PET Scan

[krohrig]

I had a PET scan over a week ago.  My history is cervical cancer and I had a radical hysterectomy with radiation and chemo two years ago.  I have been having PET Scans every 6 months.  My most recent PET scan showed a tumor on my spine that my doctor said was the cancer recurring?  She said it was "hot"  How can she say it is cancer when we haven't done a biopsy?  I would think that a most definite diagnose would be to have a biopsy.  Can you give me your input on this.  They are now talking about giving me a pelvic exenteration.  I am seeking a 2nd opinion also.  Please tell me what you think.

Thank you Karen

[Fernando Roque, MD]

Hi.  I cannot tell you if pelvic exenteration is the most appropriate option for you to take, as I do not know all the facts regarding your case.  The doctors handling your case are in a better position to do that.  I can understand your hesitancy about going through this procedure.  Pelvic exenteration is very mutilating, and will drastically alter the way you do some basic bodily processes, like defecation and urinating. You may wish to get a second opinion from another gynecologist, to see if there are other therapeutic options available to you.  

As for your other question: it is quite possible for you to have cancer recurrence two years after the initial operation.  If your cancer was in an advanced stage at the onset, there is really a possibility of recurrence even after optimal treatment.

[krohrig]

To continue our discussion about my PET Scan, so you agree that a pelvic exenteration should occur? But how do we know by taking out my rectum and vagina will "get the cancer"  I'm reading a lot about the operation and it doesn't sound like the outcome is very good.  How will my life be and how do we know the cancer isn't going to show up somewhere else.  Another question is that it has been two years since my first operation.  Why would the cancer show up now?

[Fernando Roque, MD]

Hi.  You are right when you say that a more definite diagnosis can be arrived at by means of a biopsy rather than a PET scan.  The PET scan measures the amount of fluorodeoxyglucose (FDG) taken up by tissues.  FDG is a form of radioactive glucose.  The assumption is that cancer cells are metabolically more active than normal cells (since they are rapidly dividing), hence they would take up more glucose to fuel their rapid growth.  Areas with increased uptake of FDG light up on the PET scan and are called "hot".  So PET only indirectly detects cancer cells.  What it actually identifies are areas with high metabolic rates, which are not necessarily cancerous areas.

However, your doctor is also correct when he said that the tumor in your spine is most probably cancer recurrence.  Given your prior history of cervical cancer, there is a high probability that the "hot" area in your spine represents a cancerous lesion.  In this case, it is reasonable for your doctors to forgo doing a biopsy of the spinal tumor and just assume that this is indeed cancer recurrence.  You may of course, insist on having the biopsy done.  That is your prerogative as a patient, and is also a valid option to take.