Purpose: Six years ago, in 2015, the Focused Ultrasound Foundation sponsored a workshop to discuss, and subsequently transition the landscape, of focused ultrasound as a new therapy for treating glioblastoma. Methods: This year, in 2021, a second workshop was held to review progress made in the field. Discussion topics included blood–brain barrier opening, thermal and nonthermal tumor ablation, immunotherapy, sonodynamic therapy, and desired focused ultrasound device improvements. Results: The outcome of the 2021 workshop was the creation of a new roadmap to address knowledge gaps and reduce the time it takes for focused ultrasound to become part of the treatment armamentarium and reach clinical adoption for the treatment of patients with glioblastoma. Priority projects identified in the roadmap include determining a well-defined algorithm to confirm and quantify drug delivery following blood–brain barrier opening, identifying a focused ultrasound-specific microbubble, exploring the role of focused ultrasound for liquid biopsy in glioblastoma, and making device modifications that better support clinical needs. Conclusion: This article reviews the key preclinical and clinical updates from the workshop, outlines next steps to research, and provides relevant references for focused ultrasound in the treatment of glioblastoma.

Sarcomas are tumors of mesenchymal origin that are generally resistant to systemic therapies and prone to local recurrence despite current multimodal treatment approaches. Focused ultrasound (FUS) is a noninvasive therapeutic technology that may enhance standard treatment strategies for primary solid malignancies. FUS exerts its effects through diverse mechanisms, including high-intensity focused ultrasound (HIFU) thermal ablation, histotripsy, sonodynamic therapy, immunomodulation, and hyperthermia-enhanced drug delivery. In this narrative review, we summarize the mechanisms of focused ultrasound that have been investigated for the treatment of sarcomas and highlight the results of preclinical, veterinary, and clinical studies related to this area.