Somatostatin receptor scintigraphy: its value in tumor localization in patients with Cushing's syndrome caused by ectopic corticotropin or corticotropin-releasing hormone secretion.
OBJECTIVE
To assess the feasibility of somatostatin receptor scintigraphy for patients with Cushing's syndrome caused by tumors secreting ectopic corticotropin or corticotropin-releasing hormone (CRH).


METHODS
Ten patients with Cushing's syndrome, nine with ectopic corticotropin-secreting tumors and one with a CRH-secreting tumor, were consecutively studied. For comparison purposes, eight patients with corticotropin-secreting pituitary tumors and one patient with an autonomous adrenal adenoma were investigated. In vivo tumor localization was performed for all patients using a radionuclide-coupled somatostatin analog. The results obtained with this technique were compared with those obtained with conventional imaging techniques. For some patients, the clinical effects of octreotide therapy were evaluated.


RESULTS
Somatostatin analog scintigraphy successfully identified the primary ectopic corticotropin-secreting and CRH-secreting tumors or their metastases, or both, in 8 of 10 patients; in 2 patients with corticotropin-secreting bronchial carcinoids, the tumors could not be visualized. Normal scans were obtained for the 8 patients with corticotropin-secreting pituitary tumors and the one patient with an adrenal adenoma.


CONCLUSIONS
Somatostatin analog scintigraphy can be included as a diagnostic step in the workup of Cushing's syndrome patients with a suspected ectopic corticotropin-secreting tumor or a CRH-secreting tumor.
de Herder
W W
WW
Department of Internal Medicine III, University Hospital Dijkzigt, Rotterdam, The Netherlands.
Krenning
E P
EP
Malchoff
C D
CD
Hofland
L J
LJ
Reubi
J C
JC
Kwekkeboom
D J
DJ
Oei
H Y
HY
Pols
H A
HA
Bruining
H A
HA
Nobels
F R
FR
D000182:ACTH Syndrome, Ectopic / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D000328:Adult; D000368:Aged; D001345:Autoradiography; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D003480:Cushing Syndrome / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000378:metabolism*; D015282:Octreotide / Q000627:therapeutic use; D010911:Pituitary Neoplasms / Q000378:metabolism; D011237:Predictive Value of Tests; D017481:Receptors, Somatostatin / Q000378:metabolism*; D016896:Treatment Outcome
D017481:Receptors, Somatostatin; D003346:Corticotropin-Releasing Hormone; D015282:Octreotide