Incidence and imaging characteristics of skeletal metastases detected by bone scintigraphy in lung cancer patients

Background/Aim. Detection of metastatic bone disease by skeletal scintigraphy is a classical application of nuclear medicine in cancer patients. Detection of bone metastases in patients with lung cancer is necessary for an appropriate treatment modality. The aim of this study was to report the frequency and imaging characteristics of bone metastases detected by bone scintigraphy (BS) using technetium-99m phosphonates in patients with lung cancer. Methods. We retrospectively analyzed a total of one hundred patients (78 males and 22 females), mean age of 63.3 years, with the diagnosis of lung cancer, who underwent BS during a three-year period (2003−2005). Scintiscans were classified as positive, negative and suspicious with regard to the presence of bone metastases. Results. The incidence of positive, negative and suspicious findings were 57%. 32% and 11%, respectively. Out of 57 patients with bone metastases, 51 had multiple asymmetric foci of increased tracer activity localized in the ribs, spine, extremities, pelvis, sternum, scapula and skull in 72%, 54%, 49%, 37%, 12%, 9% and 5% of scans, respectively. BS revealed solitary metastases in 6 of the patients. The lesions were located in the lower limbs in three patients and in the upper limbs, pelvis and sternum in the remaining three patients. Conclusion. Bone scintigraphy plays a significant role in staging and selecting of patients for curative lung surgery. Due to the fact that metastatic involvment of the extremities was frequently shown, our study suggests that systematic inclusion of the limbs in BS acquisition should be obligatory.