How does Chemistry detect, diagnose and treat cancer using medical isotopes?
In this report, the benefits and limitations of using medical isotopes to detect, diagnose, and treat cancer with regard to ethical and economic factors will be discussed and evaluated. Cancer is the second most leading cause of death throughout the world and the leading cause of death in Australia. Cancer is a disease caused by the uncontrolled division of abnormal cells in different parts of the body. Cancerous cells can develop within almost any type of human body tissue and therefore, there are over 100 types of cancer. If not detected and treated appropriately, cancerous cells can spread and invade other body tissues leading to severe further damage and in some cases, death. The physical impacts of cancer can overly impact one's quality of life and emotions in different ways. Not only is the impact of cancer related to the patient, but the people around them who have to deal with the effects of losing someone or watching them endure long-term pain.
The Use of Chemistry
Isotopes are atoms with the same number of protons, but differing numbers of neutrons. The have different atomic weights and can be classified as altered forms of a single element.
Medical isotopes can be artificially created through the alteration of a normal isotope’s atomic structure. This can be done by a nuclear reactor. The chemical process applied is called nuclear fusion. Nuclear fusion occurs inside nuclear reactors when two nuclei join together to make one heavier nucleus. For example, figure 1 (shown below) shows a nuclear fusion reaction for Hydrogen atoms. Hydrogen 1 and hydrogen 2 collide and produce Helium 3 (the atomic mass changes, therefore helium is the product). Figure 2 (also shown below) is a visual representation of this reaction.
Figure 1: Figure 2:
Nuclear fusion reaction
Visual representation of nuclear fission reaction.
One of the most commonly used medical isotopes when detecting cancer in the body is another version of Molybdenum-99 which decays via beta decay to form Technetium-99. Molybdenum-99 is composed of Molybdenum-98 and one extra neutron. Figure 3 (shown below) shows a written equation example of this nuclear fusion reaction.
Figure 3:
The nuclear fusion chemical reaction
A popular process that is used to detect cancer is the PET imaging test. During this procedure, medical isotopes are combined with other elements that are normally used by the body (e.g. water, ammonia, glucose) or molecules that bind to specific receptors at the site of interest. These chemical compounds are administered to the patient and can be swallowed, injected into the bloodstream or inhaled. The chemical compounds undergo a process known as Positron Emission Tomography (PET). They migrate to different parts of the body emitting radio energy that allows computers to map a full body image of a person. The computers also have the ability to image the extent or stage of cancer in the body. Scientists and doctors work together to effectively study the images and provide information about a particular cancer or areas at risk and appropriate treatment options in the future. An image of PET scanning machinery is shown in figure 4. An example of PET scan results is shown in figure 5. In figure 5, The site of cancer has been detected and circled.
Figure 4: Figure 5:
An image of PET scanning machinery An example of PET scan results (circle is location of cancer)
Implications of Science
Cancer staging is the process of measuring how far a cancer has spread and requires tests like PET scans and other imaging. Knowing the stage of cancer is important when considering the best treatment options to remove or discontinue the spread of cancer in the shortest amount of time. The longer cancer remains undetected, the more damage can be caused to one’s health and typically, the overall risk of death increases. Today, medical isotope technology is one of the leading contributors to the early detection of cancers. Early diagnosis leads to earlier informed decisions of what action can be taken to prevent the spread of the cancer. Therefore, as well as for the patient, there is less stress on the financial system, supporting family members and friends. Thus, considering these factors, both economic and ethical benefits and limitations arise.
There are a number of economic benefits as a result of the implications of medical isotopes. Earlier detection can lead to an abbreviated treatment period as well as less stress on a families’ financial planning. A patient can also be back in the workforce quicker with a steady income to rebuild his/her life. Another economic benefit is that systems that use nuclear chemistry are funded by and covered by Medicare. This means that patients who are not as financially secure as others are able to afford these procedures in order to prolong their lives.
As well as having many economic benefits, using nuclear chemistry in the medical field has some economic limitations. Machinery that is used in processes such as PET scanning can cost up to millions of dollars. Technology as such is funded and financially supported by government policies and typically, public taxes. This provides an economic limitation to those who do not require the testing themselves. Essentially, they are paying for the misfortunes of others rather than spending their money on their own issues. Another economic limitation enforced by the implications of this science is that due to the short half-life necessities of these substances, it becomes difficult to develop this technology in regional areas. Similar to this, it is also uncommon for developing countries to have easy access to this type of nuclear chemistry. Also, as medical isotopes continuously emit radiation, it is necessary for them to be stored in safe and insulated environments which tends to become expensive. Finally, the production of medical isotopes involves converting atoms of one type into another. This process takes an extreme amount of manual labour and can cost up to millions of dollars for companies and through government funding.
Using medical isotopes in cancer detection, diagnosis and treatment can not only prolong the life of an individual but improve the quality of life for their partners, parents, children and family and friends as the patient recovers and their life returns to normal. This is an ethical benefit. The use of medical isotopes in most common procedures (e.g. PET scans) also ensure a physically painless process apart from the initial administration of chemical compounds in the form of injections.
The use of medical isotopes also presents ethical limitations. Radioactive materials and elements such as medical isotopes have the potential to cause mutations and alter the DNA sequence of the human body. Ironically, long exposure to strong medical isotopes could potentially cause the spread of cancerous cells. Generally, it is unethical to use these types of materials inside the human body that have the ability to be extremely detrimental to human health. Although this limitation is a possibility, it’s unlikely that a procedure would last long enough to cause extreme harm to the human body. Therefore, various ethical implications of this factor include a possibly prolonged fault in protein production and a disruption to homeostasis.
Evaluation
The purpose of this article was to discuss the benefits and limitations of using medical isotopes to detect, diagnose and treat cancer. Conclusively, I have chosen the 4th position on the evaluation spectrum after researching and reviewing the benefits and limitations in regards to economic and ethical factors. Although there are more individual limitations of using chemistry to solve this issue, these limitations are exceeded by the feasibility of the benefits. It is unlikely that using medical isotopes for the detection, diagnosis and treatment of cancer could cause negative long-term impacts as opposed to the implications of later detecting cancer inside the body. Therefore, although the use of medical isotopes in this field has some limitations, there are more significant benefits.
Laura Sutherland
Year 10 MLC School
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