For the next couple of articles I plan on going through all treatment options for breast cancer other than surgery.
Most of this information was taken from Oncolink
Some statistics...Radiation therapy is one of the major treatment modalities for cancer. Approximately 60% of all people with cancer will be treated with radiation therapy sometime during the course of their disease. Its effectiveness as a treatment for cancer was first reported in the late 1800s. Advances in equipment technology, combined with the science of radiobiology, have led to today's highly sophisticated treatment centers. Radiation therapy can now be delivered with maximum therapeutic benefits, minimizing toxicity and sparing healthy tissues.
Radiation therapy is the use of high level radiation to destroy cells. Both tumor cells and healthy cells are affected by radiation. The radiation injures the cancer cells so they can no longer continue to divide or multiply. With each treatment, more of the cells die and the tumor shrinks. The dead cells are broken down, carried away by the blood and excreted by the body. Most of the healthy cells are able to recover. However, the damage to the healthy cells cause the side effects of radiation therapy. Radiation has its greatest effect on tissues that divide rapidly.
The dose of radiation is determined by the size, extent, type and grade of tumor and its response to radiation therapy. Complex calculations are done to determine the dose and timing of radiation in treatment planning. Often, the treatment is given over several different angles in order to deliver the maximum amount of radiation to the tumor and the minimum amount to normal tissues.
The dose of radiation administered is determined by a number of factors, including the radiosensitivity of the tumor, the normal tissue tolerance, and the volume of the tissue irradiated. The Gray, the Systeme Internationale Unit, has now replaced the "rad" (radiation absorbed dose) as the accepted term of radiation dosage. One Gray (Gy) = 100 rads; therefore, 1cGy = 1 rad.
A radiosensitive tumor is one that can be eradicated by a dose of radiation and is well tolerated by the surrounding normal tissues.
For some tumors, a "boost" or "reduced field" of radiation is administered to complete the course of therapy. These treatments are delivered to limited areas within the treatment field that are at highest risk for recurrence. In this way, the tumor can be treated with a higher dose than the normal surrounding tissues would tolerate or need. The "boost" may be aministered externally or internally.
