Using ultrasound to guide focused ultrasound treatment for bone metastases pain is feasible and effective, according to a study published online March 4 in Ultrasound Medicine & Biology.
The study findings offer patients and clinicians an alternative to MRI, which has been the modality most often used to perform the procedure but which has its limitations, wrote a team led by Leah Drost of the University of Toronto in Ontario.
"Previous generations of focused ultrasound devices have featured MR image guidance," the group wrote. "These devices have been found ... to be tolerable, effective, and noninvasive in the palliation of metastatic bone pain. ... However, potential drawbacks of such devices include the cost attached to MR equipment, the immobility of the unit, the complex positioning required of the patient, and the long treatment duration."
Drost and colleagues sought to evaluate whether a standalone, portable focused ultrasound device could be guided by diagnostic ultrasound rather than MRI for this application. The study included nine patients treated with focused ultrasound guided by ultrasound. The team assessed the procedure's safety and efficacy 10 days after it was performed.
The researchers found the following:
- The procedure was safe and tolerable. Four patients reported minor skin irritations.
- Average pain score decreased from 6.9 at baseline to 3.2 at day 10. P atients' use of analgesics also decreased from baseline to day 10.
- Six patients reported "durable" pain relief over the assessment period.
"Our study provides evidence that ultrasound-guided focused ultrasound is a safe, tolerable and versatile procedure," the researchers concluded. "It appears to be effective in achieving durable pain response in patients with painful bone metastases. Further research is required to refine the technology and optimize its efficacy."
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
