Abstract
Objective: To identify a reliable early indicator of deriving progression-free survival (PFS) benefit in patients with advanced gastroenteropancreatic neuroendocrine tumors (GEP-NETs) treated with octreotide long-acting repeatable (LAR). Methods: We investigated the images of 50 patients with well-differentiated advanced GEP-NETs treated with LAR octreotide and underwent baseline and follow-up thoracic, abdominal, and pelvic computed tomography. Receiver-operating characteristic (ROC) analysis and the Kaplan-Meier method were used to identify the optimal threshold to distinguish between those with and without significant improvement of PFS. Results: The optimal threshold for determining a response to octreotide LAR was -10% ΔSLD, with a sensitivity and specificity of 85.7% and 80%, respectively. At this threshold, 19 patients were responders and 31 were non-responders; the median PFS was 20.2 and 7.6 months in responders and non-responders (hazard ratio, 2.66; 95% confidence interval, 1.32–5.36). Conclusion: A 10% shrinkage in tumor size is an optimal early predictor of response to octreotide LAR in advanced GEP-NETs. Key points: • Octreotide LAR can significantly prolong PFS among patients with well-differentiated advanced GEP-NETs. • No optimal tumor size-based response criteria are reported in GEP-NETs with octreotide. • Ten percent tumor shrinkage is a reliable indicator of the response to octreotide for advanced GEP-NETs.
Original language | English (US) |
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Pages (from-to) | 5250-5257 |
Number of pages | 8 |
Journal | European Radiology |
Volume | 28 |
Issue number | 12 |
DOIs | |
State | Published - Dec 1 2018 |
Externally published | Yes |
Keywords
- Neuroendocrine tumors
- Octreotide
- Progression-free survival
- Response Evaluation Criteria in Solid Tumors
- Tomography, spiral computed
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging