Determining glioma response to radiation therapy using recombinant peptides.

Presently, cancer response is measured by imaging assessment of tumor volumes or by repeated biopsy to analyze pharmacodynamics. These methods of monitoring cancer response are inefficient because volume changes typically require therapy for prolonged time intervals and neoplasms within the brain are less amenable to sequential biopsies. Peptide ligands selected from phage-displayed peptide libraries can rapidly differentiate responding from resistant gliomas. These peptides, in turn, can be labeled with internal emitters to provide a means of noninvasive assessment of glioma susceptibility to radiotherapy within 24 h of therapy. This is platform technology and could allow for ineffective therapy to be modified or switched so that patients are not subjected to a delayed reassessment (2 months) of response to therapy.