NSCLC

NSCLC scans and monitoring

Scans and monitoring appointments

Different types of scans are used to help monitor if tumours are growing or shrinking inside the body.

Throughout your treatment, scans will be carried out at regular intervals to keep an eye on what effect the treatment is having – these will look at your lungs, but also other parts of your body where cancer may have started growing too. 

You may have already experienced some scans in the course of being diagnosed or if you have had previous treatments,1 but if they are new to you, then we have summarised some basic information about them below.

Left: a typical CT machine. Right: an example of a CT scan image, showing a healthy lung.

What is it, and how does it work?

CT scans take a series of X-rays, which are used to build up a 3D picture of the inside of the body.2 They use a small amount of radiation, and so are unlikely to harm you or anyone who comes into contact with you after having the scan.2

Before the scan you may have a dye injected into your body, to help certain areas be seen more clearly on the scan.3

When it comes to having the scan itself, you will lie on a flat motorised bed, which will take you through the hole in the machine until you reach the part of the body that is to be scanned.3

An X-ray machine spins around a ring that surrounds the bed and takes the X-ray images of your body.3 Inside a ring that surrounds the bed, an X-ray machine spins around and takes the X-ray images of your body.3

You’ll stay in the machine for around 10–20 minutes, and a radiographer will be on hand to support you in a nearby room. They will communicate with you through an intercom.3

After the scan, the radiographer will be able to tell you if the images the scanner has made are of a good enough quality to be used to assess your cancer, but they will not be able to give you any results.3

What should I expect?

  • You will be asked to stay as still as possible during the scan. At times you may be asked to hold your breath, and pillows or straps may be used to help support you in any specific positions3
  • You may hear a whirring noise as the X-ray machine spins in the ring around you
  • Unlike some other types of scanning machine, CT scanners are not enclosed,3 so people who are wary or afraid of enclosed spaces might find them more comfortable

A typical MRI machine

What is it, and how does it work?

MRI scans use magnetism and radio waves to create a detailed picture of your body.4 MRI scanners are large machines with a tube running through them – the inside of the tube is where the scan takes place.

Before the scan begins, you may need to have a special dye injected into your body to help make the scans even clearer.4

You will then lie flat on a motorised bed, which will slowly move you into the machine until the part of your body that is being scanned is in the centre.4 You’ll stay in the machine for around 20–30 minutes, and a radiographer will be on hand to support and talk to you from a nearby room.4

What should I expect?

  • Because powerful magnets are used, you will be asked several questions about any metal that you have in, or on, your body. If you have certain types of implants (e.g. a pacemaker, cochlear implants, surgical pins) you may not be able to have an MRI scan (in this case you will be offered another type of scan). You will also be asked to remove items of jewellery from your body4,5
  • You will also be asked to leave any metallic objects (e.g. coins, keys) or objects that can be damaged by magnets (e.g. credit cards with magnetic strips) outside the room4
  • You will need to stay as still as possible during the scan. At times you may be asked to hold your breath4
  • Some hospitals allow you to have a  family member or a friend in the room with you on the day for support4 – ask ahead of time if you would like this option. Remember that they will also be exposed to the magnetism of the scanner, and so will also be asked about metallic implants, jewellery, etc.
  • As the magnets in the machine turn on and off, they cause a loud banging noise – this is completely normal. You will be given earplugs or headphones to help quieten this. Your hospital may allow you to play music, so ask ahead of time if you can bring a CD or another music-playing device that you would like to listen to4
  • MRI machines are often enclosed, and some people can find this a little claustrophobic at times. Your radiographer will be able to help reassure you on any concerns you have around this, and most MRI machines have a button that you can press in the event that you need to talk to the radiographer4

A typical PET machine

What is it, and how does it work?

PET scans use a small amount of mild radioactivity to help visualise the inside of the body. These scans are sometimes combined with either an MRI or a CT scan. The MRI or CT helps to visualise your body, while the PET helps to show parts of the body that are using up a lot of energy (like a cancer growing).6

You will need to have a special dye (sometimes called a 'tracer') injected into your body. This is a low-dose sugar solution that is mildly radioactive.6 Any areas of your body that are using the radioactive sugar solution quickly (like a cancer) will show up on the scan, as the tracer will build up there.6 The dye needs some time to get around your body, so you may be asked to relax somewhere for a while before the scan is performed.6

When you have the scan itself, you will lie flat on a motorised bed, which will slowly move you into the scanning machine until the part of your body that is being scanned is in the centre.6

You’ll stay in the machine for around 30–90 minutes, depending on what part of your body is being scanned.7 You’ll be able to talk with the radiographer while you’re in the machine, and there will be a buzzer you can press in case you feel unwell.6

After the scan, the radiographer will be able to tell you if the images the scanner has made are of a good enough quality to be used to assess your cancer, but they will not be able to give you any results.

What should I expect?

  • You will need to stay as still as possible while in the scanner6
  • If you are having a brain scan, you will not be allowed to read while in the scanner.7 This is because activities like reading can cause your brain to accumulate a lot of the sugar solution. This creates a signal on the scan in the brain area that could drown out important signals from cancerous growths
  • Some hospitals can play music for you while the scan is taking place. Ask ahead if the hospital offers this service7
  • Because the dye you are given is radioactive, as a precaution you should avoid prolonged close contact with babies, small children, and pregnant women for some time after your scan.6 The radiographer will be able to provide you with further details about this
  • Because PET scans are combined with MRI and CT scans, you may also need to be aware of some aspects specific to these. You can learn more in the sections above

A typical bone-scanning machine

What is it, and how does it work?

Bone scans are used to find areas of bone in the body that aren’t growing normally. A mild radioactive liquid (called a 'tracer') is injected into the body to make it easier to see where bone is breaking down and repairing (which may happen in cancer).8

You may need to wait a while between having the tracer injected into your body and having the scan.8 The scan itself will take around 30–60 minutes,8 and a radiographer will be on hand in a nearby room. You will be able to communicate with them over an intercom system.

After the scan, the radiographer will be able to tell you if the images the scanner has made are of a good enough quality to be used to assess your cancer, but they will not be able to give you any results.

What should I expect?

  • You will need to stay as still as possible while in the scanner8
  • Because the dye you are given is radioactive, as a precaution you should avoid prolonged close contact with babies, small children, and pregnant women for some time after your scan. The radiographer will be able to provide you with further details about this8
  • The machine may be enclosed, which some people might find a bit claustrophobic. Your radiographer can help reassure you during these times8

A woman having an ultrasound scan

What is it, and how does it work?

Ultrasound scanners use high-frequency sound waves to visualise what is inside the body.9 There are two types of ultrasound test you may experience:

External ultrasound:
  • The sonographer (the technician who does the test) presses a special probe against your body. This emits a very-high-frequency sound that humans can’t hear. Inside the body, the sound waves bounce back off your organs and other structures. These are picked up by a microphone in the probe, which turns the sound waves into a picture
Endoscopic (internal) ultrasound:10 
  • This works in much the same way as an abdominal ultrasound, but instead of a probe being pressed into the abdomen, it is inserted either down the throat or into the bottom. These are used where it may be difficult to get an image of certain parts of the body with a regular external probe. These can sometimes be uncomfortable, so your hospital may offer you an optional sedative

Click on one of the options below to learn more 


CTComputerised tomography
MRIMagnetic resonance imaging
PETPositron emission tomography

  1. National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guideline in Oncology: Non-Small Cell Lung Cancer, Version v1 2022.
  2. Macmillan Cancer Support. CT scan (computerised tomography). 2014. Available from: https://www.macmillan.org.uk/information-and-support/diagnosing/how-cancers-are-diagnosed/tests-and-scans/ct-scan.html. Last accessed August 2021.
  3. Guy’s and St Thomas’ NHS Foundation Trust. Having a CT scan. 2017. Available from: https://www.guysandstthomas.nhs.uk/resources/patient-information/radiology/ct-scan.pdf. Last accessed August 2021.
  4. Guy’s and St Thomas’ NHS Foundation Trust. Having an MRI scan. 2017. Available from: https://www.guysandstthomas.nhs.uk/resources/patient-information/radiology/having-an-mri-scan.pdf. Last accessed August 2021.
  5. Macmillan Cancer Support. MRI scan. 2014. Available from: https://www.macmillan.org.uk/information-and-support/diagnosing/how-cancers-are-diagnosed/tests-and-scans/mri-scan.html. Last accessed August 2021.
  6. National Health Service. PET scan. 2018. Available from: https://www.nhs.uk/conditions/pet-scan/. Last accessed August 2021.
  7. Guy’s and St Thomas’ NHS Foundation Trust. PET/CT scanning - information for patients. Available from: https://www.guysandstthomas.nhs.uk/our-services/pet-imaging/patients.aspx. Last accessed August 2021.
  8. Cancer Research UK. Bone scan. 2018. Available from: https://www.cancerresearchuk.org/about-cancer/cancer-in-general/tests/bone-scan. Last accessed August 2021.
  9. Cancer Research UK. Ultrasound Scan. 2015. Available from: https://www.cancerresearchuk.org/about-cancer/cancer-in-general/tests/ultrasound-scan. Last accessed August 2021.
  10. Cancer Research UK. Endoscopy. 2015. Available from: https://www.cancerresearchuk.org/about-cancer/cancer-in-general/tests/endoscopy. Last accessed August 2021.