Chemotherapeutic management of head and neck malignancies with positron emission tomography

Antineoplastic chemotherapy in cases of nonresectable advanced malignancies of the head and neck can be very debilitating for the patient. For individual treatment planning, it is important to evaluate the early clinical effect of therapy. Morphological parameters, such as the size of the tumor and its relationship to adjacent structures, which can be determined by a number of imaging procedures, hardly reflect early therapeutic effects. Therefore, the metabolic activity of the tumor should be studied during antineoplastic therapy.

Positron emission tomography was performed in 12 patients with metastasizing squamous cell carcinomas of the oropharynx, hypopharynx, and larynx before and after the first chemotherapeutic cycle.

The fludeoxyglucose F 18 uptake was increased in all tumors and lymph nodes. In most lesions, an obvious response to treatment was observed after the first cycle of chemotherapy. However, differences in metabolic activity and changes in metabolism occurred during therapy. The treatment response varied in different lymph nodes in the same patient. There was a linear relation between metabolic change and growth rate during therapy, with different regression functions for tumors and lymph node metastases.

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 possible improvement of therapeutic measures in patients undergoing systemic chemotherapy.