99mTc-HYNIC-TOC scintigraphy is superior to 131I-MIBG imaging in the evaluation of extraadrenal pheochromocytoma.
In this investigation, the efficacy of scintigraphy using (99m)Tc-labeled hydrazinonicotinyl-Tyr3-octreotide (HYNIC-TOC) in the evaluation of extraadrenal pheochromocytoma was assessed and compared with (131)I-labeled metaiodobenzylguanidine (MIBG) imaging.


METHODS
Ninety-seven patients who were suspected of having pheochromocytoma but showed no definite adrenal abnormalities on CT were evaluated by both (99m)Tc-HYNIC-TOC scintigraphy and (131)I-MIBG imaging. The results were compared with pathology findings or clinical follow-up.


RESULTS
Of 58 patients proven to be without pheochromocytoma, (99m)Tc-HYNIC-TOC and (131)I-MIBG imaging excluded 56 and 58 patients, respectively, rendering a specificity of 96.6% for (99m)Tc-HYNIC-TOC imaging and 100% for (131)I-MIBG imaging. In the evaluation of adrenal pheochromocytoma (14 patients), the sensitivity of (99m)Tc-HYNIC-TOC scintigraphy and (131)I-MIBG imaging was 50% and 85.7%, respectively. However, in the evaluation of extraadrenal pheochromocytomas (25 patients), the sensitivity of (99m)Tc-HYNIC-TOC scintigraphy and (131)I-MIBG imaging was 96.0% and 72.0%, respectively.


CONCLUSIONS
(99m)Tc-HYNIC-TOC scintigraphy is more sensitive than (131)I-MIBG imaging in the detection of extraadrenal pheochromocytomas.
Chen
Libo
L
Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
Li
Fang
F
Zhuang
Hongming
H
Jing
Hongli
H
Du
Yanrong
Y
Zeng
Zhengpei
Z
D019797:3-Iodobenzylguanidine; D000008:Abdominal Neoplasms / Q000000981:diagnostic imaging*; D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging*; D008875:Middle Aged; D015282:Octreotide / Q000031:analogs & derivatives*; D015609:Organotechnetium Compounds; D010673:Pheochromocytoma / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies
D007457:Iodine Radioisotopes; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C410263:technetium Tc 99m hydrazinonicotinyl-Tyr(3)-octreotide; D019797:3-Iodobenzylguanidine; D015282:Octreotide