Value of radiologic correlation and follow-up scintigraphy in detecting osseous metastasis in patients with non-specific bone scintigraphy lesions

ABSTRACT

Bone scintigraphy is highly sensitive in detecting bone metastasis but specificity is only about 50-60%. The aim of this study is to evaluate the value of radiologic correlation and followwup scintigraphy in detecting osseous metastasis in patients with equivocal bone scans. Bone scan results with non-specific interpretation of bone lesions from January to December 2007 were included. Results with no evidence of bone metastasis or metastatic bone disease were excluded from the study. Correlation with radiographs [X-ray, CT-scan, MRI] and follow-up bone scan within 6 months from the initial bone scan were reviewed. Of the 2322 bone scans, 435 have non-specific findings of bone lesions. From 435, only 228 patients have records of radiograph correlation and scintigraphic follow-up. Twenty two percent of the total population showed positive findings of bone metastasis in radiographs. The percentages of the non-specific findings determined to be negative from bone metastasis on correlation with X-ray, CT-scan, MRI and follow-up bone scan were 84%, 70%,73%, and 85%, respectively, whereas osseous metastasis revealed on radiologic correlation and follow-up scan were 76%, 30%,27%, and 75%, respectively. In conclusion, the finding of osseous metastasis in bone scan is increased when correlated with radiographs and scintigraphic follow-up.