Techniques and types of EBRT

EBRT can be given using different techniques and different types of radiation. Your treatment centre may not offer all methods, but your radiation oncologist will recommend the most appropriate combination for you. 

Learn more about these types of EBRT:

• Three-dimensional conformal radiation therapy (3DCRT)
• Intensity-modulated radiation therapy (IMRT)
• Image-guided radiation therapy (IGRT)
• Stereotactic radiosurgery (SRS) and stereotactic radiation therapy (SRT)
• Stereotactic body radiation therapy (SBRT)
• Proton therapy

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Three-dimensional conformal radiation therapy (3DCRT)

• Common type of EBRT.
• The radiation therapy team use CT scans to map out the precise location of the cancer and the normal organs that need to be protected.
• The radiation beam is then shaped (conformed) so that the cancer receives most of the radiation, and surrounding tissues receive much less.
• Used to treat many different types of cancer.

Intensity-modulated radiation therapy (IMRT)

• Highly accurate type of conformal radiation therapy.
• Shapes and divides multiple beams of radiation into tiny beams (beamlets) that vary in dose.
• Used for most cancer types, especially for curative treatment.
• Volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT) are specialised forms of IMRT that deliver radiation continuously as the treatment machine rotates around the body.

Image-guided radiation therapy (IGRT)

• Uses a treatment machine that takes x-rays or CT scans at the start of each session to check that you are in the correct position for treatment.
• Markers (usually grains of gold) may have been inserted into or near the cancer so they can be seen in the x-rays or scans and used to guide positioning.
• Positioning can be very finely adjusted to deliver treatments with millimetres accuracy.
• Commonly used with many types of radiation therapy to any area of the body.
• May also be recommended for areas likely to be affected by movement, such as the lungs from breathing.

Stereotactic radiosurgery (SRS) and stereotactic radiation therapy (SRT)

• Specialised type of radiation therapy.
• Combines many small radiation fields to give precisely targeted radiation.
• SRS is delivered as one high dose and SRT is delivered as a small number of high doses.
• Used to treat small cancers in the brain while minimising the radiation reaching healthy brain tissue.
• A custom-made mask is worn to keep the head still.
• Despite the name, SRS is not surgery and does not involve any surgical cuts.

Stereotactic body radiation therapy (SBRT)

• Similar to SRS, this method delivers tightly focused beams of high-dose radiation precisely onto the tumour from many different angles.
• May be used to treat small cancers in the body, including small lung or liver cancers or small metastases (cancer that has spread away from the primary cancer).
• Sometimes called stereotactic ablative body radiation therapy (SABR).

Proton therapy

• Uses radiation from protons rather than x-rays.
• Protons are tiny parts of atoms with a positive charge that release most of their radiation within the cancer.
• Proton therapy is useful when the cancer is near sensitive areas, such as the brainstem or spinal cord, especially in children.
• Special machines called cyclotrons and synchrotrons are used to generate and deliver the protons.
• Proton therapy is not yet available in Australia (as at November 2019), but there is funding in special cases to allow Australians to travel overseas for treatment.