Spatiotemporal Radiation Dose Modulation for Tumor Targeting

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Solution Overview

Problem

Conventional external beam radiation therapy methods face challenges in minimizing the radiobiological effect on healthy tissues while maintaining a high dose rate to the target volume, leading to potential damage and reduced cancer cure rates.

Innovation Solution

The method involves modifying the temporal and spatial patterning of the radiation dose to increase the dose rate to the target volume while reducing the dose rate to surrounding healthy tissues, using spatiotemporal patterns and cellular repair considerations to minimize radiobiological effects on normal tissues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional external beam radiation therapy is used to deliver ionizing radiation to the target volume, then the radiation dose can be delivered to the tumor, but the surrounding healthy tissue receives radiation doses in excess of clinically acceptable tolerances

Engineering Contradiction:

Improveradiation dose to target volumeVSAvoidradiation dose to healthy tissue

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The radiation beam is divided into multiple sub-beams or beamlets that can be independently controlled in intensity, allowing different regions to receive different dose levels. This segmentation enables precise dose painting where tumor regions receive higher doses while healthy tissues receive reduced doses.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions within the radiation field are assigned different dose intensities based on local requirements. The multileaf collimator dynamically adjusts the intensity distribution across the beam profile to deliver high doses to tumor sub-volumes while sparing adjacent healthy tissues with lower doses.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If intensity modulated radiation therapy with multiple independently controlled beams is used, then the precision of dose delivery to the target volume is improved, but the complexity of the treatment planning and delivery system increases

Engineering Contradiction:

Improvedose delivery precisionVSAvoidtreatment planning system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The multileaf collimator leaves move dynamically during radiation delivery to modulate beam intensity in real-time. This dynamic approach allows complex intensity modulation patterns to be delivered through a relatively simple mechanical system compared to static multi-field approaches.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system controls multiple parameters including leaf positions, beam intensities, and delivery timing to achieve the desired dose distribution. By optimizing these parameters through computer planning software, the system manages complexity while achieving high precision dose delivery.

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If the radiation dose rate to healthy tissue is reduced to minimize radiobiological effects, then the biological damage to normal tissues is decreased, but the total dose delivery time increases

Engineering Contradiction:

Improveradiobiological effect on healthy tissueVSAvoidtotal dose delivery time

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The radiation delivery is organized into fractional treatments delivered at different time points. This periodic approach allows healthy tissues to repair between fractions while maintaining cumulative tumor dose, effectively managing the time-biological effect trade-off.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The treatment plan is carefully designed in advance to optimize the sequence and timing of beam deliveries. By pre-planning the intensity modulation patterns and delivery schedules, the system minimizes total treatment time while ensuring healthy tissues receive adequate repair time between high-dose exposures.

Inventive Principle:

Principle #10Preliminary action

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

This approach allows for an increased total dose to the cancer site while sparing healthy tissues, enhancing cancer cure rates without adverse effects on normal tissues, and reducing normal tissue complication probabilities.

Implementation Method 1

modulating the effective dose rate of radiation delivered to the normal tissues to a level sufficient to allow for cellular repair

Methodology Applied

Scientific EffectCellular repair:

Data Source

PatentUS8613694B2Method for biological modulation of radiation therapy

Publication Date: 2013.12.24 WISCONSIN ALUMNI RES FOUND

AI summary

A method for the biological modulation of external beam radiation therapy, in which the temporal and spatial patterning of imparted dose is modified to maximize the dose rate to the target volume while minimizing the dose rate to healthy tissues surrounding the target volume, is provided.