Brachytherapy (Radiotherapy)

What is Brachytherapy?

Brachytherapy is a radiotherapy technique used to fight cancer by directing targeted radiation to shrink tumors. The goal is to conform the dose to the size and shape of the target while minimizing the dose to surrounding healthy tissue. Sometimes, brachytherapy is referred to as "internal radiotherapy." Or it may be called "seed therapy" when treating prostate cancer using permanently placed low-dose rate (LDR) sources.

While external beam radiation therapy works by delivering a beam of radiation to the tumor from outside the body, Brachytherapy treats cancer by placing radioactive sources directly into or next to the target area. This enables clinicians to deliver a high dose to the target area with minimal impact on surrounding healthy tissues. The radiation damages the DNA within the cancer cells, inhibiting their ability to grow and reproduce. In some instances, Brachytherapy is used in conjunction with external beam radiation therapy to deliver a higher dose to a specific area.

Brachytherapy is used to treat cancers of the prostate, cervix, endometrium, breast, skin, bronchus, esophagus, and head and neck, as well as soft tissue sarcomas and several other types of cancer.1 Talk to your doctor about whether or not Brachytherapy is appropriate for your treatment.

How brachytherapy is administered depends on the technique used. There are two main types of brachytherapy: HDR (high-dose rate) and LDR (low-dose rate):

HDR brachytherapy involves placing a single high-strength radioactive source next to or inside the tumor for a short period of time, usually a few minutes, and then removing it. Typically, doctors use catheters or needles — usually called "applicators" - to direct the radioactive source to the tumor, though it depends on the area of the body being treated; in some instances, catheters may not be necessary.

HDR brachytherapy is often used to treat gynecological, lung, breast, prostate, and head and neck cancers. It is usually performed on an outpatient basis, meaning the patient does not need an overnight stay in hospital. Only a few outpatient sessions of treatment are typically needed (1 to 5), which can take place over a period of a few hours, days or weeks.

LDR brachytherapy requires that sources of radiation are placed inside the tumor permanently. This type of brachytherapy is mostly used in the treatment of prostate cancer — sometimes known as "seed therapy." For prostate treatments, the radiation sources look like tiny seeds, about the size of a grain of rice. The level of radiation given out by the seeds gradually decreases over time to almost nothing. Most of the radiation is released over 3 months, and by 9 months, the seeds are practically inactive.

In addition to LDR and HDR brachytherapy, radiation can also be delivered in short pulses of radiation (e.g. once an hour) over a total period of up to 24 hours. This is termed "pulsed dose rate" or PDR brachytherapy. PDR brachytherapy is often used to treat gynecological and head and neck cancers.