UNLABELLED: Our study assessed the predictive value of atypically located hot spots in routine 99mTc-DPD (3,3 diphosphono-1, 2-propane dicarboxylic acid tetrasodium salt) bone scanning for osseous tumor spread in patients with a history of malignant tumor. METHODS: Of 1286 scans in consecutive patients with a history of malignant tumor, but with no current evidence of osseous tumor spread, 172 displayed one or two hot spots in the following locations: transverse process of a single vertebra, manubriosternal junction, unilateral process of L5/S1, unilateral shoulder, costal cartilage, single rib, and unilateral sternoclavicular joint. The final diagnosis could be established by a control bone scan after at least 6 mo, biopsy and/or postmortem, respectively, in 135 patients. RESULTS: Of the atypical hot spots, 11.1% were the first indication for osseous tumor spread. This diagnosis was most probable for single hot spots in the rib (25%) and shoulder (21%). Conversely, hot spots in the sternoclavicular joint never indicated malignancy. CONCLUSION: The likelihood of atypically located isolated hot spots indicating osseous tumor spread is higher than expected during routine investigations in patients with a history of malignant tumor but no current evidence for malignant disease. Only hot spots in the sternoclavicular joint did not indicate metastatic disease in our study.
UNLABELLED: Our study assessed the predictive value of atypically located hot spots in routine 99mTc-DPD (3,3 diphosphono-1, 2-propane dicarboxylic acid tetrasodium salt) bone scanning for osseous tumor spread in patients with a history of malignant tumor. METHODS: Of 1286 scans in consecutive patients with a history of malignant tumor, but with no current evidence of osseous tumor spread, 172 displayed one or two hot spots in the following locations: transverse process of a single vertebra, manubriosternal junction, unilateral process of L5/S1, unilateral shoulder, costal cartilage, single rib, and unilateral sternoclavicular joint. The final diagnosis could be established by a control bone scan after at least 6 mo, biopsy and/or postmortem, respectively, in 135 patients. RESULTS: Of the atypical hot spots, 11.1% were the first indication for osseous tumor spread. This diagnosis was most probable for single hot spots in the rib (25%) and shoulder (21%). Conversely, hot spots in the sternoclavicular joint never indicated malignancy. CONCLUSION: The likelihood of atypically located isolated hot spots indicating osseous tumor spread is higher than expected during routine investigations in patients with a history of malignant tumor but no current evidence for malignant disease. Only hot spots in the sternoclavicular joint did not indicate metastatic disease in our study.