Evaluation by dual energy X-ray absorptiometry of changed bone density in metastatic bone sites as a consequence of systemic treatment.

Fourteen cancer patients with bone metastases from various primary malignancies were submitted to repeated dual X-ray absorptiometry (DEXA) scan before and after systemic antineoplastic treatments. In the nine patients with lytic lesions the Bone Mineral Density (BMD) increased after chemotherapy + pamidronate in four (by +11.2%, +7.5%, +5.0% and +6.6%, respectively), decreased in four (by -19.9%, -8.1%, -7.5%, and -7.0%, respectively) and remained unchanged in one. BMD changes paralleled variations in painful symptomatology and biochemical markers. In patients with blastic metastases the BMD on target metastatic lesions did not change after hormone therapy or chemotherapy in one case but showed a significant increase in four. BMD increase was associated to bone pain improvement and PSA decrease in two cases, and with a worsening in skeletal pain and/or serum PSA in the remaining two. Our data suggest that BMD evaluation by DEXA instrument may be a reliable tool in assessing the response of bone metastases to treatment.