FDG PET scan vs. 68Ga DOTATATE PET scan for neuroendocrine cancer

Posted by trixie1313 @trixie1313, Feb 27 11:41am

I would be curious to see if there are any laymen articles regarding the use of FDG PET scan vs. the Dotatate PET scan. In some articles if the tumor is well differentiated it appears that the Dotatate is the best use of imaging? But if undifferentiated maybe the FDG? The facility I go to will only order the FDG PET scan for me, although the same medical entity offers this at another facility about 2 hours away from where I live. Am in a quandary if I should push for the Dotatate imaging. My last two PET scans showed no emerging cancer, as did my most recent mammogram.

Hello @trixie1313

Your question is a good one and caused me to search for answers. Finding plain language information comparing relatively new diagnostic tools can be challenging. There are certainly clinical studies about it such as this one: – Comparison of the Impact of 68Ga-DOTATATE and 18F-FDG PET/CT on Clinical Management in Patients with Neuroendocrine Tumors. https://www.ncbi.nlm.nih.gov/pubmed/27516446

While not a comparison, I found this article from the Neuroendocrine Tumor Research Foundation to be helpful in describing the different NET imaging tests, written for patients: – Imaging Tests for Neuroendocrine Tumors https://netrf.org/for-patients/nets-info/diagnostic-tests-for-neuroendocrine-cancer/imaging/

I also had the opportunity to ask a Mayo Clinic radiologist and she said that Gallium 68 (Ga-68) Dotatate PET is an excellent imaging for NET tumors. However, for some people, it does not work well. PET with Ga-68 Dotatate depends on the presence or abundance of a form of receptor on cancer cells, known as somatostatin receptor type 2. Some NET tumors may not have enough of these receptors and then the tumor would not be seen by the Ga-68 Dotatate PET. If a patient's tumor does not have somatostatin receptor type 2 or not enough of them, then the FDG-PET scan (fluorodeoxyglucose-positron emission tomography scan) would be recommended.

I hope this information helps guide the discussion with your oncologist, Trixie. Have they talked about receptors with you? With this information, what questions would you ask your team to help feel confident that they and you are making the best choices?

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@hopeful33250

Hello @trixie1313

Your question is a good one and caused me to search for answers. Finding plain language information comparing relatively new diagnostic tools can be challenging. There are certainly clinical studies about it such as this one: – Comparison of the Impact of 68Ga-DOTATATE and 18F-FDG PET/CT on Clinical Management in Patients with Neuroendocrine Tumors. https://www.ncbi.nlm.nih.gov/pubmed/27516446

While not a comparison, I found this article from the Neuroendocrine Tumor Research Foundation to be helpful in describing the different NET imaging tests, written for patients: – Imaging Tests for Neuroendocrine Tumors https://netrf.org/for-patients/nets-info/diagnostic-tests-for-neuroendocrine-cancer/imaging/

I also had the opportunity to ask a Mayo Clinic radiologist and she said that Gallium 68 (Ga-68) Dotatate PET is an excellent imaging for NET tumors. However, for some people, it does not work well. PET with Ga-68 Dotatate depends on the presence or abundance of a form of receptor on cancer cells, known as somatostatin receptor type 2. Some NET tumors may not have enough of these receptors and then the tumor would not be seen by the Ga-68 Dotatate PET. If a patient's tumor does not have somatostatin receptor type 2 or not enough of them, then the FDG-PET scan (fluorodeoxyglucose-positron emission tomography scan) would be recommended.

I hope this information helps guide the discussion with your oncologist, Trixie. Have they talked about receptors with you? With this information, what questions would you ask your team to help feel confident that they and you are making the best choices?

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@hopeful33250
Thank you, Teresa. When I first asked my oncologist about doing the Dotatate, she pretty much said about the same thing plus she said if anything was found on the FDG PET, we would switch to the Dotatate. I think her reasoning was that since the only NET tumor so far has been in the breast, we would follow this way. I appreciate your researching this for me and feel much more reassured about the whole process.

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@trixie1313

@hopeful33250
Thank you, Teresa. When I first asked my oncologist about doing the Dotatate, she pretty much said about the same thing plus she said if anything was found on the FDG PET, we would switch to the Dotatate. I think her reasoning was that since the only NET tumor so far has been in the breast, we would follow this way. I appreciate your researching this for me and feel much more reassured about the whole process.

Jump to this post

I'm glad to hear that this information was reassuring to you, @trixie1313!

Are you scheduled for a new scan in the near future? Will you keep in touch and provide updates?

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@hopeful33250

I'm glad to hear that this information was reassuring to you, @trixie1313!

Are you scheduled for a new scan in the near future? Will you keep in touch and provide updates?

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@hopeful33250 Yes, they schedule me every 6 months for the FDG PET scan and I'll be having one more 6-month mammogram and then mammograms yearly (we went with partial mastectomies). So both are due in July…fingers crossed!

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