Radioisotope therapy is given as a drink or capsules that are swallowed or by injection into a vein (intravenous injection).
Cancer cells absorb the radioisotope more than normal cells and receive a higher dose of radioactivity. The same safety precautions are taken with this type of treatment as for other types of internal radiotherapy.
The most common type of radioisotope treatment is radioactive iodine. It’s mainly used to treat tumours of the thyroid gland and is given as capsules or a drink. It’s also used to treat some rarer types of cancer, such as neuroblastoma. This treatment involves a stay in hospital.
Any radioactive iodine that’s not absorbed by the thyroid will be passed out from the body in sweat and urine. You need to drink plenty of fluids during your treatment as this helps to flush the iodine out of the body. The amount of radiation in your body will be checked regularly, and as soon as it falls to a safe level, which happens after about 4-7 days, you will be able to go home.
You may need to take some special precautions after going home - for example, you may need to avoid young children and pregnant women for a short time. The hospital staff will explain these precautions to you.
Radioactive iodine doesn’t usually cause side effects, but you may feel very tired for a few weeks after having this treatment.
Treating secondary bone cancer
Radioisotope treatment can also be given for certain types of cancer that have spread to the bones (secondary bone cancer). A radioisotope called radioactive strontium is injected into a vein. You can have it as an outpatient. Before you go home you’ll be given some simple advice to follow, as your urine and blood will be slightly radioactive for a few days. You may feel tired for a few weeks, but this type of radiotherapy treatment doesn’t usually cause any other side effects.