At certain doses, radiation therapy kills cancer cells or slows their growth by damaging their DNA. Cancer cells whose DNA is damaged beyond repair stop dividing or die. When the damaged cells die, they are broken down and removed by the body.
However, radiation therapy does not kill cancer cells right away. It can take several treatments over several days, weeks or even months before DNA is damaged enough for cancer cells to die. Then, cancer cells may keep on dying for weeks or months after radiation therapy ends.
Radiation therapy may be classed as external beam or internal treatment and the type of treatment you may be offered will depend on the type, site, size and position of the tumour(s) to be treated. Your medical team will also need to assess your current health, the risk/benefit of treatment – and what other treatments you may have already had or may need to have in the future. For example – if you have already had external beam radiotherapy to a specific site of the body, you may not be able to have further therapy to that same area, because of the risk of doing more harm than good.
Radioligand Therapy – also known as PRRT
PRRT (Peptide Receptor Radionuclide Therapy) delivers radiation to specifically targeted cancer cells, with a minimal effect on healthy cells.
A radioligand is made of two parts: a ligand, which can find cancer cells that have a particular surface molecule – in Neuroendocrine Cancer – we use Octreotide as it has a particular affinity for certain Neuroendocrine Cancer cells, and a radioisotope, which emits therapeutic radiation to kill these cells. The radioligand can target cells anywhere in the body.
External Beam Radiation Therapy
(You may see this abbreviated to EBRT or DXT)
External beam radiation therapy comes from a machine that aims radiation at your cancer. The machine does not touch you, but can move around you, sending radiation to a specific part of your body from many directions.
External beam radiation therapy is a local treatment, which means it treats a specific part of your body. For example, if you have cancer in your lung, EBRT will target your lung tumour and not to your whole body.
Radiotherapy may be given after surgery to kill any cancer cells that might remain at the margins of or original site of your tumour.
EBRT may also be used as a palliative (non-curative) treatment for painful bone secondaries – if isolated in specific spots, rather than disseminated (spread throughout the skeleton).
Internal Radiation Therapies
Internal radiation therapy is a treatment in which a source of radiation is put inside your body. The radiation source can be solid or liquid.
Internal radiation therapy with a solid source is called brachytherapy. In this type of treatment, seeds, ribbons, or capsules that contain a radiation source are placed in your body, in or near the tumor. Like external beam radiation therapy, brachytherapy is a local treatment and treats only a specific part of your body. It may be used to treat cancers of the prostate gland or female reproductive system.
Internal radiation therapy with a liquid source is called systemic therapy. Systemic means that the treatment travels in the blood to tissues throughout your body, seeking out and killing cancer cells. You receive systemic radiation therapy by swallowing, through a vein via an IV line, or through an injection.
SIRT
As mentioned in Interventional Radiology.
NCUK’s Ambassador Ashley talks to fellow Ambassadors; Kath and Sally about their experiences with Radioligand Therapy (PRRT).