Tumour microcirculation as a target for XXXX .

@entity1 @entity455 @entity39 @entity5 @entity221 @entity4095
A great number of investigators have, independently, shown that @entity5 blood flow is affected by a hyperthermic treatment to a larger extent than normal tissue blood flow. While the majority of the studies on experimental @entity5 show a decrease and even a lapse in blood flow within the microcirculation during or after @entity221 , the data on @entity1 @entity5 are less conclusive. Some of the investigators do not find a decrease in circulation, while others do. Obviously, this is an important field of investigation in the clinical application of @entity221 because a shut down of the circulation would not only facilitate @entity5 heating (by reducing venous outflow, this reducing the 'heat clearance' from the @entity5 ), but would also facilitate @entity5 cell destruction. The same holds for alterations that occur subsequently to the circulatory changes, like a heat-induced decrease of tissue @entity4095 and pH. If the frequently reported circulatory collapse of the @entity5 circulation could selectively be stimulated by, e.g. acidification or by vasoactive agents, hyperthermic treatment of @entity1 would possibly be greatly facilitated and intensified. In hyperthermic @entity5 therapy a number of complex processes and interactions takes place, especially when the treatment is performed in combination with radiation therapy. One of them represents the group of processes related to the random probability of cell sterilization of individual @entity5 cells resulting in exponential survival curves which are typically evaluated with e.g. cell survival assays. This aspect has not been the issue of this paper. The other group of processes deals with the heat-induced changes in the micro-physiology of @entity5 and normal tissues which, as discussed before, may not only enhance the exponential cell kill, but which may also culminate in @entity455 with the ensuing @entity39 of the @entity5 tissue in the areas affected. If this takes place, a process of bulk killing of @entity5 cells results, rather than the random type of cell sterilization. At present it is not clear to what extent the various separate mechanisms contribute to the total effect of @entity5 control. With all these considerations in mind, one should be aware of the fact that effects, secondary to heat-induced @entity455 alone will never be efficient enough to eliminate all @entity5 cells, even though a heat reservoir is created. This is so because some malignant cells will inevitably have already infiltrated normal, surrounding structures and will therefore not be affected by changes in the @entity5 vascular bed.(ABSTRACT TRUNCATED AT 400 WORDS)
