Radionuclide therapy, which uses the radiation energy of beta rays emitted by nuclides, directly and indirectly destroys the macromolecular structure of tumor cells, causing them to become metabolically disordered and lose their ability to reproduce, resulting in the tumor cells growing old and dying.
Advantages of radionuclide therapy
Normal and diseased cells in the body are not equally sensitive to nuclide radiation. Diseased cells divide with greater activity than normal cells, are more sensitive to radiation, and have a greater ability to converge on radionuclides.
Also, because β-rays traverse a shorter path through diseased tissue, the rays destroy or suppress diseased tissue with little or no damage to normal tissue, making the treatment safe.
Types of liver cancer suitable for radionuclide therapy
So which types of liver cancer are suitable for radionuclide therapy?
Tumors that cannot be surgically removed
Because of the rapid progression of liver cancer and the multiplicity of lesions in patients with a background of cirrhosis, only 20% to 30% of patients can undergo surgical resection and liver transplantation.
If surgery is not possible, are local treatments such as radiofrequency ablation and anhydrous ethanol injection feasible? Unfortunately, these approaches are currently limited to patients with a single tumor less than 4 cm in diameter.
For most patients with inoperable hepatocellular carcinoma, hepatic artery chemoembolization is the treatment of choice.
In recent years, internal irradiation therapy has also been developed. It is based on the injection of radiopharmaceuticals (e.g., I-iodine oil, Y microspheres) into the hepatic artery to selectively retain radionuclides in the tumor tissue, leaving the normal liver tissue below the tolerated dose.
Among these, radioimmunotherapy targeting antigens associated with primary liver cancer has received particular attention. The rationale is to use the specific binding of antigens and antibodies to target radionuclides to accumulate in the local lesions of the tumor.
Tumors with depleted blood supply
For hepatocellular carcinoma with an abundant blood supply to the tumor tissue, hepatic artery chemoembolization is a recognized and effective treatment. However, once we encounter a tumor with an impoverished blood supply, the therapeutic effect of hepatic artery chemoembolization is limited.
In this setting, imaging (ultrasound, CT, MRI)-guided implantation of new radionuclide I particles has taken root, specifically for hepatocellular carcinoma with an impoverished blood supply.
Tumors in specific sites
In liver cancer, there are also “strange tumors” that are often encountered in specific locations:
- Some tumors are so large, or have portal vein thrombosis, that even with vascular intervention, the treatment effect is not obvious;
- Some tumors are so large, or have portal vein thrombosis.
- Some tumors grow and press on the bile duct, which can cause bile duct obstruction. At this time, implanting a stent can only temporarily relieve the symptoms and cannot solve the main problem;
- Some tumors are very good at “finding support” and grow close to the stomach, intestines, blood vessels and other parts of the body, so local radiofrequency ablation can easily injure innocent organs and tissues.
When the tumor infiltrates into the adjacent vital organs, even if the tumor is removed, it is only a palliative procedure, and it is difficult to achieve a satisfactory outcome.
However, if radioactive particle implantation is added to the procedure (e.g., implantation of particles in lymphatic channels, residual tumor tissue, and tumor bordering sites), surgical trauma can be reduced, operative time shortened, postoperative complications reduced, and even complete cure possible.
Tumors that do not respond well to radiotherapy
For liver cancer that does not respond well to radiotherapy, radioactive particles can be implanted in a minimally invasive way so that surgical resection can be achieved without damaging the normal function and form of the body.
In conclusion, radionuclide therapy has the advantages of minimal trauma, precise efficacy, and rapid recovery, and can be considered to complement the strengths of radionuclide therapy when traditional treatment methods are not available.
The growth of radionuclides is just beginning, and we look forward to more high technology in nuclear medicine for the benefit of liver cancer patients in the future.