Uptake of 68Ga-DOTATOC and 68Ga-DOTATATE in PET/CT of Gastroenteropancreatic Neuroendocrine Tumors


Pat. no.

Age (years)

Sex

Primary NET site

Previous treatments

Ki-67

SUVmax 68Ga-DOTATATE

SUVmax 68Ga-DOTATOC

1

49

Male

Foregut (gastric)

Surgery, SIRT, PRRT

30

11.1

13.8

2

77

Female

Midgut

Surgery, chemotherapy

5

25.5

29.2

3

70

Male

Midgut

Chemotherapy

<1

17.8

26.2

4

62

Female

Midgut (appendiceal)

Surgery, chemotherapy, PRRT

5

8.5

12.3

5

72

Male

Midgut (cecal)

Surgery

<1

24.1

30.0

6

72

Male

Midgut (duodenal)

Surgery

N.a.

7.4

10.7

7

65

Male

Midgut (ileal)

Surgery, somatostatin analogs

<2

13.8

18.4

8

79

Male

Midgut (ileal)

Surgery, chemotherapy, interferon alpha, PRRT

N.a.

18.2

21.1

9

58

Male

Midgut (ileal)

Surgery, somatostatin analogs

5

19.1

12.3

10

61

Male

Midgut (ileal)

Surgery

1

10.3

14.5

11

57

Male

Midgut (ileal)

Somatostatin analogs, PRRT

1

15.6

30.2

12

46

Male

Midgut (ileal)

Surgery, somatostatin analogs

<2

15.6

32.4

13

69

Female

Midgut (ileal)

Surgery, SIRT

40

28.0

12.9

14

54

Male

Midgut (ileal)

Surgery, somatostatin analogs, PRRT, chemoembolization

<1

17.0

12.1

15

70

Male

Midgut (ileocecal)

Surgery, somatostatin analogs, PRRT

<1

11.2

15.5

16

81

Male

Midgut (ileocecal)

Surgery, somatostatin analogs

<2

10.3

10.1

17

71

Male

Midgut (jejunal)

Surgery, somatostatin analogs

10

28.2

22.2

18

66

Male

Midgut (jejunal)

None

<1

9.9

12.0

19

48

Female

Pancreas

Surgery, somatostatin analogs

<2

6.8

6.9

20

59

Male

Pancreas

None

30

20.0

28.1

21

46

Male

Pancreas

Surgery (metastases), chemotherapy, PRRT

3

27.0

33.8

22

56

Female

Pancreas

Surgery, chemotherapy, SIRT, TACE, PRRT

10

18.9

20.0

23

55

Female

Pancreas

PRRT

5

20.0

25.5

24

67

Male

Pancreas

Surgery

5

16.4

21.5

25

66

Male

Pancreas

Surgery

5

12.8

18.1

26

53

Male

Pancreatic gastrinoma

Surgery

<1

13.8

46.6

27

50

Male

Pancreatic insulinoma

Somatostatin analogs

N.a.

30.2

60.5


CUP cancer of unknown primary, NET neuroendocrine tumor, N.a. not available, PRRT peptide receptor radionuclide therapy, SIRT selective internal radiation therapy, TACE transarterial chemoembolization




Table 2
Scan parameters
























































Scan parameter
68Ga-DOTATATE
68Ga-DOTATOC
 
Mean
SD
Range
Mean
SD
Range

Uptake time (min)
56
32
24–161
68
32
29–162

Activity per dose (MBq)
102
13
60–123
88
16
52–111

Specific activity (MBq/nmol)
48.9
24.1
16.0–95.6
41
20.6
10.9–81

Peptide per dose (μg)
6
3
2–13
6
3
2–12



3.1 Regional and Lesional Analyses


Fifty-one regions (excluding the composite region “lymph nodes”) were found positive with both 68Ga-DOTATATE and 68Ga-DOTATOC (Table 3). There was no discrepant region. On average three positive regions were found per patient with each of the imaging procedures. There was no significant difference between the two imaging procedures regarding the number of detected regions per patient or the number of patients with at least one lesion within one of the eight regions (including the composite region “lymph nodes”) (Table 4).


Table 3
Regional analyses: positive regions per patient






































































































Pat. no. (n = 20)
Regions positive*

68Ga-DOTATATE
68Ga-DOTATOC

1
2
2

3
3
3

4
4
4

5
1
1

6
1
1

9
2
2

10
2
2

11
2
2

12
2
2

14
1
1

15
2
2

17
2
2

18
4
4

19
2
2

21
4
4

22
1
1

23
5
5

24
6
6

25
3
3

26
2
2

Sum

51

51

Mean

3
3


* Excluding the composite region “lymph nodes”



Table 4
Regional analyses: lesions per region














































Region
Number of patients

68Ga-DOTATATE
68Ga-DOTATOC

Head/neck
1
1

Mediastinum
6
6

Lung
1
1

Liver
17
17

Pancreas
5
5

Abdomen/pelvis
14
14

Bone
7
7

Lymph nodes*
15
15


* Composite region

Within the defined regions (excluding the composite region “lymph nodes”) 174 lesions were detected with 68Ga-DOTATATE versus 179 lesions with 68Ga-DOTATOC (versus Table 5). The difference was significant (p = 0.043). The five lesions that were detected additionally with 68Ga-DOTATOC were found in five patients and were distributed among the following regions: “liver” (two patients), “pancreas,” “abdomen/pelvis,” and “bone.” On average 8.7 lesions were found per patient with 68Ga-DOTATATE versus 9.0 lesions with 68Ga-DOTATOC. There was no significant difference between the two imaging procedures in lesion detection with respect to tumor grading or tumor origin (foregut, midgut, pancreas).
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Sep 1, 2016 | Posted by in NUCLEAR MEDICINE | Comments Off on Uptake of 68Ga-DOTATOC and 68Ga-DOTATATE in PET/CT of Gastroenteropancreatic Neuroendocrine Tumors

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