Radiation Therapy Planning

Cat scan for radiation therapy planning at Dr. Nav Sharda's office.

Courtesy of Wikimedia Commons.  CT Scanner for Radiotherapy Planning

Radiation Simulation:

Radiation simulation is a planning session that helps the radiation therapy team design your radiation treatments. It is done to verify that the radiation is aimed at exactly the right place in the body. Simulation is usually done in one session and may take anywhere from 15 minutes to an hour or more.

A machine called a simulator is used to position your body as part of the treatment plan.  It is also used to map out the treatment area. A simulator is not a radiation treatment machine ( that is called a Linear Accelerator). The most modern type of simulator used is a CT simulator. It will take images or scans which give the healthcare team a detailed picture of the part of the body to be treated. These images are transferred to the treatment planning computer and help the radiation therapy team decide where and how to direct the radiation.  Dr. Navneet Sharda began the Cancer Care Centers with a CT Simulator on site in 2001.  This was the first Oncology facility to have a  CT simulator in the office in the entire Las Vegas, Henderson or Summerlin valley.

Navneet Sharda MD las vegas new technology CT scanner

Dr. Sharda shows off his new CT scanner.

The most comfortable position for treatment is chosen during the radiation simulation. The patient is positioned in exactly the same way each time a treatment is given.  Immobilization devices are made to support the patient and allow him/her to remain in the same position for each treatment. Forms, molds, pads or other devices are made from plastic, foam, plaster or other materials. Immobilization devices are specially made to fit the person’s shape. Marks to pinpoint the treatment area may be made on the mold rather than the skin.

Special shields or lead blocks may be used to protect normal tissue or organs from radiation. Blocks are usually made specifically for each person. Just before treatment is given, the shields or blocks are placed between the radiation therapy machine and the areas of the body that need protection.

The oncology team enters the data collected during simulation into a sophisticated computer to develop the treatment plan. The first external beam radiation treatment is usually scheduled shortly after the planning session.