The use of lutetium-177 (Lu-177) DOTA rituximab for radioimmunotherapy results in a high rate of tumor response with less radiation than current therapies, wrote lead author Dr. Andreas Lohri, from Kantonsspital Baselland in Switzerland, and colleagues (JNM, July 1, 2013, Vol. 54:7, pp. 1045-1052).
The study included 31 patients with histologically confirmed relapsed or refractory CD20-positive B-cell lymphoma. All patients received an initial dose of Lu-177 DOTA rituximab; doses were increased in steps over a maximum of seven doses, and toxicity was measured weekly up to week 10 or until recovery from the lowest level of blood cell count. Imaging with whole-body CT and FDG-PET or PET/CT was conducted at baseline and again at eight to 12 weeks.
The maximum tolerated dose using Lu-177 DOTA rituximab was 1,665 MBq/m2. Toxicity was mainly hematologic, with thrombocytopenia and leukopenia noted as the dose-limiting toxicities, and nonhematologic toxicity was minor, Lohri's group found.