Doctors abroad are using an innovative type of treatment for stage 4 prostate cancer called targeted radionuclide therapy. A radiopharmaceutical that targets prostate-specific membrane antigen, a molecular target, is injected into the body. As a result, the radioactive substance only penetrates and destroys cancer cells. Lutetium targeted radionuclide therapy is usually used. An alternative option is Actinium PSMA therapy, which is also effective in patients for whom Lutetium no longer works.
Table of Contents
- How does PSMA therapy work?
- Who may be a candidate for Actinium therapy?
- What is the process of treatment?
- Treatment results
How does PSMA therapy work?
PSMA therapy is a radiotargeted (radioligand, radionuclide) method of treating prostate cancer and a type of systemic radiation therapy. It selectively targets cancer cells with minimal damage to normal tissue.
During the procedure, a radiopharmaceutical is injected intravenously. It contains ligand molecules that bind to PSMA molecules, along with radionuclides. The ligands deliver the radioactive substances directly to cancer cells. The radioisotope accumulates only in tumor tissue, exposes it to radiation over several days, and is then excreted from the body. The patient remains in the hospital during this time.
Who may be a candidate for Actinium therapy?
Actinium therapy is not currently considered a standard cancer treatment, so it is used as an experimental procedure. Lutetium-177 PSMA therapy remains the primary option for radioligand treatment as a more thoroughly researched method.
PSMA therapy is used for prostate cancer that has metastasized to internal organs when the following treatments are no longer effective:
- Hormone therapy (castration-resistant cancer)
- Chemotherapy
- Targeted therapy
PSMA therapy may also be considered when hormone therapy is ineffective and other drug treatments are contraindicated due to poor health, or when the patient declines them because of intolerable side effects.
In these situations, Lutetium targeted radionuclide therapy is prescribed first. Actinium treatment serves as a second-line therapy. It may be used if:
- There is no response to Lutetium-177 therapy
- There was an initial response to Lutetium-177 therapy, but further treatment became ineffective and the cancer continued to progress
- Cancer recurrence in the long term after completing Lutetium-177 therapy
Actinium therapy is therefore reserved for the most severe cases when other treatments have been exhausted.
What is the process of treatment?
The patient is admitted to the hospital and undergoes an examination to rule out contraindications. This includes clinical and biochemical blood tests, urinalysis, and PSMA-PET imaging to identify tumor foci.
Each treatment consists of a single intravenous injection of the radiopharmaceutical. Cooling of the salivary glands may be applied to prevent the radionuclide from accumulating there, and crystalloid solution infusions help protect the kidneys. The patient then spends several days in isolation in a private ward.
Treatments are repeated every 6-8 weeks. After every second session, PSMA-PET is performed to measure tumor foci and determine PSA levels. These assessments are necessary to evaluate both the objective response (tumor shrinkage) and the biochemical response (reduction in PSA levels).
Treatment results
Actinium therapy can result in:
- Tumor shrinkage
- Increased life expectancy
- Reduced risk of cancer complications
- Symptom relief
Some patients achieve a complete response (disappearance of tumors) and a prolonged relapse-free period that can last several years.
Actinium therapy is also generally well tolerated, especially compared to chemotherapy. The most common side effect is dry mouth, which occurs more frequently than with Lutetium therapy. However, Actinium has less impact on the hematopoietic function of bone marrow.
For those seeking a clinic that offers Actinium targeted radionuclide therapy, the Booking Health website lists leading cancer centers worldwide with strong treatment outcomes, including for advanced-stage cancer. The site provides pricing information, clinic selection tools, appointment scheduling, and travel arrangement services.
