Higashi T, Nakayama Y, Murata A, Nakamura K, Suglyama M, Kawaguchi T &Suzuki S. Clinical evaluation of 67 Ga-citrate scanning. J. Nucl. Med. 13:196-201, 1972

For a long time, numerous investigators dreamed of using radioisotopes to delineate a malignant tumor as a positive image. However, radiopharmaceuticals clinically sufficient for tumor detection had not yet appeared. The first suggestion, in 1969, that gallium-67( 67 Ga)-citrate might localize in tumors was based on a serendipitous finding by C.I. Edwards and R.L. Hayes.’ Although nearly 20 years have elapsed since their findings, 67 Ga.citrate is still widely used to diagnose malignant tumors and inflammatory lesions. 2 ’ 3