Radiosensitization with Chemotherapeutic Agents and Hyperthermia: Effects on Linear-quadratic Parameters of Radiation Cell Survival Curves
- *Corresponding Author:
- Nicolaas A.P. Franken
Department of Radiation Oncology
Laboratory for Experimental Oncology and Radiobiology (LEXOR)
Centre of Experimental Molecular Medicine
Academic Medical Centre
University of Amsterdam P.O.Box 22700
1100 DE Amsterdam, The Netherlands
E-mail: [email protected]
Received Date: November 01, 2011; Accepted Date: December 05, 2011; Published Date: December 07, 2011
Citation: Franken NAP, Hovingh S, Rodermond H, Stalpers L, Barendsen GW, et al. (2011) Radiosensitization with Chemotherapeutic Agents and Hyperthermia: Effects on Linear-quadratic Parameters of Radiation Cell Survival Curves. J Cancer Sci Ther S5:002. doi: 10.4172/1948-5956.S5-002
Copyright: © 2011 Franken NAP, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The radio-sensitizing effects of several chemotherapeutic agents and hyperthermia have been investigated in several animal and human cell culture systems. Cells are first treated with Cisplatin, Gemcitabine, Halogenated pyrimidines or hyperthermia and thereafter irradiated with different dose of radiation up to 8 Gy. After treatment the clonogenic survival was determined and from the survival curves the values of the linear and quadratic parameters were determined using the formula S(D)/S(O)= exp-(αD+βD2).
An increase in the value of the linear parameter, α, was observed in most cases, which corresponds to an enhanced (potentially) direct lethal damage (PLD) at low doses. The quadratic parameter β, which is assumed to depend on the interaction of sublethal lesions (SLD), was rarely affected. Furthermore, it appeared that more radioresistant cell lines were more sensitised than the radiosensitive lines. Furthermore it can be concluded that radiosensitization is also dependent on cell cycle stage like plateau or exponentially growing phase or post treatment plating conditions.