IMMEDIATE CHANGES IN SUBCELLULAR STRUCTURES OF TRANSPLANTED TUMORS FOLLOWING PHOTODYNAMIC AND LASER HYPERTHERMIC THERAPY

Background and Objective: To further understand the precise process of the tumor cell degeneration after photodynamic therapy (PDT), laser h yperthermic therapy (LH), and combined treatments using an Nd:YAG lase r. It is important to examine initial morphological alteration of tumo r cells after these treatments. Study Design/Materials and Methods: In this study, nude mice bearing HeLa cell tumors were treated with PDT, LH, and combined treatments of the two. Tumor tissues obtained immedi ately after these treatments were analyzed using electron microscopy a nd morphometry. Results: In the combined treatments, which produced mo re severe effects on tumor cells, morphological features of apoptosis such as cytoplasmic condensation, blebs, and apoptotic bodies appeared in the cells, although the typical alteration in the nuclear chromati n was not seen. Conclusion: Cytoplasmic alterations may proceed more r apidly than nuclear alterations in the cellular degeneration induced b y the single or combined treatments of PDT and LH. (C) 1995 Wiley-Liss , Inc.