An interventional study of ExAblate 2000/2100 Magnetic Resonance-guided Focused Ultrasound (MRgFUS) in Undifferentiated Pleomorphic Sarcoma, sponsored by Matthew Bucknor. Terminated at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-01.
Sponsored by Matthew Bucknor · Not applicable, Interventional, and Treatment
This study is a single site, single-arm, feasibility study to evaluate the safety and efficacy of MRgFUS using the ExAblate 2100 System for the partial ablation of undifferentiated pleomorphic sarcomas.
A total of 20 adult participants will be treated with MRgFUS through this study. A matched comparison group of archived samples from patients with UPS who have not received focused ultrasound will be used as a control group to further evaluate the secondary endpoints (stratified and matched for age, sex, and history of neoadjuvant chemotherapy). All patients enrolled will receive timely standard of care surgical resection, as clinically indicated. For patients enrolled with metastatic disease pre- and post-MRgFUS biopsy samples will be obtained
PRIMARY OBJECTIVE:
I. To evaluate the overall rate and severity of adverse events following MRgFUS of newly diagnosed or metastatic undifferentiated pleomorphic sarcoma.
SECONDARY OBJECTIVES:
I. To measure possible immune response effects related to MRgFUS by serial serological analysis with flow cytometry panels (T-cell, natural killer cell, myeloid panels).
II. To measure possible immune response effects related to MRgFUS by multiplex immunohistochemistry assays of resected tumor specimens (CD3, CD4, CD8, CD19, CD68, FOXP3, PD-1, PD-L1, CD45) as well as RNA sequencing.
III. To compare possible immune response effects in patients receiving MRgFUS prior to either surgical resection or follow-up biopsy of undifferentiated pleomorphic sarcoma to either 1) a comparison group of archived samples from patients who have had resection of UPS but did not have pre-operative focused ultrasound (for patients with newly diagnosed local disease or 2) individual pre-MRgFUS biopsy analyses.
65 studies on the registry are indexed under Histiocytoma, Malignant Fibrous; 13 are open to participants now.
This study's enrollment of 5 is below the median of 53 across 56 interventional studies indexed under Histiocytoma, Malignant Fibrous.
Browse Histiocytoma, Malignant Fibrous studies →Matthew Bucknor is the lead sponsor of 2 studies on the registry; 1 is open to participants now.
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To clarify, patient's being treated with institutional standard neoadjuvant chemotherapy may be included in this study if all other inclusion/exclusion criteria are met.
Exclusion Criteria:
Any absolute contraindications for study magnetic resonance imaging (MRI) per standard University of California, San Francisco (UCSF) departmental MRI safety guidance (https://radiology.ucsf.edu/patient-care/patient-safety/mri) and additionally:
All enrolled participants will be scheduled to receive pre-operative MRgFUS with the ExAblate 2000/2100 MRgFUS system 1-4 weeks prior to surgical resection of their tumor or approximately 2 weeks after a pre-procedure biopsy of the metastatic tumor target depending on diagnosis at enrollment. For patients enrolled with metastatic disease, pre and post-MRgFUS biopsy samples will be obtained.
Device: ExAblate 2000/2100 Magnetic Resonance-guided Focused Ultrasound (MRgFUS)
The ExAblate 2100 MRgFUS system (InSightec, Inc., Dallas, Texas, USA) is a noninvasive thermal ablation device fully integrated with an MR imaging system and used for the ablation of soft tissue and bone.14-16 The ExAblate combines a focused ultrasound surgery (FUS) delivery system and a conventional diagnostic 3T Magnetic Resonance (MR) scanner. The ExAblate systems provide a real-time therapy planning algorithm, thermal dosimetry, and closed-loop therapy control. The ExAblate transducer device is an integrated component of the MR table
Also known as: ExAblate 2000/2100, MRgFUS
Proportion of participants with reported Device-Related Adverse Events
Proportion of participants with device-related adverse events will be determined by evaluating the incidence and severity of any device-related complications from the treatment day visit through the time of surgery or last post-treatment point. Patients will be followed for any reported adverse events following MRgFUS, per the Common Terminology Criteria for Adverse Events version 5.0
Time frame: Approximately 1-4 months
Percent change between baseline and post-treatment T-cell populations
Blood samples obtained at 1 week prior to MRgFUS and at 1 week post MRgFUS will be sent to the University of California, San Francisco (UCSF) Cancer Immunotherapy Lab. Flow cytometry panels will be performed to evaluate T-cell populations. Percent change between baseline and post-treatment samples will be calculated and displayed as a table
Time frame: Approximately 1-4 months
Percent change between baseline and post-treatment natural killer cell populations
Blood samples obtained at 1 week prior to MRgFUS and at 1 week post MRgFUS will be sent to the University of California, San Francisco (UCSF) Cancer Immunotherapy Lab. Flow cytometry panels will be performed to evaluate natural killer cell populations. Percent change between baseline and post-treatment samples will be calculated and displayed as a table
Time frame: Approximately 1-4 months
Percent change between baseline and post-treatment myeloid cell populations
Blood samples obtained at 1 week prior to MRgFUS and at 1 week post MRgFUS will be sent to the University of California, San Francisco (UCSF) Cancer Immunotherapy Lab. Flow cytometry panels will be performed to evaluate myeloid cell populations. Percent change between baseline and post-treatment samples will be calculated and displayed as a table
Time frame: Approximately 1-4 months
Percent change between baseline and post-treatment Cytokine Concentrations
Blood samples obtained at 1 week prior to MRgFUS and at 1 week post MRgFUS. Cytokine concentrations will also be measured. Percent change between baseline and post-treatment samples will be calculated
Time frame: Approximately 1-4 months
Presence of Immune Cell Populations in Sarcoma Tissue
The detectable presence of various immune populations in tumor specimens, including populations of CD3, CD4, CD8, CD19, CD68, FOXP3, PD-1, PD-L1, and CD45 positive cells will be determined. RNA sequencing will also be performed.
Time frame: Approximately 1-4 months
Immunohistochemistry analyses
Immunohistochemistry analyses in patients with newly diagnosed local UPS will be compared to an archived matched group of patients (matched for age, sex, and history of neoadjuvant chemotherapy) who had resection of UPS without pre-operative MRgFUS. Nanostring digital spatial profiling may also be used for tissue analysis
Time frame: Approximately 1-4 months
Plan to share: No
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This study is terminated, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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Matthew Bucknor