Detection of disease recurrence and monitoring of therapy

The detection of disease recurrence and treatment monitoring pose high demands on diagnostic modalities. Whereas serum marker levels in most cases allow an assessment of tumor load and a respective response to therapy, they do not confer information on the localization of disease. Although this diagnostic gap is filled by imaging modalities, most techniques based on morphology will come to a limit when fibrotic tissue alterations have to be differentiated from viable tumor tissue in case of suspected recurrence or when residual masses after chemotherapy have to be assessed. The metabolic information on tumor cells gained by fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging appears not only to be more sensitive and reliable in this respect, but also appears to allow assumptions on response to therapy, and ultimately on patient prognosis.