Ionising Radiation
Quantum and Nuclear

Radiotherapy

Physics Narrative for 11-14 14-16 IOP RESOURCES

Radiotherapy is a method of treating cancerous tumours using targeted beams of radiation. The radiation is delivered by a linear accelerator, which can rotate around the patient's body to deliver the radiation from different angles.


How Radiotherapy Works

Not all cancers are the same and different tumours need different treatment plans. The three main forms of treatment are surgery, chemotherapy (using drugs) and radiotherapy (using radiation).

Radiotherapy uses precisely targeted beams of high energy photons to damage the cells of a cancerous tumour, making them unable to reproduce and spread. The high energy photon beams are created and delivered using a clinical linear accelerator which can be rotated around the patient to deliver the radiation from any direction.

Screen shot from radiotherapy planning software showing a cross section of the body and positioning of beams on the tumour.

Screen shot from radiotherapy planning software showing a cross section of the body and the levels of radiation caused by the beam placement in the above image.

The radiation can damage healthy cells as it passes through normal tissue on its way to the tumour. To reduce this damage, the radiation is fired at the tumour from a series of different directions. This ensures that the cancerous tumour will receive a full dose whilst the surrounding healthy tissue receives a much lower dose.

Plan a radiotherapy treatment to a patient with a cancerous tumour in their lung using our treat the tumour interactive.

Ionising Radiation
is used in analyses relating to Radioactive dating
can be analysed using the quantity Half-Life Decay Constant Activity
features in Medical Physics

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