GAN Radiotherapy Dose Prediction for Plan Optimization

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Solution Overview

Problem

Current radiotherapy treatment planning relies heavily on manual human judgment and trial-and-error, making it difficult to determine whether a treatment plan is optimized, as the order of adjusting planning constraints can result in dose differences, and existing AI approaches lack a detailed model of treatment planning independent of the planning process.

Innovation Solution

The use of generative adversarial networks (GANs) and deep neural networks to develop a voxel-wise, 3D dose distribution model customized to a patient's anatomy, trained using anatomical data and adversarial training to predict accurate radiotherapy dose distributions, enabling automated planning and improving plan quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual human judgment and trial-and-error process are used for treatment planning, then planners can exercise professional expertise to balance target dose versus organ sparing tradeoffs, but the planning process becomes time-consuming and planners cannot determine whether a plan is fully optimized

Engineering Contradiction:
Improveplan quality assessmentVSAvoidplanning time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent creates a digital twin or copy of the treatment planning process through a GAN model trained on numerous example treatment plans. The generator network learns to replicate the dosimetrist's decision-making process by generating dose distributions that mimic expert-planned treatments, while the discriminator network evaluates these copies against ground truth plans. This copying approach enables automated plan generation and objective quality assessment without requiring actual human planners for each case.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The system enables self-service treatment planning by allowing the GAN model to autonomously generate and evaluate treatment plans without human intervention. The discriminator network serves as an automated quality assurance mechanism that independently assesses whether generated plans meet clinical standards, eliminating the need for manual review while maintaining plan quality. The model continuously self-improves through adversarial training on expanding datasets of treatment plans.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If the order of adjusting planning constraints is changed, then different dose distributions result, but this makes it difficult to anticipate the effects and ensures plans are not close to best possible

Engineering Contradiction:
Improvedose distribution accuracyVSAvoidplanning constraint adjustment complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-training the GAN model on numerous example treatment plans that encode optimal constraint adjustment sequences and dosimetrist decision-making patterns. Instead of requiring planners to manually navigate complex constraint adjustments during each planning session, the system has already learned the optimal adjustment sequences during training. When generating new plans, the model directly applies these pre-learned patterns, eliminating the need for iterative manual constraint tuning and ensuring consistent, optimized results.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If reliance on manual human skill in the planning process is maintained, then professional judgment can be applied, but objective determination of whether a new treatment plan is fully optimized cannot be achieved

Engineering Contradiction:
Improveplan optimization certaintyVSAvoidplanning process automation
Core Design Contradiction:
ReliabilityVSExtent of automation

Solution Approach 1:

The patent implements feedback through the discriminator network, which continuously evaluates generated treatment plans against ground truth plans and provides gradient feedback to the generator network. This adversarial feedback loop enables objective quality assessment by comparing new plans against a database of expert-planned treatments. The discriminator's feedback signals guide the generator to produce plans that meet clinical standards, providing automated, objective optimization verification without replacing the underlying medical expertise encoded in the training data.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS11557390B2Radiotherapy treatment plan modeling using generative adversarial networks
Publication Date: 2023.01.17 ELEKTA AB
  • US11557390B2 patent drawing
  • US11557390B2 patent drawing
  • US11557390B2 patent drawing

AI summary

Techniques for generating radiotherapy treatment plans and establishing machine learning models for the generation and optimization of radiotherapy dose data are disclosed. An example method for generating a radiotherapy dose distribution using a generative model, trained in a generative adversarial network, includes: receiving anatomical data of a human subject that indicates a mapping of an anatomical area for radiotherapy treatment; generating radiotherapy dose data corresponding to the mapping with use of the trained generative model, as the generative model processes the anatomical data as an input and provides the dose data as output; and identifying the radiotherapy dose distribution for the radiotherapy treatment of the human subject based on the dose data. Another example method for training of the generative model includes establishing values of the generative model and a discriminative model of the generative adversarial network using adversarial training, including in a conditional generative adversarial network arrangement.