Peptide receptor radionuclide therapy for neuroendocrine tumors in Germany: Initial results of a multiinstitutional cancer registry.

e14513 Background: Peptide receptor radionuclide therapy is an effective treatment option for patients with well differentiated somatostatin receptor expressing neuroendocrine tumors. However, published data results mainly from retrospective monocentric studies. Methods: We initiated a multi-institutional, prospective and board reviewed registry for patients treated with Peptide receptor radionuclide therapy in Germany in 2009. Results: In five centers, 297 patients were registered. Primary tumors were mainly derived from pancreas (117/297), small intestine (80/297) whereas 56 were of unknown primary. Most tumors were well differentiated with a median Ki67 proliferation rate of 5% (range 0.9 to 70). Peptide receptor radionuclide therapy was performed using mainly Yttrium-90 and/or Lutetium-177 as radionuclides in 1-8 cycles. Mean overall survival was estimated at 213 months with a follow up between 1 and 230 months after initial diagnosis and 87 months with a follow up between 1 and 92 months after start of Peptide receptor radionuclide therapy. Median overall survival was not yet reached. Subgroup analysis demonstrated that best results were obtained in neuroendocrine tumors with a proliferation rate below 20%. Conclusions: Our results indicate that Peptide receptor radionuclide therapy is an effective treatment well and moderately differentiated neuroendocrine tumors irrespective of previous therapies and should be regarded a one of the primary treatment options for patients with neuroendocrine tumors.