Bone scan vs 18F NaF PET

[Kentucky1]

My MO is monitoring my mets in the pelvic area with bone scans about every 3-6 months depending on my reported symptoms. I am wondering why he would choose a bone scan over the PET scan. I was under the impression that the PET is more accurate. Any feedback is appreciated. I'm getting ready to have some spot radiation done on the pelvis next week and he wants a follow up bone scan done about 2 weeks afterwards.

[6357axbz]

My guess is he is not familiar with the new pet scans and would rather compare consecutive bone scans for any changes. Bone scans don’t detect cancer, only distressed regions in the bones which may or may not be cancer.

[Tall_Allen]

He is right to monitor progression with the same kind of scan - how else would you know whether you detected more/bigger metastases because of progression or because the scan is more sensitive? There is no value in detecting more metastases with a more sensitive scan.

[Kentucky1 in reply to Tall_Allen]

Thanks for your input. So you're saying that switching between scans with different sensitivity would cause more confusion. My concern is if the PET scan is more sensitive shouldn't it have been the better choice from the start? The repeat bone scan will be about 3 weeks after the round of radiation. Is that enough time to really see any real changes. I have a feeling it's not going to show anything. Am I overthinking this?

[Tall_Allen in reply to Kentucky1]

Just because a scan can detect more doesn't mean it's the best scan for the job. There will always be more metastases that are too small to be detected by any scan. You want the type of scan that has the best chance of helping you and your doctor decide about changes in therapy. Right now, for your circumstances, that is a bone scan/CT. Some day, years from now, there will be some use found for a PET scan in your situation. There is none yet.

The bone scan 3 weeks after RT should show shrinkage.

[Kentucky1 in reply to Tall_Allen]

Thanks for the info, makes sense. I appreciate your help.

[jazj]

I believe there is evidence that treating macrometastases as early as possible is the best course of action based on what I've read. The more sensitive PSMA PET Scan will catch those earlier than a CT Bone Scan. It will likely show more spots to treat.

Why not get a second or third opinion from a Radiotherapy Oncologist at a Center of Excellence and tell us what they say? It's their job to stay up on all this and give the best expert advice. At least get one second opinion from a professional.

[Hidden]

I started with nuclear bone scans with accompanying soft tissue CT scans in 2003. Established a baseline. My 26th set of these scans was in 2010. I asked my Research Professor about using these scans when newer ones were developed once.... his reply was they were tried and true...... besides any scan is not very accurate without a baseline for comparison AND the ability to read and interpret images on the scan. On me, he pointed out the differences of arthritic hot spots, the metastatic lesions hot spots, and metastases resolution and new bone growth....... typically I would have the scans and blood work in the morning and by early afternoon, he would go over the scans and lab work.......

GD