ABSTRACT
A 26-year-old man with renal cell carcinoma underwent (99m)Tc-HDP bone scintigraphy for detecting bony metastasis after left total nephrectomy for renal cell carcinoma. (99m)Tc-HDP bone scintigraphy showed small hot lesion in the first lumbar spine. About 12 months later, he underwent spinal MRI for lower back pain. A large mass was seen around spinous process of the first lumbar spine (L1) on spinal MRI and confirmed as metastatic renal cell carcinoma by bone biopsy. (99m)Tc-HDP bone scintigraphy and (18)F-FDG PET/CT were underwent for further evaluation. (99m)Tc-HDP bone scintigraphy showed cold lesion in the first lumbar spine which was initially hot and newly developed hot lesion in the twelfth thoracic spine, and which were shown as hypermetabolic lesions in (18)F-FDG PET/CT. We report a case of bony metastasis from renal cell carcinoma which is changed from hot lesion to cold lesion in (99m)Tc-HDP bone scintigraphy and compare with (18)F-FDG PET/CT.