# US 2021/0275833 A1 · Dosimetry systems for radiation treatment using radiation-detector-triggered cameras to image cherenkov emissions or thin-sheet scintillators

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2021/0275833 A1
- Document ID: US20210275833A1
- Status: Published application
- Kind: A1
- Application number: 17/313,838
- Filed: 2021-05-06
- Published: 2021-09-09
- Earliest claimed: 2018-02-22
- Assignees: Trustees of Dartmouth College; Doseoptics, LLC
- Applicants: The Trustees of Dartmouth College; Doseoptics, LLC
- Inventors: Venkataramanan Krishnaswamy; Petr Bruza, JR.; Michael Jermyn; Brian W. Pogue; David Gladstone; Lesley A. Jarvis; Irwin Tendler
- Web page: https://patentgrep.com/patent/US20210275833A1

## CPC

- A61N 5/103: {Treatment planning systems}
- A61N 5/1071: {for verifying the dose delivered by the treatment plan}
- A61B 5/0071: {by measuring fluorescence emission}
- A61B 5/0077: {Devices for viewing the surface of the body, e.g. camera, magnifying lens}
- A61B 5/1455: using optical sensors, e.g. spectral photometrical oximeters
- A61B 5/7292: {Prospective gating, i.e. predicting the occurrence of a physiological event for use as a synchronisation signal}
- A61N 5/1045: {using a multi-leaf collimator, e.g. for intensity modulated radiation therapy or IMRT}
- A61N 5/1049: {for verifying the position of the patient with respect to the radiation beam}
- A61N 5/1068: {Gating the beam as a function of a physiological signal}
- A61N 5/1075: {for testing, calibrating, or quality assurance of the radiation treatment apparatus}
- A61N 5/1077: {Beam delivery systems}
- A61N 5/1081: {Rotating beam systems with a specific mechanical construction, e.g. gantries}
- G01T 1/023: {Scintillation dose-rate meters}
- G01T 1/15: Instruments in which pulses generated by a radiation detector are integrated, e.g. by a diode pump circuit
- G01T 1/20: with scintillation detectors
- G01T 1/2002: {Optical details, e.g. reflecting or diffusing layers}
- G01T 1/22: with Cerenkov detectors
- G01T 7/005: {calibration techniques (stabilization of spectrometer G01T1/40)}
- A61B 5/4836: {Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence)}
- A61N 2005/1054: {using a portal imaging system}
- A61N 2005/1059: {using cameras imaging the patient}
- A61N 2005/1096: {Elements inserted into the radiation path placed on the patient, e.g. bags, bolus, compensators}
- A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B)
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- G01T: MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry G01N23/00; tubes for determining the presence, intensity, density or energy of radiation or particles H01J47/00)

## Abstract

A Cherenkov-based or thin-sheet scintillator-based imaging system uses a radio-optical triggering unit (RTU) that detects scattered radiation in a fast-response scintillator to detect pulses of radiation to permit capture of Cherenkov-light or scintillator-light images during pulses of radiation and background images at times when pulses of radiation are not present without need for electrical interface to the accelerator that provides the pulses of radiation. The Cherenkov images are corrected by background subtraction and used for purposes including optimization of treatment, commissioning, routine quality auditing, R&D, and manufacture. The radio-optical triggering unit employs high-speed, highly sensitive radio-optical sensing to generate a digital timing signal which is synchronous with the treatment beam for use in triggering Cherenkov light or scintillator light imaging.

## Claims

### Claim 1

A system for dosimetry, comprising:
a radiation source adapted to provide a pulsed radiation beam to a treatment zone;
a thin sheet of scintillator disposed between the radiation source and skin of a subject, the thin sheet of scintillator being in the treatment zone;
a gated camera configured to image the sheet of scintillator;
an image capture and processing machine coupled to receive images from the gated camera; and
a first radiation-detecting triggering unit (RTU) configured to detect scattered radiation from the pulsed radiation beam and coupled to trigger the gated camera upon detecting the scattered radiation;
wherein the gated camera is configured to capture images of light from the thin sheet of scintillator during a plurality of pulses of the pulsed radiation beam while excluding light received from the thin sheet of scintillator between pulses of the plurality of pulses of the pulsed radiation beam to form a scintillation image.

### Claim 2 (depends on 1)

The system of claim 1 wherein the thin sheet of scintillator is a conformal sheet of scintillating material in contact with skin of the subject.

### Claim 3 (depends on 1)

The system of claim 1 wherein the image capture and processing machine is configured to subtract a background image from the scintillation image, the background image being obtained by the gated camera at times excluding times of pulses of the pulsed radiation beam.

### Claim 4 (depends on 3)

The system of claim 3 further comprising a second RTU, and wherein the gated camera is configured to capture images of light from the thin sheet of scintillator when both the first RTU and the second RTU detect radiation simultaneously.

### Claim 5 (depends on 3)

The system of claim 3 wherein the image capture and processing machine further comprises a database containing calibration information associated with individual thin sheets of scintillator, and the image capture and processing machine is configured to correct the scintillation image according to the calibration information.

### Claim 6 (depends on 3)

The system of claim 3 further comprising a three-dimensional (3-D) imaging camera and wherein the image capture and processing machine is configured to extract a 3-D surface model of the thin sheet of scintillator and to use the 3-D surface model to correct images received from the gated camera.