René Botha helps us understand the integral role a radiotherapist plays in radiation therapy.
Radiotherapy, when prescribed and delivered correctly, can help treat a wide variety of cancers. When a patient is prescribed radiotherapy, it takes a team of professionals working together to deliver this treatment safely and effectively. You may not meet all the members of the team, but they all play an essential role in the planning and delivery of your treatment.
This team includes your radiation or clinical oncologist, the radiotherapists and the medical physicists. Once you have met with your oncologist and he/she has prescribed radiation, you will be referred to a treatment unit where treatment will be planned and delivered by the team of radiotherapists.
What is a radiotherapist?
Radiotherapists, also known as radiation therapists or therapy radiographers, are allied health professionals who are trained in the planning of radiotherapy treatments as well as the operation of the treatment machines, such as linear accelerators, brachytherapy units, Gamma Knife treatment units and cobalt treatment units, for the delivery of radiotherapy.
Some radiotherapists spend additional time specialising in treatment planning and may be called planning radiotherapists or dosimetrists, while others spend more time working at the treatment unit to deliver the daily treatments. Both require a high level of skill and training.
Radiotherapists need a sound understanding of the types of cancer that they treat; how tumours respond to irradiation; the anatomy of the human body; and how each organ responds to radiation doses, as well as the physics and properties of different radiation beams. These factors all need to be balanced to ensure that the patient receives the highest benefit from treatment with the lowest possible toxicity.
Although, it’s a very creative profession where you need to be able to think three dimensionally, it’s also a science and it’s important that the radiotherapists are precise in their work.
Radiotherapists also work with medical physicists to ensure that treatment machines are correctly calibrated daily and that each treatment plan is correctly checked.
The radiotherapy process
The first step is for a patient to undergo a planning or “mapping” CT scan. The radiotherapist will position you in the treatment position and make/place markers on your skin so that this position can be replicated daily.
As needed, the radiation therapist will make a personalised immobilisation mask (piece of plastic mesh) or cast for treatment and then the scan is done.
The planning radiotherapist works very closely with your radiation oncologist. The radiation oncologist will prescribe the dose of radiation to be delivered and will define the area that needs to be treated on the planning scan.
The planning radiotherapist then applies radiation beams to this area, using computer modelling and calculations to arrive at the best possible treatment plan, while considering the normal tissue (heart, lung, liver, etc.) that needs to be protected.
The oncologist then evaluates the plan. Should any changes be needed, the oncologist works with the planning radiotherapist to finalise it.
At this point, a medical physicist carries out tests to verify that the planned treatment has been calculated correctly to ensure that the machine will deliver the treatment exactly as planned. This plan is then programmed into the treatment unit with instructions so that the radiotherapists at the treatment unit can deliver the planned daily dose.
At each treatment, called a “fraction”, two radiotherapists work in tandem to ensure that every parameter is correct.
They check positioning every day and at specified intervals take positioning or set-up X-rays to evaluate and verify that the position is correct throughout the course of treatment. They then operate the machine and document the treatment that has been delivered.
Radiotherapy is a challenging but exceptionally rewarding profession that has advanced since its beginning. It’s a privilege to be able to journey with patients and encourage them through treatment, especially when we’re able to help save a life!
MEET OUR EXPERT – René Botha
René Botha is a radiotherapist with a special interest in treatment planning. She works in private practice and is based at the Wits University Donald Gordon Medical Centre.