Minibeam Radiation Therapy With Tungsten Slit Collimator for the Treatment of Recurrent or Metastatic Skin or Soft Tissue Tumors, MBRT1 Trial

NCT07062003 | Recruiting DMC FDA Device

• 3 other identifiers: GMROR2471NCI-2025-0442924-004810
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

This clinical trial tests the safety and best dose of minibeam radiation therapy (MBRT) with a tungsten slit collimator for treating patients with skin or soft tissue tumors that have come back after a period of improvement (recurrent) or that spread from where they first started (primary site) to other places in the body (metastatic). Radiation therapy uses high energy x-rays, particles, or radioactive seeds to kill tumor cells and shrink tumors. Tungsten is an extremely dense metal and is commonly used for blocking x-rays for minimum radiation exposure. A tungsten slit collimator is a device that separates an initially wide beam of x-rays into several very narrow individual beams of radiation. As radiation passes through the collimator, the radiation hits regions of solid tungsten and is blocked. In the open slit regions, radiation passes through to the intended target/tumor area defined by the physician. The tungsten slit collimator then selectively blocks portions of the radiation to create an alternating pattern of higher "peak" and lower "valley" radiation dose regions. These narrow beams of radiation are referred to as "minibeams" and the general approach referred to as MBRT.

Conditions

Metastatic Malignant Skin Neoplasm; Metastatic Malignant Soft Tissue Neoplasm; Recurrent Malignant Skin Neoplasm; Recurrent Malignant Soft Tissue Neoplasm; Skin Neoplasm; Soft Tissue Neoplasm

Outcome Measures

Primary Outcomes (2)

• Maximum tolerated dose

  The maximum tolerated dose is defined as the dose level associated with a dose limiting toxicity (DLT) probability closest to the target toxicity rate (30%), which will be determined based on the time-to-event Bayesian optimal interval procedures. The incidence and proportion of patients experiencing DLTs will be summarized for each dose level and across all dose levels.

  Up to 28 days

• Incidence of adverse events

  Safety will be assessed based on reported adverse events (AEs). The severity of AEs will be graded as mild, moderate, severe, or life-threatening according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.

  Up to 12 months

Secondary Outcomes (2)

• Ability to maintain a distinct differential between peak and valley doses using film dosimetry

  Up to 12 months

• Incidence of adverse events

  At months 6, 9, and 12

Study Arms (1)

Device feasibility (MBRT with tungsten slit collimator)

EXPERIMENTAL

Patients undergo MBRT with a tungsten slit collimator over 2-3 fractions on study. Patients also undergo standard of care CT simulation on study and undergo collection of blood samples and punch or core biopsy throughout the study.

Procedure: Biopsy Procedure; Procedure: Biospecimen Collection; Procedure: Computed Tomography; Other: Medical Device Usage and Evaluation; Radiation: Minibeam Radiation Therapy

Interventions

Biopsy Procedure PROCEDURE

Undergo biopsy

Also known as: Biopsy, BIOPSY_TYPE, Bx

Device feasibility (MBRT with tungsten slit collimator)

Biospecimen Collection PROCEDURE

Undergo collection of blood samples

Also known as: Biological Sample Collection, Biospecimen Collected, Specimen Collection

Device feasibility (MBRT with tungsten slit collimator)

Computed Tomography PROCEDURE

Undergo CT

Also known as: CAT, CAT Scan, Computed Axial Tomography, Computerized Axial Tomography, Computerized axial tomography (procedure), Computerized Tomography, Computerized Tomography (CT) scan, CT, CT Scan, tomography

Device feasibility (MBRT with tungsten slit collimator)

Medical Device Usage and Evaluation OTHER

Undergo MBRT with tungsten slit collimator

Device feasibility (MBRT with tungsten slit collimator)

Minibeam Radiation Therapy RADIATION

Undergo MBRT with tungsten slit collimator

Also known as: MBRT

Device feasibility (MBRT with tungsten slit collimator)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥ 18 years
• Histologically confirmed malignancy
• Primary, recurrent, or metastatic skin or superficial soft tissue tumor amenable to palliative orthovoltage radiotherapy
• Anticipated life expectancy ≥ 30 days and anticipated capacity for follow up for ≥ 30 days
• Negative pregnancy test done ≤ 28 days prior to registration, for biological women of childbearing potential only
• Willing to provide written informed consent
• Willing to allow baseline and follow up photograph acquisition for response and toxicity assessment
• Willing and able to return to enrolling institution for follow-up during the active monitoring phase of the study
• Willing to provide blood and tissue samples for correlative research purposes

You may not qualify if:

• Hematologic, germ cell, or any other tumor that the investigational team would deem to have a high likelihood of clinical complete response with standard palliative radiotherapy (8 Gy in 1, 30 Gy in 10, etc.)
• COHORT A (INTACT SKIN) ONLY: Prior radiotherapy targeting the lesion presenting for treatment or prior adjacent radiotherapy if \> 10 Gy overlaps with a portion of the planned target
• Treatment with a B-Raf proto-oncogene, serine/threonine kinase (BRAF) inhibitor, monoclonal antibodies targeting vascular endothelial growth factor (VEGF) (bevacizumab or ramucirumab) or small molecule inhibitors inhibiting VEGF within the last 2 weeks or planned treatment with BRAF inhibitor within 4 weeks after radiation
• Treatment with an investigational drug therapy within 2 weeks prior to or 4 weeks (the DLT monitoring period) after MBRT
• Any tumor with direct extension into the spine such that targeting the spine/spinal cord could not be avoided

Sponsors & Collaborators

• Mayo Clinic: lead

Study Sites (1)

Mayo Clinic in Rochester

Rochester, Minnesota, 55905, United States

RECRUITING

Related Links

• Mayo Clinic Clinical Trials

MeSH Terms

Conditions

Skin Neoplasms; Sarcoma; Soft Tissue Neoplasms

Interventions

Biopsy; Specimen Handling

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Skin Diseases; Skin and Connective Tissue Diseases; Neoplasms, Connective and Soft Tissue; Neoplasms by Histologic Type

Intervention Hierarchy (Ancestors)

Cytodiagnosis; Cytological Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Techniques, Surgical; Surgical Procedures, Operative; Investigative Techniques

Study Officials

• Scott C. Lester, MD

  Mayo Clinic in Rochester

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Clinical Trials Referral Office

CONTACT

855-776-0015; mayocliniccancerstudies@mayo.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 2, 2025
• First Posted: July 14, 2025
• Study Start: August 11, 2025
• Primary Completion (Estimated): August 1, 2028
• Study Completion (Estimated): August 1, 2028
• Last Updated: December 9, 2025

Record last verified: 2025-12

Locations

US (1)