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68Ga-DOTATATE PET/CT for the detection of inflammation of large arteries: correlation with18F-FDG, calcium burden and risk factors.

Li X, Samnick S, Lapa C, Israel I, Buck AK, Kreissl MC, Bauer W - EJNMMI Res (2012)

Bottom Line: There was one significant correlation between 18F-FDG uptake and hypertension (0.58; p < 0.05).In this series of cancer patients, we found a stronger association of increased 68Ga-DOTATATE uptake with known risk factors of cardiovascular disease as compared to 18F-FDG, suggesting a potential role for plaque imaging in large arteries.Strikingly, we found that focal uptake of 68Ga-DOTATATE and 18F-FDG does not colocalize in a significant number of lesions.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Nuclear Medicine, University of Wuerzburg, Oberdürrbacher Str, 6, Wuerzburg, D-97080, Germany. Samnick_S@klinik.uni--wuerzburg.de.

ABSTRACT

Background: Ga-[1,4,7,10-tetraazacyclododecane-N,N',N″,N'″-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE) positron emission tomography (PET) is commonly used for the visualization of somatostatin receptor (SSTR)-positive neuroendocrine tumors. SSTR is also known to be expressed on macrophages, which play a major role in inflammatory processes in the walls of coronary arteries and large vessels. Therefore, imaging SSTR expression has the potential to visualize vulnerable plaques. We assessed 68Ga-DOTATATE accumulation in large vessels in comparison to 18F-2-fluorodeoxyglucose (FDG) uptake, calcified plaques (CPs), and cardiovascular risk factors.

Methods: Sixteen consecutive patients with neuroendocrine tumors or thyroid cancer underwent both 68Ga-DOTATATE and 18F-FDG PET/CT for staging or restaging purposes. Detailed clinical data, including common cardiovascular risk factors, were recorded. For a separate assessment, they were divided into a high-risk and a low-risk group. In each patient, we calculated the maximum target-to-background ratio (TBR) of eight arterial segments. The correlation of the TBRmean of both tracers with risk factors including plaque burden was assessed.

Results: The mean TBR of 68Ga-DOTATATE in all large arteries correlated significantly with the presence of CPs (r = 0.52; p < 0.05), hypertension (r = 0.60; p < 0.05), age (r = 0.56; p < 0.05), and uptake of 18F-FDG (r = 0.64; p < 0.01). There was one significant correlation between 18F-FDG uptake and hypertension (0.58; p < 0.05). Out of the 37 sites with the highest focal 68Ga-DOTATATE uptake, 16 (43.2%) also had focal 18F-FDG uptake. Of 39 sites with the highest 18F-FDG uptake, only 11 (28.2%) had a colocalized 68Ga-DOTATATE accumulation.

Conclusions: In this series of cancer patients, we found a stronger association of increased 68Ga-DOTATATE uptake with known risk factors of cardiovascular disease as compared to 18F-FDG, suggesting a potential role for plaque imaging in large arteries. Strikingly, we found that focal uptake of 68Ga-DOTATATE and 18F-FDG does not colocalize in a significant number of lesions.

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Related in: MedlinePlus

Comparison between high- and low-risk groups for cardiovascular disease. With regard to the 18F-FDG and 68Ga-DOTATATE uptake of big arterial vessels and calcified plaques. One asterisk indicates that comparison is significant at the 0.05 level (two-tailed).
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Figure 5: Comparison between high- and low-risk groups for cardiovascular disease. With regard to the 18F-FDG and 68Ga-DOTATATE uptake of big arterial vessels and calcified plaques. One asterisk indicates that comparison is significant at the 0.05 level (two-tailed).

Mentions: Two risk-related groups were formed to assess the differential vascular uptake of the two tracers. The summed calcification scores (CPsum) differed significantly between the two groups (p < 0.05). The TBRmean, TBRabdominal, TBRleft_iliac, and TBRright_iliac of 68Ga-DOTATATE were significantly higher in the high-risk group (at least two cardiovascular risk factors) as compared to the low-risk group (one cardiovascular risk factor at the most) (Figure 5). In contrast, for 18F-FDG, the TBRmean and TBRabdominal only showed a tendency for a higher uptake in the high-risk group; only the TBR value in the left iliac artery was found to be significantly higher (p < 0.05).


68Ga-DOTATATE PET/CT for the detection of inflammation of large arteries: correlation with18F-FDG, calcium burden and risk factors.

Li X, Samnick S, Lapa C, Israel I, Buck AK, Kreissl MC, Bauer W - EJNMMI Res (2012)

Comparison between high- and low-risk groups for cardiovascular disease. With regard to the 18F-FDG and 68Ga-DOTATATE uptake of big arterial vessels and calcified plaques. One asterisk indicates that comparison is significant at the 0.05 level (two-tailed).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3475087&req=5

Figure 5: Comparison between high- and low-risk groups for cardiovascular disease. With regard to the 18F-FDG and 68Ga-DOTATATE uptake of big arterial vessels and calcified plaques. One asterisk indicates that comparison is significant at the 0.05 level (two-tailed).
Mentions: Two risk-related groups were formed to assess the differential vascular uptake of the two tracers. The summed calcification scores (CPsum) differed significantly between the two groups (p < 0.05). The TBRmean, TBRabdominal, TBRleft_iliac, and TBRright_iliac of 68Ga-DOTATATE were significantly higher in the high-risk group (at least two cardiovascular risk factors) as compared to the low-risk group (one cardiovascular risk factor at the most) (Figure 5). In contrast, for 18F-FDG, the TBRmean and TBRabdominal only showed a tendency for a higher uptake in the high-risk group; only the TBR value in the left iliac artery was found to be significantly higher (p < 0.05).

Bottom Line: There was one significant correlation between 18F-FDG uptake and hypertension (0.58; p < 0.05).In this series of cancer patients, we found a stronger association of increased 68Ga-DOTATATE uptake with known risk factors of cardiovascular disease as compared to 18F-FDG, suggesting a potential role for plaque imaging in large arteries.Strikingly, we found that focal uptake of 68Ga-DOTATATE and 18F-FDG does not colocalize in a significant number of lesions.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Nuclear Medicine, University of Wuerzburg, Oberdürrbacher Str, 6, Wuerzburg, D-97080, Germany. Samnick_S@klinik.uni--wuerzburg.de.

ABSTRACT

Background: Ga-[1,4,7,10-tetraazacyclododecane-N,N',N″,N'″-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE) positron emission tomography (PET) is commonly used for the visualization of somatostatin receptor (SSTR)-positive neuroendocrine tumors. SSTR is also known to be expressed on macrophages, which play a major role in inflammatory processes in the walls of coronary arteries and large vessels. Therefore, imaging SSTR expression has the potential to visualize vulnerable plaques. We assessed 68Ga-DOTATATE accumulation in large vessels in comparison to 18F-2-fluorodeoxyglucose (FDG) uptake, calcified plaques (CPs), and cardiovascular risk factors.

Methods: Sixteen consecutive patients with neuroendocrine tumors or thyroid cancer underwent both 68Ga-DOTATATE and 18F-FDG PET/CT for staging or restaging purposes. Detailed clinical data, including common cardiovascular risk factors, were recorded. For a separate assessment, they were divided into a high-risk and a low-risk group. In each patient, we calculated the maximum target-to-background ratio (TBR) of eight arterial segments. The correlation of the TBRmean of both tracers with risk factors including plaque burden was assessed.

Results: The mean TBR of 68Ga-DOTATATE in all large arteries correlated significantly with the presence of CPs (r = 0.52; p < 0.05), hypertension (r = 0.60; p < 0.05), age (r = 0.56; p < 0.05), and uptake of 18F-FDG (r = 0.64; p < 0.01). There was one significant correlation between 18F-FDG uptake and hypertension (0.58; p < 0.05). Out of the 37 sites with the highest focal 68Ga-DOTATATE uptake, 16 (43.2%) also had focal 18F-FDG uptake. Of 39 sites with the highest 18F-FDG uptake, only 11 (28.2%) had a colocalized 68Ga-DOTATATE accumulation.

Conclusions: In this series of cancer patients, we found a stronger association of increased 68Ga-DOTATATE uptake with known risk factors of cardiovascular disease as compared to 18F-FDG, suggesting a potential role for plaque imaging in large arteries. Strikingly, we found that focal uptake of 68Ga-DOTATATE and 18F-FDG does not colocalize in a significant number of lesions.

No MeSH data available.


Related in: MedlinePlus