Bone-targeted Radionuclide Therapy (BTRT)

Which drug is used for the treatment and how is it carried out?

The radionuclides used (e.g. 89Sr, 153Sm-EDTMP, 186Re-HEDP) accumulate in bone regions with increased new bone formation (e.g. metastases) similar to skeletal scintigraphy. In contrast to bone scintigraphy, where the visual representation of the distribution of the radioactive substance (emitting gamma radiation) is used for diagnosis, treatment substances release therapeutically useful short-range radiation with high energy (beta radiation), which leads to targeted pain relief. In contrast to chemotherapy or drug-based pain treatment which are distributed in all tissues of the body, the substance labeled with the radionuclide looks for and binds to its own target (the tumor cells).

The radioactive drug is administered intravenously after or simultaneously with saline infusion. For legal reasons, treatment is only permitted on an officially approved nuclear medicine therapy ward. However, outpatient treatment require a stay of only several hours in the therapy ward,. On the following day, the distribution of the radionuclide in the body is documented by a whole body image using a gamma camera.

What side effects may this therapy have?

• Blood count changes

The radiation effect on the bone marrow can lead to a temporary loss of formation of blood components, which may lead to a tendency to bleed or a prolonged bleeding time after injuries (thrombocytopenia).
In rare cases, there may be a slight weakness of the immune system as a result of temporary leukopenia or a drop in the red blood cells, especially if the initial values are unfavorable.
In order to avoid such side effects, the therapy can be carried out only if you have a normal blood count.

After completion of the radionuclide treatment, your family doctor should carry out regular blood count checks for another 6 weeks because, unlike after chemotherapy, radionuclide therapy can lead to a delayed drop in values. Please inform your family doctor about this. These blood controls can also be carried out at our clinic in Homburg. After completion of the treatment, it is recommended that your family doctor carries out regular blood count checks for another 6 weeks to avoid a delayed drop in values after radionuclide therapy, unlike after chemotherapy. Please inform your family doctor about this. Of course, these blood count checks can also be carried out at our clinic in Homburg.

• Pain symptomatology

In the early phase after the treatment, i.e. in the first days after the infusion, there may be a short-term increase in pain, which may be treated with additional painkillers. This is considered by some scientists to be a sign of a good response and further pain reduction.


When can radionuclide therapy not be performed?

Unfortunately, the treatment cannot be carried out if the blood values indicate that your hematopoietic bone marrow does not have sufficient recovery capacity. Then the risk of bleeding or infection prevails over the benefit of the therapy.
In addition, it should be ruled out before treatment that a bone is at risk of fracture due to tumor-related changes. This may have serious consequences for you, e.g. in the spine. Admittedly, radionuclide therapy does not promote such fractures, but it cannot prevent them either. Therefore, in such cases another treatment (surgery, radiotherapy from outside, corset treatment, etc.) should be preferred.

Afterwards, radionuclide therapy can be reconsidered.
In case of a severe renal dysfunction, it must also be critically examined whether the treatment is feasible for you.

Can the treatment be repeated or combined with other therapies?

Clinical studies conducted in recent decades have shown the efficacy of radionuclides: Most patients experienced rapid relief of bone pain over several weeks and months with minimal side effects. This made it possible to do without painkillers or to reduce their dose. A study was also able to significantly reduce the number of radiation treatments required later.

Is it possible to combine radionuclide treatment with other treatments?

The treatment can be supplemented at any time by another therapy, should this be necessary, e.g. painkillers, hormone or anti-hormone preparations, or bone stabilizers (bisphosphonates).

Clinical studies are currently carried out to investigate the value of a combination treatment with radionuclides and chemotherapy. Such treatments are not approved outside these studies. A rather long period of time should be observed for tumor therapies to assess possible blood count changes.

Can radionuclide therapy be replaced by another form of treatment?

Possible alternative therapies are chemotherapy and treatment with painkillers. In case of localized changes, external radiation (radiation from outside instead of inside) is also possible. Your doctor will discuss with you to determine the most suitable treatment form for your special conditions.