Multi-modal imaging capsule for image-guided proton beam therapy, consisting of a biocompatible polymer layer, .sup.18O-enriched water, and a contrast agent. The biocompatible capsule may be inserted near or inside a tumor under the guidance of X-ray, magnetic resonance, or ultrasonography imaging. Upon proton beam irradiation, the capsule emits positrons, allowing the tumor to be imaged and tracked by a PET detector.

A carrier having one or more non-planar surfaces may be embedded with one or more radioactive seeds. A spherical carrier may be substantially radially symmetrical around an axis or a spherical carrier may include a non-spherical portion, such as a tapered portion that extends from a spherical portion.

Custom radioactive seed carriers are fabricated pre-operatively and/or intra-operatively to more precisely match carrier specification of a radiation treatment plan for a particular patient. One or more carrier specification component, such as a 3D printer, injection molding system, machining component, or bioprinter, may be utilized to create the custom carrier.

Multi-modal imaging capsule for image-guided proton beam therapy, consisting of a biocompatible polymer layer, .sup.18O-enriched water, and a contrast agent. The biocompatible capsule may be inserted near or inside a tumor under the guidance of X-ray, magnetic resonance, or ultrasonography imaging. Upon proton beam irradiation, the capsule emits positrons, allowing the tumor to be imaged and tracked by a PET detector.

A method of preparing a radioactive material to serve as a radiation source for an intra-lumen imaging capsule, including, receiving a radioactive substance having grains in powder form, forming a solid pellet wherein the grains of the radioactive substance are dispersed homogenously in the pellet and surrounded by less dense materials having lower radiation absorption.

Provided is a method for producing a nanoparticle having a uniform particle diameter. A method for producing a nanoparticle comprising an amphiphilic block polymer, the method comprising: with use of a nanoparticle production device that includes: a polymer solution supply channel Cp; an aqueous liquid supply channel Cw1, Cw2; a junction J of the channels; a nanoparticle formation channel Cn; and a nanoparticle-containing liquid outlet On, supplying a solution of a polymer and an aqueous liquid to the junction J; forming a nanoparticle while bringing a laminar flow of the polymer solution and a laminar flow of the aqueous liquid into contact with each other; obtaining a liquid containing the formed nanoparticle from the nanoparticle-containing liquid outlet; and controlling a particle diameter of the nanoparticle by measuring a statistic of the particle diameter of the formed nanoparticle in real time, and by controlling at least one of an amount of the polymer solution supplied to the junction and an amount of the aqueous liquid supplied to the junction such that the statistic becomes a desired value.