Minibeam radiation with a tungsten slit collimator for recurrent or metastatic skin and superficial soft tissue tumors

A Dose Finding Study of MiniBeam RadioTherapy for Skin and Superficial Soft Tissue Tumors (MBRT1)

Not applicable Interventional Mayo Clinic · NCT07062003

This trial tests whether minibeam radiation delivered through a tungsten slit collimator is safe and what dose works best for adults with recurrent or metastatic skin or superficial soft tissue tumors.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years and up
SexAll
SponsorMayo Clinic Academic / other
Drugs / interventionsbevacizumab, ramucirumab, radiation
Locations1 site (Rochester, Minnesota)
Trial IDNCT07062003 on ClinicalTrials.gov

What this trial studies

This interventional phase I protocol delivers minibeam radiation therapy (MBRT) through a tungsten slit collimator in 2–3 fractions to patients with recurrent or metastatic skin or superficial soft tissue tumors. The primary goal is to determine the maximum tolerated dose and characterize adverse events; secondary and exploratory endpoints include film dosimetry to measure peak/valley dose differentials, local progression rates at 6 and 12 months, and immune and genomic correlative studies. Participants undergo CT simulation, serial blood draws, and punch or core biopsies before and after MBRT to study systemic and tumor immune changes and DNA repair gene alterations. Patients are followed at weeks 2, 4, and 12 and months 6, 9, and 12 for safety and local control monitoring.

Who should consider this trial

Good fit: Adults (≥18 years) with histologically confirmed primary, recurrent, or metastatic skin or superficial soft tissue tumors amenable to palliative orthovoltage radiotherapy who can consent to biopsies and blood draws and return to Mayo Clinic in Rochester for treatment and follow-up.

Not a fit: Patients with hematologic or germ cell tumors, tumors expected to have a complete response to standard single-fraction or conventional palliative radiotherapy, or lesions not suitable for orthovoltage delivery are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, MBRT could improve local tumor control while reducing damage to surrounding normal skin and soft tissue by delivering concentrated narrow beams of radiation with spared regions between beams.

How similar studies have performed: Minibeam and microbeam radiation approaches have shown promising results in preclinical studies but human clinical data are limited and this application remains early and exploratory.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Where this trial is running

Rochester, Minnesota

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Metastatic Malignant Skin NeoplasmMetastatic Malignant Soft Tissue NeoplasmRecurrent Malignant Skin NeoplasmRecurrent Malignant Soft Tissue NeoplasmSkin NeoplasmSoft Tissue Neoplasm
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.