Hyperthermia-induced morphological changes in cerebral tissue of the rat.

The sensitivity of cerebral tissue to hyperthermia, its immediate effect, manifested by histological changes and the role of local blood flow, blood rheological properties, and the possible role of free radicals in development of mentioned changes have been studied. Through the cranial window local area of cerebral surface was irrigated by artificial CSF heated up to 41, 43 or 45 degrees C. Serial brain coronal sections 50 microm thick were analyzed under light microscope.

Heating characteristics of the TRIPAS hyperthermia system for deep seated malignancy.

A deep heating hyperthermia device TRIPAS (a triapplicator system) consisting of three independent, dielectrically loaded horn applicators operating in phase at 300 MHz was investigated. The heating characteristics produced by this hyperthermia system were analyzed by means of thermochromic liquid-crystal cards and a modified CDRH (Center for Devices and Regulatory Health) elliptical phantom. Both homogenous and inhomogeneous phantoms were used, simulating high and low permittivity tissues (muscle and lung).

TRIPAS: a triapplicator system with relocatable 'hot spot' at tissue depth.

Solving the problem of heat focusing and standardization of the clinical application of hyperthermia requires a mathematical prediction model. The model should include the medium constitutive parameter, and be able to predict positioning of the microwave applicators to optimize treatment planning and provide for reproducible treatment set-up. We present a configuration of 3 applicators subtended by an equilateral triangle in order to target and relocate a 'hot spot' for improved treatment of deep tumors.