CHEMOTHERAPEUTIC MANAGEMENT OF HEAD AND NECK MALIGNANCIES WITH POSITRON EMISSION TOMOGRAPHY

Objective: Antineoplastic chemotherapy in cases of nonresectable advan ced malignancies of the head and neck can be very debilitating for the patient. For individual treatment planning, it is important to evalua te the early clinical effect of therapy. Morphological parameters, suc h as the size of the tumor and its relationship to adjacent structures , which can be determined by a number of imaging procedures, hardly re flect early therapeutic effects. Therefore, the metabolic activity of the tumor should be studied during antineoplastic therapy. Design: Pos itron emission tomography was performed in 12 patients with metastasiz ing squamous cell carcinomas of the oropharynx, hypopharynx, and laryn x before and after the first chemotherapeutic cycle. Results: The flud eoxyglucose F 18 uptake was increased in all tumors and lymph nodes. I n most lesions, an obvious response to treatment was observed after th e first cycle of chemotherapy. However, differences in metabolic activ ity and changes in metabolism occurred during therapy. The treatment r esponse varied in different lymph nodes in the same patient. There was a linear relation between metabolic change and growth rate during the rapy, with different regression functions for tumors and lymph node me tastases. Conclusions: Positron emission tomography provides absolute and comparable quantitative data on tumor metabolism before and after chemotherapy. It is therefore a useful method for observation and poss ible improvement of therapeutic measures in patients undergoing system ic chemotherapy.