Cancer Part 2: Going Radioactive

As I chronicled earlier this year (see “A Sudden Case of Cancer”), I got a Thyroid Cancer diagnosis back in May of this year. In June I went through surgery which went very well. After only three weeks, I was sufficiently recovered to travel to Greece and give a keynote presentation at the SAMOS conference. My scar prevented me from taking as much as advantage as I could have of the sun and pool, but it was possible to do at least a little bit of bathing towards the end. Now, I have reached part two of the treatment, radioiodine therapy to knock out any lingering cancer cells. Basically, I am going radioactive for a few days.

Since my surgery, I have found some other people who have also gone through this particular experience. Talking to other people has turned out to be helpful to figure out how to handle things before and after the radioiodine therapy, and also provides an interesting comparison point.


The idea behind radioiodine (radioactive iodine) is rather brilliant. Since the thyroid gland tends to absorb iodine that enters the body, radioactive iodine will also aggregate in the thyroid and knock out any lingering thyroid cancer cells. The biology of the body makes for a very simple targeted attack on the cancer cells, far easier than using external radiation sources. Basically, you eat a dose of radioiodine at the body does the rest of the work.

The same mechanism is why people are given non-radioactive iodine pills as a precaution when nuclear accidents happen – by filling up on harmless iodine, the risk of radioactive iodine aggregating in thyroid and causing cancer is reduced.

Emptying Out the Iodine Stores

As can be deduced from the above, in order for the treatment to be as effective as possible, it is a good idea to deplete the body’s iodine reserves before the treatment. The less non-radioactive iodine that is present, the more radioactive iodine will be absorbed and aggregated in the correct location. Logical, but not entirely trivial to actually achieve. It requires keeping to a strict low-iodine diet.

Just what a low-iodine diet means was surprisingly difficult to get a good handle on, and there seems to be a lot of variation in advice across different medical systems and individual doctors. I hope I got it sufficiently right, but honestly I am not entirely sure I did. It is surprisingly hard to avoid iodine. It seems most countries today enrich standard salt with iodine in order to avoid iodine deficiencies… with the result that it is embedded in pretty much everything except fresh ingredients.

Low-Iodine Diet Rules

At first, I was told to avoid a few choice things like iodized salt for two weeks, by the first doctor I talked to. It was not really detailed enough to help.

When I said this was a bit vague, I got a new more detailed paper in the mail that listed many more things, but also keep the diet to one week before the therapy. Thanks to some friends, I also got hold of a very detailed list from the US. Finally, I found a very good resource from Canada which was clear enough to really help. I also heard that in Canada this diet was supposed to be kept for four weeks, not one. As I said, quite a few different variants… Happy to just do one week, but a bit concerned if it is sufficient.

A low-iodine diet (LID) cuts out a lot of things. Some rather intuitive, and some entirely unexpected. The end result is a rather dreary diet that left me feeling rather unsatisfied and bit funny.

Excerpt from the guide from Thyroid Cancer Canada that I found the most helpful.

First of all, avoiding iodized salt and anything ready-made with salt such as ketchup, mustard, sauces, and stock, makes for rather bland food. The dreaded salt hides everywhere, including in canned vegetables, tomato paste, olives, etc. Finding salt without added iodine is possible, but even that was rather suspect since the advice was to avoid sea salt. Thus, no salt seemed like the safe solution. I worked around the taste problem with other spices… but watch those spice mixes.  Basically, I used fresh peppers, tomatoes, and herbs.

Second, no seafood or anything that has grown in the sea. This was a bit of a problem since we eat quite a lot of fish in the family. In any case, fish without salt would not have been very enjoyable.  Third, no soybeans and anything made from soy, which is not too big of a deal. You can see how this kind of diet would be a real problem in a country like Japan…

Fourth, no cheese and no milk products, along with no egg yolks. That is no fun and takes away a large chunk of what we usually use to make interesting food at home. You cannot really use milk-replacement products like oatmilk either, since they are industrially made and enriched in various unpredictable ways.

Fifth, for some reason a majority of the sources indicated that tea would be a bad idea. Not all of them, which is a bit interesting. Coffee was generally accepted however, so I used black coffee as the daily caffeine provider.

There were some other concerns as well, but I ended up living off unsalted rice and pasta (forget bread, very hard to find anything that is not salted or randomly enriched in some way) along with fresh meat.  One day I tried frozen chicken and unfortunately ate it before realizing that it was frozen in a slightly salted brine. As I said before, not entirely trivial to keep to this diet.

Obviously, eating at a restaurant is entirely out of the question. Which made it a bit hard to begin the diet as I was travelling home from the US at the time. Tried to cut out salt and milk and focus on raw salads, but basically it is impossible to do LID when traveling.  

One effect of this rather peculiar diet was that it was hard to feel really full. In theory, fats are easy enough, just use oils. But large amounts of oil is rather hard to get down compared to cream.

On the other hand, I have no real right to complain. People with food allergies live with these kinds of problems all the time, and going through something like this once for a short while should serve more as an eye-opener and reminder on how tough it can be to avoid certain ingredients in food.

Thyrogen vs Levaxin

Another necessary preparation for the therapy was to push down the level of thyroid hormones in the body. This runs counter to my ongoing medication with Levaxin, which replaces the hormones that I no longer produce myself after the surgery. In the past, the solution was to simply not take Levaxin for some four weeks before the therapy, which was apparently really tough on the patients. I can imagine the tiredness and sluggishness resulting from that.

Today, there is a better solution, Thyrogen. It is a drug that pushes the hormones in the desired direction while allowing the patient to stay on Levaxin. It was simply a matter of getting it injected in the two days immediately prior to the therapy, with no other medicine adjustments needed.

However, it does have the potential for some side-effects and I got a bit dizzy and tired in the afternoons after taking it. According to the blood tests I took before the therapy, it did do the job, and it is definitely preferable to staying off of Levaxin for a month. Side effects are nothing compared to that.


In the end, it was time for the actual treatment, which was a total non-event. I just swallowed a single capsule of radioactive iodine, drank a glass of water, and made my own way back to isolation. It was a bit comical on the way back to my (isolation) room as the nurses in the ward parted way for the radioactive patient, pushing themselves against the edges of the corridor.

At this point, it was time for isolation.


The treatment makes you radioactive. That is a bit of problem around people, and in particular children. For the first three days after the treatment, Swedish standard is to stay in isolation at the hospital – they try to schedule these treatments on Fridays, since it is easier to spare a room for isolation over the weekend. I was put in a single room and the end of corridor in the ward (I guess in order to reduce the number of potentially affected neighbors), and told to stay there for the duration.

Other people who went through the same procedure in the US and Canada that I talked to were apparently told they could go home immediately, as long as there were no children in the house. The Swedish standard seems to make more sense, but it was just a standard room. No lead lining, no heavy lead door… it seems the concept is to use distance as the main shielding. A bit disappointed in not being in some advanced metal cage, but I much prefer having openable windows and normal walls.

I am writing this blog while still in isolation, as there is a lot of time to kill.

Being in isolation like this is another new experience. I would say it is similar to long-distance flight psychologically: you are stuck in a single place, you cannot go outside, you cannot exercise, there is nothing much else to do except find ways to pass the time. Food is left in the hallway outside the room for me to pick up, and I have to call the nurses for all service. Still, I have plenty of power outlets, wireless access, and the phone works.

I brought along a bunch of magazines and a book I wanted to read, and the TV in the room could read a USB key with movies that I had prepared since I was not sure whether I would have network access (originally intended to play on my laptop, but it is better on the big screen). Plus of course a laptop, phone, and Bluetooth speaker to play some music.  


After the initial three days, it will be OK to be home as long as the kids are not. My wife can be at home too, but we need to keep a safe distance between us – which is going to require some focus. However, during this time I cannot be among people in uncontrollable situations – no shopping, no going to the gym, no public transport, and no going to the office. It is a matter of time of exposure too, but the basic advice is avoid irradiating others. I should still be able to take walks or go biking, which is a lot better than sitting still at the hospital.

It is taking a toll on the family, but at least the isolation happened to coincide with fall break in the schools here, so the kids were away anyway. If that had not been the case, Swedish guidelines would have been for me to stay in a hotel for the rest of week as well. I’d much rather be home, like will be the case now.

7 thoughts on “Cancer Part 2: Going Radioactive”

  1. Jakob, a friend did the same as you and made a complete recovery. It will pass.

    I had part of my thyroid removed almost two decades ago and am on more or less the same supplement of thyroxin as I was then. Once stabilised other than the pills every morning you should notice nothing. I am still able to outrun and outexercise people half my age. You will too.

    People do not often share their thoughts and fears. That have does not surprise me. Your family and friends are most fortunate.

    Wish you a speedy recovery and hope that you do not glow in the dark for too long!



  2. Thanks!

    Yes, apart from this radioiodine, I have felt pretty much recovered. Maybe I was not clear, but this seems to be mostly following process and making sure all the cancer is gone. The diagnosis has something like a 99% recovery rate, and I do seem to be in the 99% from what I can tell currently.

    Honestly, this whole isolation is mostly annoying and a bit rough on the rest of the family. Would rather be home take care of things, but that’s how things are.

  3. One of the non-intuitive details here in the US is to not buy processed meat and poultry, even simple things like chicken breast and prepared beef stew pieces. Reason? A common cleaning solution for commercial butcher shops is Iodine-based, and chances are REALLY high that your meat is contaminated with concentrated iodine. This is not a health hazard, and the quantities are really small, but for a LID it is fatal.

  4. Hi Jakob
    I commend the candidness you have here to share and educate folks following you… you are a great teacher by birth and design ! My wife did the radioactive pill you mention (she has no cancer by doctor told her to eliminate risk that way). The experience you talked about, isolation in a room etc.. is very true ! She was locked in our master bedroom for days with all she need.
    Wish you the best

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