SRP Proposal

Senior Project Proposal

Phillip Ziqi Yang

September 28, 2014

1. Title of Project: Radiation Dosage Absorption of the Abdominal Organs and the Skin: A Comparison between Medical Imaging Practices

2. Statement of Purpose:

When you meet someone for the first time, it’s the superficial features that determine your first impression: skin color, height, facial expressions, fashion sense. But in the medical field, most of that is irrelevant. Doctors look deep inside of you and accept the person that you are. We’re not talking about the soul, it’s the guts and organs that matter.

An enormous part of medical diagnosis is focused in medical imaging. Prior to medical imaging, most medical diagnostics were based off of symptoms, which could be faulty and misleading. It is astonishing that doctors can look inside of patients and obtain valuable information without having to dissect the body. Computed Tomography (CT) and x-ray have so far been the major methods of medical imaging. But with major developments in technology and a constant expanding source of knowledge, the medical community has become increasingly aware of the adverse effects caused by medical imaging, and CT specifically. The medical community has begun searching for ways to minimize adverse effects or to find an alternative. One alternate type of scanning is the use of radionuclides, which uses radioactive elements as tracers for scanning.

In my Senior Research project, I will compare the absorbed dose from multiple practices in the organs of the abdominal cavity and the skin. How do the effects of radionuclides compare to CT and could it present a viable substitute?

3. Background:

Medical imaging and scanning machines have always been an abstract subject and topic in biology classes. Other than the few instances where it appeared on the SAT Biology Subject test, medical imaging was an irrelevant point of interest. But in the past few years, I have volunteered at the Mayo Hospital and the Radiology and Medical Imaging department is only twenty feet away from me. Every afternoon, I send multiple people to radiology for CT, Ultrasound, MRI, PET scans. Medical imaging is a staple in modern medicine but I knew very little about it and what the scans truly meant. Most of the time, I was possessed by the slight fear that I would be overdosed with radiation and develop cancer every time I took a scan.

4. Prior Research:

Nuclear Medicine draws from a wide variety of fields such as physics, chemistry, engineering, and medicine. It is different from other imaging techniques because it involves the monitoring of internal radiation instead of external radiation such as X-ray and Photon-irradiation. It would become publicly known after a successful treatment of thyroid cancer on December 7th, 1946 through the use of Iodine-131 (Henkin, 1996). Iodine-131 was initially used for therapy treatment but has since expanded into the use of medical imaging (Henkin, 1996). The most common radionuclide used today is Technetium-99m (used in 20 million nuclear medicine procedures yearly), was found in 1937 (Henkin, 1996). By the 1970s, a majority of the organs in the body could be imaged through the use of Nuclear Medicine (Henkin, 1996).

In a comparison in the various aspects of Nuclear Medicine by Fred A. Mettler et al. (2009), it was found that in the last 20-30 years, the amount of collective radiation dosage has nearly doubled. The global per-capita effective dose has increased by 65%, almost entirely due to medical procedures (Metter, 2009). It was also found that the amount of radiation dosage in the United States is also 50% more than other well-developed countries. The source of this increase in radiation dosage is almost entirely the result of increased amounts of radiologic and nuclear medicine studies, not from other sources such as factories and consumer products. The United States takes up 12% of overall radiology procedures and half of the nuclear medicine procedures (Mettler, 2009). CT scans take up 50% of the current medical dosage in the United States (Mettler, 2009). In the recent 20-30 years, PET (Photon Emission Tomography) has grown in technology, popularity, and usage (Mettler, 2009). Today, a combination of PET (Nuclear Medicine) and CT (X-ray) scanning is used.

In an article on Idaho State University's radiation information network titled "Radiation and Risk", the threshold for radiation damage and how risk is determined is explained. An average nuclear power plant worker receives 300 mrem a year in 1992 and effectively loses 15 days in their lifespan (ISU; Cohen & Lee 1991). When people say that radiation causes cancer, they are referring to how radiation changes or destroys cells. Small doses of radiation under 100 rem is fine, but anything above that will cause damage to cells that will kill or change it (ISU). Most of the cells destroyed by radiation are of little consequence because the body can easily replace them (ISU). The issue is when cells are changed to a certain extent and subject to the right circumstances that will give rise to cancerous cells (ISU).  

Other than Medical Imaging, radiation comes from many other sources. As studied by Lott (2006), there is radiation everywhere around us from the phones in our pockets to computer screens to cars. Iphones have a SAR level of around 1.1 (Lott, 2006). SAR level is a measurement of how much energy is absorbed by humans when exposed to radiation sources. So far most results are either inconclusive or subject to author bias (Ledford, 2012).

5. Significance:

We currently live in a technological and industrial advanced society. Technology is constantly evolving and we are inventing more electronic devices every year. Although the radiation from these new devices are relatively minute, it will eventually accumulate to a significant level. Radiation is also received through contamination of resources by industries. Human population is also increasing at an exponential rate. In order to meet the new and future demands, production will increase and along with it, radiation. Although industrial contamination is already regulated and  tends to be constant, it is still a factor. The vast majority of radiation increase comes from medical imaging  and that does not look like it will decrease soon with more people being born every year(Mettler, 2009). The CDC states that there are 120,000 children born with defects per year and most of them must undergo treatment and thus medical imaging. We are receiving more radiation at a younger age and lack the research regarding long term effects and radiation.

6. Description

The research for this paper will mostly consist of observation and small experiments. I will be a volunteer at the Banner Good Samaritan Hospital because I lack professional training with radioactive isotopes and do not understand the safety procedures. Half of my time will be spent with the nuclear medicine instructor at Banner Hospital learning about nuclear medicine and obtaining training alongside other college-level nuclear medicine students. The other half of my time will be with my on-site mentor, Mr. McCormick, assisting in research and observing. I will work with four to five other physicians and radiologists in the Nuclear Medicine Department learning what they do.

Additionally, I will be conducting my own research by consolidating academic sources on natural and consumer product radiation  into a comprehensive presentation. I will be using my experience and information that I obtain from Good Sam to supplement and provide data for my overall presentation.

7. Methodology :

At the Banner Good Samaritan Hospital I will obtain specifics about their medical imaging machines such as composition, purpose, rate of fire. I might be able to use some of the patient’s as information. Then I would be able to calculate the amount of radiation absorbed by the body for that specific patient, taking into account that certain parts of the body are more susceptible to becoming cancerous. Since the International Commission on Radiological Protection (ICRP) has a system (the Sievert) for evaluating this already in place, I plan to analyze their system to help assist me in my own construction. I hope that I am capable of being able to explain the Sievert to the audience.

I will choose an organ to base off of as my mathematical model, taking into consideration the different internal dimensions of the organ and its composition. Because the skin is distributed over the body in different concentrations, my project will narrow down the area to be analyzed to a specific spot. I plan to use either the anterior or posterior portion of the skin near the abdominal area. I plan to analyze the pathway of the radiation and how it might affect the different parts of the body. Afterwards, I hope that I can conduct a risk management evaluation of the organ and section of epithelial tissue. This will include an evaluation on the chances of mutation and the mitotic rate of specific cells.

8. Problems:

Because the amount of radiation that people receive on a daily basis is very small, effects might not show until much later. Since I will be creating a mathematical model of certain parts of the body, it will be incomplete. This is because of the difference in each individual cell and the composition of different parts of the skin/organ. In addition, the physical structure of each individual differs from each other and every case is unique. The ICRP’s system of Sievert might also be flawed because it also uses the average as its midpoint.

Radiation itself is also random and very difficult to track. Radiation also has different types of scattering which is sometimes too small to measure. The data will be collected under the assumption that the radiation is either absorbed by the body or has passed through. Different tissues have different mitotic rates which might also be influenced by environmental factors. The information that is drawn from the internet might also not be valid or have pre-existing conditions that the project does not meet.  Because there are numerous factors that I have to take into account, there might be some that are left out and bias the data.

9. Bibliography:

Agarwal, A., Desai, N., Makker, K., Varghese, A., Mouradi, R., Sabanegh, E., & Sharma, R. (2009, October). Effects of Radiofrequency Electromagnetic Waves (RF-EMW) from Cellular Phones on Human Ejaculated Semen: An In Vitro Pilot Study.

Avner Vengosh.(2009, March 12).High Naturally Occurring Radioactivity in Fossil Groundwater from the Middle East. In  Environmental Science and Technology.

Brandon Ledford. (2012, July). Cell Phones, Electromagnetic Radiation, and Cancer: A Study of Author Affiliation, Funding, Bias, and Results.

Cristinia Nuccetelli, Rosella Rusconi, Maurizio Forte. (2012, December). Radioactivity in Drinking Water: Regulations, Monitoring Results and Radiation Protection Issues. In Scielosp.

Cohen, B., & Lee, I. (1996). Catalogue of Risks Extended and Updates (Vol. 61).

Hendee, W. R., & O'Conner, M. K. (2012, August). Radiation Risks of Medical Imaging: Separating Fact from Fantasy. In RSNA.

Henkin R. et al. (1996). Nuclear Medicine.

Idaho State University. Radiation and Risk.

Mark S Pearce, (2012, June 7). Radiation Exposure from CT Scans in Childhood and Subsequent Risk of Leukaemia and Brain Tumours: a Retrospective Cohort Study. In The Lancelet.

Mettler, F. A., Bhargavan, M., Gilley, D. B., Gray, J. E., Ibbott, G. S., Lipoti, J. A., & McCrohan, J. L. (2009, November). Radiologic and Nuclear Medicine Studies in the United States and Worldwide: Frequency, Radiation Dose, and Comparison with Other Radiation Sources—1950–2007. In RSNA.

Sven Kühn , Urs Lott, Axel Kramer, Niels Kuster. (2006). Assessment of Human Exposure to Electromagnetic Radiation from Wireless Devices in Home and Office Environments. In Foundation for Research on Information Technologies in Society ETH Zurich, Switzerland.

(2012, May 7). What You Need To Know About Thyroid Cancer. In NIH National Cancer Institute.

(2003). Extent of Environmental Contamination by Naturally Occurring Radioactive Material and Technological Options for Mitigation. In International Atomic Energy Agency.