Superscan on both 99mTc-MDP and 153Samarium-EDTMP Bone Scans in a Patient with Breast Cancer

One month later the patient received 4.22 GBq (114 mCi) 153Samarium-EDTMP for palliation of severe bone pain. Post treatment, whole body 153Samarium scan was also a “superscan” showing very similar osseous metastases pattern to the 99mTc-MDP bone scan. Anterior and posterior whole body images 24 hours after intravenous administration of 153Sm-EDTMP demonstrate diffuse osseous metastases in a very similar pattern with the prior bone scan. However on this scan both kidneys and the bladder were not visualized, consistent with a 153Sm-EDTMP superscan (b). 153Sm-EDTMP is used for relief of bone pain predominantly in breast cancer patients with painful osteoblastic skeletal metastases. 153Sm has a half life of 46.3 hours and has a 103 keV gamma emission, suitable for scintigraphic imaging. Superscans on the conventional bone scintigraphy have been described both in metastatic and metabolic bone diseases, with different patterns and appearances of radiotracer uptake [4-8] (Figure 1b). Presence of “superscan” both on conventional 99mTc-MDP bone scan and on the 153Samarium-EDTMP bone scan of the same patient with almost identical osseous metastatic pattern has yet not been reported. A superscan indicates the extensive presence of osseous metastases. A similar superscan pattern on both conventional and 153SamariumEDTMP bone scans may indicate a better outcome for palliation of metastatic bone pain. All the lesions seen on conventional imaging will also be taking up the palliative bone treatment agent “153Samarium-EDTMP”, leading to efficient palliation of bone pain.