We will focus on the eects of hyperthermia treatment in the temperature range of 39-42°C, because it is in this temperature range that profound physiologic eects occur in tumors that can mediate improvements in drug delivery (Song et al. 2001) (Figure 16.1). ere are literally dozens of reports showing that temperatures in this range increase tumor perfusion, oxygenation, and vascular permeability (Dewhirst et al. 2005,
Song 1984). e ecacy of many drugs is limited by hypoxia, so any treatment that improves tumor oxygenation is also likely to improve the ecacy of chemotherapy (Brown and Wilson 2004). When temperatures are elevated further, however, hyperthermia can cause vascular damage, which would impede drug delivery (Song et al. 2001). ere are circumstances where thermal ablative therapy has been combined with liposomal drugs, which will be discussed later in more detail. However, even in this situation, the addition of liposomal drugs is designed to take advantage of vascular changes at the edge of the ablation zone, which again is in the mild hyperthermia temperature range (Ahmed and Goldberg 2004, Mostafa et al. 2008, Poon and Borys 2009).