Brachytherapy

Radiation therapy is subdivided into external (tele-) and internal (brachy-) therapy. Teletherapy (Greek: tele = long) comprises delivering the radiation externally to the patient's body using a linear accelerator. Conversely, brachytherapy (Greek: brachy = short) applies radioactive sources directly to or into the tumor, allowing a high dose to the tumor while sparing the surrounding healthy tissue. For the patient, this means shorter treatment periods, fewer side effects and a faster recovery.

Localized radiation to tumor cells via brachytherapy

Brachytherapy can be used either alone or in combination with other types of treatment. Sometimes it is used after surgery to ensure that all cancer cells are eliminated. It can also be used in conjunction with external beam radiation.

There are two methods of brachytherapy delivery; temporary irradiation from a removable source or continuous irradiation from permanently implanted sources:

Permanent brachytherapy (also called LDR brachytherapy) means that small radioactive seeds or implants (smaller than a grain of rice) are placed into the tumor or treatment site, where they remain permanently. The radiation dose emitted from the radiation source falls over weeks or months to almost zero. Finally, the seeds remain inactive with no lasting impact in the treatment site. Permanent brachytherapy is mainly used for the treatment of prostate cancer.

For more information, please go to the "Prostate Cancer" section. 

In temporary brachytherapy (also called high dose rate brachytherapy), sources are placed in or close to the tumor for a specified time (usually a few minutes) and removed again afterwards. The actual duration of the treatment depends on many different factors such as the required intensity of the dose delivery as well as the type, the size and the position of the tumor.

High dose rate (HDR) brachytherapy allows radiation oncologists to deliver the radiation quickly, mostly as an outpatient procedure. The two main methods of HDR brachytherapy delivery are interstitial treatment and intracavitary treatment. During interstitial radiation treatment, applicators such as needles or catheters are inserted in or adjacent to the tumor. Sometimes, surgical procedures are used to place catheters directly into the tumor. During intracavitary brachytherapy, a device, such as a tube or applicator is placed in a body cavity, e.g. the cervix or vagina.

A Radiation Oncologist will develop a specific prescription for how the radiation will be administered and what doses of radiation are necessary to achieve successful treatment, for each individual patient. The physician will also be responsible for the placement of the applicator or applicators at the target site. Imaging procedures like computed tomography (CT), ultrasound (US) or magnetic resonance imaging (MRI) are used to ensure the correct placement of these devices.

When the patient is in the radiation treatment room, a computer driven apparatus, called a remote afterloading device, pushes the radioactive source, which is attached to a wire, through the transfer tubes and the applicators to the treatment site. The radioactive source, either Cobalt-60 or Iridium-192, can be moved in millimeter increments and remain in a certain position (dwell position) for a predetermined amount of time. When the desired treatment dose has been achieved, the remote afterloading device automatically withdraws the radioactive source so there is no residual radiation or radioactivity.

Most HDR brachytherapy treatments are done with one weekly treatment for a period of up to four weeks or with one or two treatments per day for up to five days. These common indications may differ in some cases. The radiation delivery only lasts a few minutes while the procedure (also called session) including patient setup, applicator positioning, treatment planning and treatment delivery itself, last up to a few hours.


HDR Brachytherapy Animation (English)


There are two methods of brachytherapy delivery; temporary irradiation from a removable source or continuous irradiation from permanently implanted sources:

Permanent brachytherapy (also called LDR brachytherapy) means that small radioactive seeds or implants (smaller than a grain of rice) are placed into the tumor or treatment site, where they remain permanently. The radiation dose emitted from the radiation source falls over weeks or months to almost zero. Finally, the seeds remain inactive with no lasting impact in the treatment site. Permanent brachytherapy is mainly used for the treatment of prostate cancer.

For more information, please go to the "Prostate Cancer" section. 

In temporary brachytherapy (also called high dose rate brachytherapy), sources are placed in or close to the tumor for a specified time (usually a few minutes) and removed again afterwards. The actual duration of the treatment depends on many different factors such as the required intensity of the dose delivery as well as the type, the size and the position of the tumor.

High dose rate (HDR) brachytherapy allows radiation oncologists to deliver the radiation quickly, mostly as an outpatient procedure. The two main methods of HDR brachytherapy delivery are interstitial treatment and intracavitary treatment. During interstitial radiation treatment, applicators such as needles or catheters are inserted in or adjacent to the tumor. Sometimes, surgical procedures are used to place catheters directly into the tumor. During intracavitary brachytherapy, a device, such as a tube or applicator is placed in a body cavity, e.g. the cervix or vagina.

A Radiation Oncologist will develop a specific prescription for how the radiation will be administered and what doses of radiation are necessary to achieve successful treatment, for each individual patient. The physician will also be responsible for the placement of the applicator or applicators at the target site. Imaging procedures like computed tomography (CT), ultrasound (US) or magnetic resonance imaging (MRI) are used to ensure the correct placement of these devices.

When the patient is in the radiation treatment room, a computer driven apparatus, called a remote afterloading device, pushes the radioactive source, which is attached to a wire, through the transfer tubes and the applicators to the treatment site. The radioactive source, either Cobalt-60 or Iridium-192, can be moved in millimeter increments and remain in a certain position (dwell position) for a predetermined amount of time. When the desired treatment dose has been achieved, the remote afterloading device automatically withdraws the radioactive source so there is no residual radiation or radioactivity.

Most HDR brachytherapy treatments are done with one weekly treatment for a period of up to four weeks or with one or two treatments per day for up to five days. These common indications may differ in some cases. The radiation delivery only lasts a few minutes while the procedure (also called session) including patient setup, applicator positioning, treatment planning and treatment delivery itself, last up to a few hours.


HDR Brachytherapy Animation (English)