Related Experiment Video
Updated: Feb 6, 2026
12:00
4D Microscopy of Yeast
Published on: April 28, 2019
9.3K
Inverse-planned deliverable 4D-IMRT for lung SBRT
Mahdi Hamzeei1, Arezoo Modiri1, Narges Kazemzadeh1
1School of Medicine, University of Maryland, 685 W Baltimore St., Baltimore, MD, 21201, USA.
Medical Physics
|August 29, 2018
Summary
Particle Swarm Optimization (PSO)-based four-dimensional (4D) intensity-modulated radiation therapy (IMRT) improves organ at risk sparing in lung stereotactic body radiotherapy (SBRT). Optimized aperture sequencing ensures efficient delivery of complex 4D-IMRT plans.
Area of Science:
- Radiation Oncology
- Medical Physics
- Computational Biology
Background:
- Lung stereotactic body radiotherapy (SBRT) requires precise radiation delivery to target tumors while minimizing dose to surrounding organs at risk (OARs).
- Four-dimensional (4D) imaging accounts for respiratory motion, offering potential for improved OAR sparing by adapting treatment delivery to the tumor's dynamic position.
- Conventional intensity-modulated radiation therapy (IMRT) planning typically uses 3D data and may not fully exploit the potential of 4D motion for OAR sparing.
Purpose of the Study:
- To develop and evaluate a particle swarm optimization (PSO)-based technique for creating deliverable 4D-IMRT plans for lung SBRT.
- To utilize respiratory motion as an additional degree of freedom to enhance OAR sparing in 4D-IMRT.
- To present an optimization-based aperture sequencing technique for efficient delivery of 4D-IMRT plans with a large number of apertures.
Main Methods:
- A GPU-enabled PSO inverse planning engine integrated with the Eclipse treatment planning system was used to generate 4D-IMRT plans.
- Retrospective 4D CT scans and clinical beam configurations from seven lung cancer patients were utilized.
- A mixed integer optimization technique was developed for aperture sequencing, considering leaf velocity, monitor units (MUs), and respiratory phase duration to maximize delivery efficiency.
Main Results:
- 4D-IMRT plans achieved comparable planning target volume (PTV) coverage to clinical plans.
- Significant improvements in OAR sparing were observed: 39.7% for the heart, 20.5% for the esophagus, 25.6% for the spinal cord, and 2.1% for the lungs.
- The proposed aperture sequencing method reduced delivery cycles by 15.94% (4s cycle) and 15.14% (6s cycle) compared to a greedy algorithm.
Conclusions:
- PSO-based 4D-IMRT is a promising technique for enhancing OAR sparing in lung SBRT.
- Efficient delivery of 4D-IMRT plans with numerous apertures is achievable through optimized aperture sequencing.
- The developed method allows for clinically feasible delivery times for complex 4D-IMRT plans.
More Related Videos
Related Concept Videos
01:29Inverse Trigonometric Functions
279
Inverse trigonometric functions are fundamental mathematical tools that reverse the actions of standard trigonometric functions. While trigonometric functions map angles to ratios, inverse trigonometric functions perform the opposite operation by mapping a ratio back to its corresponding angle. These functions are essential in various applications, particularly in determining angles when given specific distances, such as calculating elevation angles in navigation and engineering.For a function...
279
01:23Sampling Plans
991
Sampling is a crucial step in analytical chemistry, allowing researchers to collect representative data from a large population. Common sampling methods include random, judgmental, systematic, stratified, and cluster sampling.
Random sampling is a method where each member of the population has an equal chance of being selected for the sample. It involves selecting individuals randomly, often using random number generators or lottery-type methods. For example, when analyzing the properties of a...
Random sampling is a method where each member of the population has an equal chance of being selected for the sample. It involves selecting individuals randomly, often using random number generators or lottery-type methods. For example, when analyzing the properties of a...
991
01:25Inverse Hyperbolic Functions and Their Derivatives
77
The shape of a suspension bridge cable hanging under its own weight is described by a catenary curve, which is modeled using the hyperbolic cosine function. This mathematical model accurately captures the balance between gravity and tension acting along the cable. When a particular vertical position on the cable is known, the corresponding horizontal position can be determined using the inverse hyperbolic cosine function, allowing for a detailed analysis of the cable's geometry.Inverse...
77
01:47Lung Capacity
56.4K
The air in the lungs is measured in volumes and capacities. Lung volume measures reflect the amount of air taken in, released, or left over after a lung function, like a single inhalation. Lung capacity measures are sums of two or more lung volume measures.
56.4K
01:30Derivatives of Inverse Trigonometric Functions
427
A ship tracking an approaching aircraft relies on geometric measurements to find out the aircraft’s position relative to the observer. By measuring the slant distance to the aircraft and the angle of elevation, the horizontal and vertical components of the distance can be obtained using trigonometric relationships. This geometric approach provides a basis for analyzing how the observed angle changes as the aircraft moves closer to the ship.To examine the mathematical behavior of the angle...
427
01:21Planning Nursing Care I
5.9K
The planning phase of the nursing process helps nurses set priorities, outline patient-centered goals and expected outcomes, and tailor nursing interventions to align with the aligned care plan. Through the planning phase, the nurse applies critical thinking skills to align and develop interventions according to the patient's needs. It provides continuity of care allowing patients to receive the maximum benefit from treatment. It serves as a pilot plan for allocating individual staff to a...
5.9K