RADIOIMMUNOSCINTIGRAPHY IN PATIENTS WITH BREAST ADENOCARCINOMA USING TC-99M LABELED MONOCLONAL-ANTIBODY 170H.82 - REPORT OF A PHASE-II STUDY

Fifty-three women with clinical evidence of adenocarcinoma of the brea st were studied with technetium-99m labelled monoclonal antibody (MAb) 170H.82 at protein doses of 1, 2 and 4 mg. An overall per lesion effi cacy of 83.5% sensitivity and 97.7% positive predictive value was obta ined, Efficacy appears higher in lesions restricted to the breast and local regional disease than systemic metastases. For the 2 mg dose the breast/local regional disease efficacy was 90% sensitivity and 90.2% positive predictive value. The biodistribution of this MAb was best re presented by a two-compartment model with a distribution-phase half-li fe of 4.0 +/- 1.4 h, followed by an elimination-phase half-life of 39. 6 +/- 6.6 h. In all six patients studied, the critical organ was the k idney, with a mean radiation absorbed dose of 37 +/- 6.9 mGy/GBq, The accuracy of this imaging technique allows the development of diagnosti c strategies for the routine use of the compound in patients with brea st cancer.