Hyperthermia as a safe and effective cancer treatment modality is rapidly evolving propelled by widespread research and clinical efforts worldwide. Presentations on Hyperthermia experience are now commonplace at Oncology meetings, as are congresses dedicated entirely to the intertwined interactions between basic sciences and patient treatment that together are forming the structure of a new medical specialty. Such was the XII International Symposium on Clinical Hyperthermia held in Rome, Italy, April 27 - 29, 1989. Papers presented therein constitute the backbone of this book. Biology research has provided data describing mechanisms of action for the cancer cell killing and physiological effects of Hyperthermia. Physics research has led to the development of equipment enabling treatment of many areas of the human body, as well as explained the limitations that still constrain our ability to treat, especially in the areas of deep seated tumor heating and non-invasive thermometry. The main question that will decide the future of this modality is that of its clinical use. To put it succinctly, what do we do with this potentially useful tool in an everyday clinical oncological practice . -- ? This is the main question addressed in this book as "Consensus on Hyperthermia for the 1990s. " The book in- cludes 28 presented papers and 25 invited chapters from some of the leading experts in the field. Their basic mechanisms of action were physics principles, treatment quality assurance and especially, clinical indications.