[The value of radiotherapy in treating paranasal sinus tumors]

A multidisciplinary treatment conception is necessary for carcinomas of the paranasal sinuses because of the generally very advanced stage (90% bone destruction). Surgery is the most important therapy part. However, it is difficult to obtain complete recovery by surgery alone, because in most cases the tumor has infiltrated into adjacent tissues (nasopharynx, pterygoid muscles, ethmoidal plate, sphenoidal sinus, base of the crane), where a radical operation is not possible. Therefore radiotherapy plays an important role: it shall destroy malignant cells which could not be eliminated by surgery. The optimum succession of operation and irradiation is still a subject of controversial discussion, although preoperative irradiation is preferred by the majority. Preoperative irradiation is said to destroy peripheral tumorous structures (microfoci), to reduce the tumor volume, thus facilitating the surgical removal of the tumor core and, last but not least, to decrease the risk of implantation and dissemination of malignant cells by devitalizing the tumor cells. Intraarterial chemotherapy has also been combined with surgery and radiotherapy, but no unanimous opinion has yet been built with respect to the efficiency of this method. Astonishing results have been achieved with recently developed conceptions of a "trimodal combined therapy" consisting of reduction surgery, radiotherapy, limited intraarterial and mostly topic application of 5-fluorouracil, and special care to the operation cavity during several weeks. These conceptions should be investigated by means of prospective multicentric studies. Primary lymph node metastases are treated by functional or radical neck dissection with subsequent postoperative irradiation in case of severe invasion, especially if a capsular perforation with infiltration of perinodular tissue is histologically demonstrated. Opinions are divided about prophylactic irradiation of the clinically negative neck aiming at a destruction of subclinical metastases. Many authors recommend to take a wait-and-see attitude. In case of certain risk factors an irradiation could possibly be discussed.