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Utah mom reflects on radioactive iodine cancer treatment, which has stood test of time

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A bottle of multiple doses of radioactive iodine with a pill containing one dose. Radioactive iodine is used to treat thyroid cancers and diseases. (University of Utah Health)

Estimated read time: 6-7 minutes

SALT LAKE CITY — Shirley Crepeaux was a little hesitant when doctors proposed radioactive iodine as a treatment for her thyroid cancer about 12 years ago. She trusted her doctors at the Huntsman Cancer Institute, but she was still terrified and afraid.

“When faced with leaving a 12-year-old alone and my husband a widower or drinking some poison, I’ll drink some poison,” she said.

Crepeaux, now 54, is mom to four children. When she was diagnosed with cancer, her youngest was 12.

“We tried to make the cancer diagnosis a big nonevent as much as we possibly could,” she said.

The radioactive iodine treatment, however, was definitely an event.

She was given a tiny vial to drink while alone in a specific room and was given a lot of warnings through a speaker system telling her not to spill it or drop it. She said it tasted salty.

After drinking it, she was told to stay away from pregnant people and children for a week. She spent a week in her bedroom. Crepeaux said it was “pretty miserable,” but her husband did what he could to help her stay in contact with the family, including video calls to the breakfast table and waves through the window.

“In the big scheme of things, it was a week out of my life and then I was back to being myself,” she said.

How it works

Thyroid cancer is one of the more common cancers, and one of the easiest to treat — partially due to radioactive iodine.

Dr. Dev Abraham at the Huntsman Cancer Institute said radioactive iodine was first used in the 1930s and 1940s, around the same time chemotherapy was being developed, and the treatment became popular in the 1960s. It treats thyroid cancers and disorders and Graves’ disease, which causes the thyroid to overproduce hormones.

“It’s stood the test of time,” Abraham said.

What has changed throughout the time it has been used is the dosage, Abraham said there have been more reports recently showing a small but statistically significant increase showing too much radioactive iodine can cause a higher risk of other cancers, causing dosages to be brought down in the last five to 10 years.

Radioactive iodine is used to treat thyroid cancers and disorders. Because it is a radioactive substance, many precautions are taken to reduce exposure. (Photo: University of Utah Health)

Radioactive iodine is administered in a capsule or drink, and Abraham said it is a unique targeted treatment. Thyroid tissues, including tissue from thyroid cancer that has spread throughout the body, will be destroyed by the treatment once it enters the cell. Other cells that come in contact with the radioactive iodine in the blood won’t be affected.

“It is a treatment that is specifically determined by the ability of the tissue to uptake, or pick up, or trap iodine. So iodine trapping tissues are specifically susceptible to being killed by this low-grade radioactivity,” Abraham said.

Before taking a dose of radioactive iodine, doctors like Abraham will help a patient starve their thyroid and thyroid cancer tissues from iodine by avoiding certain foods to make it so those cells are hungry and will absorb more of the radioactive iodine.

Most often, the treatment is used after much of the cancer is removed in surgery to address leftover thyroid tissue that could have cancer cells or cancer cells that have spread, something that is more common in thyroid cancers than in many other cancers.

He said in many cancers, spread to other areas leads to a worse prognosis. But with radioactive iodine, spread of thyroid cancer does not necessarily mean a worse prognosis.

Long-term effects

Abraham said although one death is too many, there are not very many patients who die from thyroid cancer. The American Cancer Society estimates there have been about 43,800 new cases of thyroid cancer in 2022 and about 2,230 deaths.

The main goal of radioactive iodine is to reduce the frequency of recurrence of thyroid cancer, he said.

Crepeaux continues to have appointments with Abraham every year, he said he has cared for her for years and that it seems she will continue to do very well and the radioactive iodine treatment was effective.

Crepeaux is one of few thyroid cancer patients who have residual disease, small amounts of cancer left behind that do not grow. Abraham said these are probably dying thyroid cancer cells, and in most patients, cancer cells remaining but not progressing is as good as a cure.

Because of the radioactive iodine treatment, Crepeaux is constantly dealing with a dry nose, throat and eyes. She said she always has her water bottle with her and uses products to help add moisture.

Abraham said this is one of the reasons treatment should be tailored to the patient, using the smallest effective dose. He said two doses are sometimes used in severe cases, but rarely three.

If the cancer did come back and Crepeaux were to decide to have a second dose of radioactive iodine, she said it would lead to her having no tears, spit or saliva — even more discomfort.

Optimism

Crepeaux was a hairdresser for 30 years, but now she is in school to become a medical assistant.

“This is something that happened to me. It’s not who I am. I’m Shirley and I’ll always be Shirley. A little salty. A little raunchy. … I don’t take guff from anybody. And if I love you, I love you with everything. … I won’t let cancer or anything else change that or define me,” she said.

She said it’s thanks to her primary physician that she got screened for thyroid cancer. If she hadn’t, she could have died within a few years. When it was found, it was between stage three and four and had already spread into her lungs. Her only symptom up to that point had been shoulder pain and difficulty swallowing.

Now, Crepeaux encourages everyone to feel for lumps on their thyroids doing self-checks, or ask their doctor to do a check during a yearly physical.

Crepeaux was told after her surgery she would have a very whispery, raspy voice, but therapy and her loud voice helped save her voice — although she said it takes a lot more effort now to produce an audible voice.

“Fortunately, I was one of those people with an abrasively loud voice prior to the surgery, so now I just have a normal voice,” she said.

Her laugh, however, is still the same loud laugh, a laugh that brings in more laughs from others in the room.

Overall, Crepeaux shared a message that there is hope and encouraged others going through similar situations to be grateful and focus on the little things that bring them happiness.

“Most people with cancer are living with it, they’re not dying with it,” she said.

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Emily Ashcraft joined KSL.com as a reporter in 2021. She covers courts and legal affairs, as well as health, faith and religion news.

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Science

Promising new electric iodine thruster passes key test in orbit

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A new electric thruster that blasts out iodine has now been successfully tested in orbit, a milestone that could help lead to significantly tinier, simpler, cheaper and higher-performance engines for satellites and spacecraft, a new study reports.

Conventional rockets use chemical reactions to drive propulsion. In contrast, electric thrusters produce thrust by using electric power to accelerate propellants such as electrically charged ions away from a spacecraft.

Electric propulsion generates much less thrust than chemical rockets, making it too weak to launch a spacecraft from Earth’s surface. But electric thrusters are highly efficient at producing thrust, given the small amount of propellant they carry. This makes them very useful for spacecraft that are already in space.

Related: Superfast spacecraft propulsion systems (images)

Side view of a flight model of the NPT30-I2 iodine electric propulsion system firing in a vacuum chamber. (Image credit: ThrustMe)

Currently, xenon gas is the propellant of choice in electric thrusters. However, xenon is rare, making up less than 1 part per 10 million in Earth’s atmosphere. It is also expensive, at about $3,000 per 2.2 pounds (1 kilogram). Moreover, the gas requires bulky pressurized tanks, as well as complex networks of pipes, valves and pumps to shuttle it around a propulsion system.

A possible alternative to xenon that researchers have explored over the past 20 years is iodine, the same element often packaged with table salt and used as an antiseptic. Iodine is cheaper and more abundant than xenon and can be stored unpressurized as a solid that changes directly into a gas when heated, potentially enabling significant miniaturization and simplification. Previous research has shown electric thrusters using iodine can prove more efficient than ones employing xenon in ground-based tests.  

However, iodine presents challenges of its own when it comes to propulsion. For example, iodine is highly corrosive, posing a potential danger to electronics and other systems onboard spacecraft. In addition, vibrations during launch and spacecraft motion once in orbit can make solid iodine break into pieces, which may damage the propulsion system, among other problems. 

Now scientists have for the first time launched an iodine-based electric thruster into space and showed that it can help propel a spacecraft in orbit.

“We show that iodine can be safely used in space, bringing an option for propulsion systems onboard even the smallest spacecraft,” said study lead author Dmytro Rafalskyi, chief technical officer and co-founder of space propulsion company ThrustMe, which is headquartered near Paris.

The new electric thruster, the NPT30-I2 from ThrustMe, fits within a single package about 4 inches by 4 inches by 4 inches (10 centimeters by 10 centimeters by 10 centimeters) in size and about 2.6 pounds (1.2 kg) in mass. It served as the propulsion system for a 44-pound (20 kg) cubesat, the Beihangkongshi-1 satellite operated by Chinese satellite company Spacety, which launched into space on a Long March 6 rocket on Nov.
6, 2020. 

Ground radar stations confirmed that the NPT30-I2 helped the miniature satellite maneuver in orbit. All in all, the new thruster let out puffs of iodine that cumulatively boosted the cubesat’s altitude by more than 1.8 miles (3 kilometers).

The new findings show that iodine is not only a viable propellant, but can also achieve nearly 50% more efficient propulsion than xenon, because of factors such as how iodine is easier to electrify than xenon. The company has opened a production line for these new thrusters and has already delivered more than 10 of them to satellite manufacturers worldwide, Rafalskyi said.

“Our team of roughly 10 engineers and a few PhDs reached something that was a dream of the propulsion community for decades,” Rafalskyi said.

To deal with the problem of corrosion, the scientists developed ceramics and polymers to protect metal components within the satellite. To keep the iodine from shattering, they strengthened it by embedding the iodine crystals in a porous ceramic block.

“We are pioneers in using iodine, but that doesn’t mean that we don’t encourage others to switch to this propellant,” Rafalskyi said. “We are very open about our research results, and look forward to seeing more and more propulsion manufacturers converting to iodine.”

The new thruster could help tiny satellites and large networks of satellites, such as SpaceX’s Starlink megaconstellation, perform maneuvers in space, such as avoiding collisions, staying in orbit and changing from one orbit to another.

“Currently, the majority of the smallest satellites don’t have any propulsion options due to the complexity, cost and risks associated with the use of standard propulsion systems,” Rafalskyi said. “Iodine enables powerful propulsion for even the smallest satellites due to inherent properties of iodine. In-space maneuverability becomes accessible to any user, including universities and small startups.”

In the future, the researchers want to scale up their research to cover large Earth-orbiting satellites as well as deep space missions, Rafalskyi said.

The scientists detailed their findings in the Nov. 18 issue of the journal Nature.

Originally published on Space.com. Follow us on Twitter @Spacedotcom or on Facebook. 



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Science

In a space first, scientists test ion thrusters powered by iodine

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The ThrustMe engine in operation on Earth, in a vacuum chamber.


ThrustMe

For a few years now, ion propulsion technology’s sci-fi mechanics have raised the standard for flying spacecraft, replacing fiery rocket tails as the new in-thing. Ion propulsion can be about 10 times faster than normal fuel and can continuously run for prolonged periods of time, gaining a wicked amount of speed along the way. 

One drawback, however, is it’s typically employed with xenon thrusters. JAXA’s Hayabusa2 mission used the classic xenon as a fuel. Xenon, a heavy noble gas, is exceptionally rare on Earth, pricey and difficult to maintain. That’s why French aerospace company ThrustMe is pursuing a plan for better ion propulsion tech. They suggest using iodine instead of xenon.

Iodine is incredibly prevalent, inexpensive and easy to store with minimal effort. Seaweed, printing ink, dairy and even table salt are rich in the non-reactive element. 

“Iodine is significantly more abundant and cheaper than xenon and has the added advantage that it can be stored unpressurized as a solid,” Dmytro Rafalskyi, CTO and co-founder of ThrustMe, said in a statement. 

Along with his team, Rafalskyi developed a working propulsion system with an iodine ion thruster, called the NPT30-I2. It includes all of ion technology’s needed subsystems and fits within a single package of roughly 10x10x10 centimeters (about 4x4x4 inches).

Using iodine as fuel for spacecraft has been toyed with in the past. But what sets ThrustMe apart is it actually sent a satellite into space with its device — and the operation was a success. It published its results on Wednesday in the journal Nature.

“Although iodine is viewed as a game-changing propellant and has been investigated by companies, universities and space agencies around the world,” the team writes in their paper, “no system has previously been tested in space.”

ThrustMe integrated its system into the Beihangkoshi-1 research satellite, which is operated by the global space company Spacety. The craft was launched into orbit by a Long March 6 rocket on Nov. 6, 2020. Since then, the ThrustMe team has been scrutinizing every aspect of the propulsion system, and according to its observations, everything worked as expected.

“Having our results peer-reviewed and publically accessible provides the community with further confidence and helps to create a benchmark within the industry,” Ane Aanesland, CEO and co-founder of ThrustMe, said in a statement.

The breakthrough of ion propulsion

For a spacecraft to move forward, it needs to propel something backward. This notion is the classic Newtonian sentiment “every action has an equal and opposite reaction.” Normal combustion engines ignite chemicals in fuel, creating gas (and wonderful flames), that is pushed out the exhaust at the bottom of the spacecraft. This propels it upward. 

The issue with that technique of propulsion for spacecraft is it only works in short bursts — the “action” of the engine needs to always be “on” for the spacecraft’s opposite “reaction.”

Ion thrusters are a bit different. Instead of jetting out an intense stream of fuel, they take advantage of a concept called ionization. The process works something like this:

Every atom of every element has some amount of electrons, particles with a negative charge, and protons, particles with a positive charge. When an atom is neutral, typically its stable state, its number of electrons equals its number of protons. That creates a net zero charge for the atom. 

When an atom is ionized, the electron amount changes — what ion propulsion systems are after. 

An ion thruster works to take and remove electrons from a bunch of atoms, turning them into charged “ions.” Once there’s an even number of negative ions and positive ions, a neutral environment called a plasma is created. The key with plasma is it responds to electric or magnetic fields. 

Ion thrusters have magnetic grids inside to induce fields and ultimately expel the positive ions. Ions propelled at exceedingly fast speeds out of the back of the spacecraft push the spacecraft forward. A bonus point? The thrusters use significantly less “fuel” than chemical rockets.

Even though the push is super light at first — one NASA scientist describes the initial propulsion to be as light as a gentle blow — it picks up speed over time. Over days, months or years, the velocity compounds upon itself.

Xenon is normally used for the operation because as it’s a noble gas, it’s easier to pluck off or pop on electrons. It also already lives in a gaseous state, which helps move the plasma-induction process along. But, as per ThrustMe, iodine atoms are a fair competitor.

Is iodine better?

Iodine has a few of its own limitations. The main reason scientists haven’t gone through with building iodine thrusters in the past is that the element is too corrosive in a solid state. But to keep iodine as a player in the thruster game, storing it as a solid is necessary because that enables the cheapest maintenance. 

The team writes that “iodine has a high electronegativity that can lead to corrosion with many common materials” and that “vibrations during launch and spacecraft motion once in orbit can cause solid iodine to break into pieces, which may damage the propulsion system or lead to poor thermal contact during heating.”

But on the bright side, the crew got around that hurdle by using ceramic containers to carry its iodine atoms in the thrusters, which appeared to help. They also found the solid iodine could easily be heated to become a gas and begin the ion propulsion process.

It should also be noted that other companies are looking to novel compounds for ion thrusters as well, such as SpaceX. The researchers say SpaceX chose krypton as a propellant for Starlink satellites. “However,” they write in the paper, “krypton has a higher ionization threshold and lower atomic mass than both xenon and iodine, and the required propulsion system power increases by more than 25% to achieve the same thrust level.”

All in all, more research is likely needed to determine the viability of iodine-based thrusters, particularly because this is the first demonstration of the device, but ThrustMe’s successful mini-satellite spaceflight could be a solid first step.

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Science

New Electric Propulsion Engine For Spacecraft Test-Fired in Orbit For First Time

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For the satellites spinning around Earth, using electricity to ionize and push particles of xenon gets them to go where they need to go. While xenon atoms ionize easily and are heavy enough to build thrust, the gas is rare and expensive, not to mention difficult to store.

 

Thanks to new research, we could soon have an alternative. Enter iodine. 

Full in-orbit operation of a satellite powered by iodine gas has now been carried out by space tech company ThrustMe, and the technology promises to lead to satellite propulsion systems that are more efficient and affordable than ever before.

The iodine electric propulsion system firing in a vacuum chamber. (ThrustMe)

“Iodine is significantly more abundant and cheaper than xenon, and has the added advantage that it can be stored unpressurized as a solid,” says Dmytro Rafalskyi, the CTO and co-founder of ThrustMe.

While earlier ground-based tests of iodine propulsion engines had been promising, getting it working in space is the clearest sign yet that this can be the future of small-scale spacecraft engines – and that our exploration of space can practically continue.

The team used iodine to fuel a 20 kg (44 pound) CubeSat satellite with an engine named the NPT30-I2, which was launched on 6 November 2020. Maneuvers were carried out successfully, and iodine was shown to achieve higher ionization efficiency than xenon too.

Besides the benefits we’ve already talked about, iodine-based systems could also be built in significantly smaller and simpler forms than current satellites: unlike xenon and other propellants, iodine can be stored on board in its solid form before it’s converted into a gas, so there’s no need for bulky, high-pressure gas tanks.

 

“The successful demonstration of the NPT30-I2 means we can proceed to the next step in the development of iodine propulsion,” says Rafalskyi.

“In parallel with our in-space testing we have developed new solutions allowing increased performance and have commenced an extensive ground-based endurance testing campaign to further push the limits of this new technology.”

The layout of the iodine engine. (Rafalskyi et al., Nature, 2021)

Tens of thousands of satellites are expected to be launched into orbit across the next decade, so finding ways to make them as efficient and as affordable as possible is key if we’re to keep on exploring and analyzing Earth and the Universe around us.

The use of iodine in making satellites more affordable, more efficient and more compact has multiple potential benefits in how satellite constellations can be deployed, trained to avoid each other, and disposed of when they’ve reached the end of their useful lives.

Challenges remain: iodine is highly corrosive, which means ceramics are required to protect the satellite parts, and at the moment iodine engines aren’t as responsive as their xenon counterparts. However, this is a major step forward for the technology.

“Publication of these historic results is not only important for ThrustMe, but also for the space industry in general,” says ThrustMe CEO and co-founder Ane Aanesland.

“Having our results peer-reviewed and publically accessible provides the community with further confidence and helps to create a benchmark within the industry.”

The research has been published in Nature.

 

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