Predictable Relief from Painful Bone Mets
Cancer that metastasizes (spreads) to the bone can eventually lead to severe bone pain. Initially, the pain may come and go. Often, it’s worse a night. Early on, there are medications that can relieve the pain, but as it becomes more agonizing many patients end up on morphine. In addition, bone mets can weaken bones and lead to painful fractures that are difficult to heal. Thus, treating the bone tumors themselves in order to diminish their growth, progression and pain is an important management strategy for metastatic bone disease.
Treating painful metastatic bone tumors
Depending on the type of cancer, the number and size of bone tumors, and how accessible the location is, there have been three traditional local interventions: surgery, needle ablation (insertion of a probe to deliver lethal energy to the tumor), and radiation therapy. The first two are invasive and sometimes recovery is itself painful. Radiation is completely noninvasive, but pain relief is not immediate since radiation takes time to stop the growth of cancer cells. Also, it is not effective for everyone. Roughly 60–74% of patients gain pain relief, but over 40% of patients are still not controlled after a second course of radiation.[i]
Fortunately, a more recent treatment has emerged that is as precise as surgery without being invasive, and has comparable or better success than radiation without waiting long for relief. It is called MRI-guided Focused Ultrasound (MRgFUS) or simply Focused Ultrasound (FUS). Published studies since 2015 have been demonstrating its safety and effectiveness.
How FUS works
FUS uses a simple principle of beaming soundwaves (sonic energy) from several different angles to meet at a focal point. Each beam passes harmlessly through tissue until they intersect at the target. There, they generate heat over 57°C. For bone mets, the nerves in the outer tissue of the bone that surrounds the tumor are destroyed by the heat, quickly ending the pain messages to the brain; this also destroys the blood vessels in the same area of the outer covering, which may help deprive the tumor of the nourishment it needs for its own blood supply, causing tumor die-off. In many cases, the focal point can reach the tumor itself, destroying a mass of tumor cells which thus decreases the tumor’s pressure on surrounding tissue.[ii] Advantages of FUS include precision targeting and real-time temperature monitoring, outpatient treatment, and (unlike radiation) there is no dose limit so it can be repeated if necessary.
A study published in August, 2020 identified three predictors for successful pain reduction of bony mets treated with FUS.[iii] They had 99 participants, 96 of whom were women. Pain reduction was measured by Numerical Rating Scale pain scores, and daily morphine dose amounts over 3 months of follow-up. At that point, based on pain scores and morphine doses, participants were classes as either responders or nonresponders to the FUS treatment.
The study authors found that the three factors linked with the most successful pain relief were higher amount of ultrasound energy deposited on the bone surface, the imaging evidence after the procedure of destroyed blood vessels (looks like a black band on the surface of the bone when scanned by MRI), and female gender. Participants who had all three factors were responders who had the most pain reduction, with a success rate of 93%.
Although the follow-up period of 3 months was relatively short, the high rate of success shows that FUS may safely, effectively and reliably help more bone mets patients than conventional beam radiation, especially when the patients have the three predictive factors described in the study.
The Sperling Medical Group is pleased to be able to offer FUS for painful bone mets. For more information, or to contact us, visit Sperling Medical Group.
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.
[i] Bertrand A, Iannessi A, Natale R, Beaumont H. Focused ultrasound for the treatment of bone metastases: effectiveness and feasibility. J Ther Ultrasound. 2018; 6: 8.
[ii] Chan M, Dennis K, Huang Y, Mourgenot C et al. Magnetic Resonance–Guided High-Intensity-Focused Ultrasound for Palliation of Painful Skeletal Metastases: A Pilot Study. Technol Cancer Res Treat. 2017 Oct; 16(5): 570–576.
[iii] Bitton RR, Rosenberg J, LeBlang S, Napoli A et al. MRI-Guided Focused Ultrasound of Osseous Metastases: Treatment Parameters Associated With Successful Pain Reduction. Invest Radiol. 2020 Aug 26.