Radiotherapy QA Using Couch-Moved Phantom Motion Simulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radiotherapy devices face challenges in accurately delivering radiation doses to moving subjects due to physiological motions such as respiratory and cardiac movements, which are not adequately addressed by current quality assurance methods, particularly those using static phantoms or complex and expensive respiratory motion phantoms.
Innovation Solution
A method involving a phantom disposed on a patient couch that simulates subject motion by moving the couch to replicate respiratory and other physiological movements, allowing for integrated and automated quality assurance by comparing measured values with expected values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a static phantom is used for quality assurance, then the device complexity is reduced, but the measurement precision deteriorates because the phantom cannot account for subject motion during treatment
Solution Approach 1:
The patent applies the dynamics principle by transforming the static phantom into a dynamic system. The patient couch is programmed to execute motion patterns that replicate physiological movements (respiratory, cardiac, peristalsis) during treatment delivery. This allows the phantom to simulate the dynamic conditions of a moving subject without requiring complex internal mechanisms within the phantom itself, thus maintaining simplicity while improving measurement accuracy.
Solution Approach 2:
The patent uses the patient couch as an intermediary element to introduce motion into the quality assurance setup. Rather than making the phantom itself complex and self-moving, the couch acts as a mediator that imparts controlled motion to the phantom, enabling motion simulation while keeping the phantom design simple and the overall system manageable.
2Measurement precision
If a respiratory motion phantom is used to simulate subject motion, then the measurement precision is improved, but the device complexity and cost increase significantly
Solution Approach 1:
The patent extracts the motion simulation function from the phantom itself and transfers it to the patient couch system. This separation allows the phantom to remain a simple, static object while the couch handles the complexity of motion generation through pre-programmed patterns, thereby improving measurement accuracy without increasing phantom engineering complexity or cost.
Solution Approach 2:
The patient couch is utilized for multiple purposes: patient positioning during treatment and motion simulation during quality assurance. By programming the couch to execute various motion patterns (respiratory, cardiac, peristalsis), it serves as a universal motion generation platform that eliminates the need for specialized, complex motion phantoms for each type of physiological movement.
3Adaptability or versatility
If the patient couch is moved to simulate subject motion, then the adaptability is improved by accounting for physiological movements, but the ease of operation deteriorates due to additional control requirements
Solution Approach 1:
The patent applies preliminary action by pre-programming the patient couch with motion patterns that replicate physiological movements. These motion sequences are prepared in advance and automatically executed during quality assurance tests, eliminating the need for manual real-time control during the actual testing process and thereby maintaining ease of operation while achieving high adaptability.
Solution Approach 2:
The system enables self-service quality assurance by allowing the radiotherapy device to test its own motion compensation capabilities using the programmable couch and phantom setup. The automated execution of motion patterns and treatment delivery, followed by dose measurement and comparison with treatment plan predictions, creates a self-validating process that reduces operational complexity.
Data Source
AI summary
A quality assurance method for a radiotherapy device is disclosed. The method comprises disposing a phantom on a patient couch of the radiotherapy device, moving the patient couch to simulate motion of a subject, determining a measured value associated with the phantom, and comparing the measured value to an expected value. A radiotherapy device is also disclosed, the radiotherapy device comprising a radiation source configured to apply a radiation beam, a patient couch, a phantom disposable on the patient couch, and a controller communicatively coupled to the patient couch. A computer-readable medium storing instructions is also disclosed. A phantom for a radiotherapy device is also disclosed.