Confused about PET scan

[Dora J]

Hello,

I am at wits end.  I had PET scan two weeks ago and got results from doctor this week.  I have a 1.1 cm lung nodule, it was found on CT scan in January when I was very sick with Covid and Flu.

I decided to see a Pulmonologist, and he ordered a PET scan.   He said the nodule was too small to do a biopsy.  The PET scan came back inconclusive on the nodule.  It shows a SUV Max of 1.6 similar and slightly higher than the average blood pool uptake.  Now they recommend a biopsy or wait three months for a follow up CT scan.  I am beside myself, it was all I could do to get the PET scan.  How do you know what the average SUV is?  I hear there are a lot of risks having a lung biopsy.  I just need some clarification.

Dora

 

[LilyMir]

Hi Dora, sorry you have this scare but try to take deep breaths and not panic. The SUV you reported seems quite low but 1.1 cm is a biggish lesion so the doctors must follow up on this. They may opt for rescanning every X months to see if there is any growth. They may offer biopsy. Depending on location, biopsy (in a skilled dr's hand) is routine unless the location of the lesion is complicated or near critical anatomy like the heart of the flood vessels. Try not to worry too much (so hard, I know!) but make sure they followup since even if it is lung cancer, catching it very early means chances for a cure are very high. Best wishes!

[LouT]

Dora,

Let's start with a base facts; most lung nodules (60%) are benign, and PET Scans are an estimating tool (btw 1.6 is not a strong indicator of cancer).  Biopsy is the definitive diagnostic tool.  The following is from our section Lung Cancer 101 (which can be found here)

"Many different tests are used to diagnose lung cancer and determine whether it has spread to other parts of the body. Some can also help to decide which treatments might work best.

The steps and tests used in diagnosing lung cancer include medical history, imaging tests, laboratory tests, biopsies, and biomarker tests.

Only a biopsy can provide a definite diagnosis of lung cancer, so, until biopsy results come back, a person does not know for sure whether he or she has lung cancer. Many other diseases, including other types of cancer, can cause masses to form in the lung. Imaging tests can be used to find out where the possible cancer is and whether it has spread, but they can never be used alone to make a diagnosis."

In my case I had a small nodule, failed CT-guided biopsy, and inconclusive SUV reading of 2.5 so I had to wait a few months.  In my case the nodule grew so I had a lobectomy and have been cancer free since May 2019.  Again, most nodules are benign so until you have a definitive biopsy result please try not to let this get to you too much.  Trust me, I know it's difficult but do whatever you can to occupy yourself positively until you have a follow up.  Right now the odds are in your favor.  Stick around and please keep us updated.

Lou

[Tom Galli]

Dora,

Welcome here. The language of our disease can be quite daunting to new folks. Here is a glossary that I use frequently to ascertain the meaning of acronyms and terms associated with lung cancer.

PET scans--I've had too many in my 19-year survivor journey but along the way I've learned about the obtuse language used by radiologists to characterize and describe the results of the test. Here is something I wrote that explains the PET scan, how it works, and the meaning of words used to describe findings.

Now to your questions: how do you know what the average SUV is and what are the risks associated with a lung biopsy?

Normally, generally, usually, a Standard Uptake Value (SUV) of 2.0 or smaller is considered normal. There is more information in the PET scan link about SUVs that are higher than 2.0.

A lung biopsy, also known as a tissue biopsy, is well explained here. This information also provides some discussion of procedure risk, but these should be explained by the performing physician before you have the procedure. I've had 5 rigid bronchoscopies, 2 nonrigid bronchoscopies, and one transthoracic needle biopsy. Additionally, I had a specialized transthoracic procedure to insert five 1 mm gold fiducial markers around a lung tumor before a precision radiation treatment. The rigid bronchoscopy requires general anesthesia and the principal risk is driven by adverse reactions to anesthesia. Additionally, I was told I would have a very painful throat and would have difficulty swallowing for several days. Both proved true.

The nonrigid bronchoscopy required "light" anesthesia and therefore anesthesia-related risks were lower. But a painful throat and difficulty swallowing were side effects I experienced.

A transthoracic needle biopsy can normally be performed using a local anesthetic and there is very little anesthesia risk associated with this procedure. Depending on where the lung nodule or tumor is located, there may be a risk of a collapsed lung. This was an easy procedure for me, but I was a little unnerved seeing the doctor position the long needle used in the procedure. My specialized transthoracic procedure was performed under general anesthesia so those risks attached. Again, the doctor explained the risk of a collapsed lung. This risk was higher because he had to enter my lung in 5 distinct locations to position the fiducial markers. A collapsed lung is also called a pneumothorax and the glossary I linked explains what that term means.

I hope this helps to answer your questions. Stay connected to us. We are not physicians, but we have a unique understanding of our disease, the many treatments, side effects, and risks.

Stay the course.

Tom

[Karen_L]

Hi Dora, 

This is all scary stuff, isn’t it? It’s ironic that, on a lung cancer forum, you hear so many people talk about taking deep breaths. But slow, deep-as-you can breaths do have a positive physiological impact on anxiety.

You’re at the point of needing a diagnosis about initial testing. That means more testing, for which your doctor is suggesting biopsy or waiting and watching. Because you’ve come to our discussion board, it seems that you’d like to rule out or diagnose lung cancer. 

As you consider your options, it’s really good to find doctors who specialize in lung cancer and other issues of the lung. The Mayo Clinic lung program, a federally designated cancer center, has centers in Phoenix and Scottsdale, which is about an hour from where you list in your information. Many of us travel long, long distances for diagnosis and treatment; don’t let an hour prevent you from acting. 

Here’s information about the lung program. https://www.mayoclinic.org/departments-centers/lung-cancer-program/home/orc-20474481

Here is information about testing: https://www.mayoclinic.org/departments-centers/lung-cancer-program/sections/tests-procedures/orc-20474595

I’m with Lily on the importance of catching lung cancer early. I’ve had two biopsy-getting procedures, which yielded tissue that enabled a precise diagnosis and targeted treatment. It was an outpatient procedure; I some discomfort for several days, but it was no big deal. 

Keep us posted.

Karen