Limits...
PET/CT imaging of neuroendocrine tumors with (68)Gallium-labeled somatostatin analogues: An overview and single institutional experience from India.

Sharma P, Singh H, Bal C, Kumar R - Indian J Nucl Med (2014)

Bottom Line: Recently, positron emission tomography/computed tomography (PET/CT) with (68)Gallium ((68)Ga)-labeled somatostatin analogues has shown excellent results for imaging of NETs and better results than conventional SSTR scintigraphy.In this review we have discussed the utility of (68)Ga-labeled somatostatin analogue PET/CT in NETs for various established and potential indications.In addition we have also shared our own experience from a tertiary care center in India.

View Article: PubMed Central - PubMed

Affiliation: Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India.

ABSTRACT
Neuroendocrine tumors (NETs) are rare neoplasms characterized by overexpression of somatostatin receptors (SSTRs). Functional imaging plays a crucial role in management of NETs. Recently, positron emission tomography/computed tomography (PET/CT) with (68)Gallium ((68)Ga)-labeled somatostatin analogues has shown excellent results for imaging of NETs and better results than conventional SSTR scintigraphy. In this review we have discussed the utility of (68)Ga-labeled somatostatin analogue PET/CT in NETs for various established and potential indications. In addition we have also shared our own experience from a tertiary care center in India.

No MeSH data available.


Related in: MedlinePlus

A 28-year-old male with uncontrolled hypertension and left adrenal mass. Urinary metanephrine was mildly elevated. He underwent 68Ga-DOTANOC PET/CT for characterization of the adrenal mass. MIP PET image (a) show intense tracer uptake in left suprarenal region (arrow). Transaxial CT (b) and PET/CT (c) images showed increased tracer uptake in the large left suprarenal mass with central necrosis (arrow) suggesting pheochromocytoma. Postoperative histopathology confirmed pheochromocytoma
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3928745&req=5

Figure 6: A 28-year-old male with uncontrolled hypertension and left adrenal mass. Urinary metanephrine was mildly elevated. He underwent 68Ga-DOTANOC PET/CT for characterization of the adrenal mass. MIP PET image (a) show intense tracer uptake in left suprarenal region (arrow). Transaxial CT (b) and PET/CT (c) images showed increased tracer uptake in the large left suprarenal mass with central necrosis (arrow) suggesting pheochromocytoma. Postoperative histopathology confirmed pheochromocytoma

Mentions: The diagnosis of pheochromocytoma is established biochemically by measuring the level of urinary and plasma catecholamines and their metabolites (24-h total metanephrine and/or catecholamine).[69] Imaging is important for the localization of tumor and excluding possibility of multifocal lesions before surgery. CT or MRI provide excellent morphologic details and have high sensitivity in the depiction of pheochromocytoma, but their specificity is low. 123/131I-Metaiodobenzylguanidine (MIBG) scintigraphy is currently the functional imaging method of choice for the localization of pheochromocytomas and paragangliomas. It provides high sensitivity and specificity, but is not without limitations.[70] From in vitro and in vivo studies, it has been established that SSTR 2, 3, and 4 are expressed in pheochromocytoma and paraganglioma.[71] Usually the expression of SSTR receptors is increased in malignant pheochromocytomas and paragangliomas.[72] Previous studies with 111In-Octerotide have shown higher sensitivity for detecting metastatic pheochromocytoma than for detecting benign pheochromocytoma, but the overall sensitivity remains low (~30%).[72] Limited literature is available with respect to 68Ga-DOTA-peptide imaging in pheochromocytoma and paraganglioma, majority from our center. Win et al., compared 68Ga-DOTA-TATE PET with 123I-MIBG in five patients with pheochromocytoma and showed that 68Ga-DOTA-TATE PET showed more lesions, with higher uptake and better resolution.[73] Maurice et al., compared 68Ga-DOTA-TATE PET with 123I-MIBG in 15 patients with pheochromocytoma/paraganglioma.[74] They recommended that 68Ga-DOTA-TATE PET should be used as the first line investigation for paraganglioma and metastatic disease. In the largest study till date, Naswa et al., from our center showed the superiority of 68Ga-DOTA-NOC PET/CT over 131I-MIBG in 35 patients with pheochromocytoma/paraganglioma.[75] 68Ga-DOTA-NOC PET/CT showed a diagnostic accuracy of 97.1% on per-patient and 98% on lesion-wise analysis [Figure 6]. No significant relationship was however observed between the degree of tracer uptake (SUVmax) and lesion size and no difference was seen between adrenal and extra-adrenal lesions. A combination of 68Ga-DOTA-NOC PET/CT and 18F-FDG PET/CT is able to preoperatively characterize indeterminate adrenal masses.[76] Naswa et al., have also shown the utility of 68Ga-DOTA-NOC PET/CT for imaging of carotid body chemodectoma, by demonstrating additional lesions or metastasis.[77] A recent study by Sharma et al., from our center has shown the superiority of 68Ga-DOTA-NOC PET/CT over conventional imaging (CT/MRI) and 131I-MIBG in head and neck paraganglioma.[78] In that series of 26 patients, 68Ga-DOTA-NOC PET/CT showed more lesions as compared to 131I-MIBG (P < 0.0001) and conventional imaging (P = 0.015). More importantly, a combination of CT/MRI and 131I-MIBG scintigraphy detected only 53/78 (67.9%) lesions and was also inferior to PET/CT (P < 0.0001). Other PET tracers like 18F-FDG, 18F-FDOPA, and 11C-hyroxyephidrine have been evaluated with variable results in pheochromocytoma/paraganglioma and their role viz-à-viz 68Ga-DOTA-peptides needs to be evaluated.[79]


PET/CT imaging of neuroendocrine tumors with (68)Gallium-labeled somatostatin analogues: An overview and single institutional experience from India.

Sharma P, Singh H, Bal C, Kumar R - Indian J Nucl Med (2014)

A 28-year-old male with uncontrolled hypertension and left adrenal mass. Urinary metanephrine was mildly elevated. He underwent 68Ga-DOTANOC PET/CT for characterization of the adrenal mass. MIP PET image (a) show intense tracer uptake in left suprarenal region (arrow). Transaxial CT (b) and PET/CT (c) images showed increased tracer uptake in the large left suprarenal mass with central necrosis (arrow) suggesting pheochromocytoma. Postoperative histopathology confirmed pheochromocytoma
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3928745&req=5

Figure 6: A 28-year-old male with uncontrolled hypertension and left adrenal mass. Urinary metanephrine was mildly elevated. He underwent 68Ga-DOTANOC PET/CT for characterization of the adrenal mass. MIP PET image (a) show intense tracer uptake in left suprarenal region (arrow). Transaxial CT (b) and PET/CT (c) images showed increased tracer uptake in the large left suprarenal mass with central necrosis (arrow) suggesting pheochromocytoma. Postoperative histopathology confirmed pheochromocytoma
Mentions: The diagnosis of pheochromocytoma is established biochemically by measuring the level of urinary and plasma catecholamines and their metabolites (24-h total metanephrine and/or catecholamine).[69] Imaging is important for the localization of tumor and excluding possibility of multifocal lesions before surgery. CT or MRI provide excellent morphologic details and have high sensitivity in the depiction of pheochromocytoma, but their specificity is low. 123/131I-Metaiodobenzylguanidine (MIBG) scintigraphy is currently the functional imaging method of choice for the localization of pheochromocytomas and paragangliomas. It provides high sensitivity and specificity, but is not without limitations.[70] From in vitro and in vivo studies, it has been established that SSTR 2, 3, and 4 are expressed in pheochromocytoma and paraganglioma.[71] Usually the expression of SSTR receptors is increased in malignant pheochromocytomas and paragangliomas.[72] Previous studies with 111In-Octerotide have shown higher sensitivity for detecting metastatic pheochromocytoma than for detecting benign pheochromocytoma, but the overall sensitivity remains low (~30%).[72] Limited literature is available with respect to 68Ga-DOTA-peptide imaging in pheochromocytoma and paraganglioma, majority from our center. Win et al., compared 68Ga-DOTA-TATE PET with 123I-MIBG in five patients with pheochromocytoma and showed that 68Ga-DOTA-TATE PET showed more lesions, with higher uptake and better resolution.[73] Maurice et al., compared 68Ga-DOTA-TATE PET with 123I-MIBG in 15 patients with pheochromocytoma/paraganglioma.[74] They recommended that 68Ga-DOTA-TATE PET should be used as the first line investigation for paraganglioma and metastatic disease. In the largest study till date, Naswa et al., from our center showed the superiority of 68Ga-DOTA-NOC PET/CT over 131I-MIBG in 35 patients with pheochromocytoma/paraganglioma.[75] 68Ga-DOTA-NOC PET/CT showed a diagnostic accuracy of 97.1% on per-patient and 98% on lesion-wise analysis [Figure 6]. No significant relationship was however observed between the degree of tracer uptake (SUVmax) and lesion size and no difference was seen between adrenal and extra-adrenal lesions. A combination of 68Ga-DOTA-NOC PET/CT and 18F-FDG PET/CT is able to preoperatively characterize indeterminate adrenal masses.[76] Naswa et al., have also shown the utility of 68Ga-DOTA-NOC PET/CT for imaging of carotid body chemodectoma, by demonstrating additional lesions or metastasis.[77] A recent study by Sharma et al., from our center has shown the superiority of 68Ga-DOTA-NOC PET/CT over conventional imaging (CT/MRI) and 131I-MIBG in head and neck paraganglioma.[78] In that series of 26 patients, 68Ga-DOTA-NOC PET/CT showed more lesions as compared to 131I-MIBG (P < 0.0001) and conventional imaging (P = 0.015). More importantly, a combination of CT/MRI and 131I-MIBG scintigraphy detected only 53/78 (67.9%) lesions and was also inferior to PET/CT (P < 0.0001). Other PET tracers like 18F-FDG, 18F-FDOPA, and 11C-hyroxyephidrine have been evaluated with variable results in pheochromocytoma/paraganglioma and their role viz-à-viz 68Ga-DOTA-peptides needs to be evaluated.[79]

Bottom Line: Recently, positron emission tomography/computed tomography (PET/CT) with (68)Gallium ((68)Ga)-labeled somatostatin analogues has shown excellent results for imaging of NETs and better results than conventional SSTR scintigraphy.In this review we have discussed the utility of (68)Ga-labeled somatostatin analogue PET/CT in NETs for various established and potential indications.In addition we have also shared our own experience from a tertiary care center in India.

View Article: PubMed Central - PubMed

Affiliation: Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India.

ABSTRACT
Neuroendocrine tumors (NETs) are rare neoplasms characterized by overexpression of somatostatin receptors (SSTRs). Functional imaging plays a crucial role in management of NETs. Recently, positron emission tomography/computed tomography (PET/CT) with (68)Gallium ((68)Ga)-labeled somatostatin analogues has shown excellent results for imaging of NETs and better results than conventional SSTR scintigraphy. In this review we have discussed the utility of (68)Ga-labeled somatostatin analogue PET/CT in NETs for various established and potential indications. In addition we have also shared our own experience from a tertiary care center in India.

No MeSH data available.


Related in: MedlinePlus