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Nuclear medicine imaging in the evaluation of endocrine hypertension.

Sharma P, Kumar R - Indian J Endocrinol Metab (2012)

Bottom Line: Common endocrine causes of hypertension include pheochromocytoma, Cushing's syndrome, primary hyperaldosteronism, and thyroid disorders.It has established role in patients of pheochromocytoma/paraganglioma, Cushing's syndrome, aldosteronism, and thyroid disorders.We present a brief overview of role of nuclear medicine imaging in endocrine hypertension.

View Article: PubMed Central - PubMed

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

ABSTRACT
Endocrine hypertension forms a small (< 5%) but curable subset of patients with hypertension. Common endocrine causes of hypertension include pheochromocytoma, Cushing's syndrome, primary hyperaldosteronism, and thyroid disorders. Nuclear medicine imaging plays an important role in evaluation of patients with endocrine hypertension. It has established role in patients of pheochromocytoma/paraganglioma, Cushing's syndrome, aldosteronism, and thyroid disorders. We present a brief overview of role of nuclear medicine imaging in endocrine hypertension. Development of newer radiotracers might further broaden the role of nuclear medicine in these patients.

No MeSH data available.


Related in: MedlinePlus

Images of a 42-year-old male patient with presenting with hypertension. Anterior (a) and posterior (b) planar MIBG images show focal area of tracer uptake in left suprarenal region (arrow). CT (c) images show a left suprarenal mass which show MIBG uptake in SPECT (d) and SPECT-CT (e) images (arrow). A diagnosis of pheochromocytoma was made which was confirmed on histopathology. In this patient SPECT and SPECT-CT provided no added advantage over planar images
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Figure 1: Images of a 42-year-old male patient with presenting with hypertension. Anterior (a) and posterior (b) planar MIBG images show focal area of tracer uptake in left suprarenal region (arrow). CT (c) images show a left suprarenal mass which show MIBG uptake in SPECT (d) and SPECT-CT (e) images (arrow). A diagnosis of pheochromocytoma was made which was confirmed on histopathology. In this patient SPECT and SPECT-CT provided no added advantage over planar images

Mentions: Similar to the sympathetic nervous system, pheochromocytoma and most extra-adrenal paragangliomas express cell membrane norepinephrine transporters (NET) through which catecholamine can enter cells to be stored in vesicle. Metaiodobenzylguanidine (MIBG) has been used for diagnostic imaging in pheochromocytoma because of its resemblance to norepinephrine and its good affinity and uptake by the NET.[8] Until recently the gold standard functional imaging method for pheochromocytoma was scintigraphy with I-131MIBG, with sensitivity of 77%-90% and excellent specificity of 95%-100%.[9] However, it is scintigraphy with another radionuclide, I-123 MIBG, which offers the option of performing single photon emission tomography (SPECT) and is reported to have sensitivity of 83%-100% and specificity of 95%-100% for detecting pheochromocytoma.[61011] Scintigraphy imaging with I-123 MIBG, compared with I-131 MIBG, is advantageous because of its optimal δ-emissions and lack of ß-particles that result in a lower absorbed dose.[12] In addition, the I-123 isotope can be visualized with SPECT imaging, further increasing its diagnostic accuracy. Importantly, the normal adrenal medullary may show physiological uptake of both I-131and I-123 MIBG.[1314] Unfortunately availability of I-123 MIBG, compared to I-131 MIBG, is limited and it is not available in India and many other countries. Suboptimal sensitivity of MIBG scintigraphy might be associated with the relatively low affinity of MIBG to the NET, the lack of storage granules or the loss of transporters by tumor cell de-differentiation.[15] Furthermore, medication use interfering with MIBG uptake in patients could result in false-negative results.[16] SPECT with I-123MIBG improves the identification of lesions in case of lesions with limited uptake or those with central necrosis. Recent use of SPECT-CT in such patients has shown further improved its utility with accurate anatomical localisation.[17] In a recent study by Fukuoka et al. showed that SPECT-CT detected additional lesions in 81% patients for I-123MIBG and 53% patients for I-131MIBG when compared to planar scintigraphy.[18] The experience at our centre is similar, with I-131 MIBG SPECT-CT providing advantage over planar scintigraphy for small lesions, lesions with necrosis and extra-adrenal lesions [Figures 1 and 2].


Nuclear medicine imaging in the evaluation of endocrine hypertension.

Sharma P, Kumar R - Indian J Endocrinol Metab (2012)

Images of a 42-year-old male patient with presenting with hypertension. Anterior (a) and posterior (b) planar MIBG images show focal area of tracer uptake in left suprarenal region (arrow). CT (c) images show a left suprarenal mass which show MIBG uptake in SPECT (d) and SPECT-CT (e) images (arrow). A diagnosis of pheochromocytoma was made which was confirmed on histopathology. In this patient SPECT and SPECT-CT provided no added advantage over planar images
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3475893&req=5

Figure 1: Images of a 42-year-old male patient with presenting with hypertension. Anterior (a) and posterior (b) planar MIBG images show focal area of tracer uptake in left suprarenal region (arrow). CT (c) images show a left suprarenal mass which show MIBG uptake in SPECT (d) and SPECT-CT (e) images (arrow). A diagnosis of pheochromocytoma was made which was confirmed on histopathology. In this patient SPECT and SPECT-CT provided no added advantage over planar images
Mentions: Similar to the sympathetic nervous system, pheochromocytoma and most extra-adrenal paragangliomas express cell membrane norepinephrine transporters (NET) through which catecholamine can enter cells to be stored in vesicle. Metaiodobenzylguanidine (MIBG) has been used for diagnostic imaging in pheochromocytoma because of its resemblance to norepinephrine and its good affinity and uptake by the NET.[8] Until recently the gold standard functional imaging method for pheochromocytoma was scintigraphy with I-131MIBG, with sensitivity of 77%-90% and excellent specificity of 95%-100%.[9] However, it is scintigraphy with another radionuclide, I-123 MIBG, which offers the option of performing single photon emission tomography (SPECT) and is reported to have sensitivity of 83%-100% and specificity of 95%-100% for detecting pheochromocytoma.[61011] Scintigraphy imaging with I-123 MIBG, compared with I-131 MIBG, is advantageous because of its optimal δ-emissions and lack of ß-particles that result in a lower absorbed dose.[12] In addition, the I-123 isotope can be visualized with SPECT imaging, further increasing its diagnostic accuracy. Importantly, the normal adrenal medullary may show physiological uptake of both I-131and I-123 MIBG.[1314] Unfortunately availability of I-123 MIBG, compared to I-131 MIBG, is limited and it is not available in India and many other countries. Suboptimal sensitivity of MIBG scintigraphy might be associated with the relatively low affinity of MIBG to the NET, the lack of storage granules or the loss of transporters by tumor cell de-differentiation.[15] Furthermore, medication use interfering with MIBG uptake in patients could result in false-negative results.[16] SPECT with I-123MIBG improves the identification of lesions in case of lesions with limited uptake or those with central necrosis. Recent use of SPECT-CT in such patients has shown further improved its utility with accurate anatomical localisation.[17] In a recent study by Fukuoka et al. showed that SPECT-CT detected additional lesions in 81% patients for I-123MIBG and 53% patients for I-131MIBG when compared to planar scintigraphy.[18] The experience at our centre is similar, with I-131 MIBG SPECT-CT providing advantage over planar scintigraphy for small lesions, lesions with necrosis and extra-adrenal lesions [Figures 1 and 2].

Bottom Line: Common endocrine causes of hypertension include pheochromocytoma, Cushing's syndrome, primary hyperaldosteronism, and thyroid disorders.It has established role in patients of pheochromocytoma/paraganglioma, Cushing's syndrome, aldosteronism, and thyroid disorders.We present a brief overview of role of nuclear medicine imaging in endocrine hypertension.

View Article: PubMed Central - PubMed

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

ABSTRACT
Endocrine hypertension forms a small (< 5%) but curable subset of patients with hypertension. Common endocrine causes of hypertension include pheochromocytoma, Cushing's syndrome, primary hyperaldosteronism, and thyroid disorders. Nuclear medicine imaging plays an important role in evaluation of patients with endocrine hypertension. It has established role in patients of pheochromocytoma/paraganglioma, Cushing's syndrome, aldosteronism, and thyroid disorders. We present a brief overview of role of nuclear medicine imaging in endocrine hypertension. Development of newer radiotracers might further broaden the role of nuclear medicine in these patients.

No MeSH data available.


Related in: MedlinePlus