Correlation of 68Ga-DOTATATE accumulation in pituitary adenoma with the corresponding hormone levels in the patients

Objectives This study was designed to determine the value of 68Ga-DOTATATE PET/CT in identifying the pituitary adenoma and correlate the 68Ga-DOTATATE accumulation with the corresponding hormone levels in the patients, which was compared with 18F-FDG PET/CT in the same patients.

Methods 68GA-DOTATATE and 18F-FDG PET/CT were performed in 47 patients (Female 30, Male 17, aged 15-68 years) with suspicious adenoma on MRI and were diagnosed as pituitary adenoma pathologically or clinically. The mean SUV and the volume of the tumors were measured and the active tumor volume (ATV) was calculated by volume×SUVmean. The hormone levels at the same period were collected for correlation.

Results In the 47 patients, 20 were proved with growth hormone (GH) adenoma, 10 had adrenocorticotropic hormone (ACTH) tumor, 7 had prolactin (PRL) adenoma, and 10 had non-functional adenomas. All adenomas were found with both 68GA-DOTATATE accumulation and 18F-FDG uptake except for one patient who was also negative MRI but confirmed with a very small ACTH adenoma by surgery and pathology finally. Significant correlations were found between the ATV in 68GA-DOTATATE PET/CT with the serum insulin-like grown factor-1 levels in the patients with GH tumor (n=20, P=0.033) and the serum PRL levels in the patients with PRL tumor (n=7, P=0.007), but not with the 24-h urinary cortisol levels in patients with ACTH tumor (n=9, P=0.600). There was no significant difference of 68GA-DOTATATE accumulation between the different kinds secretary adenomas and the non-functional adenomas (P>0.05). There was significant correlation between the 68GA-DOTATATE accumulation and the 18F-FDG uptake in the adenomas (P<0.01).

Conclusions The 68GA-DOTATATE-avid tumor volume seemed to have a correlation with the hormone levels in patients with pituitary PRL or GH adenoma.