The natural progression of breast cancer is to spread to bone, especially to the spine. These metastatic tumors are notoriously common and can cause pain, spine fractures, and neurologic problems, seriously reducing quality of life. Patients with metastatic tumors in the spine may receive minimally invasive surgical treatment followed by radiation therapy. This surgery has a low rate of complications, is very effective, and can be performed in an outpatient surgery center under local anesthesia, with the patient awake. Even multiple levels of the spine can be treated successfully.

Despite the success of this surgery, the radiation therapy following surgery currently has a number of important shortcomings. As the spine is irradiated to treat the tumors, the spinal cord and nerves are also exposed to radiation. The spinal cord and nerves can tolerate some radiation exposure, and special techniques can be used to minimize exposure to the spinal cord. Even so, the presence of the spinal cord often limits the radiation that can be safely delivered to treat the tumors. In addition, the current form of radiation therapy is inconvenient for the patient, typically requiring about 10 outpatient visits, which negatively impacts the patient's quality of life.

The goal of this study is to explore whether radiation therapy can be delivered internally during the existing minimally invasive spine surgery by implanting radioactive particles into the bone. Implantation of these radioactive particles would be used instead of standard radiation therapy. The proposed procedure will be designed to deliver radiation to tumors in the bone of the spine while not irradiating the surrounding tissues, especially the spinal cord.

The aims of this study are (1) to use computer models to identify the specific type of radioactive particles that should be implanted in the bone to achieve the desired radiation treatment; (2) to develop procedures to implant the radioactive particles, (3) to perform laboratory experiments to verify that the computer models we are using are indeed working correctly, and (4) to develop initial quantitative treatment guidelines for the proposed procedure. This initial study will focus on the spine of the middle and upper back because that is the region where metastatic tumors in bone are most common.

If successful, this innovative treatment would offer the advantage of sparing the spinal cord and other surrounding tissues from radiation, sparing the patient about 10 additional visits to the hospital for radiation therapy, potentially improving radiation treatment of the tumors, and potentially reducing the rate of recurrence. This procedure may also be especially valuable for patients who previously did not respond to conventional radiation therapy or who had a recurrence. Finally, this procedure would potentially lead to similar treatments for metastatic tumors in other bones, such as the hip, where radiation therapy is typically used in combination with surgical treatment.

In summary, the proposed treatment has the potential to dramatically improve the patient's quality of life by relieving pain, reducing the time spent at the hospital, potentially improving treatment of existing tumors in the spine, and potentially reducing the chance of recurrence. Depending on the specific results of this study, this new treatment may reach clinical trials within the next 5 to 10 years.