[Radiological diagnosis of late effects on thoracic organs after chemotherapy and/or radiation therapy as well as after radionuclide therapy]

Abstract

With respect to the considerable risk involved in oncologic therapy methods, especially when bleomycin is administered, a specific observation of the possibly fatal side effects is necessary. As, for example, a regression of pulmonary alterations caused by bleomycin is possible when they are detected early, the call for early recognition of developing lesions is becoming more and more urgent. Conventional radiologic diagnosis is scarcely important in early recognition, but X-ray computed tomography is a suitable imaging method because it is able to visualize tiny intrapulmonary and pleural alterations. The CT image of bleomycin pneumopathy is variable. There are irregular, partly sharply defined nodular structures. They are generally found in peripheric sites near to the pleura with the exception of the pleura mediastinalis. Contrary to functional investigations such as the determination of the CO diffusion capacity which are equipment- and cost-consuming, X-ray computed tomography does not only offer a qualitative information on an existing pneumopathy, but provides also a precise localization of these pulmonary alterations. Computed tomography is a method for the quantitative assessment of the peripheral lung density with the same amount of information as the measurement of the gas transfer per pulmonary volume unity. However, it offers the advantage of a simultaneous qualitative visual judgement of the organ, i.e. not only the types and dimensions of pulmonary lesions can be assessed, but the physiologic effect of these lesions, i.e. the pulmonary function, can be determined by quantitative density measurement, too. Thus quantitative computed tomography represents an alternative in the assessment of the pulmonary function. According to the recommendations of Bellamy et al., it should be combined to routine computed tomography of the thorax. The method of choice for the diagnosis of anthracycline cardiotoxicity is radionuclide ventriculography. A decrease of the left ventricle expulsion to less than 45% is considered as a critical value. However, cardiac side effects of cytostatic drugs can be detected early in the individual course, so that late effects in the sense of irreversible cardiomyopathy are prevented.