If you have been scheduled for a PET-CT scan, you might be wondering what the experience will be like. This guide explains what to expect at each step so you can feel more informed and confident about the process.

When you are dealing with a cancer diagnosis, having access to precise information about what is happening inside your body can make all the difference. A PET-CT scan is one of the most advanced imaging tools available today. It allows doctors to see not just the structure of your organs and tissues, but also how they function.

PET-CT stands for Positron Emission Tomography – Computed Tomography. It combines two types of scans in one session, giving doctors a much more specific and accurate picture than traditional imaging alone.

The CT scan captures detailed images of your body’s structure, like a high-resolution map showing the shape, size, and location of organs and tissues.

The PET scan goes a step further, showing how active your cells are. It uses a small amount of radioactive glucose to highlight areas where cells are consuming more energy, which often happens with cancer cells.

By combining these scans, doctors don’t just see where something is, they see how it’s behaving. This makes it far easier to detect cancer activity early, determine how far it’s spread, plan the most effective treatment, and track how well it’s working.

It’s this deeper level of insight that helps explain why PET-CT is often recommended, even when it means a bit more planning or cost. The right information, at the right time, can make all the difference.

Before your scan: How to prepare

Preparing for a PET-CT scan involves a few important steps to make sure the results are as accurate as possible. Your care team will give you specific instructions, but here is what you can generally expect:

1. Fasting is important

You will likely be asked not to eat for 4–6 hours before your scan. This ensures the tracer works properly. Water or black coffee may be allowed—always confirm with your doctor.

2. Keep physical activity low

Avoid exercise for at least 24 hours prior. This prevents muscle uptake of glucose which can interfere with the scan.

3. Medication and health conditions

Inform your care team about all medications and existing conditions like diabetes or infections, which can influence tracer absorption.

4. Dress comfortably

Wear loose-fitting, metal-free clothing. You might be asked to change into a gown. Remove jewellery and watches.

During the scan: Step-by-step

Knowing what to expect on the day can go a long way in easing any anxiety. When you arrive for your PET-CT scan, you’ll be welcomed by a friendly team who’ll guide you through each step and make sure you’re comfortable.

A PET-CT scan is painless and typically takes between 1.5 to 2 hours from start to finish.

1. Radiotracer injection

After a small IV line is inserted, the radiotracer is administered. You will rest quietly for 45–60 minutes to allow it to circulate. Try to remain still and relaxed.

2. The scan itself

You'll lie on a narrow bed that moves through a large, ring-shaped scanner. The scan is non-invasive and lasts about 20–30 minutes. You’ll be monitored the entire time and can communicate with the technician if needed.

After the scan: What happens next?

1. Minimal side effects

Most people feel fine. The tracer exits your body naturally in hours. Stay hydrated to help it flush out quicker.

2. Waiting for results

Many patients experience "scanxiety" while waiting for results. That’s completely normal. Try to remember that this scan is a vital step toward better, more targeted care.

Here are a few tips to manage the waiting period:

• Stay informed. The scan guides your doctors to make the best decisions.
• Stay busy. Light activities help pass time more easily.
• Talk it out. Speak to someone you trust or join a support group.
• Focus on purpose. This scan is your path to clarity and personalised care.

Your doctor will review the results, usually within a few days, and discuss what they mean for your treatment.

3. Safety and radiation exposure

PET-CT uses a very low dose of radiation. The radiotracer leaves your system quickly, but you may be advised to limit close contact with young children or pregnant people for the rest of the day—purely as a precaution.

How PET-CT supports your treatment

A PET-CT scan does more than just provide images; it gives your doctor critical insights into your cancer’s behaviour and treatment response.

• Staging: Reveals how far cancer has spread.
• Treatment planning: Guides decisions about surgery, chemo, or radiation.
• Monitoring progress: Follow-up scans show tumour activity changes.
• Adjusting care: Allows your doctor to pivot treatment early if needed.

This kind of real-time information ensures your care plan evolves with your needs.

Frequent questions patients ask

• Is it painful? No. Other than a small IV prick, the scan is painless.
• Will I feel the radiation? No. You won’t feel the tracer or its effects.
• Can I bring someone with me? Yes, but they may need to wait outside during the scan due to radiation safety protocols.
• How should I prepare if I have diabetes? Your care team will provide specific guidance about managing your glucose and medications beforehand. Always disclose this upfront.

Treatment designed with you in mind

Knowing what to expect can make a significant difference in how you experience your PET-CT scan. While it may sound complex, the process is straightforward, safe, and designed with your comfort in mind.

At Life Healthcare, we understand how important it is to feel confident and supported at every step of your cancer journey. Our teams are here to guide you through the process, answer your questions, and ensure you have access to advanced imaging tools like PET-CT, so you and your doctors can make the most informed decisions about your care.

If you are scheduled for a PET-CT scan or want to learn more about how it fits into your treatment plan, visit our Health Library or speak to your Life Healthcare team.