Hyperthermia as a supplement to chemotherapy
The interaction of hyperthermia and cytostatic drugs can be independent, additive and synergistic.
The most important mechanisms leading to an interactive effect with cytostatic drugs include an increased intratumoural drug concentration, which is to be attributed to increased blood flow and enhanced permeability of the membrane leading to increased intracellular absorption. In addition, an increased intracellular drug metabolism and an accelerated reaction rate in an increased temperature environment have been demonstrated.
To date it has been shown for a great variety of chemotherapy agents that the combination of chemotherapy with hyperthermia serves to counteract resistance to chemotherapy. Supra-additive cytotoxic effects were observed mainly in combination with alkylating agents and platinum derivatives.
Current research findings are of value that now investigate the optimal intervals between infusion and hyperthermia. For example, with Gemcitabine a 24-hour interval between infusion and application of hyperthermia is the most effective.
(e.g., Joan M.C. Bull, Glenna L. Scott, Frederick R. Strebel, Dwight H. Oliver, Bharat Raval, and Steven M. Koch; The University of Texas Houston Medical School, Houston, TX 77005).