UNTERSUCHUNGEN ZUR BIOKINETIK TUMORAFFINER YTTRIUM-ZUBEREITUNGEN - 1. TEIL

Differences of yttrium biokinetics after application to male tumor-bearing mice of ⁸⁷Y-citrate were studied in comparison to a ⁸⁷Y-NTA-EDTMP-Ca mixture after variation of both the manner of application (intraperitoneal vs. intratumoral) and the tumor type (mamma carcinoma vs. melanoma). The application of ⁸⁷Y as NTA-EDTMP-Ca preparation led - in comparison to the citrate form applied so far - to a similar radionuclide tumor accumulation and distinctly lower extratumoral radioactivities in liver, spleen and skeleton with clearly more favorable tumor/background ratios. Melanomas showed a significantly higher radioactivity accumulation (factor 2-3) after injection of ⁸⁷Y-NTA-EDTMP-Ca than mamma carcinomas. Intratumoral application led to high initial radioactivities in the tumors. Radioactivity concentrations which are comparable with those after intraperitoneal application were achieved within 4 h after intratumoral application. The application of the EDTMP-containing mixture promises in comparison to the traditional citrate form higher radiation doses in the tumor related to the whole-body radiation exposure. The consequences for a possible tumor therapy will be further investigated.