Monte Carlo Material Maps for Proton Therapy Implants

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Solution Overview

Problem

Current proton therapy treatment planning systems inaccurately characterize metal implants due to CT image artifacts, leading to incorrect dose calculations and exclusion of patients with implants from treatment.

Innovation Solution

A system and method using Monte Carlo simulations to determine the material composition, density, and geometry of implants by analyzing particle counting data and representation data, generating a material map for accurate dose calculation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If CT images are used to calculate dose in proton therapy treatment planning, then dose calculation can be performed, but metal implants cause severe artifacts leading to inaccurate characterization of the implant and surrounding tissues

Engineering Contradiction:
Improvedose calculation capabilityVSAvoidimplant characterization accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary material map generation process that acts as a mediator between the CT images and dose calculation. This material map, generated through Monte Carlo simulations, translates the artifact-prone CT data into accurate material composition and density information, enabling precise dose calculation without being affected by metal artifacts

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the conventional direct CT-to-dose calculation mechanism with a Monte Carlo simulation-based material map generation process. This substitution uses probabilistic particle interaction modeling to overcome the deterministic limitations of traditional CT-based dose calculation in the presence of metal implants

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If manual override of Monte Carlo dose calculation is performed to address implant inaccuracies, then dose accuracy may be improved, but the process becomes time-consuming and often inaccurate or not feasible due to lack of detailed implant information

Engineering Contradiction:
Improvedose calculation accuracyVSAvoidtreatment planning time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs self-service by automatically generating material maps through Monte Carlo simulations using available imaging data. The process autonomously characterizes implant materials and surrounding tissues without requiring manual intervention or external implant specifications, thereby maintaining high accuracy while minimizing time loss

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The material map generation is performed as a preliminary step before dose calculation. By pre-characterizing the implant and surrounding tissues through simulation, the system prepares accurate input data in advance, eliminating the need for time-consuming manual overrides during the dosimetry process

Inventive Principle:
Principle #10Preliminary action

3Reliability

If metal implant patients are excluded from general guidelines to avoid poor clinical outcomes, then patient safety is improved, but fewer patients can receive proton therapy

Engineering Contradiction:
Improveclinical outcome reliabilityVSAvoidtreatment availability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent fundamentally changes the input parameters for dose calculation by using material maps derived from Monte Carlo simulations instead of conventional CT-based parameters. This parameter transformation enables accurate dosimetry for implant patients, allowing the treatment system to adapt to previously excluded patient populations while maintaining clinical reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The material map generation approach serves multiple functions: it characterizes implants, characterizes surrounding tissues, and enables dose calculation for diverse patient populations including those with metal implants. This universal method replaces the need for separate handling protocols, expanding treatment availability across all patient types

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables accurate dose calculation for patients with implants, allowing more patients to receive proton therapy by overcoming CT artifact inaccuracies.

Implementation Method 1

Proposed solutions, such as overriding techniques and various metal artifact reduction algorithms, to address these inaccuracies have been time-consuming as well as ineffective in addressing the artifacts. For example, the detailed dimension and material properties of implants are generally not described in surgical notes or otherwise available, so a manual override of Monte Carlo (MC) dose calculation in treatment planning systems could be inaccurate or not feasible.

Methodology Applied
Scientific EffectMonte Carlo simulation:

Implementation Method 2

The method may include receiving particle counting data and representation data for a volume of interest of a patient for one or more sessions. The method may further include determining most probable energy (MPE) using particle energy determined from the particle counting data.

Methodology Applied
Scientific EffectParticle energy measurement:

Data Source

PatentUS12531161B2Systems and methods for generating material maps for treatment planning using Monte Carlo methods
Publication Date: 2026.01.20 EMORY UNIVERSITY
  • US12531161B2 patent drawing
  • US12531161B2 patent drawing
  • US12531161B2 patent drawing

AI summary

The disclosure relates to systems and methods for accurate generation of material maps of volume of interests, for example, that include implants, for proton radiation therapy. In one implementation, the method may include determining most probable energy (MPE) using particle energy determined from particle counting data. The method may include generating a plurality of simulations that simulate interactions using different combination of properties for the volume of interest determined from representation data and/or from a database to determine most probable energy (MPE) for each simulation. The method may include comparing the MPE determined using the particle counting data to the MPE determined from each simulation. The method may further include selecting one simulation of the plurality of simulations based on the comparing. The method may also include generating a material map for the volume of interest using the one or more properties corresponding to the one simulation.