Carcinoid syndrome other imaging findings: Difference between revisions
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{{Carcinoid syndrome}} | {{Carcinoid syndrome}} | ||
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==Overview== | ==Overview== | ||
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==Other Imaging Findings== | ==Other Imaging Findings== | ||
For localization of both primary lesions and metastasis, the initial imaging method is Octreoscan, where <math>{}^{111}</math>Indium labelled [[somatostatin]] analogues ([[octreotide]]) are used in [[scintigraphy]] for detecting tumors expressing [[somatostatin]] receptors. Median detection rates with octreoscan are about 89%, in contrast to other imaging techniques such as CT scans and MRI with detection rates of about 80%. Usually on CT scan, one will note a spider-like/crab like change in the messentery due to the fibrosis from the release of serotonin. PET scans, which evaluate for increased metabolism of glucose, may also aid in localizing the carcinoid lesion or evaluating for metastases. | For localization of both primary lesions and metastasis, the initial imaging method is Octreoscan, where <math>{}^{111}</math>Indium labelled [[somatostatin]] analogues ([[octreotide]]) are used in [[scintigraphy]] for detecting tumors expressing [[somatostatin]] receptors. Median detection rates with octreoscan are about 89%, in contrast to other imaging techniques such as CT scans and MRI with detection rates of about 80%. Usually on CT scan, one will note a spider-like/crab like change in the messentery due to the fibrosis from the release of serotonin. PET scans, which evaluate for increased metabolism of glucose, may also aid in localizing the carcinoid lesion or evaluating for metastases. | ||
===Endoscopic Ultrasonography (EUS)=== | |||
Endoscopic ultrasonography (EUS) may be a sensitive method for the detection of gastric and duodenal carcinoids and may be superior to conventional ultrasound, particularly in the detection of small tumors (2 mm–3 mm) that are localized in the bowel lumen. In one study, the EUS was reported to have an accuracy of 90% for the localization and staging of colorectal carcinoids. | |||
===Positron Emission Tomography (PET)=== | |||
A promising approach for positron emission tomography (PET) as an imaging modality to visualize GI carcinoids appears to be the use of the radioactive-labeled serotonin precursor 11C-5-hydroxytryptophan (11C-5-HTP). With 11C-5-HTP, tumor detection rates have been reported to be as high as 100%, and some investigators have concluded that 11C-5-HTP PET should be used as a universal detection method for detecting NETs. | |||
===Angiography=== | |||
MRI angiography has replaced angiography to a large extent. However, selective and supraselective angiography may be useful to: | |||
*Demonstrate the degree of tumor vascularity | |||
*Identify the sources of vascular supply | |||
*Delineate the relationship of the tumor to adjacent major vascular structures | |||
*Provide information regarding vascular invasion | |||
===Localization=== | ===Localization=== | ||
Tumour localization may be extremely difficult. Barium swallow and follow-up examination of the intestine may occasionally show the tumour. Capsule video endoscopy has recently been used to localized the tumour. Often laparotomy is the definitive way to localize the tumour. | Tumour localization may be extremely difficult. Barium swallow and follow-up examination of the intestine may occasionally show the tumour. Capsule video endoscopy has recently been used to localized the tumour. Often laparotomy is the definitive way to localize the tumour. | ||
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[[Category:Disease]] | [[Category:Disease]] | ||
[[Category:Types of cancer]] | [[Category:Types of cancer]] | ||
[[Category:Hematology]] | [[Category:Hematology]] | ||
[[Category:Endocrinology]] | [[Category:Endocrinology]] | ||
Revision as of 14:07, 23 September 2015
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Carcinoid syndrome other imaging findings On the Web |
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American Roentgen Ray Society Images of Carcinoid syndrome other imaging findings |
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Risk calculators and risk factors for Carcinoid syndrome other imaging findings |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Parminder Dhingra, M.D. [2]
Overview
Other Imaging Findings
For localization of both primary lesions and metastasis, the initial imaging method is Octreoscan, where <math>{}^{111}</math>Indium labelled somatostatin analogues (octreotide) are used in scintigraphy for detecting tumors expressing somatostatin receptors. Median detection rates with octreoscan are about 89%, in contrast to other imaging techniques such as CT scans and MRI with detection rates of about 80%. Usually on CT scan, one will note a spider-like/crab like change in the messentery due to the fibrosis from the release of serotonin. PET scans, which evaluate for increased metabolism of glucose, may also aid in localizing the carcinoid lesion or evaluating for metastases.
Endoscopic Ultrasonography (EUS)
Endoscopic ultrasonography (EUS) may be a sensitive method for the detection of gastric and duodenal carcinoids and may be superior to conventional ultrasound, particularly in the detection of small tumors (2 mm–3 mm) that are localized in the bowel lumen. In one study, the EUS was reported to have an accuracy of 90% for the localization and staging of colorectal carcinoids.
Positron Emission Tomography (PET)
A promising approach for positron emission tomography (PET) as an imaging modality to visualize GI carcinoids appears to be the use of the radioactive-labeled serotonin precursor 11C-5-hydroxytryptophan (11C-5-HTP). With 11C-5-HTP, tumor detection rates have been reported to be as high as 100%, and some investigators have concluded that 11C-5-HTP PET should be used as a universal detection method for detecting NETs.
Angiography
MRI angiography has replaced angiography to a large extent. However, selective and supraselective angiography may be useful to:
- Demonstrate the degree of tumor vascularity
- Identify the sources of vascular supply
- Delineate the relationship of the tumor to adjacent major vascular structures
- Provide information regarding vascular invasion
Localization
Tumour localization may be extremely difficult. Barium swallow and follow-up examination of the intestine may occasionally show the tumour. Capsule video endoscopy has recently been used to localized the tumour. Often laparotomy is the definitive way to localize the tumour.