quality assurance at wellspring

Quality Assurance at Wellspring

The program is in place to ensure that patients are treated properly and that the radiation treatments are being delivered safely and accurately

Recent articles in the news have raised questions and concerns about the accuracy and safety of radiation treatments.

The process of monitoring and verifying both safety and accuracy is included in the quality assurance (QA) program.

Radiation therapy is one of the safest, most effective ways to treat cancer. There were an estimated 35.4 million radiotherapy treatments on Varian and Tomotherapy machines last year.

Errors do occur, but they are extremely rare, with less than 0.0001 percent of treatments involving an incident that puts a patient at risk of harm.

QA Starts with the staff or medical team that is taking care of the patient

People…make the difference

The first and most important component of a QA program is the personnel.

All cancer treatments are performed under the direction of physicians who are board certified radiation oncologist, the daily administration is performed by certified and state licensed radiation therapists (RTT),

the computer and dose calculations are performed by RTT’s who are certified in dosimetry and

oversight of the machines, computers and all dose plans and calculations are supervised by certified medical physicists.

Certification and Radiation Therapy

Radiation Oncologists certified by the American Board of Radiology and licensed by the State

Medical Physicists certified by the American Board of Radiology and licensed by the State of Florida

Medical Radiation Dosimetrists certified by the Medical Dosimetry Certification Board

Radiation Therapists certified by the American Registry of Radiologic Technologists and license by the State of Florida

The Role of the Radiation Oncologist

The Role of the Radiation OncologistIndividualized patient evaluation

Detailed history and physical of patient Discussion of treatment options with patient including probability

of success, possible side effects, etc. Decision on specific course of treatment, informed consent Prescription for radiation therapy is put into the electronic chart

(Aria) and password protected so that the computer will not allow the patient to receive more than the dose and technique programmed in by the doctor

Two questions everyone thinks about

Are they hitting the right spot?

Am I getting the right dose?

Hitting the right spot

Targeting of the tumor and avoiding healthy normal tissue requires several steps

Simulation – the patient is put into a position that can be reproduced every day and imaging studies are performed to visualize all the important normal anatomy and identify the tumor target

Simulation

At the time of simulation the patient is placed in a reproducible position, often with immobilization.

For patients with cancer in the head or neck area a face mask (auqaplast) is usually made to hold the head still and allow the targeting markings to be painted on the mask. For other areas of the body a vaclock bag will mold around the body to ensure that the patient is in the same position every day.

Skin marks or tattoo's are used to match the laser mounted in the room and on the machine

CT scan, MRI or PET is obtained at this time

CT images are then imported into the treatment planning computer

In the simulation process the CT and PET scan images are used to create a computer reconstruction of the patient and cancer

PET and CT Scan used to create radiation target

PET Scan , showing cancer in right tongue

Computer generated reconstruction, the target area is in red

Using the computer generated images the physician can carefully target the cancer and avoid normal structures

Treatment Plan QA

After a plan has been approved by the Physician, it is sent to the Physicist for review

The Physicist checks to make sure all information (prescription, simulation, etc.) has been entered correctly into the computer

At a minimum, the Physicist checks the calculated beam-on time for each field using a hand calculation or independent computer program

Hitting the right spot

During the daily treatment the patient is positioned in the same position as the simulation, lasers, skin marks or tattoo's and immobilization are used to verify the correct position. Everyday the lasers are checked prior to the start of the day.

The daily set up is performed by certified RTT’s

Hitting the right spot

Once the patient is laying on the radiation table, images can be taken to verify that the beam is targeting the correct site (called portal imaging) or on the Tomotherapy machine a true CT scan is obtained daily prior to treatment

Hitting the right spot…the same machine that produces the radiation can take a picture at the same time and the image (portal image) is compared with the computer generated target image (DRR)

DRR – computer generated image

The portal image showing the actual area treated that day

CT Scan prior to radiation Tomo image after only 19 treatments

cancer cancer

With image guided therapy (Tomotherapy) a CT scan is obtained prior to every treatment to check the accuracy of the targeting and determine if the tumor is shrinking or changing position

Importance of daily CT targeting on Tomotherapyand adjusting the treatment daily

Very little bowel gas on initial study and the dose (red) targets the prostate gland closely

large bowel gas on later treatment day and the dose (red) will cover half the rectum if an adjustment is not made

If no adjustment was made

Actual treatment on Tomotherapy prior to treating the patient, the radiation beam (in red) was shifted upward and no longer hits the rectum

Two questions everyone thinks about

Are they hitting the right spot?

Am I getting the right dose?

Using the proper dose of radiation

“It may be a bit over-exposed”

Radiation History

Radiation has been used to treat patients since the late 1890’s and there is extensive information available about the proper and safe dose

Information about the safe and effective doses of radiation

Tables about the safe and recommended doses of radiation can be found on our web site, and the NCCN now publishes online, very detailed information about recommended doses of radiation

Am I getting the right dose?

After the patient has been simulated and computer plans generated by the staff and reviewed by the physicist, the physician enters the dose into the electronic chart and locks this in with a password, this prevents the machine or the staff from exceeding this dose.

How do I know if the machine has been calibrated correctly and am actually receiving the dose called for by the computer plans or the physicians prescription ?

Calibrating and verifying that the machines and computers are working properly - 5 steps

1. Every day prior to treating patients, the linear accelerator and TomoTherapy machines are tested with a device (the QA beam checker) that verifies that the output of the machine is correct in shape, energy level and dose

Calibrating and verifying that the machines and computers are working properly - 5 steps

2. The machines also undergo monthly and annual evaluation and calibration by the medical physicist to verify they are exactly calibrated

Calibrating and verifying that the machines and computers are working properly - 5 steps

3. On a regular basis a device (TLD) is radiated to a fixed dose and then mailed to an outside expert center (MD Anderson) to independently verify that the dose output is accurate, as well as a body ‘phantom’ is used to verify the proper dose distribution

Calibrating and verifying that the machines and computers are working properly - 5 steps

4. Other radiation measurement devices are placed on the patient (mosfet and electronic dosimeters) to independently verify that the patients is receiving the dose predicted by the computer plan

Calibrating and verifying that the machines and computers are working properly - 5 steps

5. Prior to treating the patient with any complex plan (e.g. IMRT or Tomotherapy) a measurement device (called a phantom) is treated with the patient’s dose plan to verify that the computer calculations and the shaping devices (MLC) are working properly

Machine Quality Assurance

The QA program at Wellspring complies with standards set by:– State of Florida Radiation Control Regulations

(64E-5 Florida Administrative Code)– Reports published by the American Association of

Physicists in Medicine (AAPM)– Reports published by the National Council of

Radiation Protection (NCRP)