Brachytherapy

Brachytherapy treatment plan is created and governed by a radiation oncologist, who is a highly trained physician specializing in treating cancer with radiotherapy. The radiation oncologist will require a team, including a medical physicist, dosimetrist, radiation therapist, radiation therapy nurse and in some cases, a surgeon to conduct the procedure. However, the radiation oncologist is the one who evaluates the patient and determines the appropriate therapy, including how much radiation to deliver.

In permanent brachytherapy, needles that are pre-filled with the radioactive brachytherapy seeds are inserted into the tumor. Then the needle or device is removed, leaving the radioactive seeds behind. Sometimes these seeds may be implanted in sessions using a device that inserts them individually at regular intervals. An appropriate imaging means such as an ultrasound, X-ray, MRI or CT scan may be used to assist the physician in positioning brachytherapy seeds at the right place. After implantation, some additional imaging can be done to verify seed placement.

Temporary brachytherapy starts with placing a delivery device, such as a catheter, needle, or applicator, into the tumor. Methods of imaging such as an ultrasound, MRI, or CT scan will help position the radiation sources correctly. The delivery device can either be inserted into a body cavity such as vagina (intracavitary brachytherapy) or applicators such as needles or catheters can be inserted into body tissues (interstitial brachytherapy). Device implantation will depend on the location of cancer.

Radiation using brachytherapy procedure can be delivered at three different levels:

• High-dose-rate (HDR):

  HDR brachytherapy is given for over 10 to 20 minutes per session, but it can take several hours worth of preparation, which includes device placement. HDR brachytherapy is mostly conducted as an outpatient procedure, although sometimes patients are admitted for one to two days to have several HDR brachytherapy sessions using the same applicator.

  HDR brachytherapy delivers a specified dose of radiation to the tumor in a short burst using a remote-afterloading machine. This will help protect the patient from unnecessary exposure to radiation. This procedure can be repeated a couple of times on the same day.

• Low-dose rate (LDR):

  LDR is delivered at a continuous rate of radiation for over 20 to 50 minutes. The patient needs overnight hospitalization so the delivery device can remain in place throughout the treatment. The radiation oncologist may insert the radioactive particle manually through the delivery device and remove the material and delivery device after the treatment.

• Pulsed dose-rate (PDR):

  PDR brachytherapy is delivered in a similar way of LDR, but the treatment takes place in periodic pulses instead of continuous radiation.

For patients who have received brachytherapy for prostate cancer or any other types of cancer, limiting physical activity for at least three to five days is important. You can experience some level of grogginess after the procedure, however, it will last for only a few hours. You will be prescribed a few emergency medicines that you can take in case you experience pain or any other type of discomfort.

There are some side effects associated with all kinds of radiation therapy. However, the acute, sub-acute, or long-term side effects of brachytherapy depend on the location of the tumor being treated and the type of brachytherapy being used.

Some acute side effects of brachytherapy are

• Localized bruising,
• Bleeding, swelling,
• Fatigue and discomfort within the implanted region.

But these are temporary side effects and usually resolve within a few days following completion of treatment.

Usually, brachytherapy does not cause any long-term side effects, but in a few cases, it may cause urinary and digestive problems. But in that case as well, long-term side effects are usually mild or moderate in nature and there are many palliative medicines that are available to cope with the symptoms.