6-[F-18]Fluoro-L-dihydroxyphenylalanine positron emission tomography is superior to conventional imaging with (123)I-metaiodobenzylguanidine scintigraphy, computer tomography, and magnetic resonance imaging in localizing tumors causing catecholamine excess.
BACKGROUND
Catecholamine excess is rare, but symptoms may be life threatening.


OBJECTIVE
The objective of the study was to investigate the sensitivity of 6-[F-18]fluoro-l-dihydroxyphenylalanine positron emission tomography ((18)F-DOPA PET), compared with (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy and computer tomography (CT)/magnetic resonance imaging (MRI) for tumor localization in patients with catecholamine excess.


METHODS
All consecutive patients with catecholamine excess visiting the University Medical Center Groningen, Groningen, The Netherlands, between March 2003 and January 2008 were eligible.


METHODS
Forty-eight patients were included. The final diagnosis was pheochromocytoma in 40, adrenal hyperplasia in two, paraganglioma in two, ganglioneuroma in one, and unknown in three.


METHODS
Sensitivities and discordancy between (18)F-DOPA PET, (123)I-MIBG, and CT or MRI were analyzed for individual patients and lesions. Metanephrines and 3-methoxytyramine in plasma and urine and uptake of (18)F-DOPA with PET were measured to determine the whole-body metabolic burden and correlated with biochemical tumor activity. The gold standard was a composite reference standard.


RESULTS
(18)F-DOPA PET showed lesions in 43 patients, (123)I-MIBG in 31, and CT/MRI in 32. Patient-based sensitivity for (18)F-DOPA PET, (123)I-MIBG, and CT/MRI was 90, 65, and 67% (P < 0.01 for (18)F-DOPA PET vs. both (123)I-MIBG and CT/MRI, P = 1.0 (123)I-MIBG vs. CT/MRI). Lesion-based sensitivities were 73, 48, and 44% (P < 0.001 for (18)F-DOPA PET vs. both (123)I-MIBG and CT/MRI, P = 0.51 (123)I-MIBG vs. CT/MRI). The combination of (18)F-DOPA PET with CT/MRI was superior to (123)I-MIBG with CT/MRI (93 vs. 76%, P < 0.001). Whole-body metabolic burden measured with (18)F-DOPA PET correlated with plasma normetanephrine (r = 0.82), urinary normetanephrine (r = 0.84), and metanephrine (r = 0.57).


CONCLUSIONS
To localize tumors causing catecholamine excess, (18)F-DOPA PET is superior to (123)I-MIBG scintigraphy and CT/MRI.
Fiebrich
Helle-Brit
HB
Department of Medical Oncology, University Medical Center Groningen, 9700 RB Groningen, The Netherlands.
Brouwers
Adrienne H
AH
Kerstens
Michiel N
MN
Pijl
Milan E J
ME
Kema
Ido P
IP
de Jong
Johan R
JR
Jager
Pieter L
PL
Elsinga
Philip H
PH
Dierckx
Rudi A J O
RA
van der Wal
Jacqueline E
JE
Sluiter
Wim J
WJ
de Vries
Elisabeth G E
EG
Links
Thera P
TP
D019797:3-Iodobenzylguanidine; D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism; D000311:Adrenal Glands / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D002395:Catecholamines / Q000097:blood / Q000378:metabolism* / Q000652:urine; D002648:Child; D002675:Child, Preschool; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010235:Paraganglioma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism; D049268:Positron-Emission Tomography / Q000379:methods; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D055815:Young Adult
D015415:Biomarkers; D002395:Catecholamines; D019275:Radiopharmaceuticals; C043437:fluorodopa F 18; D019797:3-Iodobenzylguanidine; D004295:Dihydroxyphenylalanine