68Ga-DOTA-TATE PET vs. 123I-MIBG in identifying malignant neural crest tumours.

PURPOSE: We aimed to compare imaging with (123)I-MIBG and (68)Ga-DOTA-TATE in neural crest tumours (NCT) to see if the latter could offer more advantage in detecting extra lesions and have higher sensitivity for malignant lesions.

PROCEDURES: We retrospectively reviewed 12 patients (M = 10, F = 2; age range 20-71 years) with NCT (phaeochromocytomas = 7, paragangliomas = 4, medullary thyroid cancer = 1) who underwent both (68)Ga-DOTA-TATE positron emission tomography (PET) or PET/computed tomography (CT) and (123)I-MIBG single-photon emission computed tomography within 6 months. Visual assessment of all lesions and measurement of target/non-target (T/N) ratio in selected lesions were performed. Five patients (aged 50 or less) had SDHB screening results correlated with imaging results of both radiopharmaceuticals. All patients had contrast-enhanced CT and/or other cross-sectional imaging.

RESULTS: (68)Ga-DOTA-TATE PET showed tumour lesions in ten out of 12 patients with confirmed disease, while (123)I-MIBG showed lesions in five out of 12 patients. In one patient, both (68)Ga-DOTA-TATE PET and (123)I-MIBG were negative, but CT, magnetic resonance imaging, and 2-deoxy-2-[(18)F]fluoro-D-glucose PET scans identified a lesion in the thorax. (68)Ga-DOTA-TATE and (123)I-MIBG detected a total of 30 lesions, of which 29/30 were positive with (68)Ga-DOTA-TATE and 7/30 with (123)I-MIBG. We also found higher incidence of SDHB positive results in patients with positive (68)Ga-DOTA-TATE.

CONCLUSION: Our limited data suggest that (68)Ga-DOTA-TATE is a better imaging agent for NCT and detects significantly more lesions with higher T/N ratio compared to (123)I-MIBG. (68)Ga-DOTA-TATE was more likely to detect malignant lesions as indicated by correlating imaging results with SDHB screening.