Related Experiment Video
Updated: Feb 6, 2026
08:12
A Volumetric Method for Quantification of Cerebral Vasospasm in a Murine Model of Subarachnoid Hemorrhage
Published on: July 28, 2018
8.4K
A hybrid volumetric dose verification method for single-isocenter multiple-target cranial SRS
Saeed Ahmed1,2, Jeff Kapatoes3, Geoffrey Zhang1
1Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL, USA.
Journal of Applied Clinical Medical Physics
|August 17, 2018
Summary
This study validates the PerFraction system for volumetric dose verification in stereotactic radiosurgery (SRS) VMAT treatments. The system demonstrated high accuracy, with 99.2% agreement with film measurements, supporting its use in clinical practice.
Area of Science:
- Medical Physics
- Radiation Oncology
- Radiosurgery
Background:
- Accurate dose verification is crucial for stereotactic radiosurgery (SRS) Volumetric Modulated Arc Therapy (VMAT).
- Commercial systems like PerFraction (PF) aim to streamline this process by integrating data from electronic portal imaging devices and accelerator log files.
Purpose of the Study:
- To validate the PerFraction (PF) system for semi-empirical volumetric dose verification in SRS VMAT treatments.
- To assess the agreement between PF-reconstructed dose and absolute film measurements.
Main Methods:
- PerFraction (PF) system used multi-leaf collimator positions from EPID movies and accelerator log files to reconstruct dose.
- Dose reconstruction performed on patient CT datasets using a superposition/convolution algorithm.
- Validation conducted against radiochromic film measurements in a cylindrical phantom for multi-target SRS VMAT plans.
Main Results:
- Planar dose agreement between PF and film was 99.2 ± 1.1% using 3%/1 mm gamma analysis.
- Point dose differences in low-gradient areas were below 3%.
- Submillimeter agreement in dose centroids and volumetric agreement at the 3%/1 mm level were achieved.
Conclusions:
- The PerFraction (PF) system shows high accuracy and agreement with film measurements for SRS VMAT dose verification.
- The tool is suitable for patient-specific quality assurance in routine radiosurgical clinical practice.
- Understanding the system's capabilities and limitations is key for effective clinical application.
Keywords:
Patient-specific SRS QA
Related Concept Videos
01:11Bioavailability Study Design: Single Versus Multiple Dose Studies
246
Bioavailability studies are essential for understanding how a drug is absorbed, distributed, metabolized, and excreted in the body. These studies assess the extent and rate at which the active pharmaceutical agent becomes available at the site of action. The design of bioavailability studies can involve single-dose or multiple-dose regimens, each with distinct advantages and limitations.Single-dose studies are the preferred approach due to their simplicity and reduced drug exposure for...
246
01:25Determination of Multiple Dosing Parameters: Loading and Maintenance Doses
246
A loading dose is an essential pharmacological strategy to rapidly achieve the target plasma drug concentration necessary for an immediate therapeutic effect. This approach is especially critical for drugs characterized by slow absorption or extended half-lives, where delaying therapeutic plasma levels could compromise treatment outcomes. By administering a loading dose, clinicians ensure a prompt onset of drug action, even for agents with complex pharmacokinetic profiles.Achieving steady-state...
246
03:00Self-Evaluation: Self-Enhancement and Self-Verification
5.8K
Social psychologists have documented that feeling good about ourselves and maintaining positive self-esteem is a powerful motivator of human behavior (Tavris & Aronson, 2008). In the United States, members of the predominant culture typically think very highly of themselves and view themselves as good people who are above average on many desirable traits (Ehrlinger, Gilovich, & Ross, 2005). Often, our behavior, attitudes, and beliefs are affected when we experience a threat to our...
5.8K
01:21Dose Size and Dosing Frequency: Determination Methods
310
Determining the optimal dose size and dosing frequency in pharmacotherapy is crucial for achieving therapeutic effectiveness while minimizing adverse effects. This article explores the methodologies employed in determining these parameters, focusing on their significance and interplay to tailor dosing regimens.Dose Size: Dose size refers to the amount of a drug administered in a single dose. It is determined based on the drug's pharmacodynamics and pharmacokinetics properties and...
310
01:21Drug Accumulation During Multiple Dosing: Repetitive IV Injections
289
Calculating drug dosage and accumulation in multiple-dose regimens is crucial for achieving therapeutic efficacy while avoiding toxicity. This involves determining the plasma drug concentrations over time to optimize dosing schedules. The principle of superposition is fundamental in this process, allowing for the prediction of drug concentration in plasma following multiple doses based on single-dose data.The principle of superposition asserts that the plasma concentration-time curves from...
289
01:24Drug Accumulation During Multiple Dosing: Intermittent IV Infusions
263
Intermittent intravenous (IV) infusion is a method of drug administration where medications are delivered over short infusion periods followed by intervals of no drug delivery. This approach helps to prevent sustained high drug concentrations in the bloodstream, reducing the risk of adverse effects associated with prolonged exposure. Unlike continuous infusion, steady-state concentrations may not be achieved during a single dosing cycle but can be reached through repeated...
263