Metabolic and receptor imaging in predicting a clinical outcomes for patients (pts) with neuroendocrine tumors: Comparison of FDG-PET with Indium-111 pentetreotide

Abstract

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Objectives: To determine whether FDG-PET and/or Indium-111 Pentetreotide individually or collectively can predict patient outcome.

Methods: 29 patients with previously diagnosed neuroendocrine tumors underwent both FDG-PET and Indium-111 Pentetreotide Imaging between 7/31/02 and 5/4/07. The images were evaluated for presence of abnormality as well as for extent of abnormality.Tumor burden was graded on a 1-4 scale. Clinical outcome determined if the pt was alive or had expired. Time to outcome was measured in months from imaging date to outcome as well as diagnosis date to outcome. Kaplan-Meyer survival curves were calculated based on time to outcomes compared to imaging results with both FDG-PET and Indium-111 Pentetreotide.

Results: 11 subjects had (-)PET and (-)Octreotide(Octreo)scans. Of these 11, all are alive and well.10 pts were(+) on both PET& Octreo. Of these,8 of 10 had expired.5 pts had (+)PET and (-)Octreotide,4 of these 5 pts have expired.3 pts had (+)Octreo & (-)PET with all 3 pts alive. Kaplan-Meyer analysis demonstrated a significant survival difference between subjects who were PET(-) & PET(+) (P =0.0048). Octreo(-)compared with Octreo(+) also demonstrated a higher survival probability (P =0.0082). High tumor burden shortened survival.

Conclusions: Of pts with neuroendocrine tumors, those with (+)FDG-PET studies had a generally poor prognosis and a more rapid clinical deterioration on those with (-)FDG-PET scans.Although the numbers are relatively small, subjects with (+)Pentetreotide scans and (-)PET scans are still living and suggest PET to be the main determinant in determining prognosis and survival times.