Distribution of radioiodinated estramustine binding protein antibody in mice with DU-145 prostate cancer xenograft.
BACKGROUND
Estramustine phosphate (EMP) and estramustine binding protein antibody (EMBP-AB) accumulate in the mouse prostate. The distribution of radioiodinated EMBP-AB in tumor mice was investigated to assess its therapeutic potential against prostate cancer.


METHODS
Mice with DU-145 prostate cancer xenografts received 243 microCi of I-125-labeled EMBP-AB (RI-EMBP-AB). The concentration of activity in different organs was measured 4 h after the injection.


RESULTS
The blood contained 0.45% of the injected dose per gram, the prostate 2.4%, the testes 0.95% and the tumor 0.65%. Radioactivity in these organs decreased more rapidly than in other organs. The doses of radiation absorbed by the prostate and the tumor, assuming a 1 mCi injected dose, were 1.81 and 0.92 cGy, respectively.


CONCLUSIONS
Most other organs would receive relatively high doses of radioactivity, were I-125 to be used in therapeutic doses. Therefore, RI-EMBP-AB is not beneficial in radionuclide treatment as compared to possible EMP applications.
Ståhlberg
Kaarlo
K
Department of Urology, Helsinki University Central Hospital, Helsinki, Finland. kaarlo.stahlberg@hus.fi
Kairemo
Kalevi
K
Karonen
Sirkka-Liisa
SL
Taari
Kimmo
K
Rannikko
Sakari
S
D000818:Animals; D000906:Antibodies / Q000276:immunology / Q000378:metabolism; D045744:Cell Line, Tumor; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D000922:Immunotoxins / Q000493:pharmacokinetics* / Q000494:pharmacology; D007457:Iodine Radioisotopes / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism*; D029584:Prostatic Secretory Proteins / Q000276:immunology*; D011877:Radionuclide Imaging; D014018:Tissue Distribution; D014183:Transplantation, Heterologous
D000906:Antibodies; D000922:Immunotoxins; D007457:Iodine Radioisotopes; D029584:Prostatic Secretory Proteins; C028321:estramustine-binding protein