Radionuclides represent a means of functional imaging, which is able to ref
lect the metabolic state of tissues. Recently developed radiotracers and ol
der radiotracers with newer applications, imaged through single photon emis
sion computed tomography (SPECT) and positron emission tomography (PET), ca
n provide significant information in the diagnosis, grading, therapy respon
se or recurrence of primary musculoskeletal tumors. The unique ability of t
hese radiotracers to demonstrate non-invasively the efflux pump rate, which
is a common reason of therapy failure, as well as the metabolic and prolif
erative rates of the tumors should be a powerful tool in the orthopaedic on
cology in the evaluation of musculoskeletal tumors. (C) 2001 Elsevier Scien
ce Ireland Ltd. All rights reserved.