What is Brachytherapy?

There are several ways of giving radiation dosage toBrachytherapy can be delivered with devices known
a cancerous tumor. The most common method is toas implants. These devices may be in the form of
deliver the required dosage from an external beamneedles or seeds or ribbons. Brachytherapy can be
of radiation produced outside the body. In this casedelivered with permanent or temporary implants.
the source of radiation beam is located 80-100 cmThese implants might be temporary or permanent.
from the body of the person receiving radiation.Temporary implants usually have a longer half-life and
Sometimes placing the source of radiation within thehigher energies compared to the permanent implants.
tumor might have advantages over deliveringAll temporary implants are inserted into the tumor
radiation from an external source. This method ofduring surgery. The duration of treatment for the
delivering required radiation from an internal sourcetemporary implant is usually 1-3 days.
embedded within the tumor is called brachytherapy.Interstitial low-dose rate (LDR) brachytherapy is
If you are aware of the inverse square law in physicsusually used for cancers involving the mouth and oral
you would know the dosage of radiation therapycavity, pharynx. This mode of treatment is often
delivery changes by a great proportion dependingused in the treatment of sarcomas. Prostate cancer
upon the distance of the radiation source to thetreatment is the most common form of LDR
intended target. In brachytherapy the source ofbrachytherapy using seeds. Uterine cancer is the
radiation is within the tumor volume and the propermost common application of intracavitary LDR
placement of these sources of radiation within thetreatment. These patients are often isolated to
tumor is of crucial importance.prevent radiation exposure to nursing and other
There are several radioactive isotopes used in thesupportive staff during the care of the person.
brachytherapy. These include radium-226, cesium-137,The most common uses of high-dose rate (HDR)
cobalt-60, iridium192, iodine-125, gold-198 andbrachytherapy includes treatment of esophageal
palladium-103. Radium has a longer half-life comparedcancer, lung cancer and recently breast cancer and
to some of the other radioactive isotopes. In theprostate cancer. Most HDR treatments are done as
past radium was the primary isotope used inoutpatient procedures allowing the patients to return
brachytherapy, but recently radium has been largelyto home the same day as treatment. Patients who
replaced by cesium, gold and iridium, which haveare receiving treatment for prostate cancer is an
relatively shorter half-life and lower energies andexception who may remain in the hospital for 2-3
because of this the radiation from these isotopes candays during the treatment.
be easily shielded.