Treating Cancer with Radiation
There are two broad categories of radiation therapy treatments:
- External beam radiation therapy (EBRT) – External beam is non-invasive and is typically performed once per day for about 6 -7 weeks. Each treatment takes about 30 to 60 minutes. To avoid long-term side effects, care must be taken to ensure healthy tissues are not irradiated
- Internal (brachy-) therapy – There are two types of Brachytherapy — high dose-rate (HDR) and low dose-rate (LDR). Both HDR and LDR brachytherapy have similar cancer control and long-term survival rates compared to EBRT and surgery.
A small diameter radiation source is placed directly into or close to the prostate tumor for a specified time, usually a few minutes, and then removed. During a typical treatment session, additional sources are placed into different locations within the prostate until the entire gland has been adequately irradiated. Most HDR brachytherapy treatment sessions are repeated once per week for a period of 4 to 5 weeks.
The radiation sources are permanently implanted into and around the tumor during a single procedure. The localized radiation dose that is emitted from the radiation source weakens over weeks or months to almost zero. Finally, the small implants become inactive with no lasting impact and will permanently remain in the prostate gland.