Question: how has medicine developed throughout the years you have worked as a radio physicist?

Rob Brass answered on 14 Jun 2016:

I’m not too sure about medicine as a whole, I only really deal with radiotherapy, but we’ve advanced a fair bit!

When I started we’d just got rid of our last Cobalt60 machine (the last one in the UK!). Instead of generating radiation electronically, these old machines used to contain a large block of radioactive Cobalt and we simply used to expose the patient to it for a certain amount of time to give the dose. When you’re using a radioactive source like this you obviously only have 1 energy available and it was quite low, whereas now we have the ability to use energies 4 or 5 times greater than before, allowing us to treat further into the patient.

Also, for the first couple of years that I worked here we still used old x-ray film to plan our most simple patients. We’d take an x-ray, the doctor would draw on it what he’d like to treat and that would be that! Nowadays every patient is CT scanned so we have a full 3D image set and a much better idea of what doses we’re giving to what.

We’ve developed a technique called SABR (say it Sabre, like a sword 🙂 ). Due to the accuracy of our equipment now, for certain patients we are able to give a much higher dose per treatment, meaning they need less daily treatments. They often only need to come in 3 – 5 times, rather than 20! This is obviously much better for the patient. Bringing this into use though required a lot of research! Giving high doses in a single shot is a lot more risky, but the rewards are greater.

Last thing i’ll mention is something called VMAT, or arc therapy. This is where the machine rotates around the patient while delivering dose, meaning that the dose to the normal tissues is more spread out while still giving a high dose to the tumour. This was just coming into use when i started but we’ve had to do a lot of work so we can use it for more and more areas on the body.

All these, plus lots more, have happened in the 4 and a half years since I started, and these are only at my hospital! It’s quite cool because you’d think that in this day and age we would have got to a point where we cant really improve much more but theres always ways to improve!