Quality Assurance Program Radiation Oncology Center of Olathe

The Radiation Oncology Center at Olathe has an extensive quality assurance program to verify the accurate and reliable delivery of all radiation therapy treatments.  All aspects of the radiation therapy treatment delivery process and related procedures are reviewed and monitored under our QA program.  These processes are briefly summarized below.

Linear Accelerator Quality Assurance

The linear accelerator is the machine which actually delivers the radiation used to treat our patients.  In order to assure the quality and consistency of the radiation beams and other components of the performance of radiation therapy, we undergo extensive quality assurance procedures.  These procedures include:

Daily treatment calibration and verification.  Prior to each day’s treatment all important functions of the machine are verified to be within expected specified levels and recorded.  The radiation output, the flatness of the beam, the energy of the beam, and the doses delivered are tested and recorded.  Some treatments require highly sophisticated therapy which includes image-guided radiation therapy and the ability to monitor patient position throughout the course of therapy, often to a small fraction of one millimeter.  All energies and types of radiation are verified during this process to be functioning optimally.  The machine movement, the position of field, and other features of the machine are verified daily.  This ExacTrac image-guided radiotherapy system is also calibrated and verified daily. 

The linear accelerator is equipped with what is referred to as a “record and verify” system.  Every treatment and component of treatment is programmed via computer to correspond to the specially designed treatment plan prior to the actual implementation of therapy and corresponding delivery of a radiation treatment.  All critical components of the data entered into the computerized record and verify system are checked by more then one technician or professional staff member prior to therapy being delivered. The computer verifies each of the parameters of treatment (type of radiation, energy of radiation, shape of radiation, and beam-modifying devices as examples) before any treatment can be delivered.  The machine verifies that every component of the treatment machine has been properly oriented – i.e. it matches the specially designed plan for that particular patient - prior to allowing the machine to turn on.  It then records the exact parameters of the treatments for the medical record precisely as it was given.

Patients who require intensity-modulated radiation therapy receive treatment which requires the sophisticated delivery of a myriad (often times greater than 100) number of beamlets.  To verify the accurate delivery of this type of treatment, a board certified physicist subjects each treatment plan to a quality assurance program prior to treatment implementation.  A devise called a ‘phantom’ is irradiated by the linac giving the therapy which has been programmed to be implemented on a daily basis.  This phantom is equipped with an ionization chamber which measures and verifies that the dose of radiation therapy is administered precisely according to prescription and that the radiation therapy is administered to the precise correct shape and distribution as the treatment plan.  This occurs prior to any patient’s treatment being initiated for intensity-modulated radiation therapy. 

Weekly verification of the parameters of linear accelerator function, including the multileaf collimator position and functionality, is conducted.  Additionally, each patient’s treatment is reviewed by a board certified medical physicist as well as a physician on a weekly basis. 

Complete monthly and yearly quality assurance review and testing of the machine specifications, functions and radiation dose distributions are conducted according to current published national standards. 

Every year, all of the types of radiation beams which are utilized at our center in the treating of patients are measured and reviewed by the Radiologic Physics Center, RPC, at MD Anderson Cancer Center.  This procedure evaluates the accuracy of each of the radiation beams and ensures that the amount of radiation administered is precisely accurate for all energies and beams of radiation therapy. 

Intensity Modulated Radiation Therapy Radiation Physics Center Quality Assurance Program

The Radiation Oncology Center of Olathe is one of an elite group of radiation oncology departments in the United States which have undertaken the MD Anderson Cancer Center Radiation Physics Center evaluation of our intensity-modulated radiation therapy program.  To meet the standards of this evaluation, institutions need to administer an intensity-modulated radiation therapy to a phantom and pass very strict evaluation of accuracy of both dose and geometry of the radiation distribution.  The Radiation Oncology Center of Olathe has taken this evaluation and passed with outstanding results. 

Simulation

The simulation procedure is the procedure whereby patients are placed in the treatment position, and information is collected to permit the planning procedure.  This occurs utilizing a CT-based treatment planning system. A strict quality assurance program is implemented for this process that is similar to that for the linac itself.  This ensures that the laser beams on the CT and the linac operate precisely as planned on a comparative basis.  The functionality of the CT scan including slice thickness, contrast, spacial resolution, and other variables, are evaluated weekly to ensure the highest quality of image acquisition is accomplished for this component of the procedure.

Treatment Planning Quality Assurance Program

The treatment planning system utilized at ROCO is the latest iteration of the Pinnacle Treatment Planning System, a product of Phillips Healthcare.  This treatment planning system uses highly reliable mathematics and treatment planning procedures to calculate and ensure the accurate delivery of radiation.  After treatment is planned on the Pinnacle System, each beam is then evaluated by a separate program to ensure that the calculation of dose is precise.  This RADCALC Program is a second stand-alone system which checks to ensure correct calculation of dose, both for normal external beam treatments and intensity-modulated radiation therapy treatments. All therapy plans are reviewed and approved prior to implementation by a certified medical dosimetrist, a board certified radiation physicist as well as the physician.