Understanding PET Scan for Cancer: Process and Benefits
Dr. Vrundali Kannoth•7 minutes•16 Sep 2025
PET Scan for Cancer: How It Works and What to Expect
Has your doctor recommended a PET scan for cancer for you or a loved one? Are you worried about what it means, how it works, and whether it hurts? There are probably thousands of questions racing in your mind, and you’ve no idea where to begin. Well, first, let's take a deep breath and start by understanding the test before jumping to any conclusions. This standard procedure helps healthcare providers detect various conditions, including cancer. While effective at finding tumour cells, it's not a definitive diagnostic tool on its own. In this article, we'll explore the PET scan cancer meaning, different types of PET scans, and their accuracy. Learn how they work and how to prepare for the screening.
What is PET scan test for cancer?
A PET scan is a special imaging test that helps oncology doctors see how your organs and tissues work. It uses a safe, injectable chemical called a radiotracer and a PET scanner to create detailed images and find bright spots that are often signs of cancer.
Some of the common types of PET scan for cancer include:
- •FDG PET-CTUses a glucose-based tracer called FDG to find tumours such as lung, lymphoma, head and neck, colorectal, and breast cancers.
- •PSMA PETUses a tracer that binds to the Prostate-Specific Membrane Antigen (PSMA), a protein found in high amounts on prostate cancer cells.
- •DOTATATE PETTailored for certain rare cancers like neuroendocrine tumours (NETs), it relies on a Gallium-68 DOTATATE tracer to identify these specific cancer types.
- •Full-Body PET ScanExamines the entire body in one session to check if cancer has spread (metastasised).
When is a PET scan recommended and what does it show?
A doctor might recommend a PET scan test for cancer when other tests like bloodwork, MRIs, or X-rays suggest abnormal cell presence, but need further confirmation. It can find out:
- •Where the cancer is located in your body
- •How large the tumour is
- •Whether the cancer has spread to other areas
Furthermore,
PET scan test for cancer: Procedure and preparation
A medical PET scan for cancer is a pretty painless and straightforward procedure with nothing to worry about. Your healthcare provider will guide you through each step and answer any questions you have about the procedure. It usually takes around two hours, with 60 minutes for the first radiotracer phase and 30 minutes for the scanning phase.
How is PET scan done for cancer?
Let’s now walk you through the whole process of PET scan cancer screening:
Step 1: At the initial stage
Before the start of the PET scan procedure for cancer, your radiologist will insert an IV line into your arm or hand vein to inject the radiotracer that helps highlight active areas in your body. You will need to rest quietly for around an hour while the tracer moves through your bloodstream and gets absorbed. Try to limit movement during this waiting period. Perhaps listen to an audiobook or music to calm your nerves.
Step 2: During the procedure
Once you're ready, your healthcare team member takes you into the scanning room. Here you will find the PET machine that looks like a large doughnut hole. All you need to do is lie on a kind of table on your back, and it will take about 30 minutes for the scan to complete. Make sure that you remain still, as any movement can blur your images. The radiologist will be monitoring you through a screen from the control room while capturing images. If you feel any sort of discomfort, there is an intercom in the room through which you can talk to your healthcare team.
Step 3: After the procedure
After your PET scan procedure for cancer is completed, you can return to your normal activities, unless your healthcare provider gives you specific instructions. Be sure to drink extra water throughout the day to help your body clear the tracer naturally. Moreover, try to fill your time with enjoyable activities that take your mind off waiting for results. You could catch up with friends, watch a favourite show, or spend time on a hobby you love.
Getting ready for a PET scan cancer diagnosis: Tips for a comfortable experience!
- •Fast for 4 to 6 hours before your appointment, but stay hydrated with plain water.
- •Wear loose-fitting, comfortable clothes without metal zippers or buttons.
- •Leave jewelry and watches at home to avoid removing them at the facility.
- •Inform your doctor beforehand of the medications that you take, allergies you might have and if you're breastfeeding or expecting.
- •Avoid exercising for 24 hours before your PET scan cancer screening.
- •Bring something relaxing to do during the waiting period, like a book or music.
- •Arrive about 15 minutes early to complete the essential paperwork.
- •Inform your healthcare team if you experience anxiety in enclosed spaces, so they can assist you in feeling more comfortable.
- •Make your last meal low in carbohydrates and high in protein, as this can improve scan clarity.
Can a PET scan detect cancer? Accuracy and limitations of the test
If you’re wondering whether can PET scan show cancer, it does have its strengths and limitations when it comes to making a diagnosis. Understanding these can help you know what to expect when your doctor recommends one.
How accurate is a PET scan for cancer?
PET scan cancer accuracy varies based on the type of cancer. Some types that have high metabolic activity and use a lot of glucose tend to show up strongly on PET scans. It is also very reliable for detecting recurrence or metastasis.
Moreover, when combined with a CT scan for cancer (known as PET/CT), the results are generally very reliable because the scan provides both functional and structural details. For instance, PET/CT has shown a sensitivity of 94.4% and a specificity of 82.5%.
Do all cancers show up on a PET scan?
No, not every type of cancer will show up clearly on a standard PET scan, especially those that do not detect glucose-based tracer. These include prostate cancer, certain thyroid cancers, mucinous tumours, and some neuroendocrine tumours. Furthermore, very small tumours, slow-growing cancers, or tumours that have been previously treated may not appear well, even on advanced scans.
What does a PET scan show for cancer? Results and follow-up
A radiologist reviews cancer in PET scan by looking for bright spots called hotspots that show where the tracer collects. Moreover, they check SUV values (Standardised Uptake Values) that measure how much tracer has been absorbed:
- •Higher SUVOften suggests more active or aggressive cells, such as cancer
- •Moderate SUVRelated to inflammation, healing tissue, or benign growths
- •Lower SUVIndicates normal or less active tissue
Remember, whatever your PET scan cancer diagnosis results might be, today's medical advances offer many effective treatment options and real hope for a better future.
Final words on the PET scan and cancer diagnosis
A PET scan for cancer is a highly advanced imaging tool for tumour detection that is used alongside others to get an accurate picture of your condition. If your doctor recommends a PET scan, try not to worry or feel overwhelmed, as it's just a normal test like any other. Remember, a cancer diagnosis is simply one chapter in your story and not the ending. With modern cancer centres today like EverHope, you can find advanced treatment, dedicated support, and care focused on your complete well-being.
If you’re ready to take the first step, schedule an appointment with Everhope Cancer Center specialists to safeguard your future.
FAQs on the PET scan for cancer
Yes, a PET scan for cancer is a more accurate test than any other to find clusters of cancer cells that have metastasised, or spread to other tissues or organs.
No, a PET scan cancer screening is not painful, but it can cause mild discomfort when the needle with the tracer is inserted into your body. Additionally, some individuals may experience slight swelling at the injection site for a brief period.
PET scans for breast cancer are moderately accurate but have limitations. They detect about 68% of small tumours and 92% of larger tumours. However, they're not very effective for detecting in situ carcinomas, with only 2-25% sensitivity for these early-stage cancers.
The PET scan for cancer cost in India typically ranges from ₹10,000 to ₹25,000, varying based on your city, hospital, and scan type. Regular FDG PET-CT scans usually cost less, while a special scan or full body PET scan for cancer may cost more.
A PET scan for cancer is read by looking for bright spots (hotspots) where the tracer collects in high amounts and SUV values that show how active these areas are. The results are then compared with other tests to confirm if it’s cancer.
Table of Content
- PET Scan for Cancer: How It Works and What to Expect
- What is PET scan test for cancer?
- PET scan test for cancer: Procedure and preparation
- How is PET scan done for cancer?
- Getting ready for a PET scan cancer diagnosis: Tips for a comfortable experience!
- Can a PET scan detect cancer? Accuracy and limitations of the test
- What does a PET scan show for cancer? Results and follow-up
- Final words on the PET scan and cancer diagnosis