Die Strahlenbiologie hat sich von einem Forschungszweig, mit dem sich noch vor wenigen J ahrzehnten nur die Strahlentherapeuten und vereinzelte Biologen beschaftigten, zu einem Arbeitsgebiet entwickelt, das die gesamte Medizin und weiteste Gebiete der Biologie interessieren muB. Auf dem Gebiet der Radiologie wird die Radiobiologie von zwei verschiedenen Richtungen gefOrdert. Einerseits - hier ist der Ursprung dieser vVissenschaft zu suchen - ergeben sich aus der klinischen Beobachtung Fragestellungen, die man auf experimentellem \Veg zu beantworten versucht. Andererseits bearbeitet eine besondere Gruppe von Biologen, die vornehmlich die ionisierende Strahlung als Instru ment benutzt, ihre Probleme. Beide Gebiete haben enge Verbindung, sollten sich gegen seitig fOrdern und konnen auch vereint, sogar durch dieselbe Person, ihre praktische Auswirkung erfahren. Zuerst haben die Radiologen ihre mannigfaltigen Probleme selbst aufzuklaren versucht. Mit zunehmender Verbesserung und Verfeinerung der Methode hat sich im Rahmen der Radiologie die besondere Arbeitsrichtung der Radiobiologie ausgesondert, die heute zum Teil eigene Wege geht. Die Radiobiologie gewinnt fur die Strahlentherapie immer mehr an Bedeutung, so daB man versucht ist, die Hoffnung auszudrucken, daB die Radiobiologie berufen sein wird, die Radiotherapie aus der empiri schen Sphare in eine exakt fundierte zu fum'en. In noch starkerem MaB hat sich auf dem Gebiet der Radiodiagnostik die Situation gewandelt. Ohne grundliche radiobiologische Kenntnisse kann die Anwendung ionisierender Strahlen fUr Untersuchungszwecke heute nicht mehr verantwortet werden. Die Nuclearmedizin vereinigt auf radiobiologischem Gebiet die Forderungen, die fur Radiotherapie und -diagnostik aufgestellt wurden.

Advances in Radiation Biology, Volume 9, provides an overview of the state of knowledge in radiation biology. The book contains nine chapters and begins with a study on the ways in which physical and chemical agents might trigger "regulatory dysfunction" and how these agents might interact with each other. This is followed by separate chapters on the mechanisms underlying changes in vascular function after doses of radiation in the therapeutic range and their role in the development of late effects in normal tissues; the future of hypoxic cell sensitizers in the clinical setting; DNA strand break formation by ionizing radiation; and major pathways which result in radiation-induced loss of cellular proliferative capacity. Subsequent chapters deal with the solid-state radiation chemistry of DNA; radiosensitivity of proliferating mammalian cells; the use of microwave/radiofrequency energy cancer treatment; and the decline of basic radiobiology.

What is biophysics? As with all subjects which straddle traditional boundaries between fields, it eludes a precise definition. Furthermore, it is impossible to do biophysics without having a certain foundation of knowledge in biology, physics, physical chemistry, chemistry and biochemistry. One approach to a biophysics textbook would be to refer the student to the literature of these neighboring fields, and to leave the selection of the appropriate supplementary material up to the student. The editors of this volume are of the opinion that it is more useful and less time-consuming to present a selection of the supplementary knowledge, in concentrated form, together with the subject matter specific to biophysics. The reader will thus find in this book introductions to such subjects as the structure and function of the cell, the chemical structure of biogenic macromolecules, and even theoretical chemistry. What, indeed, is biophysics? Must we consider it to include physiology, electromedicine, radiation medicine, etc. ? The field has evolved continuously in recent years. Molecular understanding oflife processes has come more and more to the fore. Just as the field of molecular physics has developed to describe structures and processes in the realm of non-living systems, there has been a corresponding development of molecular biophysics.

The biologic effects of radiation on normal tissues and tumors represent a complex area for investigation. These effects are of far-reaching consequence to the diagnostic radiologist and the radiation oncologist having a significant impact not only in concepts relative to radiation protection but also in concepts relative to tumor biology and its response to radiation injury. The volume edited by SCHERER, STREFFER, and TROTT represents an extension of basic radiation biology data into the effects of radiation in producing pathology in organs and tissues. The data presented by the multiple authors involved in this text cover essentially all tissues in the body with specific definition of radiopathology changes and their impact on clinical care of the patient. This volume represents an important and significant contribution toward a better understanding of these effects and the pathology produced by radiations. L. W. BRADY H.-P. HEILMANN F. HEUCK M. W. DONNER Philadelphia Hamburg Stuttgart Baltimore Preface This book represents an attempt to describe the clinical radiobiology of complications arising in different organs after radiotherapy of cancer patients. Since by their very nature malignant tumors infiltrate the organ in which they have arisen and the neighboring tissues, curative radiotherapy requires the planned irradiation of considerable amounts of healthy but potentially or microscopically involved normal tissues and organs with the full target dose. This may lead to early or late normal tissue radiation injury.

Human health as well as aquatic and terrestrial ecosystems are threatened from increa sing levels of environmental radiation of various sources, many of them of anthropoge nic causality: large areas of the former Soviet Union suffer from radioactive pollution, in particular after the Chemobyl accident; the increase in the incidence of UVB radiati on at the Earth's surface as a result of a progressive depletion of stratospheric ozone is a global problem that requires international concerted actions; in areas of former uranium mining the natural radiation level is substantially increased due to elevated radon levels; a growing portion of the population involved in air traffic is exposed to increased levels of natural radiation; and with the International Space Station an increasing number of astronauts will be exposed to the complex field of cosmic radiation. To estimate the corresponding risks, a better knowledge of the underlying radiobiological mechanisms at the molecular, cellular and system level is required. This book is the result of a multidisciplinary effort to discuss the current state of knowledge of the fundamental processes that result from interactions of environmental radiation -ionizing as well as UV radiation -with living matter and the existing radiati on protection concepts, and then to define future research work needed as fundamental information for the assessment of risks from increased levels of environmental radiation to human health and ecosystem balance. It comprises the key lectures and statements presented at the NATO Advanced Research Workshop.