Depending on the location of the primary tumour approximately 30-80% of patients with advanced cancer develop bone metastases, with pain as a common and devastating consequence (Ripamonti, 200, 2001; Portenoy 2011; Lipton 2010; Coleman 2006; Suva 2011). Metastatic bone pain strongly interferes with quality of life and daily functioning of patients and their families (Mantyh 2014; Paice and Ferrell 2011). Intermittent episodes of extreme pain, either occurring spontaneously or by movement of the affected limb, are often referred to as “breakthrough” pain, as it breaks through the opiate pain palliation regime, and is refractory to pharmacologic pain treatment. Metastatic bone pain affects mobility, productivity and independence, placing an increasing burden on health-care and social care systems.

In Summary
There is a clinical need for a treatment that provides rapid pain relief with a lasting effect, at least to bridge the time it takes for EBRT to take effect. In addition, since 30-40% percent of patients do not respond to EBRT, alternative treatment strategies could be of added value for the large group of patients that we are currently unable to treat effectively. Pain palliation may be substantially improved by including magnetic resonance image guided high intensity focused ultrasound (MR-HIFU) as alternative or in addition to EBRT.