Radiotherapy treats cancer by using high-energy X-rays to destroy cancer cells, while doing as little harm as possible to normal cells. Radiotherapy is usually given in combination with a short course of chemotherapy (chemo-radiation) to prime the cancer cells and make them more sensitive to damage by the radiation. It is used less often than surgery or chemotherapy in the treatment of pancreatic cancer.
Radiotherapy may be given:
- Before surgery to try to shrink the cancer and make it easier to remove (neo-adjuvant);
- After surgery to try to reduce the chance of the cancer coming back (adjuvant); (Both neo-adjuvant and adjuvant radiotherapy for cancer of the pancreas are still experimental treatments.)
- In combination with chemotherapy to shrink the cancer and keep it under control for as long as possible (known as chemoradiation); or
- To help to relieve symptoms such as pain, particularly if a bone is involved.
The side-effects of radiotherapy are related to the unwanted damage sustained by surrounding tissue. To minimise these unwanted effects, the total dose of radiation is split into anything up to 20 parts and given, for example, every weekday for four weeks. The dose of radiotherapy used to relieve symptoms such as bone pain is usually lower, so you may have a shorter course of treatment and a lesser chance of side-effects.
All radiotherapy is targeted towards the tumour, but by using complex computer models the focus of this targeting can be improved (“stereotactic radiotherapy”). This approach allows a higher dose to be administered in a shorter time with the same side-effects. “Cyberknife” is an example of this form of therapy. While there are potential advantages from shorter treatment courses and perhaps fewer side-effects, there is no evidence as yet that it is more effective than standard treatments.