TY - JOUR T1 - Treatment with <sup>177</sup>Lu-DOTATOC of Patients with Relapse of Neuroendocrine Tumors After Treatment with <sup>90</sup>Y-DOTATOC JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1310 LP - 1316 VL - 46 IS - 8 AU - Flavio Forrer AU - Helena Uusijärvi AU - Daniel Storch AU - Helmut R. Maecke AU - Jan Mueller-Brand Y1 - 2005/08/01 UR - http://jnm.snmjournals.org/content/46/8/1310.abstract N2 - Therapy with [90Y-DOTA0, Tyr3]-octreotide (DOTATOC, where DOTA = tetraazacyclododecane tetraacetic acid and TOC = d-Phe-c(Cys-Tyr-d-Trp-Lys-Thr-Cys)-Thr(ol)) is established for the treatment of metastatic neuroendocrine tumors. Nevertheless, many patients experience disease relapse, and further treatment may cause renal failure. Trials with 177Lu-labeled somatostatin analogs showed less nephrotoxicity. We initiated a prospective study with 177Lu-DOTATOC in patients with relapsed neuroendocrine tumors after 90Y-DOTATOC treatment. Methods: Twenty-seven patients, pretreated with 90Y-DOTATOC, were included. The mean time between the last treatment with 90Y-DOTATOC and 177Lu-DOTATOC was 15.4 ± 7.8 mo (SD). All patients were injected with 7,400 MBq of 177Lu-DOTATOC. Restaging was performed after 8–12 wk. Hematotoxicity or renal toxicity of World Health Organization grade 1 or 2 was not an exclusion criterion. Results: Creatinine levels increased significantly, from 66 ± 14 μmol/L to 100 ± 44 μmol/L (P &lt; 0.0001), after 90Y-DOTATOC therapy. The mean hemoglobin level dropped from 131 ± 14 to 117 ± 13 g/L (P &lt; 0.0001) after 90Y-DOTATOC therapy. 177Lu-DOTATOC therapy was well tolerated. No serious adverse events occurred. The mean absorbed doses were 413 ± 159 mGy for the whole body, 3.1 ± 1.5 Gy for the kidneys, and 61 ± 5 mGy for the red marrow. After restaging, we found a partial remission in 2 patients, a minor response in 5 patients, stable disease in 12 patients, and progressive disease in 8 patients. Mean hemoglobin and creatinine levels did not change significantly. Conclusion: 177Lu-DOTATOC therapy in patients with relapse after 90Y-DOTATOC treatment is feasible, safe, and efficacious. No serious adverse events occurred. ER -