RESEARCH ARTICLE Dosimetry results suggest feasibility of radioimmunotherapy using anti-CD138 (B-B4) antibody in multiple myeloma patients Caroline Rousseau & Ludovic Ferrer & Stéphane Supiot & Manuel Bardiès & François Davodeau & Alain Faivre-Chauvet & Pierre Baumgartner & John Wijdenes & Marie Lacombe & Jacques Barbet & Thierry Guillaume & Philippe Moreau & Jean Luc Harousseau & Françoise Kraeber-Bodéré & Michel Cherel Received: 29 November 2011 / Accepted: 13 February 2012 / Published online: 3 March 2012 # International Society of Oncology and BioMarkers (ISOBM) 2012 Abstract Syndecan-1 (CD138), a heparan sulfate proteo- glycan, is constantly expressed on tumor cells in multiple myeloma (MM). This surface antigen is an attractive candi- date for targeted therapy, especially radioimmunotherapy (RAIT). We report preliminary biodistribution and dosime- try results obtained in refractory MM patients in a phase I/II RAIT study using iodine-131-labeled anti-CD138 (B-B4) monoclonal antibody (mAb). Four patients with progressive disease were enrolled after three lines of therapy. They received 370 MBq (20 mg/m 2) of 131 I-B-B4 for the dosim- etry study. Each patient underwent a whole body (WB) CT and four WB emission scans at days D0, D1, and D3–4. Images were corrected for attenuation and scatter to assess doses absorbed by organs and bone marrow (BM). Blood and urine samples were additionally collected. Dosimetry was conducted using the MIRD method. Images obtained 1 h after 131 I-B-B4 injection showed high BM and liver uptake without kidney uptake. The BM uptake confirmed BM involvement as detected by pre-inclusion FDG PET/CT. Absorbed doses were calculated at 2.03±0.3 mGy/MBq for the liver, 1.10±0.9 mGy/MBq for the kidneys, and 0.52± 0.20 mGy/MBq for the BM. Grade III thrombocytopenia C. Rousseau (*) : P. Baumgartner : M. Lacombe : F. Kraeber-Bodéré : M. Cherel Nuclear Medicine Department, Comprehensive Cancer Center ICO Gauducheau, IRCNA, Saint Herblain, France e-mail: caroline.rousseau@ico.unicancer.fr C. Rousseau : L. Ferrer : S. Supiot : M. Bardiès : F. Davodeau : A. Faivre-Chauvet : J. Barbet : F. Kraeber-Bodéré : M. Cherel Cancer Research Center CRCNA, Nantes University, INSERM UMR 892, Nantes, France L. Ferrer Medical Physics Department, Comprehensive Cancer Center ICO Gauducheau, IRCNA, Saint Herblain, France S. Supiot Radiotherapy Department, Comprehensive Cancer Center ICO Gauducheau, IRCNA, Saint Herblain, France A. Faivre-Chauvet : F. Kraeber-Bodéré Nuclear Medicine Department, University Hospital, Nantes, France J. Wijdenes Diaclone, Besancon, France T. Guillaume : P. Moreau : J. L. Harousseau Hematology Department, University Hospital, Nantes, France J. L. Harousseau Comprehensive Cancer Center ICO Gauducheau, IRCNA, Saint Herblain, France Tumor Biol. (2012) 33:679–688 DOI 10.1007/s13277-012-0362-y