Spine-like Phantom Reference for Dynamic CT Alignment

Solution Overview

Problem

Current radiation oncology phantom systems lack a fixed point of reference for accurate alignment during pre-treatment CT scans, and existing tumor tracking blocks do not provide a realistic representation of tumors in terms of size, shape, and density, leading to inaccuracies in radiation delivery.

Innovation Solution

A fixed-point mammalian spine-like apparatus provides an accurate and fixed alignment point of reference for pre-treatment CT scans, while a tumor tracking block with a variable size, shape, and density target object, along with metal fiducial markers, is designed to realistically represent tumors within the phantom system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a dynamic phantom system is used to simulate patient motion during radiotherapy, then the realism of representing patient anatomy is improved, but the alignment accuracy for pre-treatment CT scans deteriorates due to lack of fixed reference points

Engineering Contradiction:

Improverealism of patient motion simulationVSAvoidalignment accuracy for pre-treatment CT

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The phantom system is divided into two distinct segments: a fixed reference frame containing stable anatomical landmarks (spine, ribs) and a dynamic patient body portion that moves to simulate respiration. This segmentation allows the fixed portion to provide accurate alignment references while the dynamic portion maintains realistic motion simulation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Fixed reference points (fiducial markers, anatomical landmarks) are introduced as intermediaries between the moving patient body and the stationary imaging/radiation delivery system. These intermediaries provide stable reference frames for alignment while allowing the patient body to move independently.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If a simple plastic cube with a perfectly shaped sphere is used as a target object, then the ease of identification and tracking is improved, but the realism of representing actual tumors deteriorates

Engineering Contradiction:

Improveease of target identification and trackingVSAvoidrealism of tumor representation

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The target object incorporates localized high-contrast features (metal fiducial markers, high-density inserts) within a tissue-equivalent material matrix. This creates local quality differences that enhance detectability while maintaining overall tumor-like appearance and density characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The target object is constructed as a composite material system combining tissue-equivalent plastic or rubber with metal fiducial markers and/or high-density inserts. This composite structure provides both the realistic density and texture of actual tumors and the enhanced tracking capability through metal markers visible on imaging systems.

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If a target object with uniform density is used in the tracking block, then the ease of manufacturing is improved, but the accuracy of representing variable tumor density deteriorates

Engineering Contradiction:

Improveease of target block fabricationVSAvoidaccuracy of tumor density representation

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The target object incorporates localized high-contrast features (metal fiducial markers, high-density inserts) within a tissue-equivalent material matrix. This creates local quality differences that enhance detectability while maintaining overall tumor-like appearance and density characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The target object is constructed as a composite material system combining tissue-equivalent plastic or rubber with metal fiducial markers and/or high-density inserts. This composite structure provides both the realistic density and texture of actual tumors and the enhanced tracking capability through metal markers visible on imaging systems.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS12285632B2Fixed-point mammalian spine-like apparatus that provides an accurate and fixed alignment point of reference for pre-treatment CT while phantom and radiation detectors of a dynamic radiation oncological phantom system are in motion and a tumor tracking block with a target object of variable size, shape, and density and metal fiducial markers used to mark tumors in human treatment

Publication Date: 2025.04.29 KEMPENICH AARON ANTHONY

AI summary

A fixed-point mammalian spine-like apparatus and a tumor tracking block with a variable size, shape, density target object and metal fiducial markers used to mark tumors in human treatment are disclosed. The tumor tracking block is configured in shape and size to fit into a dock of a dynamic radiation oncological phantom system with the target tracked in coordination with a linear accelerator. The fixed-point mammalian spine-like apparatus provides an accurate and fixed alignment point of reference for pre-treatment dose delivery evaluation the target is in motion. The fixed-point mammalian spine-like apparatus includes a connector that attaches to a frame of the phantom system, ensuring that the alignment point of reference of planning CT data to pre-treatment CT (kV or MV) is proper and accurate, while allowing the phantom with its detectors to be in motion, realistically representing a human under treatment.