DOSIMETRIC EVALUATION OF IMMUNOSCINTIGRAPHY USING INDIUM-111-LABELED MONOCLONAL-ANTIBODY FRAGMENTS IN PATIENTS WITH OVARIAN-CANCER

This study reports the biodistribution and dosimetry for a monoclonal antibody against ovarian carcinoma. Eight patients received 140 MBq In-111-OV-TL 3 F(ab')2; thereafter gamma camera imaging was performed daily up to 96 hr. By using the conjugated view counting method, activity in the organs was quantitated by phantom calibration and by whole-body measurements using a whole-body counter with the conjugated view counting method. Red bone marrow uptake was derived from regions of interest over the lumbar vertebrae and iliac crest. In both methods, organ uptake varied only slightly with time, having a mean value of approximately 18%, 4%, 6% and 17% of the injected dose in the liver, spleen, kidneys and red bone marrow, respectively. The mean radiation dose to these organs was 0.9, 1.5, 1.2 and 0.5 mGy/MBq. The effective dose equivalent was 0.4 mSv/MBq. In this study, two different methods of uptake calculations, result in similar values of organ uptake.