Pantai Hospital Kuala Lumpur nuclear medicine specialist Dr Wong Teck Huat says Actinium-225 has the potential to effectively treat cancer without inflicting as much damage to the body as compared to beta radiation treatment.
THE dramatic rise in the number of people developing cancer is alarming.
Fortunately, technological advancements have been able to improve treatment of this disease that claimed nearly 10 million lives worldwide in 2020.
In Malaysia, targeted alpha therapy (TAT) using Actinium-225 is among the latest cancer treatments.
Pantai Hospital Kuala Lumpur nuclear medicine specialist Dr Wong Teck Huat says Actinium-225 in nuclear medicine is a valuable option for advanced-stage cancer patients as it could help alleviate their symptoms, and perhaps even prolong their lives.
“Actinium-225 is a radioisotope that emits alpha particles, meaning it gives off radioactive energy (alpha).”
He explains that cancer in nuclear medicine is treated by exposing cancerous cells to alpha or beta radiation.
Among the two types of radiation, alpha is less harmful to surrounding cells when used to treat cancer.
However, the impact of alpha radiation to the cancer cells is many folds greater than beta radiation, which explains its superior treatment efficacy.
“The alpha particles of Actinium-225 travel a very short distance, reaching only the length of several cells. This limits the damage done to surrounding or nearby healthy cells and tissues,” he says.
“The Actinium 225 radioisotope is bound to a targeting molecule, which will then latch onto a specific target on the cancer cell (similar to key-lock interaction). One of the most widely-studied cancer targets is the prostate membrane specific antigen (PSMA), which is found in abundance on aggressive prostate cancer cells”
“When the radioisotope decays, it emits high-energy alpha particles that destroy the cancer cell’s DNA, killing it indefinitely,” says Dr Wong.
He points out that Actinium-225 is a better treatment compared to beta radiation therapy as it limits damage to other surrounding cells.
“Radioisotope treatment is generally better tolerated by patients as compared to chemotherapy, which will not only inflict damage on cancer cells, but also attacks fast-growing cells, such as in the hair, bone marrow and intestines – causing symptoms such as hair loss, anaemia, infections and sore mouth.”
“However, radioisotope treatment has proven to be effective in eliminating cancer with less side effects.”
Meanwhile, post-treatment care after undergoing Actinium-225 therapy is relatively easy.
“The patient can even return home on the same day after the treatment,” says Dr Wong.
He adds that the Actinium-225 injected into a patient during treatment will not cause health hazards to the surrounding people, but cautions that the patient needs to take care of hygiene to avoid contaminating the household.
“This radioisotope is excreted in the urine, so patients must be careful about this.”
“The side effect to the kidneys is caused by the radioisotope when it travels through the kidneys. This side effect occurs with similar rates in Actinium-225 and Lutetium-177 treatments.”
For those who remain sceptical about Actinium-225, Dr Wong points out that worldwide trials using the radioisotope against advanced metastatic prostate cancer have produced positive results.
“Actinium-225 offered confidence-inspiring results in treating even metastasised and late-stage prostate cancers.”
“End-stage cancer patients who thought they had no hope of living were given a second chance of life,” he says.
“Among prostate cancer patients, the most common place that cancer cells will spread to is the bone, causing bone pain and fracture which further impair their quality of life.”
“Actinium-225 PSMA treatment has been safely given to patients with extensive disease in the bones.”
Though dubbed “the rarest drug” in some published research papers, Dr Wong said patients need not worry about Actinium-225’s supply.
“Whenever there is demand for a certain product or service, the market will naturally cater to meet such demands.”
“There is currently a list of manufacturers all around the world which are actively attempting to increase the supply of Actinium-225.”
Additionally, he shares that Actinium-225 can be artificially produced using meticulous, highly specific skills and the right methods.
“Atoms have protons and neutrons. The number of protons defines which atom category the atom belongs to. The numbers of protons and neutrons can be changed when we remove or add them to the atom. Researchers have found the methods and are working on the execution now,” he says.
Production of Actinium-225 requires the right expertise and facilities, including a very powerful accelerator or nuclear reactor, as well as methods to separate the radioisotope from hundreds of other isotopes encountered during the manufacturing process.
Dr Wong hopes usage of Actinium-225 can progress further in Malaysia to benefit more cancer patients with a wider range of treatments to choose from.
He adds that more needs to be done to raise awareness regarding nuclear medicine treatments among the public and doctors alike. All hospitals providing cancer treatments should establish multidisciplinary tumour boards so that nuclear medicine specialists can cooperate with other specialists to improve patients care.
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Keywords: Dr Wong Teck Huat, Pantai Hospital Kuala Lumpur, nuclear medicine, cancer, Actinium-225
