Abstract: The present application discloses compositions and methods of use of dual-labeled molecules comprising a fluorescent probe and a radionuclide. The labeled molecules are of use for detection, imaging and/or diagnosis of diseased tissues, such as tumors. In preferred embodiments, the dual-labeled molecules are of use in pre-operative and/or intraoperative imaging, for example to detect margins of malignant tissues to facilitate surgical resectioning. In more preferred embodiments, a radioprotective agent such as an oxygen radical scavenger is used to decrease radiolysis of the fluorescent signal. The labeled molecules bind to a disease-associated antigen, such as a tumor-associated antigen. Exemplary molecules include antibodies, antibody fragments, bispecific antibodies, targetable constructs and targeting peptides, such as bombesin analogues.