The discrepancy between 99mTc-MDP bone scintigraphy and 18F-FDG positron emission tomography in lung and prostate cancer is related to these radiotracers’ mechanisms of uptake and retention [1, 2].

Slide A shows increased osteoblastic activity (mainly) within bone metastases of prostate cancer on 99mTc-MDP bone scintigraphy. Slide B shows increased utilization of deoxyglucose within the primary tumour and the very aggressive metastatic lesions of lung cancer on 18F-FDG positron emission tomography.