Palliative treatment of metastatic bone pain with radiopharmaceuticals: A perspective beyond Strontium-89 and Samarium-153

Purpose: The present review article aims to provide an overview of the available radionuclides for palliative treatment of bone metastases beyond ⁸⁹Sr and ¹⁵³Sm. In addition, it aims to review and summarize the clinical outcomes associated with the palliative treatment of bone metastases using different radiopharmaceuticals. Materials and methods: A literature search was conducted on Science Direct and PubMed databases (1990 - 2015). The following search terms were combined in order to obtain relevant results: "bone", "metastases", "palliative", "care", "therapy", "treatment", "radiotherapy", "review", "radiopharmaceutical", "phosphorus-32", "strontium-89", "yttrium-90", "tin-117m", "samarium-153", "holmium-166", "thulium-170", "lutetium-177", "rhenium-186", "rhenium-188" and "radium-223". Studies were included if they provided information regarding the clinical outcomes. Results and conclusions: A comparative analysis of the measured therapeutic response of different radiopharmaceuticals, based on previously published data, suggests that there is a lack of substantial differences in palliative efficacy among radiopharmaceuticals. However, when the comparative analysis adds factors such as patient's life expectancy, radionuclides' physical characteristics (e.g. tissue penetration range and half-life) and health economics to guide the rational selection of a radiopharmaceutical for palliative treatment of bone metastases, ¹⁷⁷Lu and ¹⁸⁸Re-labeled radiopharmaceuticals appear to be the most suitable radiopharmaceuticals for treatment of small and medium/large size bone lesions, respectively. - Highlights: • An overview of several radiopharmaceuticals is presented.; • Clinical outcomes are reviewed and summarized. • It is suggested a lack of substantial differences in terms of palliative efficacy. • ¹⁷⁷Lu and ¹⁸⁸Re-labeled radiopharmaceuticals appear to be the most suitable.