Life Redefined: Is “Weapons of Mass Destruction” an Overstatement?
In my last article, Are We Becoming Weapons of Mass Destruction?, I wrote about my personal experience with radioactive iodine and my belief that we need stricter guidelines to protect those around us from being exposed to harmful radiation. I’m going to talk a bit more about this topic today and take a look at exactly what the United States Nuclear Regulatory Commission says about the radiation exposure from patients who receive I-131. Before I get into that, I need to provide you with a bit of background information.
In the United States, our I-131 dose is measured in millicurie (mCi). The SI unit of measurement is giga-Becquerel (GBq) and 100mCi=3.7GBq. OK, so mCi and GBq measure radioactivity. These measurements do NOT imply how much radiation will be absorbed by your body. If you have had external beam radiation, your dose may have been given in the unit Gray (Gy). This DOES imply how much radiation will be absorbed. The unit Gray measures the deposited energy of radiation. To get an idea of what a Gray is, here’s an example: if you were to have an abdominal x-ray, you would receive about 1.4 milli-gray. If you were having external beam radiation for the treatment of lymphoma, you would likely receive somewhere between 20 and 40 gray. The next unit of measurement I want to introduce is the Sievert (Sv). The Sievert measures the biological effects of radiation. This measurement is also referred to as the “equivalent dose.”
OK, so “mCi”and “GBq” tell us the amount of radioactivity. “Gray” tells us how much radiation is absorbed. “Sievert” is an adjusted-Gray—it tells us the biological effects of the absorbed dose.
Are you tracking? There is a reason I’m telling you about all of these radiation units of measurement. When we’re talking about the potential harm that we’re causing to those around us after we have taken I-131, we’re talking about how many Sieverts they are receiving from us. We are talking about the biological effects the absorbed radiation has on their body. Now, let’s take a closer look at what the United States Nuclear Regulatory Commission states in the Code of Federal Regulations regarding the release of patients who have received a radioactive byproduct (eg, I-131):
a) A licensee may authorize the release from its control of any individual who has been administered unsealed byproduct material or implants containing byproduct material if the total effective dose equivalent to any other individual from exposure to the released individual is not likely to exceed 5 mSv (0.5 rem).
b) A licensee shall provide the released individual, or the individual’s parent or guardian, with instructions, including written instructions, on actions recommended to maintain doses to other individuals as low as is reasonably achievable if the total effective dose equivalent to any other individual is likely to exceed 1 mSv (0.1 rem). If the total effective dose equivalent to a nursing infant or child could exceed 1 mSv (0.1 rem) assuming there were no interruption of breast-feeding, the instructions must also include—
- 1. Guidance on the interruption or discontinuation of breast-feeding; and
- 2. Information on the potential consequences, if any, of failure to follow the guidance.
c) A licensee shall maintain a record of the basis for authorizing the release of an individual in accordance with § 35.2075(a).
d) The licensee shall maintain a record of instructions provided to a breast-feeding female in accordance with § 35.2075(b).
What this means is, the hospital is legally allowed to release patients receiving I-131 IF the total effective dose equivalent to any person as a result of exposure to the patient who received I-131 is not likely to be above 5 mSv. The NRC provides a formula for calculating the expected total effective dose equivalent and this number should be calculated by an employee in your hospital’s nuclear medicine department prior to giving you the I-131. This guideline also says that the federal government mandates that the hospital provide patients with a list of WRITTEN guidelines to be followed upon release from the hospital IF the total effective dose equivalent to another person may exceed 1 mSv.
Did you catch that? If the biological effect of the absorbed dose that a person is likely to receive from being in contact with a patient who has received I-131 is calculated to be less than 1 mSv, the hospital is not required to provide you with any written instructions to minimize radiation exposure to others. Problem? I think so.
Members of the Society of Nuclear Medicine wrote a letter to the editor of the New York Times following all the hype in the news about patients who receive I-131 being a danger to those around them. They do bring up a valid point that risk versus benefit must be balanced. They bring up the valid point that if hospitalization was required for isolation, treatment may not be provided in a timely fashion as a result of a lack of available isolation rooms, staff, etc. They also reference a study (yes, just one study) that was published in the Journal of the American Medical Association that shows members of the same household of patients who received I-131 received less than the dose allowed by the NRC to the general public (5 mSv). However, this study is not without limitations. It does not consider the radiation exposure to household members from ingested I-131 (eg, drinking after a patient who received I-131). Additionally, the study did not control participants’ compliance to the guidelines (ie, wearing the dosimeters 24 hours a day to completely measure radiation exposure).
Perhaps what makes me consider this statement from the members of the Society of Nuclear Medicine to be meaningless more than anything else is their reference to I-131 as a “painless treatment.” I can only speak from personal experience, but my I-131 treatments have been anything but painless. In addition to the physical pain (extreme nausea, fried salivary glands), I also experienced emotional duress during the time I received treatment.
Yes, the topic of concern in the news is all about whether or not we should be hospitalized for isolation. But what is the real issue? I think it is lack of awareness. Do I want to be called a dirty bomb? No. But does being called a dirty bomb open my eyes to the severity of the issue? YES. I certainly do not think I can march into the office of the NRC and demand them to revise the guidelines. However, I do think that if I keep sharing my story I can raise awareness. And so can you. The more we speak out about these issues, the more awareness we raise. With awareness comes funding, with funding comes research, and with research comes answers.
So what do you think? Should we be provided with information and guidelines and precautions regardless of the dose of I-131 we receive? Is all of this an awareness issue? Do you take offense to being called a dirty bomb or a weapon of mass destruction?
Talk to me, peeps.
Tags: Code of Federal Regulations, exposure to radiation, I-131, Is "Weapons of Mass Destruction" an Overstatement?, Life Redefined, Life Redefined written by Joanna Isbill, Nuclear Regulatory Commission, Radioactive Iodine, RAI, Society of Nuclear Medicine, thyroid cancer patients, thyroid cancer treatment