Do cysts absorb radioactive glucose during PET/CT scan? - 1269060

marianne
Posts:5

A recent CT scan with contrast shows shrinkage of a Liver spot on the left lobe to 5 mm that had previously appeared as 20 mm on a PET/CT scan.

The jury is still out as to whether the spot is a cyst or a tumor, and so, shrinkage does not mean tumor responded to chemo vs. cyst may have shrunken on its own. (Biopsy could not be performed due to location under the lung.)

Would a cyst have appeared as a hot spot on a PET/CT scan at all--or only a tumor? Thanks!

Marianne

PS Have requested a dedicated ultrasound of Liver to differentiate fluid-filled cyst from solid tumor. Hopefully an US will provide a definitive answer--but curious about the glucose absorption by a cyst.

DX 11/25/2014 Biopsy/diagnosis of anal cancer
PET/CT scan report: Stage 4 SSC of Anal Canal with mets to Liver (lymph nodes--inguinal and perianal)
TX 12/22/2014 through 2/2/2015 Chemoradiation (Nigro Protocol)
CT Scan with contrast 3/9/2015 showed 75% reduction (perianal lymph node involvement not shown)

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JimC
Posts: 2753

HI Marianne,

Welcome to GRACE, and congratulations on the shrinkage of the liver nodule/cyst. A cyst can show up on a PET scan, but often with a lower level of uptake. That doesn't definitively determine whether it's a benign cyst or cancer, but the lower SUV does tip the balance a bit toward a benign finding.

JimC
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audreyainsworth
Posts: 1

PET/CT scan is an advanced nuclear imaging process that combines both into one machine. This machine has supplied by medical companies. It reveals details about cell and tissue’s structure and function in the body during a single imaging process. During this process, the patient is initially injected with a glucose solution, which has small level of radioactive material, absorbed by the exact organs or tissues being scan. It shows damaged or cancerous cells where the glucose are taken up and determine at what rate the tumor is using the glucose.