Radiation therapy uses high-energy rays or particles to destroy cancer cells. Radiation may be used for neuroendocrine tumours and carcinomas:
The amount of radiation given during treatment, and when and how it is given, will be different for each person.
Targeted therapy means the treatment is delivered directly to the cancer cell (the target). Targeted radiation therapy is given by attaching radioactive material to an agent (usually a biological therapy drug) that binds to receptors on the cancer cell. This allows the radiation to be delivered directly to the cancer cell and limits its effects on normal cells.
Somatostatin is a peptide that binds to somatostatin receptors on neuroendocrine tumour cells. Somatostatin prevents the neuroendocrine cells from producing hormones by blocking these receptors. Because somatostatin has a short half-life (1–2 minutes), long-acting drugs with the same action (congeners) have been manufactured. Octreotide (Sandostatin) and lanreotide (Somatuline) are somatostatin congeners used to treat neuroendocrine tumours. For targeted radiotherapy, the drug is attached to radioactive tracers and injected into the person.
Targeted radiotherapy with radiolabelled somatostatin congeners is effective in treating some neuroendocrine cancers. It is also called peptide receptor radionuclide therapy (PRRT). In PRRT, a radioactive material (a radioactive isotope) is usually joined to octreotide. It travels throughout the body and attaches to receptors on cancer cells. The radiation from the radioactive isotope kills the cancer cells. Depending on how many cancer cells are destroyed, this treatment may relieve symptoms, increase survival and improve quality of life.
Some of these same radiolabelled somatostatin congeners are used to diagnose neuroendocrine tumours or carcinomas. They are given in lower doses when used for diagnosis.
Special safety precautions are taken after systemic radiation therapy. A person may also be given amino acids and potassium iodide to protect other organs (liver and thyroid) from the effects of the radioactive isotopes. Regular tests to check kidney function may be used to detect any kidney damage due to this type of radiation therapy.
Commonly used radioactive isotopes are:
External beam radiotherapy has limited use in the treatment of neuroendocrine carcinomas. It is used to treat brain and bone metastases.
I want everyone to win their battles like we did. That’s why I’ve left a gift in my will to the Canadian Cancer Society.
For more than 50 years, the Canadian Cancer Society’s transportation program has enabled patients to focus their energy on fighting cancer and not on worrying about how they will get to treatment.