Questions About Ruthenium 106 and Brachytherapy

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In summary: Then you'll be able to answer the remaining questions.In summary, ruthenium 106 is used in brachytherapy and has a half-life of 1.02 years. It decays by beta emission to rhodium 106, which is not a stable isotope. When considering a microgram of ruthenium 106 inserted into the body for therapy, there are approximately 5.68 x 10^15 atoms present. After 1.02 years, there are approximately 2.09 x 10^15 atoms remaining, which is equivalent to 0.368 micrograms. After 0.90 years, there are approximately 5.20 x 10^15 atoms remaining, which is
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mandy9008
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Homework Statement



1. Ruthenium 106 is used in brachytherapy. It has a half-life of 1.02 years. Ruthenium 106 decays by beta emission (e-) to rhodium 106. The mass of ruthenium 106 is 105.907330 u and the mass of rhodium 106 is 105.907288 u. Rhodium 106 is not a stable isotope of rhodium. Consider a microgram of ruthenium 106 inserted into the body for therapy.

How many atoms of ruthenium are in a microgram of ruthenium 106?

After 1.02 years have passed, how many micrograms of ruthenium are present in the body?

After 0.90 years have passed, how many micrograms of ruthenium are present in the body?

After six half lives have passed, how many ruthenium atoms are still present in the body from the therapy?

Write out the equation representing the beta decay (e-) of ruthenium 106.

If the electron comes off with 0.0354 MeV of energy, determine the energy of the antineutrino.

Why is it important in brachytherapy to realize that rhodium is not a stable isotope?
If rhodium were not a stable isotope what considerations must one make?

I have answered/solved most of these questions, but I am not 100% sure that they are right.

Homework Equations



N(t) = No e -t/t1/2



The Attempt at a Solution



How many atoms of ruthenium are in a microgram of ruthenium 106?
1 microgram = 10-6 g
10-6g ((6.022 x 1023 atoms/mol) / (106 g/mol)) = 5.68 x 1015 atoms

After 1.02 years have passed, how many micrograms of ruthenium are present in the body?
N(t) = No e -t/t1/2
No = 5.68 x 1015 atoms
t=1.02 yrs
t1/2=1.02 yrs

5.68 x 1015 atoms e(-1.02/1.02) = 2.09 x 1015 atoms

2.09 x 1015 atoms (106 g/mol / (6.022 x 1023 atoms/mol)) = 3.68 x 10-7g = 0.368 micrograms

After 0.90 years have passed, how many micrograms of ruthenium are present in the body?

N(t) = No e -t/t1/2
No = 5.68 x 1015 atoms
t=0.09 yrs
t1/2=1.02 yrs

5.68 x 1015 atoms e(-0.09/1.02) = 5.20 x 1015 atoms

5.20 x 1015 atoms (106 g/mol / (6.022 x 1023 atoms/mol)) = 9.15 x 10-7g = 0.915 micrograms

After six half lives have passed, how many ruthenium atoms are still present in the body from the therapy?
To find the six half lives, I divided the half life, 1.02 yrs, by 2, 6 times, giving me 0.00796875 yrs

5.68 x 1015 atoms e(-0.00796875/1.02) = 5.64 x 1015 atoms

Write out the equation representing the beta decay (e-) of ruthenium 106.
I am not sure what equation this is asking for. My guess would be for the Q factor..
Q=(mass of reactants-mass of products) c2
Q=(105.907330u - 105.907288u)c2

If the electron comes off with 0.0354 MeV of energy, determine the energy of the antineutrino.
I am not sure on this one. Could someone help me to get started, please?

Why is it important in brachytherapy to realize that rhodium is not a stable isotope?
If rhodium were not a stable isotope what considerations must one make?

I am not really sure why a stable isotope would be necessary for this.
 
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  • #2
You're missing a factor in the exponent. If the half-life is 1.02 years, then after 1.02 years half of the original amount will have decayed - that's why it's called a half-life. I suggest you go back and review the relation between the half-life and the exponential decay constant (usually called lambda).
 

1. What is Ruthenium 106 and how is it used in brachytherapy?

Ruthenium 106 is a radioactive isotope of the element ruthenium. It is used in brachytherapy, which is a type of radiation therapy that involves placing a radioactive source inside the body near a tumor to deliver a high dose of radiation to the cancer cells.

2. What types of cancer can be treated with Ruthenium 106 brachytherapy?

Ruthenium 106 brachytherapy is commonly used to treat eye tumors (e.g. ocular melanoma), skin tumors, and some types of gynecological cancers. It can also be used to treat tumors in other areas of the body, such as the head and neck.

3. How does Ruthenium 106 brachytherapy compare to other forms of radiation therapy?

Ruthenium 106 brachytherapy is a targeted form of radiation therapy, meaning that the radiation is delivered directly to the tumor and does not affect the surrounding healthy tissue as much as other forms of radiation therapy. It also has a shorter treatment time and fewer side effects, making it a favorable option for some patients.

4. Is Ruthenium 106 brachytherapy safe for patients?

Yes, Ruthenium 106 brachytherapy is a safe and effective treatment option for many types of cancer. The amount of radiation delivered during the treatment is carefully controlled and monitored to ensure the safety of the patient and healthcare providers.

5. How is Ruthenium 106 brachytherapy administered?

Ruthenium 106 brachytherapy is administered by placing a small radioactive seed or wire near the tumor, either directly or through a catheter. The seed or wire is then removed after the prescribed amount of time, typically a few minutes to a few days, depending on the specific treatment plan.

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