# US 9,435,895 B2 · Multi-modality dosimeter for use with arc-based radiotherapy quality assurance phantom

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

- Number: US 9,435,895 B2
- Document ID: US9435895B2
- Status: Granted
- Kind: B2
- Application number: 14/702,148
- Filed: 2015-05-01
- Published: 2015-11-05
- Granted: 2016-09-06
- Earliest claimed: 2014-05-02
- Applicants: Mark Ruschin; Alexander Lightstone; Ian Parkinson; Harry Easton; David Beachey; Anthony Kim
- Inventors: Mark Ruschin; Alexander Lightstone; Ian Parkinson; Harry Easton; David Beachey; Anthony Kim
- Web page: https://patentgrep.com/patent/US9435895B2

## CPC

- G01T 1/04: Chemical dosimeters (G01T1/06, G01T1/08 take precedence)
- A61N 5/1075: {for testing, calibrating, or quality assurance of the radiation treatment apparatus}
- G01T 1/08: Photographic dosimeters {(photometry G01J1/52)}
- G01T 1/161: Applications in the field of nuclear medicine, e.g. in vivo counting {(apparatus for radiation diagnosis A61B6/00)}
- G01T 7/005: {calibration techniques (stabilization of spectrometer G01T1/40)}
- A61N 5/1081: {Rotating beam systems with a specific mechanical construction, e.g. gantries}
- A61N 2005/1076: {using a dummy object placed in the radiation field, e.g. phantom}
- 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)
- 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)

## Abstract

A dosimeter that is configured to assist with patient-specific quality assurance (“QA”) in arc-based radiotherapy, such as stereotactic radiotherapy, is provided. The dosimeter facilitates acquiring multiple different dosimetric measurements simultaneously. For instance, the dosimeter can be configured to acquire dosimetric measurements from multiple different modalities, including gel dosimetry and film dosimetry, and is configured for simultaneous use with a diode-array QA phantom.

## Claims

### Claim 1

A dosimeter, comprising:
a film assembly comprising a plurality of film inserts arranged in a parallel stacked arrangement, each film insert being configured to receive a film;
a film holder configured to receive the film assembly and having a cylindrical outer surface that is sized to be received by a bore of a cylindrical QA phantom; and
wherein each of the plurality of film inserts includes a plurality of markers configured to imprint a pattern on a film inserted in each film insert.

### Claim 2 (depends on 1)

The dosimeter as recited in claim 1, further comprising a gel dosimeter insert, and wherein the film holder is further configured to receive the gel dosimeter insert.

### Claim 3 (depends on 2)

The dosimeter as recited in claim 2, wherein the film assembly comprises the gel dosimeter insert in addition to the plurality of film inserts, wherein the gel dosimeter insert is also arranged in the parallel stacked arrangement.

### Claim 4 (depends on 1)

The dosimeter as recited in claim 1, wherein the plurality of markers for each of the plurality of film inserts is arranged differently such that a different pattern is imprinted on a film inserted in each different film insert.

### Claim 5

A non-transitory computer-implemented method for comparing dose measurements obtained with a multimodality dosimeter with a clinical treatment plan, the steps of the method comprising:
(a) receiving dose measurement data in a computer system, the dose measurement data being obtained with a multimodality dosimeter;
(b) generating a scaled calibration curve based on calibration data using the computer system;
(c) generating scaled dose measurement data by scaling the received dose measurement data using the scaled calibration curve using the computer system;
(d) co-registering the scaled dose measurement data, using the computer system, with a clinical treatment plan stored in a memory;
(e) comparing the scaled dose measurement data with the clinical treatment plan using the computer system; and
(f) generating a report based on comparing the scaled dose measurement data with the clinical treatment plan.

### Claim 6 (depends on 5)

The non-transitory computer-implemented method as recited in claim 5, wherein the dose measurement data received in step (a) comprises multiple different dose measurements.

### Claim 7 (depends on 6)

The non-transitory computer-implemented method as recited in claim 6, wherein step (a) comprises producing average dose measurement data by computing an average of the multiple different dose measurements and storing the average dose measurement data as the dose measurement data.

### Claim 8 (depends on 6)

The non-transitory computer-implemented method as recited in claim 6 wherein the multiple different dose measurements comprise dose measurements obtained with multiple different dose measurement modalities.

### Claim 9 (depends on 8)

The non-transitory computer-implemented method as recited in claim 8, wherein the multiple different dose measurement modalities include film measurements and gel dosimetry measurements.

### Claim 10 (depends on 9)

The non-transitory computer-implemented method as recited in claim 9, wherein the film measurements include film measurements obtained in multiple different planes-of-interest.

### Claim 11 (depends on 5)

The non-transitory computer-implemented method as recited in claim 5, wherein the calibration data used in step (b) comprises a plurality of calibration films.

### Claim 12 (depends on 5)

The non-transitory computer-implemented method as recited in claim 5, wherein the calibration data used in step (b) comprises a native calibration curve.

### Claim 13 (depends on 5)

The non-transitory computer-implemented method as recited in claim 5, wherein step (b) includes scaling a primary calibration curve based on the calibration data.

### Claim 14 (depends on 13)

The non-transitory computer-implemented method as recited in claim 13, wherein the primary calibration curve is scaled by comparing a mean pixel value at each dose level in the received dose measurement data to the primary calibration curve and applying a correction factor to the primary calibration curve based on comparing the mean pixel value at each dose level to the primary calibration curve.

### Claim 15 (depends on 5)

The non-transitory computer-implemented method as recited in claim 5, wherein step (e) includes comparing the scaled dose measurement data with the clinical treatment plan based on an absolute dose gamma comparison.

### Claim 16 (depends on 5)

The non-transitory computer-implemented method as recited in claim 5, wherein step (e) includes comparing the scaled dose measurement data with the clinical treatment plan based on a distance-to-agreement comparison.