An interventional study of Biopsy Procedure and Biospecimen Collection in Metastatic Malignant Skin Neoplasm, Metastatic Malignant Soft Tissue Neoplasm and Recurrent Malignant Skin Neoplasm, sponsored by Mayo Clinic. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-11.
Sponsored by Mayo Clinic · Not applicable, Interventional, and Treatment
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.
PRIMARY OBJECTIVE:
I. To determine the maximum tolerated dose (MTD) of MBRT and describe the adverse events of treatment.
SECONDARY OBJECTIVE:
I. To assess the ability to maintain a distinct differential between peak and valley doses using film dosimetry.
EXPLORATORY OBJECTIVES:
I. To estimate the rate of freedom from local progression at 6 and 12 months after the start of MBRT.
II. To evaluate pre-treatment and post-treatment differential abundance of peripheral blood immune cell populations and their activation markers.
III. Explore germline and somatic mutations in homologous recombination (HR) genes and their association with freedom from local progression.
IV. Quantify the immune phenotypes and cell signaling in the tumor microenvironment pre-MBRT and post-MBRT using bulk ribonucleic acid (RNA)-sequencing (seq) data.
OUTLINE:
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.
After completion of study treatment, patients are followed up at weeks 2, 4, and 12, and months 6, 9, and 12.
604 studies on the registry are indexed under Skin Neoplasms; 126 are open to participants now.
This study's planned enrollment of 60 is close to the median of 55 across 408 interventional studies indexed under Skin Neoplasms.
Browse Skin Neoplasms studies →Mayo Clinic is the lead sponsor of 3,269 studies on the registry; 672 are open to participants now.
Of its 452 completed or terminated interventional studies of FDA-regulated products, 321 (71%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
Undergo biopsy
Also known as: Biopsy, BIOPSY_TYPE, Bx
Undergo collection of blood samples
Also known as: Biological Sample Collection, Biospecimen Collected, Specimen Collection
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
Undergo MBRT with tungsten slit collimator
Undergo MBRT with tungsten slit collimator
Also known as: MBRT
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.
Time frame: 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.
Time frame: Up to 12 months
Ability to maintain a distinct differential between peak and valley doses using film dosimetry
Film dosimetry will be obtained for every patient treatment. Radiochromic film will be placed directly on the tumor. Will measure and record peak and valley doses as well as the resulting peak-to-valley dose ratio.
Time frame: Up to 12 months
Incidence of adverse events
Safety will be assessed by CTCAE 5.0 by investigating (1) grade 3 AEs deemed possibly, probably, or definitely related to study treatment and (2) all grade 4-5 AEs regardless of attribution to the study treatment. The proportions of patients with these AEs at months 6, 9, and 12 will be evaluated.
Time frame: At months 6, 9, and 12
Started Aug 2025 (actual). Primary completion is estimated for Aug 2028, 35 months after the start.
Of 94 non-industry interventional studies with no phase under Skin Neoplasms, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 49. This study's planned 35 months is above that.
Counting every sponsor, half of 116 studies reached it within 27 months; a quarter within 10 and three quarters within 66.
How these figures are worked out, and which studies are left out of them.
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