Radioimmunotherapy with alpha-particle emitters: microdosimetry of cells with a heterogeneous antigen expression and with various diameters of cells and nuclei.
Intercellular variations in the level of antigen expression and in cellular and nuclear radii were taken into account in a model used to estimate cell survival for an in vitro experiment with antibodies containing alpha-particle emitters that target the cell surface. Using measured variations in these characteristics for cells of two human cancer cell lines, the model gave results for cell survival and the fundamental parameter of radiation sensitivity, z(0), that differ substantially from those obtained using only mean values. The cell survival may be underestimated by a factor of 100 if only mean values of these cellular parameters are used, and calculated values of z(0) may be overestimated by a factor of 2. Most of this effect stems from the variation in antigen expression. The magnitudes of the differences were found to be a function of the fractions of mean specific energy delivered by surrounding activity and by activity bound to the cells.
Kvinnsland
Y
Y
Department of Nuclear Medicine, The Norwegian Radium Hospital, 0310, Norway.
Stokke
T
T
Aurlien
E
E
D000512:Alpha Particles / Q000627:therapeutic use*; D018951:Antigens, CD20 / Q000032:analysis; D000951:Antigens, Neoplasm / Q000032:analysis*; D001859:Bone Neoplasms / Q000276:immunology / Q000473:pathology; D002051:Burkitt Lymphoma / Q000276:immunology / Q000473:pathology; D002467:Cell Nucleus / Q000528:radiation effects / Q000648:ultrastructure; D048429:Cell Size; D002470:Cell Survival / Q000528:radiation effects; D004735:Energy Transfer; D005434:Flow Cytometry; D006801:Humans; D008954:Models, Biological; D012516:Osteosarcoma / Q000276:immunology / Q000473:pathology; D010446:Peptide Fragments / Q000032:analysis; D016499:Radioimmunotherapy; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D013946:Thymopoietins / Q000032:analysis; D014407:Tumor Cells, Cultured / Q000276:immunology / Q000528:radiation effects / Q000648:ultrastructure
D018951:Antigens, CD20; D000951:Antigens, Neoplasm; D010446:Peptide Fragments; D013946:Thymopoietins; C051920:splenotritin