| Treatment planning is a standard term in using | | | | or oblique directions so that normal tissue may be |
| radiation therapy for cancer. It is used to describe | | | | spared. |
| the development of an individualized dosage of | | | | The number and frequency of treatments is based |
| radiation prescribed to treat cancer in a specific | | | | on the tumor lethal dose of radiation or the amount |
| patient. The goal of treatment planning is to deliver | | | | of radiation necessary to destroy the cells of a |
| maximal radiation necessary to destroy the tumor | | | | particular type of tumor. This amount of radiation |
| cells, but to deliver the minimal radiation to normal | | | | delivered in a single dose would be detrimental to the |
| cells. The treatment is individualized for the specific | | | | health of the patient receiving the treatment and |
| patient based on the radiation dosage necessary, | | | | would not be the most effective approach. Thus, the |
| volume of tissue to be radiated and the number of | | | | tumor lethal dose is divided and administered in |
| frequency of treatments and the physiologic and | | | | smaller doses given on a regular basis. It aims to |
| psychological status of the patient. | | | | produce as minimal radiation therapy side effects as |
| The dosage of radiation for specific tumors has been | | | | possible. |
| established using information gained through clinical | | | | The usual time frame is radiation therapy given |
| research. The dosage for prostate cancer radiation | | | | Monday through Friday for 2 to 8 weeks. Dividing the |
| treatment is calculated in rads or grays. A rad or the | | | | treatments promotes repair of normal cells damaged |
| radiation absorbed dose is a measured unit indicating | | | | by radiation and also increases the therapeutic |
| the dose of ionizing radiation absorbed by the tissue. | | | | responses of the tumor to the treatment. As cells |
| A gray is equal to 100 rads. The dosage is related to | | | | are destroyed, tumor size decreases and more |
| the radiosensitivity of the cells contained within the | | | | oxygen are delivered to the remaining cells. As the |
| tissue. Four factors determine radiosensitvity. They | | | | tumor decreases in size, cell cycling is also stimulated |
| are the division rate of the cells, degree of cell | | | | and growth is increased. As noted previously, |
| differentiation, size and extent of the tumor and the | | | | radiation therapy is more effective with an optimal |
| tumor location and environment. | | | | oxygen level and when cells are rapidly dividing. |
| The volume of tissue radiated includes the tumor and | | | | Preexisting illness and a poor nutritional state can |
| the smallest possible amount of surrounding normal | | | | compound adverse effects of radiation therapy. The |
| tissue. Ports are body sites or areas through which | | | | site of radiation also affects the physiologic status. |
| radiation is directed toward the tumor. The skin | | | | Additionally, the ability of a patient to tolerate |
| outlining the port or treatment field is marked using | | | | treatment is affected by the psychological and |
| various dyes or inks. Another approach for sparing | | | | emotional status. That is why before treatment, you |
| normal tissue from excessive radiation is to use | | | | must have be emotionally, physically, and mentally |
| alternate ports of entry for delivery of treatment. | | | | prepared for what can happen to you. |
| Therapy can be directed from ventral, dorsal, lateral, | | | | |