BRACHYTHERAPY

Brachytherapy

Brachytherapy is one type of radiation therapy used to treat cancer. Brachytherapy involves placing adirectly inside or next to the tumor. Brachytherapy, also called 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 beam radiation treatment. Brachytherapy is used to treat cancers throughout the body, including the prostate, cervix, head and neck, skin, breast, gallbladder, uterus, vagina, lung, rectum, and eye.

Temporary or Permanent Brachytherapy

Brachytherapy may be either temporary or permanent. In temporary brachytherapy, a highly radioactive material is placed inside a catheter or slender tube for a specific amount of time and then withdrawn.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). In temporary brachytherapy, a delivery device, such as a catheter, needle, or applicator, is placed into the tumor using imaging such as fluoroscopy, ultrasound, MRI or CT to help position the radiation sources. The delivery device may be inserted into a body cavity such as the vagina or uterus (intracavitary brachytherapy) or applicators (usually needles or catheters) may be inserted into body tissues (interstitial brachytherapy) such as breast or prostate.



HDR BrachytherapyWith HDR brachytherapy, a specified dose of radiation is delivered to the tumor in a short burst using a remote-afterloading machine that stores a very powerful source of radioactive isotopes (Iridium-192). The HDR treatment lasts only about 10 to 20 minutes; although, the entire procedure (including placement of the delivery device) may take up to several hours. This may be repeated a couple times in a day before the delivery device (catheter/needle) is removed and the patient returns home. With low-dose rate (LDR) brachytherapy, the patient is treated with radiation delivered at a continuous rate over one to two days. A patient receiving LDR brachytherapy will stay overnight at the hospital. This is so the delivery device can remain in place throughout the treatment period. Pulsed dose-rate (PDR) brachytherapy is delivered in a similar way, but the treatment occurs in periodic pulses (usually one per hour) rather than continuously.

Brachytherapy Seed Implementation 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 months, the radioactivity level of the implants eventually diminishes to nothing. The inactive seeds then remain in the body, with no lasting effect on the patient..

 

(REFERENCE. RadiologyInfo.org from ACR and RSNA)