Treatment Planning For Prostate Cancer Using Radiation Therapy

Treatment planning is a standard term in using radiation therapy for cancer. It is used to describe the development of an individualized dosage of radiation prescribed to treat cancer in a specific patient. The goal of treatment planning is to deliver maximal radiation necessary to destroy the tumor cells, but to deliver the minimal radiation to normal cells. The treatment is individualized for the specific patient based on the radiation dosage necessary, volume of tissue to be radiated and the number of frequency of treatments and the physiologic and psychological status of the patient.

The dosage of radiation for specific tumors has been established using information gained through clinical research. The dosage for prostate cancer radiation treatment is calculated in rads or grays. A rad or the radiation absorbed dose is a measured unit indicating the dose of ionizing radiation absorbed by the tissue. A gray is equal to 100 rads. The dosage is related to the radiosensitivity of the cells contained within the tissue. Four factors determine radiosensitvity. They are the division rate of the cells, degree Cardarine of cell differentiation, size and extent of the tumor and the tumor location and environment.

The volume of tissue radiated includes the tumor and the smallest possible amount of surrounding normal tissue. Ports are body sites or areas through which radiation is directed toward the tumor. The skin outlining the port or treatment field is marked using various dyes or inks. Another approach for sparing normal tissue from excessive radiation is to use alternate ports of entry for delivery of treatment. Therapy can be directed from ventral, dorsal, lateral, or oblique directions so that normal tissue may be spared.

The number and frequency of treatments is based on the tumor lethal dose of radiation or the amount of radiation necessary to destroy the cells of a particular type of tumor. This amount of radiation delivered in a single dose would be detrimental to the health of the patient receiving the treatment and would not be the most effective approach. Thus, the tumor lethal dose is divided and administered in smaller doses given on a regular basis. It aims to produce as minimal radiation therapy side effects as possible.

The usual time frame is radiation therapy given Monday through Friday for 2 to 8 weeks. Dividing the treatments promotes repair of normal cells damaged by radiation and also increases the therapeutic responses of the tumor to the treatment. As cells are destroyed, tumor size decreases and more oxygen are delivered to the remaining cells. As the tumor decreases in size, cell cycling is also stimulated and growth is increased. As noted previously, radiation therapy is more effective with an optimal oxygen level and when cells are rapidly dividing.

Preexisting illness and a poor nutritional state can compound adverse effects of radiation therapy. The site of radiation also affects the physiologic status. Additionally, the ability of a patient to tolerate treatment is affected by the psychological and emotional status. That is why before treatment, you must have be emotionally, physically, and mentally prepared for what can happen to you.