[Clinical usefulness of 99mTc-PMT whole body scans in the diagnosis of bone metastases from hepatocellular carcinoma].

The diagnostic value of whole body scanning using 99mTc-N-pyridoxylmethyltryptophan (PMT) was evaluated in 16 patients with bone metastases from hepatocellular carcinoma, in comparison with 99mTc-MDP. Of the 72 known lesions of bone metastases, 63 (87.5%) were detected by 99mTc-PMT scintigraphy, which demonstrated increased uptake of radionuclide. However, 99mTc-MDP bone scintigraphy detected only 45 lesions (62.5%), which were shown as increased, decreased, or mixed patterns of uptake. Thus 99mTc-PMT scintigraphy was more sensitive than 99mTc-MDP bone scintigraphy. In addition, the latter showed poor specificity because of its high false positive rate due to degenerative change. All lesions undetected by 99mTc-PMT scintigraphy were located in areas that overlapped the liver or bowel activity. In conclusion, it is recommended that whole body 99mTc-PMT scintigraphy be combined with 99mTc-MDP bone scintigraphy for the detection of bone metastases from hepatocellular carcinoma.