A PET scan 1 year post transplant stated " no lesions." Does that mean no active lesions or no lesions at all, even ones that have healed?
My husband only had a skeletal survey done pre-transplant, and I always wondered since it came back only with " osteopenia" that perhaps he did have lesions that were just too small for the X-ray to pick up.
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blair77 - Who do you know with myeloma?: My husband
- When were you/they diagnosed?: April 2013
- Age at diagnosis: 43
Re: "No lesions" on PET scan - what does it mean?
Hey Blair,
The way I understand it from my onc, is that that a radiologist looking at a PET/CT scan of a multiple myeloma patient is going to be primarily looking for cancerous "hot spots" where the FDG (radioactive sugar) collects in one's body. In the case of multiple myeloma, these hot spots could appear in either active lytic lesions (these are the ones that are on the bone that punch holes in your skeleton) or in active focal lesions (within the bone, which can also wreak havoc). Having either type of lesion is not good news.
If either of these types of lesions no longer have active cancerous cells present, then the PET/CT simply won't pick up on the lesions like an xray or MRI would, regardless if the lytic lesion had healed over or not. Note that the "healing" of lytic lesions is not common and this remains a subject with differing opinions in the multiple myeloma community.
If you aren't sure about what multiple myeloma hot spots look like on a PET/CT or want to see more of a discussion on this subject, see this link:
http://www.myelomapennstate.net/Contents/10a-BoneDis-PET.htm
"Bone lesions should be at least 5-10mm in size to be visualized at PET.
While x-rays are unable to differentiate between old and inactive bone lesions and new lesions, the PET scan shows only active myeloma lesions. This is particularly useful when evaluating treatment response.
PET/CT is better than MRI in determining the remission status, because inactive lesions may persist and lead to a false-positive MRI."
The way I understand it from my onc, is that that a radiologist looking at a PET/CT scan of a multiple myeloma patient is going to be primarily looking for cancerous "hot spots" where the FDG (radioactive sugar) collects in one's body. In the case of multiple myeloma, these hot spots could appear in either active lytic lesions (these are the ones that are on the bone that punch holes in your skeleton) or in active focal lesions (within the bone, which can also wreak havoc). Having either type of lesion is not good news.
If either of these types of lesions no longer have active cancerous cells present, then the PET/CT simply won't pick up on the lesions like an xray or MRI would, regardless if the lytic lesion had healed over or not. Note that the "healing" of lytic lesions is not common and this remains a subject with differing opinions in the multiple myeloma community.
If you aren't sure about what multiple myeloma hot spots look like on a PET/CT or want to see more of a discussion on this subject, see this link:
http://www.myelomapennstate.net/Contents/10a-BoneDis-PET.htm
"Bone lesions should be at least 5-10mm in size to be visualized at PET.
While x-rays are unable to differentiate between old and inactive bone lesions and new lesions, the PET scan shows only active myeloma lesions. This is particularly useful when evaluating treatment response.
PET/CT is better than MRI in determining the remission status, because inactive lesions may persist and lead to a false-positive MRI."
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
Re: "No lesions" on PET scan - what does it mean?
Here is an excerpt from my most recent Pet/CT scan:
This seems to indicate that a PET scan will show both active and inactive lytic lesions.
There are multiple stable sclerotic and lytic lesions scattered throughout the skeleton, representing treated myeloma lesions. No new suspicious FDG avid lesions identified."
This seems to indicate that a PET scan will show both active and inactive lytic lesions.
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goldmine848 - Name: Andrew
- When were you/they diagnosed?: June 2013
- Age at diagnosis: 60
Re: "No lesions" on PET scan - what does it mean?
You make a good point Andrew. As I re-read the bullets in the link above, I now note that the statements I referenced were made purely in the context of a PET scan and not a PET/CT scan (which is mentioned later) So, perhaps PET/CTs do reveal the presence of non-active lesions?
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
Re: "No lesions" on PET scan - what does it mean?
I think the answer to the original question depends, as the discussion so far has indicated, on whether the scan was just a PET scan or a PET/CT scan.
If it was just a PET scan, then it will mainly show what Multibilly mentioned -- the presence, or lack thereof, of myeloma cells in the bone marrow.
If it was a PET/CT scan, then it should also reveal if there are any lytic lesions, new or old. The CT scan part of the PET/CT scan, it's worth keeping in mind, is still using x-rays as the basis for the imaging it's doing. CT scans just process the results of the x-raying in a hifalutin way (CT = "computed tomography").
From the Wikipedia article on PET-CT scans:
"Positron emission tomography–computed tomography (better known as PET-CT or PET/CT) is a medical imaging technique using a device which combines in a single gantry system both a positron emission tomography (PET) scanner and an x-ray computed tomography (CT) scanner, so that images acquired from both devices can be taken sequentially,"
From the Wikipedia article on CT scans:
"X-ray computed tomography (X-ray CT) is a technology that uses computer-processed X-rays to produce tomographic images (virtual 'slices') of specific areas of a scanned object, allowing the user to see inside the object without cutting. Digital geometry processing is used to generate a three-dimensional image of the inside of the object from a large series of two-dimensional radiographic images taken around a single axis of rotation."
As always, it's useful in these situations to review Dr. Kapoor's posting on PET scans and other imaging:
https://myelomabeacon.org/forum/pet-scans-for-multiple-myeloma-t3687.html
Hope this helps a bit.
If it was just a PET scan, then it will mainly show what Multibilly mentioned -- the presence, or lack thereof, of myeloma cells in the bone marrow.
If it was a PET/CT scan, then it should also reveal if there are any lytic lesions, new or old. The CT scan part of the PET/CT scan, it's worth keeping in mind, is still using x-rays as the basis for the imaging it's doing. CT scans just process the results of the x-raying in a hifalutin way (CT = "computed tomography").
From the Wikipedia article on PET-CT scans:
"Positron emission tomography–computed tomography (better known as PET-CT or PET/CT) is a medical imaging technique using a device which combines in a single gantry system both a positron emission tomography (PET) scanner and an x-ray computed tomography (CT) scanner, so that images acquired from both devices can be taken sequentially,"
From the Wikipedia article on CT scans:
"X-ray computed tomography (X-ray CT) is a technology that uses computer-processed X-rays to produce tomographic images (virtual 'slices') of specific areas of a scanned object, allowing the user to see inside the object without cutting. Digital geometry processing is used to generate a three-dimensional image of the inside of the object from a large series of two-dimensional radiographic images taken around a single axis of rotation."
As always, it's useful in these situations to review Dr. Kapoor's posting on PET scans and other imaging:
https://myelomabeacon.org/forum/pet-scans-for-multiple-myeloma-t3687.html
Hope this helps a bit.
Re: "No lesions" on PET scan - what does it mean?
Nice follow up Cheryl. I think you've got the right take on this.
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
Re: "No lesions" on PET scan - what does it mean?
Actually, there is debate ongoing, with regards to the ideal specificity, and which modality provides it. Throw in functional MRI, and the debate rages.
Back to the original question: Blair congrats to your hubby's clean PET SCAN.
Back to the original question: Blair congrats to your hubby's clean PET SCAN.
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Rneb
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