Three-dimensional (3D) conformal radiation therapy (3D-CRT) uses 3D images on a computer.
The 3D images allow clinicians to shape beams of radiation around the shape and size of the tumour in a focused (conformed) way. This allows high doses of radiation to be given with greater accuracy, while reducing the amount of radiation damage to the surrounding healthy tissue.
This treatment increases the chances of recovery as higher levels of radiation are more effective for shrinking and killing tumours.
Compared to 2D conventional radiation therapy, 3D-CRT delivers a higher dose of radiation to a more targeted area.
In 2D radiation therapy, radiotherapy beams are directed at the tumour only from one direction, which causes all the normal tissue in front of and behind the tumour to get the full radiation dose.
In 3D conformal radiation therapy, radiotherapy beams enter from more than one direction (such as from the front and side), such that only the tumour which is at the point of focus of all the beams, gets the full dose. Normal tissues get only a fraction of the dose, hence reducing normal tissue injury. 3D CRT allows higher doses to be delivered safely.
2D radiation therapy is mostly reserved for lower dose treatments such as palliative whole brain radiotherapy, or radiotherapy for bone pain.
3D-CRT is suitable both for curative high dose treatment as well as palliative lower dose treatments.
Compared to 3D-CRT, intensity modulated radiotherapy (IMRT) and volumetric arc therapy (VMAT) further improve the shaping of the radiation dose to match the tumour.
In 3D-CRT, the shape of the radiation dose is essentially limited to simple squares or rectangles because of uniform intensity across each radiation field.
IMRT and VMAT use of a greater number of radiation fields combined with variation of beam intensity within each radiation field. This approach allows the oncologist to create any shape to match the tumour and spare normal organs.
For example, where a tumour wraps round a normal organ, IMRT/VMAT can create a C-shaped radiation dose to treat the tumour and spare the normal organ in the centre.
3D conformal radiation therapy is most useful for tumours that are close to important organs and structures in the body.
This method prevents the healthy body tissues and organs from radiation damage.
This therapy can be used to treat cancers such as:
Radiation therapy can cause side effects. They may be the result from the treatment itself or from radiation damage to the healthy cells around the treatment area. Side effects may vary depending on the kind of tissue structures near the tumour being irradiated.
In rare instances, a new cancer different from the first one being treated may develop years later. After treatment, your doctor will regularly check for complications and recurrent or new cancers.
Find out more about the risks of radiation therapy.
Parkway East Hospital is the preferred private hospital for residents in the eastern coast of Singapore.
We provide holistic, customised treatment in a caring environment. Patients can expect attentive care and support from our team of specialists and nurses as we help you navigate your way through treatment to recovery.