Quantitative and Qualitative Intrapatient Comparison of 68Ga-DOTATOC and 68Ga-DOTATATE: Net Uptake Rate for Accurate Quantification
Open Access
- 30 December 2013
- journal article
- clinical trial
- Published by Society of Nuclear Medicine in Journal of Nuclear Medicine
- Vol. 55 (2), 204-210
- https://doi.org/10.2967/jnumed.113.126177
Abstract
Quantitative imaging and dosimetry are crucial for individualized treatment during peptide receptor radionuclide therapy (PRRT). 177Lu-DOTATATE and 68Ga-DOTATOC/68Ga-DOTATATE are used, respectively, for PRRT and PET examinations targeting somatostatin receptors (SSTRs) in patients affected by neuroendocrine tumors. The aim of the study was to quantitatively and qualitatively compare the performance of 68Ga-DOTATOC and 68Ga-DOTATATE in the context of subsequent PRRT with 177Lu-DOTATATE under standardized conditions in the same patient as well as to investigate the sufficiency of standardized uptake value (SUV) for estimation of SSTR expression. Methods: Ten patients with metastatic neuroendocrine tumors underwent one 45-min dynamic and 3 whole-body PET/CT examinations at 1, 2, and 3 h after injection with both tracers. The number of detected lesions, SUVs in lesions and normal tissue, total functional tumor volume, and SSTR volume (functional tumor volume multiplied by mean SUV) were investigated for each time point. Net uptake rate (Ki) was calculated according to the Patlak method for 3 tumors per patient. Results: There were no significant differences in lesion count, lesion SUV, Ki, functional tumor volume, or SSTR volume between 68Ga-DOTATOC and 68Ga-DOTATATE at any time point. The detection rate was similar, although with differences for single lesions in occasional patients. For healthy organs, marginally higher uptake of 68Ga-DOTATATE was observed in kidneys, bone marrow, and liver at 1 h. 68Ga-DOTATOC uptake was higher in mediastinal blood pool at the 1-h time point (P = 0.018). The tumor-to-liver ratio was marginally higher for 68Ga-DOTATOC at the 3-h time point (P = 0.037). Blood clearance was fast and similar for both tracers. SUV did not correlate with Ki linearly and achieved saturation for a Ki of greater than 0.2 mL/cm3/min, corresponding to an SUV of more than 25. Conclusion: 68Ga-DOTATOC and 68Ga-DOTATATE are suited equally well for staging and patient selection for PRRT with 177Lu-DOTATATE. However, the slight difference in the healthy organ distribution and excretion may render 68Ga-DOTATATE preferable. SUV did not correlate linearly with Ki and thus may not reflect the SSTR density accurately at its higher values, whereas Ki might be the outcome measure of choice for quantification of SSTR density and assessment of treatment outcome.This publication has 33 references indexed in Scilit:
- Nuclear medicine imaging of neuroendocrine tumoursClinical Medicine, 2012
- Gallium-68 somatostatin receptor PET/CT: Is it time to replace 111Indium DTPA octreotide for patients with neuroendocrine tumors?Endocrine, 2012
- THERANOSTICS: From Molecular Imaging Using Ga-68 Labeled Tracers and PET/CT to Personalized Radionuclide Therapy - The Bad Berka ExperienceTheranostics, 2012
- Cost comparison of 111In-DTPA-octreotide scintigraphy and 68Ga-DOTATOC PET/CT for staging enteropancreatic neuroendocrine tumoursEuropean Journal of Nuclear Medicine and Molecular Imaging, 2011
- Functional imaging in phaeochromocytoma and neuroblastoma with 68Ga-DOTA-Tyr3-octreotide positron emission tomography and 123I-metaiodobenzylguanidineEuropean Journal of Nuclear Medicine and Molecular Imaging, 2011
- 68Ga-DOTA-TATE PET vs. 123I-MIBG in Identifying Malignant Neural Crest TumoursMolecular Imaging & Biology, 2010
- The Role of 68Ga-DOTATATE PET in Patients with Neuroendocrine Tumors and Negative or Equivocal Findings on 111In-DTPA-Octreotide ScintigraphyJournal of Nuclear Medicine, 2010
- Bone Metastases in Patients with Neuroendocrine Tumor: 68Ga-DOTA-Tyr3-Octreotide PET in Comparison to CT and Bone ScintigraphyJournal of Nuclear Medicine, 2009
- Comparison between 68Ga-DOTA-NOC and 18F-DOPA PET for the detection of gastro-entero-pancreatic and lung neuro-endocrine tumoursEuropean Journal of Nuclear Medicine and Molecular Imaging, 2008
- Functional imaging of neuroendocrine tumors with combined PET/CT using 68Ga‐DOTATATE (DOTA‐DPhe1,Tyr3‐octreotate) and 18F‐FDGCancer, 2008