Y Radioembolization in the Treatment of Neuroendocrine Neoplasms: Results of an International Multicenter Retrospective Study.

In neuroendocrine neoplasms (NENs), the presence of distant metastases has a severe impact on survival leading to a relevant decrease in the 5-y survival rate. Here, Y radioembolization (Y RE) might be an important treatment option; however, data to support clinical benefits for Y RE are scarce. Therefore, the purpose of this study was to analyze the use of Y RE in NEN patients with hepatic metastases in an international, multicenter retrospective analysis and assess the potential role of Y RE in a multimodal treatment concept. In total, 297 angiographic evaluations in NEN patients before Y RE were analyzed. Baseline characteristics and parameters derived from imaging evaluation and Y RE were analyzed. Tumor response was assessed using RECIST 1.1, and survival data were collected. Mean overall survival (OS) between different groups was compared using Kaplan-Meier curves and the log rank test. A value of less than 0.05 indicated statistical significance. After Y RE, the disease control rate according to RECIST 1.1 was 83.5% after 3 mo and 50.9% after 12 mo. OS in the entire population was 38.9 ± 33.0 mo. High tumor grade ( < 0.006) and high tumor burden ( = 0.001) were both associated with a significant decrease in OS. The presence of extrahepatic metastases ( = 0.335) and the type of metastatic vascularization pattern ( = 0.460) had no influence on OS. Patients who received Y RE as second-line therapy had a slightly longer but not statistically significant OS than patients who had Y RE in a salvage setting (44.8 vs. 30.6 mo,  = 0.078). Hepatic and global progression-free survival after Y RE was significantly decreased in heavily pretreated patients, compared with patients with second-line therapy ( = 0.011 and  = 0.010, respectively). Y RE could be an important alternative to peptide receptor radionuclide therapy as second-line treatment in patients with progressive liver-dominant disease pretreated with somatostatin analogs.