Cell-Mediated Immune Response in Patients Undergoing Prostatic Hyperthermia

Abstract

The use of hyperthermia (HT) treatment regimes for advanced cancer of the prostate (CaP) and symptomatic benign prostatic hyperplasia (BPH) has now led to the accumulation of considerable clinical experience (Bichler et al. 1992; Perlmutter 1992; Meier et al. 1992), although the mechanisms underlying HT-evoked remissions of prostatic diseases are not known. Most of the HT systems applied at present for the treatment of prostatic disease use various frequencies of microwave (MW) radiation as the source of thermal energy (Perlmutter 1992), with 2450 MHz, 915 MHz, and 434 MHz being most frequently utilized. The MW energy of these frequencies is rapidly absorbed in tissues and effective penetration of 434–2450 MHz MWs to tissues surrounding HT antennas is relatively limited (see Chap. 13). A transurethral (TUHT), 630- or 915-MHz MW applicator described by Astrahan et al. (1989), which wasbuilt of three antennas located in a modified Foley-type catheter, could effectively heat periurethral tissues to a depth of about 0.5–1.0 cm (Chap. 13). When the applicator was installed intraurethrally and the feedback thermoregulation was set at 46°C, a cylindrical volume approximately 4 cm in length and 0.5 cm outward from the catheter was heated from 47°C to 42°C. The temperature gradient was measured as 6°C/cm of prostatic tissue (Astrahan et al. 1991). Similar temperature gradients were registered during transrectal hyperthermia (TRHT) of the prostate with the use of systems and applicators at 2450 MHz (Magin et al. 1980).