POSITRON EMISSION TOMOGRAPHY - A NEW TOOL FOR CHARACTERIZATION OF MALIGNANT DISEASE AND SELECTION OF THERAPY

Present therapy for cancer patients is based primarily on tumor histol ogy and anatomy. Despite treatment advances, clinicians have often bee n frustrated by their inability to assess tumor biology. Metabolic ima ging by positron emission tomography is a promising new technology tha t has opened up a whole realm of study in oncology. Glucose metabolism , hemodynamics, oxygen utilization, protein synthesis and thymidine in corporation may yield valuable data regarding tumor aggressiveness and stage, and allow assessment of tumor response early during treatment, before morphological changes are detectable. Other metabolic determin ations, including tumor hypoxia and estrogen receptor density, may pre dict tumor response to therapy, and lead to selection of more appropri ate treatment regimens, such as with neutrons or hypoxic cell sensitiz ers for documentably hypoxic tumors. While further clinical validation is required, positron emission tomography promises to provide vital i nformation complementary to present anatomical imaging modalities that will aid oncologists in optimal management of their patients.