⁶⁸Ga-DOTATATE PET/CT versus ¹¹¹In-octreotide scintigraphy in patients with neuroendocrine tumors: a prospective study

To compare ⁶⁸Ga-DOTA-DPhe1,Tyr3-octreotate (⁶⁸Ga-DOTATATE) positron-emission tomography/computed tomography (PET/CT) findings with those of conventional ¹¹¹In-octreotide scintigraphy in patients with neuroendocrine tumors (NETs).

This was a single-center prospective study including 41 patients (25 males; mean age, 55.4 years) with biopsy-proven NETs who underwent whole-body ¹¹¹In-octreotide scintigraphy and whole-body ⁶⁸Ga-DOTATATE PET/CT. The patients had been referred for tumor staging (34.1%), tumor restaging (61.0%), or response evaluation (4.9%). Images were compared in a patient-by-patient analysis to identify additional lesions, and we attempted to determine the impact that discordant findings had on treatment planning.

Compared with ¹¹¹In-octreotide scintigraphy, ⁶⁸Ga-DOTATATE PET/CT revealed more lesions, the additional lesions typically being in the liver or bowel. Changes in management owing to the additional information provided by ⁶⁸Ga-DOTATATE PET/CT occurred in five patients (12.2%), including intermodal changes in three (7.3%) and intramodal changes in two (4.9%). In addition, ⁶⁸Ga-DOTATATE PET/CT yielded incidental findings unrelated to the primary NET in three patients (7.3%): Hürthle cell carcinoma of the thyroid, bowel non-Hodgkin lymphoma, and a suspicious breast lesion.

We conclude that ⁶⁸Ga-DOTATATE PET/CT is superior to conventional ¹¹¹In-octreotide scintigraphy for the management of NETs because of its ability to determine the extent of the disease more accurately, which, in some cases, translates to changes in the treatment plan.