Fabrication and irradiation of a radioactive isotope skin patch

Inventors

Sarazin, Frédéric • Zimmerman, Jeramy • Morneau, Rachel • Ritter, Martin • Westerly, David • Diot, Quentin

Assignees

Colorado School of Mines • University of Colorado Colorado Springs

Abstract

A novel treatment method is disclosed, wherein a patch configured to be placed on a patient's skin is activated, before placement, to deliver localized radiotherapy to a diseased area of the skin. The disclosed devices and methods minimize or prevent collateral damage to the neighboring tissues. In most cases, the disclosed devices and methods include coating a contoured, solid, flexible or conformal substrate with one or more lanthanide elements and then activating (e.g. neutron irradiation) the elements such that its resulting radioisotope emits beta-particles into the diseased skin surface when applied to the patient's skin. Novel processes are described for fabricating and irradiating the lanthanide-based skin patch, for example a holmium-based skin patch.

Core Innovation

The invention relates to a skin patch device for treating a skin condition in a patient, where a substrate layer and an isotope foil layer are configured for neutron activation. A foil layer comprising an isotope of a lanthanide element selected from a specified group is irradiated with a neutron flux to convert the isotope into a radioisotope that emits beta particles during decay. The device is structured so the foil layer is spatially uniform, with thickness varying by less than 10% over the area disposed on the substrate layer.

The skin patch further includes an encapsulation layer disposed over the foil layer, wherein the encapsulation material is selected based on temperature and radiation resistance in the radiation process. In manufacturing, the invention comprises preparing a substrate layer selected for temperature and radiation resistance, depositing at least one isotope foil layer with spatially uniform thickness that varies by less than 10% over the deposited area, and adding an encapsulating material selected for temperature and radiation resistance over the deposited foil layer.

In additional device configurations, the patch may include a backing layer adjacent the substrate layer that comprises a backing material selected to block radiation from the foil layer after activation. The isotope layer can be positioned over an area between the substrate layer and the encapsulation layer, and thickness is constrained to a uniform thickness range with less than 10% variation over the area. The invention also covers configurations with additional structural layers, including optional modulation and/or radioprotective layers and optional second foil layers, to modify radiation reaching the skin after activation.

Claims Coverage

The document provides three independent claim sets covering a skin patch device, a method of manufacturing the skin patch device, and another skin patch device configuration. Across these independent claims, the coverage emphasizes activation of a beta-emitting radioisotope from an isotope foil layer using neutron flux, spatial thickness uniformity limits, temperature- and radiation-resistant substrate and encapsulation materials, and radiation blocking or modulating features via backing and additional layers.

Across the independent claims, the core claimed inventive subject matter is a skin patch device and its manufacture that uses neutron flux activation of a lanthanide/yttrium isotope metal foil to generate beta-emitting radioisotopes, while requiring spatially uniform isotope-layer thickness with less than 10% variation and employing temperature- and radiation-resistant substrate and encapsulation materials. The independent device claims further add a backing layer selected to block radiation after activation and constrain isotope-layer thickness within a defined uniform range.

Stated Advantages

Documented Applications