Tumor Response and Clinical Benefit in Neuroendocrine Tumors After 7.4 GBq 90Y-DOTATOC

The aim of this prospective phase II study was to evaluate the tumor response of neuroendocrine tumors to high-dose tar-geted irradiation with 7.4 GBq/m2 of the radiolabeled soma-tostatin analog 90Y-1,4,7,10-tetra-azacyclododecan-4,7,10-tri-carboxy-methyl-1-yl-acetyl-D-Phe-Tyr3-octreotide (DOTATOC). In addition, we investigated the clinical benefit of 90Y-DOTATOC regarding the malignant carcinoid syndrome and tumor-associ-ated pain. Methods: Thirty-nine patients (mean age, 55 y) with progressive neuroendocrine gastroenteropancreatic and bron-chial tumors were included. The treatment consisted of 4 equal intravenous injections of a total of 7.4 GBq/m2 90Y-DOTATOC, administered at intervals of 6 wk. After each treatment cycle, a standardized clinical benefit assessment using the National Cancer Institute grading criteria (NCI-CTC) was performed. Re-sults: The objective response rate according to World Healt