The present challenge in the treatment of tumors is to reduce the number of patients that still die as a result of primary tumors. Today, the percentage of such deaths remains high at 30%, even when all the common therapeutic methods, namely surgery, radiotherapy, and chemotherapy, are applied. In order to reduce this percentage, new types of radiation sources with a higher linear energy transfer have been intro duced, such as neutrons and pions. Fractionation patterns have been modified and radiosensitizers have been applied to in crease biological efficiency. Studies of the combined application of chemotherapy and radiotherapy have been made to find the best therapeutic effect. In the early 1970s biological findings confirmed the effect of hyperthermia on tumor cells. The first clinical studies on hyper thermia treatment demonstrated that it resulted in better local tumor control. Further application of this treatment modality showed that hyperthermia should be used in addition to radio therapy and chemotherapy. Despite these encouraging results, hyperthermia has not been introduced into common clinical use, due primarily to technical problems. There are a number of methods of transferring heat into tumors; however, with regard to physical conditions, an op timum method has not yet been found. One of the reasons is that up to now we have had no reliable method of obtaining thermal mapping of all parts of the human body. Such measurements are required not only for dosimetric purposes but also for the regula tion of a hyperthermic system."

Tumour therapy depends essentially on being able to destroy the clonogenic activity of tumour cells while keeping the damage to the normal tissue low. Clinical experience shows that tumour response varies greatly even if tumours with the same localisation, clinical, and histopathological staging are compared. Some tumours appear to be resistant to conventional radiotherapy (X-rays, y-rays or fast electrons) or chemotherapy. In these cases new therapy modalities are necessary. Combined therapy modalities seem to have advan- tages for some resistant tumours; one possibility of such a treatment is to combine radiotherapy or chemotherapy with hyperthermia. This means that the local tumour, the tumour region or even the whole body of the patient has to be heated to temperatures between 40 to 45 C (in case of whole body hyperthermia to 42 C maximal) for a certain time (usually 30-60 min are adequate). Hyperthermia has a long tradition in medicine as a treatment modality for various diseases. Inscriptions of the old Egyptians and texts of the Greeks have pointed out its importance. Usually whole body hyperthermia has been used by the induction of fever. Local hyperthermia began around 1900 when Westermark treated unre- sectable cervix carcinomas with hot water in a metallic coil. By the beginning of this century an increase of radiation effects was hy- pothesised with hypothermia and later observed. However, only in the 1960s and 1970s were systematic investigations started which showed radiosensitisation and chemosensitisation by hyperthermia in cells and tissues including tumours.

Die lahrestagung der Deutschen Gesellschaft fUr Hiimatologie fand im Oktober 1976 nach 21 lahren zum erstenmal wieder in Freiburg statt. 1955 war der KongreBprasident unser unvergessener Ludwig Heitmeyer, der besonders auf dem Gebiete des Eisenstoffwechsels maBgebliche methodische und klinische Pionierarbeit geleistet hat. Die 3 Hauptthemen dieser Tagung sind daher teilweise durch den "genius loci" mitbestimmt (Abb. 1). Abb.1. Ludwig Heilmeyer, 1899-1969 Der Eisenstoffwechsel ist schon seit der Frtihgeschichte ein Problem der Menschheit, dessen Storungen die haufigste Ursache fUr Bluterkrankungen darstellt. Die Phylogenese vom A vertebraten tiber die Vertebraten zum Men- schen ware ohne das Auftreten des eisenhaltigen Hamoglobinmolekiils gar nicht moglich gewesen, schaffte es doch die Voraussetzung der reversiblen Oxygena- tion und damit der zahlreichen Redox-Reaktionen aller einfachen und kompli- zierten Gewebe und Korperorgane. Das so einfach erscheinende Eisenatom kommt in zwei-und dreiwertiger Form vor. Das_zweiwertige Eisen hat an seiner AuBenschale nur 6 d-Elektronen, das dreiwertige Eisen-Ion 5 d-Elektronen. Beide Eisenformen haben gewohnlich eine oktahedrale Koordination, wie aus der Abb. 2 hervorgeht. Vorwort x L, k-_____ -+------::::::==---::~L, L, '"'--=-----+----'~ Abb. 2. Modell des Eisenatoms L, In dieser Form ist das zentrale Metall-Ion umgeben durch vier Liganden-Ato- me LI-L4 an den Ecken des Vierecks und hat auBerdem zwei zusatzliche Liganden-Atome L5 und L6.