EP-4736941-A1 - MULTI-LEAF COLLIMATORS, RADIATION TREATMENT DEVICES, AND CONTROL METHODS THEREOF

EP4736941A1EP 4736941 A1EP4736941 A1EP 4736941A1EP-4736941-A1

Abstract

An MLC is provided, the MLC includes: a plurality of leaves; first driving mechanisms connected to the leaves and configured to drive the leaves to move to form a radiation field; and at least one leaf head mechanism mounted on at least one corresponding leaf of the leaves and configured to adjust the radiation field.

Inventors

ZHANG, JIAN
SONG, BIN
QU, Yixiang

Assignees

Shanghai United Imaging Healthcare Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20251031

Claims (15)

A multi-leaf collimator, comprising: a plurality of leaves; a first driving mechanism connected to the leaves and configured to drive the leaves to move to form a radiation field; and at least one leaf head mechanism mounted on at least one corresponding leaf of the leaves and configured to adjust the radiation field.
The multi-leaf collimator of claim 1, wherein each leaf head mechanism includes: leaf heads, each of which has a thickness less than a thickness of the corresponding leaf; and a second driving mechanism configured to drive the leaf heads to move relative to the corresponding leaf.
The multi-leaf collimator of claim 2, wherein the corresponding leaf includes a first end close to the radiation field center, a second end away from the radiation field center, a third end close to a radiation source, and a fourth end away from the radiation source, the leaf head mechanism is mounted on the first end or the fourth end.
The multi-leaf collimator of claim 3, wherein the leaf head mechanism is mounted on the first end, the first end includes a first recess member, the first recess member including first motion guide grooves disposed inside, each leaf head includes a first protrusion member matching the first recess member, and the first motion guide grooves are configured to mount the first protrusion members of the leaf heads and limit a motion direction of the leaf heads.
The multi-leaf collimator of claim 4, wherein the first end further includes an extension member closer to the radiation field center relative to the first recess member, each leaf head further includes an abutting member closer to the radiation field center relative to its first protrusion member, and the second driving mechanism is mounted on the extension member and connected to the abutting members of the leaf heads to drive the leaf heads to move relative to the corresponding leaf.
The multi-leaf collimator of any one of claims 1-5, wherein the leaves include radiation shielding material, and the radiation field is formed by the leaves.
The multi-leaf collimator of any one of claims 2 to 6, wherein the second driving mechanism includes a base, a control film mounted on the base, and a control power supply, the control film is connected to the leaf heads, the control power supply is configured to apply a voltage to the control film to cause the control film to produce a target deformation, and the target deformation of the control film drives the leaf heads to move.
The multi-leaf collimator of claim 7, wherein the control film comprises a plurality of control sub-films arranged in parallel, and the control power supply is configured to individually apply the voltage to each control sub-film.
The multi-leaf collimator of claim 7 or 8 , wherein the multi-leaf collimator further includes a processing device and sensors, each of the sensors is mounted on one of the leaf heads, and the processing device is configured to: determine an initial magnitude of the voltage applied by the control power source based on a response model of the control film and second target displacements of the leaf heads, wherein the response model reflects a relationship between the voltage and a mechanical deformation of the control film; obtain actual displacements of the leaf heads collected by the sensors after motions of the leaf heads; and determine an updated magnitude of the voltage based on the second target displacements and the actual displacements of the leaf heads.
The multi-leaf collimator of any one of claims 2-9, wherein the leaf heads are configured to move collectively with the corresponding leaf driven by the first driving mechanism, or the leaf heads are configured to move independently driven by the second driving mechanism while the corresponding leaf is stationary, and the second driving mechanism is different from the first driving mechanism.
The multi-leaf collimator of any one of claims 2 to 10, wherein the second driving mechanism is configured to individually drive each leaf head to move.
A radiation therapy device, including the multi-leaf collimator of any one of claims 1 to 11.
A double-layer multi-leaf collimator, including an upper multi-leaf collimator and a lower multi-leaf collimator, wherein the upper multi-leaf collimator is closer to a radiation source than the lower multi-leaf collimator, and each of the upper multi-leaf collimator and the lower multi-leaf collimator is the multi-leaf collimator of claim 2.
A method for controlling the multi-leaf collimator of claim 10, implemented on a computing device having at least one processor and at least one storage device, the method comprising: for each leaf, determining a first target displacement of the leaf based on contour information of a target radiation field corresponding to a target object; and controlling the first driving mechanism to drive the leaf to move based on the first target displacement to form the radiation field; for each leaf head, determining a second target displacement of the leaf head based on contour information of the radiation field and the contour information of the target radiation field; and controlling the second driving mechanism to drive the leaf head to move based on the second target displacement to adjust the radiation field.
The method of claim 14, further comprising obtaining optical image data of the multi-leaf collimator that is collected after motions of the plurality of leaves; and determining the contour information of the radiation field based on the optical image data.

Description

TECHNICAL FIELD The present disclosure relates to the field of radiation treatment technology, and in particular, relates to a multi-leaf collimator, a radiation treatment device, and a control method thereof. BACKGROUND Radiation treatment is one of the most important methods for treating tumors, and precise radiation treatment helps improve treatment effect while reducing harm to patients during treatment. A multi-leaf collimator (MLC) is a core device enabling precise radiation treatment, implementing a conformal and intensity-modulated therapy, and enhancing therapeutic outcomes. The MLC with a high resolution helps doctors to target a treatment region more precisely and minimize damage to surrounding healthy tissues in the radiation treatment, which improves the treatment effectiveness and reduces side effects. However, due to the constraints of the MLC's transmission mechanism, the thickness of its leaves cannot be made too thin, which often results in relatively low resolution for the MLC. Therefore, it is desirable to provide an MLC with a high resolution, a radiation treatment device including such MLC, and a control method thereof. SUMMARY According to an aspect of the present disclosure, a multi-leaf collimator is provided. The multi-leaf collimator comprises a plurality of leaves; a first driving mechanism connected to the leaves and configured to drive the leaves to move to form a radiation field; and at least one leaf head mechanism mounted on at least one corresponding leaf of the leaves and configured to adjust the radiation field. In some embodiments, each of the leaves has at least one corresponding leaf head mechanism. In some embodiments, each leaf head mechanism includes leaf heads, each of which has a thickness less than a thickness of the corresponding leaf; and a second driving mechanism configured to drive the leaf heads to move relative to the corresponding leaf. In some embodiments, the corresponding leaf includes a first end close to the radiation field center, a second end away from the radiation field center, a third end close to a radiation source, and a fourth end away from the radiation source, wherein the leaf head mechanism is mounted on the first end or the fourth end. In some embodiments, the leaf head mechanism is mounted on the first end, and the first end includes a first recess member. The first recess member includes first motion guide grooves disposed inside. Each leaf head includes a first protrusion member matching the first recess member. The first motion guide grooves are configured to mount the first protrusion members of the leaf heads and limit a motion direction of the leaf heads. In some embodiments, the first end further includes an extension member closer to the radiation field center relative to the first recess member. Each leaf head further includes an abutting member closer to the radiation field center relative to its first protrusion member, and the second driving mechanism is mounted on the extension member and connected to the abutting members of the leaf heads to drive the leaf heads to move relative to the corresponding leaf. In some embodiments, the leaf head mechanism is mounted on the fourth end, and the fourth end includes a suspension member suspended on the fourth end of the corresponding leaf. The suspension member includes a second recess member, and the second recess member includes second motion guide grooves disposed inside. Each leaf head includes a second protrusion member matching the second recess member, and the second motion guide grooves are configured to mount the second protrusion members of the leaf heads and limit a motion direction of the leaf heads. In some embodiments, the second driving mechanism is mounted on a recess bottom surface of the second recess member and connected to the second protrusion members of the leaf heads to drive the leaf heads to move relative to the corresponding leaf. In some embodiments, the leaves include radiation shielding material, and the radiation field is formed by the leaves. In some embodiments, the second driving mechanism includes a base, a control film mounted on the base, and a control power supply. The control film is connected to the leaf heads. The control power supply is configured to apply a voltage to the control film to cause the control film to produce a target deformation, and the target deformation of the control film drives the leaf heads to move. In some embodiments, the control film comprises a plurality of control sub-films arranged in parallel, and the control power supply is configured to individually apply the voltage to each control sub-film. In some embodiments, the control film includes at least one of an ion-exchange polymer metal composite (IPMC) or a memory alloy material. In some embodiments, the multi-leaf collimator further includes a processing device and sensors. Each of the sensors is mounted on one of the leaf heads, and the processing device is config