6533b7d0fe1ef96bd125a1f5

RESEARCH PRODUCT

Direct Measurement of Reoxygenation in Malignant Mammary Tumors after a Single Large Dose of Irradiation

subject

description

Due to functional and morphological abnormalities of the terminal vascular bed in malignant tumors, a severe restriction of convective transport occurs even in very early growth stages. This leads to nutritional deprivation of the cancer cells and to unfavourable cellular microenvironments as well. During advanced tumor growth stages, the nutritional deprivation and the milieu conditions get worse because pronounced deterioration of diffusive transport is superimposed on the insufficient blood supply. This transport limitation is mainly caused by increases of intercapillary distances and by decreases of vascular surface areas per unit tissue volume. Moreover, these peculiarities of the tumor microcirculation are randomly spread over the whole tumor mass. Besides these spatial inhomogeneities, temporal heterogeneities of the supply conditions are also evident in tumors (for a review see Vaupel et al., 1981)