Concomitant low dose-rate irradiation and cisplatin treatment in ovarian carcinoma cell lines sensitive and resistant to cisplatin treatment.
Human ovarian carcinoma parental and cisplatin-resistant cells were evaluated for their radiation sensitivity to high and low dose-rate irradiation and for the effectiveness of cisplatin in radiosensitization. The cisplatin resistant variant A2780cp showed increased radiation resistance for both low dose-rate (LDRI) and high dose-rate irradiation. For cisplatin treatment for 1 h before and after HDRI there was radiosensitization in only the cisplatin-resistant variant. Concomitant cisplatin treatment during LDRI resulted in radiosensitization in both cell lines with dose-modifying factors ranging from 1.6 to 5.8. In this case greater radiosensitization was achieved in the parental cell line. In both cell lines the dose-modifying factors were larger when the cisplatin was refreshed every 6 h instead of 12 h during LDRI. These data show that cisplatin may be a very effective radiosensitizer when given during LDRI which is used in brachytherapy.
Raaphorst
G P
GP
Medical Physics Department, Ottawa Regional Cancer Center, Ontario, Canada.
Wang
G
G
Stewart
D
D
Ng
C E
CE
D000970:Antineoplastic Agents / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002945:Cisplatin / Q000494:pharmacology*; D003131:Combined Modality Therapy; D004351:Drug Resistance; D005260:Female; D006801:Humans; D010051:Ovarian Neoplasms / Q000473:pathology / Q000628:therapy*; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D002945:Cisplatin