The role of radionuclides in clinical oncology

The major role of radionuclides in clinical oncology is, in the broadest sense, "tumor scanning". This includes evaluating specific organs for the presence of tumor (usually with different radiopharmaceuticals for each organ) or the entire body (generalized tumor searches with radiopharmaceuticals with 67Ga-citrate or 111Inlabeled bleomycin). The clinician uses these agents in the initial evaluation of the extent of tumor (staging) and in the subsequent management of the patient with cancer to assess response to treatment, to detect early relapse, and to assist in making decisions concerning treatment. The uses and limitations of the agents currently available for tumor scanning are summarized in this review (by major tumor type) from the perspective of the practicing oncologist. Other potential roles for radionuclides, including use as components of combined modality treatment programs, use as labels for antibodies or as drugs for both diagnosis and treatment, and use in the prediction of response to treatment, which are of great interest now and which will become realities for the oncologist in the future, are also considered.