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CT mimicking renal dynamic scan: Lack of physiological uptake in the spleen of a newborn and the pituitary gland in congenital hyperinsulinism
Rev Esp Med Nucl Imagen Mol. 2014;33(6):382–383
Interesting image 68
Ga-DOTANOC PET/CT mimicking renal dynamic scan: Lack of physiological uptake in the spleen of a newborn and the pituitary gland in congenital hyperinsulinism 68
Ga-DOTANOC PET/TC scan imitando dinámica renal: Falta de captación fisiológica en el bazo y la hipófisis de un recién nacido en el hiperinsulinismo congénito G. Kumar, V.S. Dhull, S. Karunanithi, C. Bal, R. Kumar ∗ Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India
a r t i c l e
i n f o
Article history: Received 30 September 2013 Accepted 5 December 2013 Available online 17 July 2014
We present a case of 25-day-old neonate who presented with recurrent and persistent hypoglycemia refractory to medical treatment. At 22 h of life, the baby developed hypoglycemia (22 mg/dl), put on glucose infusion rate (GIR) of 6 mg/kg/min gradually increased to 12 mg/kg/min. In view of persistent hypoglycemia, hydrocortisone 5 mg/kg/day was started on day 3. The baby gradually required GIR of 24 mg/kg/min and multiple drugs (octreotide 25 mcg/kg/min, chlorthiazide 7.5 mg/kg/day, diazoxide 20 mg/kg/day and hydrocortisone 10 mg/kg/day). Critical sample of the baby showed hyperinsulinism (10.11 U/ml), cortisol and C
peptide were normal. The baby was maintaining sugar on multiple drugs on day 15 and all drugs were gradually reduced over a period of 10 days and is now on diazoxide 5 mg/kg/day only. In view of persistent hypoglycemia refractory to medical treatment, the baby was referred for 68 Ga-labeled [1,4,7,10-tetraazacyclododecane1,4,7,10-tetraacetic acid]-1-NaI3-octreotide (DOTANOC) positron emission tomography/computed tomography (PET/CT) to localize the lesion. 68 Ga-DOTANOC PET/CT showed the physiological excretion of the radiotracer through kidneys, ureters and bladder; thus mimicking a renal dynamic scan (Fig. 1A). No significant
Fig. 1. 68 Ga-DOTANOC maximum intensity projection PET images revealed the physiological excretion of the radiotracer through kidneys, ureters and bladder; thus mimicking a renal dynamic scan (A). Transaxial CT and PET/CT images of pituitary gland (B, C) and spleen (D, E), which revealed no significant physiological 68 Ga-DOTANOC uptake. Also, no abnormal uptake was noted in the pancreas (A).
∗ Corresponding author. E-mail address: [email protected] (R. Kumar). 2253-654X/$ – see front matter © 2013 Elsevier España, S.L.U. and SEMNIM. All rights reserved. http://dx.doi.org/10.1016/j.remn.2013.12.002
G. Kumar et al. / Rev Esp Med Nucl Imagen Mol. 2014;33(6):382–383
physiological 68 Ga-DOTANOC uptake was noted in spleen or pituitary (Fig. 1B–E). Also, no abnormal uptake was noted in the pancreas. In congenital hyperinsulinism of infancy (CHI), the preoperative differentiation of focal from diffuse form is important from management point of view. Although, 18 F-fluoro-DOPA PET imaging is the norm, somatostatin receptor (SSTR) imaging has also been used. Five subtypes of SSTR (SSTR 1–5) have been discovered. 68 Ga-DOTANOC is an octreotide-based radiopharmaceutical which carries a high affinity particularly for SSTR 2 and 5.1 The physiologic uptake of 68 Ga-DOTANOC in spleen is due to higher expression of SSTR 2 (particularly SSTR 2a) mRNA in spleen which gradually increases with age.2 Fetal pituitary expresses SSTR 2 as early as 16 weeks of fetal life but the developmental pattern of expression varies considerably.3 The uptake in the pancreas appeared very diffuse and mild to be considered significant (SUVmax pancreas = 0.85; SUVmax liver = 0.96). Although immunohistochemical analysis of human pancreatic tissue sections has revealed that SSTR2 is the main type present in both -cells and ␣-cells, but the exact age of maturation is not known.4 Therefore, present case highlights the fact that the physiological distribution of 68 GaDOTANOC can differ in early life due to incomplete/immature expression of the SSTR and has to be kept in mind while
383
reporting such cases. Future studies are warranted to substantiate the incomplete/immature expression of the SSTR in early life. Funding No funding received from any organization for this study. Conflict of interest The authors declare that there is no conflict of interest. References 1. Dutta S, Venkataseshan S, Bal C, Rao KL, Gupta K, Bhattacharya A, et al. Novel use of somatostatin receptor scintigraphy in localization of focal congenital hyperinsulinism: promising but fallible. J Pediatr Endocrinol Metab. 2009;22:965–9. 2. Ferone D, Pivonello R, Kwekkeboom DJ, Gatto F, Ameri P, Colao A, et al. Immunohistochemical localization and quantitative expression of somatostatin receptors in normal human spleen and thymus: implications for the in vivo visualization during somatostatin receptor scintigraphy. J Endocrinol Invest. 2012;35:528–34. 3. Goodyer CG, Grigorakis SI, Patel YC, Kumar U. Developmental changes in the expression of somatostatin receptors (1–5) in the brain, hypothalamus, pituitary and spinal cord of the human fetus. Neuroscience. 2004;125:441–8. 4. Kailey B, van de Bunt M, Cheley S, Johnson PR, MacDonald PE, Gloyn AL, et al. SSTR2 is the functionally dominant somatostatin receptor in human pancreatic - and ␣-cells. Am J Physiol Endocrinol Metab. 2012;303:E1107–16.
Interesting image 68
Ga-DOTANOC PET/CT mimicking renal dynamic scan: Lack of physiological uptake in the spleen of a newborn and the pituitary gland in congenital hyperinsulinism 68
Ga-DOTANOC PET/TC scan imitando dinámica renal: Falta de captación fisiológica en el bazo y la hipófisis de un recién nacido en el hiperinsulinismo congénito G. Kumar, V.S. Dhull, S. Karunanithi, C. Bal, R. Kumar ∗ Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India
a r t i c l e
i n f o
Article history: Received 30 September 2013 Accepted 5 December 2013 Available online 17 July 2014
We present a case of 25-day-old neonate who presented with recurrent and persistent hypoglycemia refractory to medical treatment. At 22 h of life, the baby developed hypoglycemia (22 mg/dl), put on glucose infusion rate (GIR) of 6 mg/kg/min gradually increased to 12 mg/kg/min. In view of persistent hypoglycemia, hydrocortisone 5 mg/kg/day was started on day 3. The baby gradually required GIR of 24 mg/kg/min and multiple drugs (octreotide 25 mcg/kg/min, chlorthiazide 7.5 mg/kg/day, diazoxide 20 mg/kg/day and hydrocortisone 10 mg/kg/day). Critical sample of the baby showed hyperinsulinism (10.11 U/ml), cortisol and C
peptide were normal. The baby was maintaining sugar on multiple drugs on day 15 and all drugs were gradually reduced over a period of 10 days and is now on diazoxide 5 mg/kg/day only. In view of persistent hypoglycemia refractory to medical treatment, the baby was referred for 68 Ga-labeled [1,4,7,10-tetraazacyclododecane1,4,7,10-tetraacetic acid]-1-NaI3-octreotide (DOTANOC) positron emission tomography/computed tomography (PET/CT) to localize the lesion. 68 Ga-DOTANOC PET/CT showed the physiological excretion of the radiotracer through kidneys, ureters and bladder; thus mimicking a renal dynamic scan (Fig. 1A). No significant
Fig. 1. 68 Ga-DOTANOC maximum intensity projection PET images revealed the physiological excretion of the radiotracer through kidneys, ureters and bladder; thus mimicking a renal dynamic scan (A). Transaxial CT and PET/CT images of pituitary gland (B, C) and spleen (D, E), which revealed no significant physiological 68 Ga-DOTANOC uptake. Also, no abnormal uptake was noted in the pancreas (A).
∗ Corresponding author. E-mail address: [email protected] (R. Kumar). 2253-654X/$ – see front matter © 2013 Elsevier España, S.L.U. and SEMNIM. All rights reserved. http://dx.doi.org/10.1016/j.remn.2013.12.002
G. Kumar et al. / Rev Esp Med Nucl Imagen Mol. 2014;33(6):382–383
physiological 68 Ga-DOTANOC uptake was noted in spleen or pituitary (Fig. 1B–E). Also, no abnormal uptake was noted in the pancreas. In congenital hyperinsulinism of infancy (CHI), the preoperative differentiation of focal from diffuse form is important from management point of view. Although, 18 F-fluoro-DOPA PET imaging is the norm, somatostatin receptor (SSTR) imaging has also been used. Five subtypes of SSTR (SSTR 1–5) have been discovered. 68 Ga-DOTANOC is an octreotide-based radiopharmaceutical which carries a high affinity particularly for SSTR 2 and 5.1 The physiologic uptake of 68 Ga-DOTANOC in spleen is due to higher expression of SSTR 2 (particularly SSTR 2a) mRNA in spleen which gradually increases with age.2 Fetal pituitary expresses SSTR 2 as early as 16 weeks of fetal life but the developmental pattern of expression varies considerably.3 The uptake in the pancreas appeared very diffuse and mild to be considered significant (SUVmax pancreas = 0.85; SUVmax liver = 0.96). Although immunohistochemical analysis of human pancreatic tissue sections has revealed that SSTR2 is the main type present in both -cells and ␣-cells, but the exact age of maturation is not known.4 Therefore, present case highlights the fact that the physiological distribution of 68 GaDOTANOC can differ in early life due to incomplete/immature expression of the SSTR and has to be kept in mind while
383
reporting such cases. Future studies are warranted to substantiate the incomplete/immature expression of the SSTR in early life. Funding No funding received from any organization for this study. Conflict of interest The authors declare that there is no conflict of interest. References 1. Dutta S, Venkataseshan S, Bal C, Rao KL, Gupta K, Bhattacharya A, et al. Novel use of somatostatin receptor scintigraphy in localization of focal congenital hyperinsulinism: promising but fallible. J Pediatr Endocrinol Metab. 2009;22:965–9. 2. Ferone D, Pivonello R, Kwekkeboom DJ, Gatto F, Ameri P, Colao A, et al. Immunohistochemical localization and quantitative expression of somatostatin receptors in normal human spleen and thymus: implications for the in vivo visualization during somatostatin receptor scintigraphy. J Endocrinol Invest. 2012;35:528–34. 3. Goodyer CG, Grigorakis SI, Patel YC, Kumar U. Developmental changes in the expression of somatostatin receptors (1–5) in the brain, hypothalamus, pituitary and spinal cord of the human fetus. Neuroscience. 2004;125:441–8. 4. Kailey B, van de Bunt M, Cheley S, Johnson PR, MacDonald PE, Gloyn AL, et al. SSTR2 is the functionally dominant somatostatin receptor in human pancreatic - and ␣-cells. Am J Physiol Endocrinol Metab. 2012;303:E1107–16.