Histotripsy for neuroendocrine liver metastases: Early single-institution outcomes and safety

Histotripsy is a novel, noninvasive, nonionizing focused ultrasound technology that mechanically destroys tissue via cavitation. Neuroendocrine tumors, which frequently metastasize to the liver and follow an indolent course, may be particularly well-suited for histotripsy, and we report an early experience.

This retrospective analysis summarizes the first 32 patients consecutively treated with histotripsy in a neuroendocrine practice. Intraoperative targeting and cavitation were performed with the EDISON system. Clinical outcomes, postprocedural imaging, and adverse events were assessed.

Of 36 patients consecutively evaluated, 32 underwent histotripsy to at least 1 liver tumor. Twenty-seven patients had neuroendocrine tumors. Neuroendocrine tumor primary sites include the small intestine (16), pancreas (8), lung (2), and cecum (1). The treatment intent for patients with neuroendocrine tumors was full coverage of all known liver disease in 2 patients, with partial treatment in the remaining patients. Of the 19 tumors with full treatment intent, 100% showed a complete response. Partial treatments showed stable disease. Minor adverse events included skin irritation and transient pain. Major adverse events included acute kidney injury in 3 patients and 1 death post-treatment related to respiratory distress in the setting of underlying respiratory compromise.

Histotripsy is a promising noninvasive treatment for metastatic neuroendocrine tumors, offering effective tumor control when full coverage is achieved. Tumor histolysis may induce acute kidney injury, suggesting a need to appropriately select patients based on acute kidney injury risk, limit treated volume per session, and closely monitor urine output and color during treatment. These early findings support further study across broader patient populations.