Thus, polar compounds cannot enter the brain but can enter the interstitial fluids of most other tissues.

For obtaining the distribution of absorbed dose in tumor and surrounding tissues after implant of seeds, the software, Interstitial Treatment Planning System of seeds (ITPSS 1.0) was programmed.

Note also that the inflammatory infiltrates of chronic inflammation are more likely to be interstitial (within tissues) rather than exudative (above surfaces or in spaces) like acute inflammation.