A recent study of one man at the Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, The Netherlands combined both treatment modalities, radiopharmaceuticals and bisphosphonates, to combat bone pain caused by bone metastases. Their results were surprising.

Bone-seeking radiopharmaceuticals and bisphosphonates are both an indicated treatment for men with prostate cancer when painful osseous metastases develop. To treat pain symptoms or to prevent skeletal-related events either of these procedures is often used individually.

The combined use of bone-seeking radiopharmaceuticals and bisphosphonates is controversial because of assumed competition between both phosphonate-compounds at the bone level. This study was to see if both of these drugs might have an additive or even synergistic palliative effect.

The subject of this study was a man with hormone-refractory prostate cancer (HRPC) with multiple painful osseous metastases. They treated him with samarium-153-ethylenediaminetetramethylphosphonic acid ((153)Sm-EDTMP; Quadramet, CIS bio International, Saclay, France) in combination with zoledronic acid (Zometa). He was treated for 6 months with 4 weekly intervals of zoledronic acid in combination with 3 monthly intervals of (153)Sm-EDTMP. The researchers reported no negative interactions in this single man. They reported that toxicity was low, and efficacy high. He experienced a total relief of pain, a significant decrease of prostate-specific antigen (PSA) and, surprisingly, a significant decrease of tumor burden.

Clearly, this is a study of only one individual and we cannot assume that his response to the combination of drugs will be universal; however, this study clearly demonstrates that this strategy needs to be immediately studied to see if it could become a better alternative for treating men with bone metastases.

J Palliat Med. 2009 Jul;12(7):649-51.
Lam MG, de Klerk JM, Zonnenberg BA.

PubMed Abstract
PMID: 19594354

Joel T Nowak MA, MSW