DESCRIPTION: (Applicant's Description) Management of brain and head and neck cancer is one of the great therapeutic dilemmas of modern medicine. The problem is compounded by a lack of well-defined tumor risk factors and the inaccuracies in pretreatment staging. Traditional diagnostic imaging modalities are focused mainly on defining the anatomic lesion and are unable to provide information about the various physiological and functional factors that affect malignancy. The purpose of this research project is to determine the appropriate role of MR physiological techniques in the clinical management of patients with brain, head and neck cancer based on the outcome measure of progression-free survival. The proposed research is designed to further develop new imaging techniques in the brain and head and neck (rCBV, Diffusion) and evaluate these and other more established imaging methods (MRSI, MRI) by comparison with histopathology and to evaluate the potential of the measured physiological parameters to provide prognostic indicators of response to radiotherapy. Study aims include: 1) to develop and improve pulse sequences and quantification of rCBV and diffusion in the brain, and perfusion, diffusion, and 1H MRSI in the head and neck; 2) validate these techniques by comparison of measurements to histopathology in untreated cerebral gliomas and diseased lymph nodes of patients with squamous cell carcinoma of the head and neck; 3) investigate the role of the physiological properties measured by these techniques to provide early and late indicators of response to radiotherapy for cerebral gliomas and lymph nodes involved in squamous cell carcinoma of the head and neck. It is anticipated that results from the proposed research will help develop a single clinical imaging examination that will provide conventional MRI as well as the added physiological and functional information obtained with these techniques, some of which would normally require invasive biopsy procedures. Moreover, the candidate expects that the correlation of these physiological parameters and anatomical MRI will improve characterization of cancers of the brain and head and neck. While this study is anticipated to provide new information specific to cerebral gliomas and head and neck carcinomas, since these techniques measure physiological and functional characteristics, these results may provide further insight into the mechanisms and physiology of all human cancer.