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

Study 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.

Primary Outcome

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.

Conditions Studied

Interventions

• PROCEDURE Biospecimen Collection
• PROCEDURE Computed Tomography
• PROCEDURE Biopsy Procedure
• OTHER Medical Device Usage and Evaluation
• RADIATION Minibeam Radiation Therapy

Study Locations (1)