How Brachytherapy Is Beneficial In Treating Cancer?
Brachytherapy is a term which describes widely varying processes with varying degrees of invasiveness. Patients must discuss the process experts with their radiation oncologist.
EBRT (External Beam Radiation Therapy) includes high-energy x-ray beams produced by a machine which are aimed at the tumor from outside the body.
Brachytherapy is an advanced therapy of cancer. This therapy involves placing of a radioactive substance directly inside or adjacent to the tumor itself, providing a high radiation dose to the tumor while decreasing the radiation exposure in the nearby healthy tissues.
It also known as Internal Radiation Therapy that allows a physician to utilize a higher total dose of radiation to heal a smaller area in a shorter time than is likely with external beam radiation treatment.
The term “brachy” is a Greek word used for short distance. Brachytherapy is a radiation therapy provided at a short distance: precise, localized and high-tech.
Brachytherapy is Applied to Heal Cancers All Through the Body, Involving:
- Head and neck
Is There Any Particular Preparation Required For The Procedure?
Your physician will decide which preparations require to be done before your brachytherapy process. They may involve:
- Blood tests
- Bowel preparation
- Chest X-rays
- Pre-treatment ultrasound, CT scan or MRI
- Electrocardiogram (EKG)
Before the actual treatment process, the physician may also utilize computer program to plan this cancer therapy.
A few days before your process, you will be given specific instructions on how to plan this therapy process.
How is the Brachytherapy Performed?
Brachytherapy can be either temporary or permanent. In temporary brachytherapy, a highly radioactive substance is kept inside a catheter or a small tube for a particular amount of time and then withdrawn. It can be administered at a LDR (Low Dose Rate) or HDR (High Dose Rate).
In this temporary process, a delivery device like needle, catheter or applicator is located into the tumor by imaging like ultrasound, fluoroscopy, MRI or CT to aid positions the radiation sources. The delivery device can be placed into a body cavity like the uterus or vagina (intracavitary brachytherapy) or applicators (generally catheters or needles) can be placed into the body tissues (interstitial brachytherapy).
Permanent brachytherapy also known as seed implantation includes placing radioactive seeds or pellets (approx the size of a grain of rice) inside or near the tumor by needles and to leave them there permanently. Seeds may also be rooted using a device that adds them individually at daily intervals. Ultrasound, X-ray, CT scan or MRI may be utilized to help the physician in placing the seeds. Additional imaging tests might be done after the implantation to make sure seed is placed in the right way. After a few months, the radioactive level of the implants ultimately reduces to nothing. The immobile or inactive seeds then remain in the body, with no long-lasting effect on the patient. At times, these inactive metallic seeds can activate metal detectors at airport.
Treatments may be carried at a high dose-rate (HDR) up to 10 to 20 minutes per session or at a low dose-rate (LDR) up to 20 to 50 hours. Treatment can also be conveyed in periodic pulses (PDR or pulsed dose-rate).
HDR brachytherapy is generally an outpatient process, though patients are sometimes admitted to the hospital for 1 to 2 days to have various HDR treatments applying the same applicator. With HDR brachytherapy, a specific dose of radiation sent to the tumor in a short burst utilizing a remote-after-loading machine which stores a very strong source of radioactive isotopes (Iridium 192). It is done to defend the personnel from unnecessary exposure to radiation. This HDR treatment lasts just 10 to 20 minutes, though, the whole process (involving the placement of the delivery device) might take up to some hours. It may be repeated many times a day before the delivery device is taken out and the patient returns home. Patients might get up to 10 separate HDR brachytherapy treatments above one or more weeks.
With LDR or low dose-rate brachytherapy, the patient is cured with radiation sent at a constant rate over 1 to 2 days. A patient with LDR brachytherapy stays approximately one night in hospital.
PDR or Pulsed dose-rate brachytherapy is applied in a similar way, but the treatment happens in periodic pulses (generally one per hour) rather than constantly. The physician may add the radioactive material manually by the delivery device and later eliminates the material and delivery device when the treatment is completed.
Alternatively, the patient may be shifted to a shielded treatment room which contains a remote after loading unit that adds the radioactive material to the delivery device within the tumor side. The radioactive material is automatically excluded when somebody enters the patient’s room and when the treatment is done.
When the Brachytherapy treatment is finished, the delivery device is eliminated from the patient.
- Mhow Cantt, Indore