Center for Cancer Care
Radiation Therapy Treatment Planning Process
After a consultation with the radiation oncologist, a multi-step planning process takes place before the radiation treatments begin.
A simulation session is scheduled as the first step of the planning process. During this session, the radiation oncologist and radiation therapist plan out the course of treatment. A simulator uses fluoroscopic x-rays to visualize a patient's internal organs and correctly determine the treatment fields. It also has the ability to take x-rays to verify the treatment area.
Patients are asked to lie on a table and are placed in an appropriate position to target the tumor. Depending on the part of the body that is treated, an immobilization device may be required. The device prevents any movement during the treatment and is custom made to fit the patient's body. It is sometimes necessary to place wires on the skin or to use radio-opaque contrast to help define the normal tissues. X-rays are obtained to visualize the areas of interest. Marks are placed on the skin to be used as daily references points. These marks need to remain in place for the course of treatment.
After the simulation, a CT scan is done in the Radiology Department to assist in the planning of the daily delivery of the radiation treatment. At this time, the patient is positioned in the scanner exactly as during the simulation. The scan outlines the areas of interest and the information is forwarded to Radiation Oncology for planning. After the treatment planning process is complete, the Radiation Oncology staff then calls to schedule a verification simulation prior to the first radiation treatment.
During this time, the radiation oncologist and the dosimetry/physics team decide what type of radiation to use, the dose of radiation and the best ways to target the cancer. This decision is based on the size of the tumor, how sensitive the tumor is to radiation and the ability of the normal tissue in the area to withstand the radiation.
Three-dimensional (3-D) treatment planning software is utilized to design and optimize the radiation therapy treatment for patients. This software allows the physicians to view a patient's tumor three-dimensionally, enabling them to judge the most effective strength of the treatment beam to use, while minimizing damage to the healthy tissues surrounding the tumor.
Plan Verification Simulation
Once the medical team has completed the treatment plan for the patient's course of therapy, a simulation to confirm the plan specifications takes place. The parameters of the plan are verified prior to the first day of radiation treatment. X-rays are taken as documentation of the treatment plan. After the verification is complete, an appointment for the patient's first radiation treatment is scheduled.
Radiation therapy usually requires five treatments per week, Monday through Friday, for two to eight weeks. Other schedules are sometimes used. The radiation therapists work with the patient in scheduling the daily appointments.
During treatment, the radiation therapist places the patient on the treatment table in the same position that was used during the simulation. The positioning or immobilization devices used in simulation are used throughout the patient's radiation therapy. A set of x-ray images is obtained to ensure proper positioning for the treatment. These images are repeated weekly for verification purposes. After the images are verified, the first radiation treatment begins. Radiation treatments are much like getting an x-ray, the patient does not see or feel anything. During treatment, the radiation therapists monitor the patient through the use of an intercom and closed circuit television system.
Weekly Physician Visits
Throughout the course of treatment, patients visit with the radiation oncologist and nursing staff weekly. These visits allow questions to be answered and any side effects to be addressed. Nurses and radiation oncologists are available to answer questions or concerns at any time.
The radiation oncologist will see the patient periodically after treatment ends in order to assess the long-term outcome of therapy. The radiation oncologist will determine the number of appointments.