Antitumor effect of radioactive cisplatin (Pt-191) on nude mice

Purpose: To investigate the effect of Pt-191-cisplatin in vivo in terms of the antitumor effect and general toxicity on tumor-bearing nude mice. Methods and Materials: Tumor-bearing (human squamous cell carcinoma, AB) nu de mice were divided into four groups and given, i.p,, physiological saline (controls), cisplatin, Pt-191-cisplatin (80 MBq/mg), or Pt-191-cisplatin ( 160 MBq/mg), respectively, Mortality and weight were used as parameters for monitoring general toxic effect, while specific growth delay (SGD) and the area under the logarithm of the relative tumor size curve (AUC-log[RTS]) w ere used to evaluate the antitumor effect of the treatments. Results: Both SGD and AUC-log(RTS) values showed that Pt-191-cisplatin was significantly (P < 0.05) more effective in retarding tumor growth than nonr adioactive cisplatin, No differences in mortality between the different gro ups could be observed and no significant differences in weight change betwe en the mice treated with cisplatin or Pt-191-cisplatin could be seen. Conclusion: Pt-191-cisplatin is a more effective drug than nonradioactive c isplatin in retarding tumor growth on nude mice without adding systemic tox ic effects. We believe that radioactive cisplatin may prove to be an altern ative to conventional cisplatin; however, the possible toxic effects on org ans at risk have to be thoroughly investigated. (C) 2001 Elsevier Science I nc.