What should I expect during a PET scan for CLL

What to Expect During a PET Scan for CLL

A PET scan (positron emission tomography) is an imaging test that helps your oncology team see how active your CLL is and whether it's responding to treatment. Here's what you should know about the experience:

Before Your Scan

Preparation:

• You'll typically fast (not eat) for 4-6 hours before the scan
• Wear comfortable, loose clothing without metal (zippers, buttons with metal)
• Arrive 15-30 minutes early for check-in
• Let your team know about any medications you're taking

The Injection:

• A technician will inject a radioactive tracer (usually a glucose-based substance) into your arm through an IV
• This tracer is safe—the radiation dose is very small and leaves your body naturally
• You'll wait 45-60 minutes after injection while the tracer circulates through your body and concentrates in areas of disease activity

During the Scan

The Experience:

• You'll lie on a flat table that slides into a large, donut-shaped machine
• The scan is painless and quiet (you may hear some humming)
• The entire process takes about 20-30 minutes
• You need to stay still during imaging—the technician will give you specific instructions
• You can communicate with the technician through an intercom if needed

Why This Matters for CLL

According to NCCN Guidelines for CLL, PET scans play an important role in evaluating disease progression and detecting a serious complication called Richter transformation (when CLL transforms into a more aggressive lymphoma). The guidelines specifically note that:

• PET/CT scans help identify the best sites for biopsy if your doctor suspects disease progression
• A maximum standardized uptake value (SUVmax) ≥10 on PET scan has been shown to be a useful marker to distinguish Richter transformation from stable CLL in patients treated with chemotherapy or chemoimmunotherapy
• However, the guidelines emphasize that PET alone is not sufficient—if your doctor suspects transformation, a lymph node biopsy may still be needed for definitive diagnosis

After Your Scan

• You can resume normal activities immediately
• Drink plenty of water to help flush the tracer from your system
• The radioactive tracer will naturally leave your body within 24 hours
• Results typically come back within 1-2 business days

Questions to Ask Your Oncology Team

1. Why specifically are we doing this PET scan now? (Is it to assess treatment response, check for progression, or evaluate for transformation?)
2. What are we looking for on this scan compared to my last one?
3. When will I get the results, and how will we discuss them?
4. If the scan shows concerning findings, what's the next step? (Will I need a biopsy or additional testing?)
5. Are there any specific symptoms or changes I should report before the scan?

Important Context

PET scans are a valuable tool in CLL management, but they're part of a bigger picture. Your doctor will combine PET results with your blood work, physical exam findings, and other tests to make decisions about your care. If your scan shows areas of concern, your team may recommend additional testing like a biopsy to confirm what's happening.

This information is for educational purposes only. Always consult your healthcare team for personalized medical advice and decisions.