The next three days are a bit full on as we try to get more information to make a decision on treatment options beyond immunotherapy. I have several scans, bloods, oncologist appointments to review my final cycle of chemo, scan results and immunotherapy (or placebo) treatment.
Today I’m having a PET-CT scan. Although it is one of the most informative and caught my secondary tumour early, this is my least favourite scan experience. Out of all the treatment and investigations I have had this is always one of the loneliest with way too much time to think.
Firstly, let me tell you (as best I can) what a PET is and then what it is like. It stands for Positron Emission Tomography and it is medical imaging technique that uses a radioactive isotope (Oh Joy, and this is my 4th in just over a year) attached to a biological molecule (often glucose labelled with radioactive fluorine). This is called FDG for short because the chemical name is very long and I have forgotten it. This lovely cocktail is used to produce a 3D map of functional processes in the body.
You have to fast for 6+ hours for it, so the cells using glucose use the FDG not other stuff you have eaten. I nearly screwed this up today as I ate a fruit pastel in my mum’s car on the way to the station, fortunately I realised (only after sucking the sugar off) and spat it out the window (class). The kids thought this was hilarious, not sure my Mum was that impressed with my manners or my forgetfulness. Anyway, I breathed a sigh of relief when my blood sugar levels were 4.8% and in the normal range they’d expect for someone who hadn’t eaten since before 7am. I had visions of this ridiculously small amount of sugar being fast tracked to any remaining pesky cancer cells and ruining the scan. Think I was a bit neurotic this morning.
It takes about 60-90 mins for the cells in the body to uptake the FDG. The clever scanning machine then detects radiation emitted by the fluorine isotope and produces a map to reflect glucose use in the body. With me so far? In a nutshell, the more glucose used the more an area shows up ‘hot’. Cancer cells are rapidly dividing cells so tend to be hot spots. Other areas of high glucose activity are the heart and areas of historic or recent trauma (surgery sites, radiotherapy damage etc).
We are looking for rogue cancer cells in other parts of my body as well as a detailed look at what is going on in and around the lymph nodes in my axilla (armpit to you and I) as this is the site of my secondary tumour. Chemo is a systemic treatment so it should have reached parts other treatments cannot (to coin a phrase). That said triple negative cancer cells are pesky, aggressive, unpredictable little so and so’s and have a habit of popping up when and where you least expect them. They can also develop resistance to chemo. I am hoping we can get this PET-CT result in tomorrow’s appointment as I’m keen to know what we might do next to out fox this disease.
The clever radiographers combine a CT (structure and anatomy) with the PET (info about how the tissues function metabolically). The pic below sort of explains this.
It is a bit like google maps combining the map view with a satellite or street view.
So whilst PET-CT is kind of the best at spotting cancer cells on the move or hiding in new places, its not my favourite scan to have. That got me thinking (3 hours on your own not moving does this) about my top 5 scans! So here they are for a bit of informative fun.
- CT scan – quick efficient and contrast dye can go through my port
- MRI scan – noisy and long, but if you do yoga breathing it’s ok. Contrast dye can also go through port.
- Bone scan – radioactive injection through cannula can be tricky and the 3hr wait for it to do its job can be a pain if you don’t plan for it (I normally meet someone for lunch!!). But the scan itself very close to your body, but it is quick and you don’t have to keep away from people. Everyone is in the room with you so you don’t feel isolated.
- Ultra sound – this is pretty easy and painless, but it comes in at number 4 as I question its accuracy in measuring invasive cancers. I’ve had a tumour that has supposedly shrunk by 50 and 40%. This gave my oncologist, surgeon and family false hope. Instead of removing a 24mm tumour the reality was 96 mm of live cancer and no clear margins (so probably more still there). I don’t trust ultra sounds much!
- PET-CT – the lonely scan or the leper scan. As soon as they give you the radioactive tracer injection (which can take ages due to cannula issues) the clock is ticking. They take you to a small room where you have to sit completely still for 60-90 mins. You then have another 30 mins in the scanner and have to keep away from people for several hours afterwards. Pregnant women and young children are a no no. Members of staff back away from you as their Geiger counters start clicking at you.
I’ve just remembered mammogram! Now that was genuine pain, having a tumour squashed between two plates and scanned. That would be number 6. Bone density tomorrow – no idea what that entails.
Turns out PET scans at this big teaching hospital aren’t as lonely as the (very posh) place I had my previous scans. All the people are lovely and most of the patients are in bays together rather than tiny cell like rooms with sci-fi loud speakers. This space is rather comically called the ‘Hot Waiting Area’ and we have our own ‘hot’ toilet. They let you read here too (unless they are scanning your brain) so that’s a good way to pass the time. I’m also writing this.
The hot area was full of glowing patients waiting to be scanned, so I ended up on a trolley in a freezing cold recovery room from 12.45 til 15.15. It was quiet, but cold. They had a backlog of patients so once my cannula was in (second attempt) I waited a while before getting the radioactive cocktail. The pic below shows the (presumably) lead casing the injection comes in to stop the staff being exposed to too much radiation. Blimey I’m going to be glowing like the Ready Break boy when I get out of here.
During the wait I can’t help worry about next treatment steps, if its spread any where else. If so what this means for prognosis, continuation on the trial etc etc. I haven’t had my latest CT scan results yet either (that’s tomorrow after bloods and a bone density scan). Had to break out a second metal free scan outfit this week!
The PET-CT Scan itself is fine. They come and collect me about 15.15 ask me to use the ‘hot toilet’ and then I get in the scanner. They wrap me up in a weighted cover and blanket so I don’t move my arms and then whiz me gently up and down on the scanner for about 30 mins. In complete silence. Quite soothing, but way too much time to think – as if the 2.5 hours in a room on your own hasn’t sent you into neurosis.
Once off the scanner you are reminded that you mustn’t have prolonged contact with small children or pregnant women for a few hours. Tricky as a mother of two and travelling home on a crowded tube and train in the school summer holidays.
Before leaving the centre, I have a hot cup of tea from a styrene cup to try and get warm, two free biscuits and my packed lunch. It’s gone 4pm and I’m starving and a bit spaced out. It’s now pouring with rain and my metal free outfit is soaked through. I’m hoping the PET-CT results will be ready for my appointment tomorrow, but let’s see.
This post is a bit technical, but I thought it would be useful for people going through or supporting others having a PET-CT scans.