RT Journal Article
SR Electronic
T1 Inflammation-Based Index and <sup>68</sup>Ga-DOTATOC PET–Derived Uptake and Volumetric Parameters Predict Outcome in Neuroendocrine Tumor Patients Treated with <sup>90</sup>Y-DOTATOC
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1014
OP 1020
DO 10.2967/jnumed.119.236935
VO 61
IS 7
A1 Elin Pauwels
A1 Sofie Van Binnebeek
A1 Vincent Vandecaveye
A1 Kristof Baete
A1 Hubert Vanbilloen
A1 Michel Koole
A1 Felix M. Mottaghy
A1 Karin Haustermans
A1 Paul M. Clement
A1 Kristiaan Nackaerts
A1 Eric Van Cutsem
A1 Chris Verslype
A1 Christophe M. Deroose
YR 2020
UL http://jnm.snmjournals.org/content/61/7/1014.abstract
AB We performed post hoc analyses on the utility of pretherapeutic and early interim 68Ga-DOTATOC PET tumor uptake and volumetric parameters and a recently proposed biomarker, the inflammation-based index (IBI), for peptide receptor radionuclide therapy (PRRT) in neuroendocrine tumor (NET) patients treated with 90Y-DOTATOC in the setting of a prospective phase II trial. Methods: Forty-three NET patients received up to 4 cycles of 90Y-DOTATOC at 1.85 GBq/m2/cycle with a maximal kidney biologic effective dose of 37 Gy. All patients underwent 68Ga-DOTATOC PET/CT at baseline and 7 wk after the first PRRT cycle. 68Ga-DOTATOC–avid tumor lesions were semiautomatically delineated using a customized SUV threshold–based approach. PRRT response was assessed on CT using RECIST 1.1. Results: Median progression-free survival and overall survival (OS) were 13.9 and 22.3 mo, respectively. An SUVmean higher than 13.7 (75th percentile) was associated with better survival (hazard ratio [HR], 0.45; P = 0.024), whereas a 68Ga-DOTATOC–avid tumor volume higher than 578 cm3 (75th percentile) was associated with worse OS (HR, 2.18; P = 0.037). Elevated baseline IBI was associated with worse OS (HR, 3.90; P = 0.001). Multivariate analysis corroborated independent associations between OS and SUVmean (P = 0.016) and IBI (P = 0.015). No significant correlations with progression-free survival were found. A composite score based on SUVmean and IBI allowed us to further stratify patients into 3 categories with significantly different survival. On early interim PET, a decrease in SUVmean of more than 17% (75th percentile) was associated with worse survival (HR, 2.29; P = 0.024). Conclusion: Normal baseline IBI and high 68Ga-DOTATOC tumor uptake predict better outcome in NET patients treated with 90Y-DOTATOC. This method can be used for treatment personalization. Interim 68Ga-DOTATOC PET does not provide information for treatment personalization.