Brachytherapy sometimes referred to as seed implantation, uses a small
radioactive seed like pellet that is implanted directly into and around the
prostate. The pellet or seed, which is about the size of a grain of rice, is
usually only used in patients that have a relatively slow growing prostate
cancer. The radioactive seeds are able to deliver a high dose of radiation to
the tumor in an area no larger than a centimeter. Adjacent areas receive very
little or no radiation. This allows the surgeon to administer higher doses
without harming normal cells.
How does Brachytherapy decrease the tumor?
Ionizing radiation, emitted by the seed, is used to kill the cancer causing
cells. The surgeon will place the radioactive seed directly into or very close
to the cancerous tumor. The radiation from the implant seed kills the tumor by
destroying the cell’s DNA. When the cancer cell begins to divide and reproduce,
it is unable to do so because the DNA is no longer intact. This causes the
cancer to die.
Ionizing radiation, emitted by the seed, is used to kill the cancer causing
cells. The surgeon will place the radioactive seed directly into or very close
to the cancerous tumor. The radiation from the implant seed kills the tumor by
destroying the cell’s DNA. When the cancer cell begins to divide and reproduce,
it is unable to do so because the DNA is no longer intact. This causes the
cancer to die.
 | (Left) Brachytherapy seeds being prepared for
implantation.
(Right) The size of a Brachytherapy seed compared to a US dime.. |  |
Two Types of
Brachytherapy
Permanent Brachytherapy
The procedure for permanent Brachytherapy usually takes about an hour
depending on how many seeds are implanted into the prostate. Patients can
receive anywhere from 40 to 100 seeds. The seeds will remain in the prostate
giving off radiation for weeks to months. Due to the small size of the seed,
they cause little discomfort and are left in place after their radiation
material is used up. The actual implantation process is painless because general
or spinal anesthesia has been given to the patient. Since there are no incisions
or stitches there is little pain after the procedure.
Temporary Brachytherapy
The radiation oncologist will use the assistance of a CT scan to help place
catheters into the tumor. The catheters will be the delivery device and pathway
for the high dose-rate (HDR) Brachytherapy treatment. The delivery device
remains in the patient while they receive treatments. Treatments can be done in
the outpatient setting over the course of one or more weeks. However, some
patients are admitted to the hospital if they are going to have several
treatments on a daily basis. Once the treatment regimen is complete, the
catheters are removed.