PET-CT in Lymphoma — What It Shows

No, the scan itself is painless. The only discomfort is a small needle prick when the FDG tracer is injected into a vein, similar to a routine blood test. Once the tracer is given, you rest quietly and then lie still on a soft bed that moves slowly through the scanner. There is no loud noise and no tunnel-like tightness. Most people find it calm and easy. If you feel anxious about lying still or have claustrophobia, tell our team beforehand. We will explain each step, stay nearby, and help you feel comfortable. You deserve a scan experience that feels supportive, not stressful.

A regular CT scan shows the size, shape, and location of lymph nodes and organs. It is very good at structure but cannot tell whether a lump is active lymphoma or harmless scar tissue. A PET-CT adds a second layer of information. The PET part shows how metabolically active the tissue is by using an FDG sugar tracer that lights up active lymphoma. By combining both into one scan, your doctor sees not just where something is, but whether it is alive and growing. This is especially helpful after treatment, when a leftover lump may simply be scar tissue rather than active disease.

A PET-CT does involve a small dose of radiation from both the tracer and the CT part. For someone with lymphoma, the benefit of accurate staging and response checking clearly outweighs this small risk. The information guides important treatment decisions and can prevent under- or over-treatment. The tracer is short-lived and leaves your body within hours, especially if you drink extra water. We follow safe-dose principles and avoid repeating scans that will not change your plan. If you are pregnant, breastfeeding, or planning pregnancy, tell us first, as we may adjust or postpone the scan. Your safety guides every decision we make.

A specialist usually reads your PET-CT images within a day or two, sometimes the same day depending on the centre's workload. At CION, results are not just handed to you on paper. Your scan is reviewed and discussed with your treating team, often in our tumour board, so the findings fit into your full picture. We then explain the results to you in a 45-minute consultation, in plain language, including your Deauville score and what it means for your next step. We walk this journey with you, so you never have to interpret a confusing report alone. If anything is unclear, you can always ask for a second review.

Yes, fasting is important. You should not eat for about 6 hours before the scan, though you can and should drink plain water. Avoid sugary drinks, juice, tea with sugar, and chewing gum. The reason is that the scan uses a sugar tracer. If your blood sugar is high from a recent meal, the tracer cannot work properly and the images may be hard to read. If you are diabetic, tell us in advance so we can guide your medication and meal timing safely. Avoid heavy exercise the day before, as active muscles can take up the tracer and affect the images. Our team gives you a clear preparation checklist beforehand.

Yes, this is one of its most valuable uses. By comparing a scan done during or after treatment with your baseline scan, your doctor can see whether the lymphoma is shrinking and becoming less active. An interim scan, often after two cycles of therapy, can show an early response and help decide whether your plan can stay gentle or needs to change. An end-of-treatment scan checks whether the disease has fully responded. The Deauville score puts this into a clear number. Seeing real evidence that treatment is working brings genuine reassurance. If the response is incomplete, your team can adjust the plan sooner rather than later.

A leftover lump after lymphoma treatment is common and often not a cause for alarm. Lymphoma can leave behind scar or fibrous tissue even after the active disease is gone. This is exactly where PET-CT helps. If the lump shows low or no tracer uptake, with a Deauville score of 1 to 3, it is usually inactive scar tissue rather than living lymphoma. If it lights up brightly, your team will look more closely and may suggest further tests or a biopsy. A scan finding is always read alongside your symptoms and blood work. Your doctor will explain clearly what your specific result means for you.

It is most useful for FDG-avid lymphomas, which take up the sugar tracer strongly. This includes most Hodgkin lymphomas and many aggressive non-Hodgkin lymphomas like diffuse large B-cell lymphoma. For these, PET-CT is excellent for staging and checking response. Some slow-growing or low-grade lymphomas take up little tracer, so PET-CT may be less helpful, and your doctor might rely more on CT or other tests. This is why we never order the scan automatically. Your specialist first considers your exact lymphoma subtype and what question needs answering. If a PET-CT will not change your treatment plan, we will tell you honestly and avoid an unnecessary test.

The cost depends on the centre, the area scanned, and whether it is a baseline, interim, or follow-up scan. We believe in transparent costs, so we give you a clear estimate before anything is booked, with no hidden charges. We also only recommend a scan when it genuinely guides your care, because our decisions are made for healing, not billing. If you would like a written estimate for your situation, share your reports with us and request a cost estimation. Our team will explain what the scan involves, why it is being suggested, and exactly what you can expect to pay. You should never feel pressured into a test you do not need.

In most cases, yes. A PET-CT does not use sedation, so you stay fully awake and alert throughout. After the scan, you can usually resume normal activities, eat as usual, and return home or to work. We do ask you to drink plenty of water to help flush the tracer out of your body. The tracer's radioactivity fades quickly within a few hours. As a simple precaution, it is wise to limit close, prolonged contact with pregnant women and very young children for the rest of the day. Our team will give you clear, personalised after-care advice before you leave, so you know exactly what to do.