performed in the UCLA Brachytherapy Suite on an outpatient basis.
- Intraluminal Implant: the catheters are inserted into a "tube" structure such as the bronchus, esophagus, or bile duct. These are also performed on an outpatient basis.
- Interstitial implant: are more complex. The implants are done in the operating room with the patient under local, general or spinal anesthesia. Interstitial catheters are inserted through the body tissue to encompass the tumor.
Low Dose Rate (LDR) Implants
LDR was once the only type of brachytherapy available. In this type of brachytherapy, the source of radiation stays in place for one to seven days. Most patients are hospitalized for the duration of this treatment, and once the treatment is completed, the radiation source is removed.
High Dose Rate (HDR) Implants
During HDR brachytherapy, the radiation source is in place for 10 to 20 minute periods and then removed. Depending on cancer type, HDR treatments may occur once or twice a day for two to five days or once a week for two to five weeks. During the course of treatment, the applicator may stay in place, or it may be put in place before each treatment. As with LDR implants, the applicator will be removed once treatment is finished.