An Introduction to Radiotherapy

What is radiotherapy? Radiotherapy is the treatment of cancer with very powerful x-rays These x-rays are also known as ionising radiation. The machine we use is called a linear accelerator (or linac for short)

A Patients treatment pathway When a patient finds out that they have cancer they see a specialist doctor in cancer treatment called an Oncologist. The doctor prescribes a course of treatment for the patient. Before we can give treatment we need to plan what we want to do. This involves: CT Scans for planning Planning the treatment Delivering the treatment

CT Scans The patient lies on the bed and the bed then moves through the hole at the top (which we call a doughnut!) We put special markers on the patient which we can look at later. These are very small steel balls that show up on the scan. When we have finished the scan we give the patient a small permanent mark (tattoo) with ink where we had the markers.

What a CT scan looks like

A treatment Plan

Shaping the beam The linac head makes a square shaped treatment beam There are special shaping devices (called leaves) in the linac head which move to change the shape of the beam to fit the treatment site better This is called a Multi-leaf collimator By shaping the beam like this we can accurately target the cancer and also minimise any damage to surrounding areas of the body

Delivering the treatment Treatment is delivered by therapy radiographers. We are given a treatment plan to work from by the planning department. This plan uses the tattoo marks put on the patient when they had their CT scan as reference points. The patient lies on the bed and we align the tattoos up to lasers set in the wall The laser

How the linac moves The linac moves around the patient on the bed and can deliver treatment from any angle as the doctor wants The patient does not see or feel anything at all during their treatment

Treating the patient When we treat the patient we have to be in a separate room but we watch them all the time on tv screens to see they are ok. We can talk to them through an intercom. We usually play music for patients while they have their treatment so they can relax

Keeping us safe Because radiation can be dangerous if not correctly controlled we need to be safe while we are working. To keep the radiation inside the room we have very thick walls and doors. These doors weigh up to 9 tons!

Immobilisation Some patients will need to have a ‘shell’ made. This keeps them still so we can give accurate treatment Two types of shells Electron shell/shielding Photon shell as in picture

Checking we are in the right place Some patients need to have a check x-ray every day to make sure we are treating in the correct place. We match this daily x-ray image against a plan image We cannot see the cancer on our pictures but we can match the bones to each other so we know we are in the right place On some patients we have to make sure we treat within 3mm of our target. On others our limit is 5mm

What is my job title? Diagnostic Radiographer Therapy Radiographer Nurse Doctor

What exams do I need to be a Therapy Radiographer? GCSE’s including English Maths and at least 1 Science Biology, Physics and Chemistry 3 A levels of which 1 must be science Go to University for 3 years to study and work as a Therapy Radiographer

Looking after the linacs As well as doctors, radiographers and nurses we have a team of bio-engineers who look after the linacs to make sure they work properly We also have a team of physicists who regularly check that they deliver the correct dose.