High false negative rate of Tc-99m MDP whole-body bone scintigraphy in detecting skeletal metastases for patients with hepatoma

Abstract

Technetium-99m methylene diphosphonate (Tc-99m MDP) whole-body bone scintigraphy (BS) has been widely used for detecting bone metastases. The aim of this study is to investigate the diagnostic accuracy of BS in detecting skeletal metastases for hepatocellular carcinoma (HCC) patients. In addition, the anatomic distribution of the metastatic bone lesions and the prognoses of the HCC patients are also analyzed. We retrospectively reviewed BS results of 179 consecutive HCC patients from January 2005 to December 2006 in our institution. The false negative (FN) rate, sensitivity, and specificity of BS were evaluated by patient-based and region-based analyses. A total of 59 patients (33.0%) were confirmed of bone metastases. A total of 25 of these 59 patients (46.3%) had at least one lesion categorized as BS FN, and the bone metastatic status for 10 patients (17.0%) was underestimated by BS. The most observed metastatic site was spine while the most observed sites with FN of BS were the lower extremity. In total, there were 122 metastatic regions and 33 regions (27.0%) were FN of BS. Patients without any metastases survived significantly longer than any of other groups with metastases. High FN rate of Tc-99m MDP BS in detecting metastatic bone lesions for HCC patients was observed. In our opinion, careful history taking, meticulous examination, and a high index of suspicion are important for HCC patients with unexplained progressive pain in the musculoskeletal system. Even with negative results from Tc-99m MDP BS, the possibility of skeletal metastases cannot be indiscriminately excluded.