4 Ablation Approaches to Treat Painful Bone Metastasis

“These are the days of miracle and wonder…” sang Paul Simon in his song “The Boy in the Bubble.” When it comes to treating painful tumors that have spread to the bone from their primary location (breast, prostate, lung, etc.) the clinical world has entered a new age in medicine. Bone is the third most common site affected by cancer spread, and the source of the most devastating side effects from metastasis. One of the worst side effects is pain, and research shows that despite good pain management strategies using drugs, undertreatment of bone pain is common.ⁱ In addition, medications eventually lose effectiveness as bone tumors progress. On the other hand, new therapies based on blocking the ways tumor cells hijack healthy bone processes are extending longevity for bone mets patients.
 

Surgical treatment

Besides drug therapies, surgical techniques have been a standard of care for alleviation of pain, removing as much tumor as possible, and bone reconstruction. For many patients, surgery has provided much-needed easing of pain, and restored function. Surgery is not always feasible, however, and all invasive surgeries have some risks, including infection and a painful recovery.
 

Thermal ablation

A significant alternative to surgery is the use of extreme heat or cold to destroy the bone tumor and deaden the nerves that carry pain messages to the brain. This is called thermal ablation (literally, “temperature destruction”). Unlike surgery, which relies on visual guidance when the body is opened, thermal ablation is guided by real-time imaging such as ultrasound, CT scans, or MRI scans. The ablation types range from minimally invasive to noninvasive, and they are efficient, safe, well tolerated, and have more rapid recovery than open surgery. The four most commonly used types of thermal ablation are:

1.Radiofrequency ablation (RFA) is minimally invasive. A probe with an electrode at the tip is inserted into the lesion, and an electric current is run into the electrode. This generates lethal heat that destroys an area of the lesion. The probe is relocated and the procedure repeated until the entire target has been treated, together with any involved nerves. There may be residual pain after the RFA but it usually resolves quickly and for most patients, pain improves within days or weeks.

2.Cryoablation (freezing) is also minimally invasive because it involves probe insertion. In this case, the hollow insulated probe, which has a sharp sealed tip that is not insulated, circulates a freezing agent. Extreme cold is generated at the tip, which creates the destruction of the lesion and the nerves. Depending on the tumor or treatment damage, cement can be inserted when the probe is withdrawn to strengthen the bone. Recovery is rapid and pain relief is very quick, usually within days.

3.Microwave ablation (MWA) is a third type of heat ablation using a probe. In this case, the tip of the probe delivers microwaves – same principal as “nuking” food but a different targeted delivery system – with great precision. As with RFA, extreme heat is created. There is generally little to no residual treatment pain, and relief from bone pain is comparable to cryoablation.

4. MRI-guided Focused Ultrasound (MRgFUS) has a unique advantage over other types of thermal ablation because it is completely noninvasive. No skin is broken because it uses sonic energy (sound waves) that are beamed into the body from an external source. The sound waves are aimed from a number of different angles. They are completely harmless until they intersect precisely at the targeted lesion. When the beams meet, they create intense heat in the same way that a magnifying glass under sunlight can focus light into a single bright dot that will quickly grow very hot. The thermal energy of MRgFUS is as precise, safe and effective as RFA, MWA and cryoablation, but with the least amount of time needed for recovery. As with the other ablations, bone pain is quickly eased.
 
Compared with open surgery, thermal energy is indeed a wonder, and the easing of bone pain feels miraculous. On top of that, the ability to direct sound waves into bone metastasis without physically penetrating skin and bone is incredibly appealing to cancer patients who have endured endless needles, IVs, and other surgical procedures.

If you or a loved one suffers from painful bone metastasis, contact the Sperling Medical Group to learn more about MRgFUS and what it can do for you.

_______________________________
ⁱLipton A, Berenson JR, Body J, Boyce BF et al. Advances in treating metastatic bone cancer: summary statement for the First Cambridge Conference. Clin Cancer Res. 2006 Oct 14;12(20Pt2):6209s-6212s.