Fractal Dimension Characteristic Analysis for Dose Verification in Intensity Modulation Radiation Therapy

2012 ◽  
Author(s):  
Jia-Ming Wu ◽  
Tsair-Fwu Lee ◽  
Ching-Jiang Chen ◽  
Chung-Ming Kuo ◽  
Shyh-An Yeh
Keyword(s):  
Radiation Therapy ◽  
Fractal Dimension ◽  
Intensity Modulation ◽  
Dose Verification ◽  
Characteristic Analysis ◽  
Dimension Characteristic

scholarly journals Dose Verification in Intensity Modulation Radiation Therapy: A Fractal Dimension Characteristics Study

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jia-Ming Wu ◽  
Chung-Ming Kuo ◽  
Ching-Jiang Chen
Keyword(s):  
Radiation Therapy ◽  
Fractal Dimension ◽  
Fractal Dimensions ◽  
Intensity Modulation ◽  
Planning System ◽  
Treatment Planning System ◽  
Characteristic Analysis ◽  
Qualitative Comparison ◽  
Fractal Characteristic ◽  
Dimension Characteristic

Purpose.This study describes how to identify the coincidence of desired planning isodose curves with film experimental results by using a mathematical fractal dimension characteristic method to avoid the errors caused by visual inspection in the intensity modulation radiation therapy (IMRT).Methods and Materials.The isodose curves of the films delivered by linear accelerator according to Plato treatment planning system were acquired using Osiris software to aim directly at a single interested dose curve for fractal characteristic analysis. The results were compared with the corresponding planning desired isodose curves for fractal dimension analysis in order to determine the acceptable confidence level between the planning and the measurement.Results.The film measured isodose curves and computer planning curves were deemed identical in dose distribution if their fractal dimensions are within some criteria which suggested that the fractal dimension is a unique fingerprint of a curve in checking the planning and film measurement results. The dose measured results of the film were presumed to be the same if their fractal dimension was within 1%.Conclusions.This quantitative rather than qualitative comparison done by fractal dimension numerical analysis helps to decrease the quality assurance errors in IMRT dosimetry verification.

Roughness-Length-Based Characteristic Analysis of Intracranial EEG and Epileptic Seizure Prediction

2020 ◽  
Vol 30 (12) ◽  
pp. 2050072
Author(s):  
Yanli Zhang ◽  
Rendi Yang ◽  
Weidong Zhou
Keyword(s):  
Fractal Dimension ◽  
Roughness Length ◽  
Epileptic Seizures ◽  
Prediction Algorithm ◽  
Patient Specific ◽  
Gradient Boosting ◽  
Seizure Prediction ◽  
Characteristic Analysis ◽  
Intracranial Eeg ◽  
Interictal Eeg

To identify precursors of epileptic seizures, an EEG characteristic analysis is carried out based on a roughness-length method, where fractal dimensions and intercept values are extracted to measure the structure complexity and the amplitude roughness of EEG signals in different phases. Using the significant changes of the fractal dimension and intercept in the preictal phase with respect to those in the interictal phase, a patient-specific seizure prediction algorithm is then proposed by combining with a gradient boosting classifier. The probabilistic outputs of the trained gradient boosting classifier are further processed by threshold comparison and rule-based judgment to distinguish preictal EEG from interictal EEG and to generate seizure alerts. The prediction algorithm was evaluated on 20 patients’ intracranial EEG recordings from the Freiburg EEG database, which contains the preictal periods of 65 seizures and 499[Formula: see text]h interictal EEG. Setting the seizure prediction horizon as 2[Formula: see text]min, averaged sensitivity values of 90.42% and 91.67% with averaged false prediction rates of 0.12/h and 0.10/h were achieved for seizure occurrence periods of 30 and 50[Formula: see text]min, respectively. These results demonstrate the ability of fractal dimension and intercept metrics in predicting the occurrence of seizures.

Fast radiographic film calibration procedure for helical tomotherapy intensity modulated radiation therapy dose verification

2005 ◽  
Vol 32 (6Part1) ◽  
pp. 1566-1570 ◽  
Author(s):  
Yulong Yan ◽  
Nikos Papanikolaou ◽  
Xuejun Weng ◽  
Jose Penagaricano ◽  
Vaneerat Ratanatharathorn
Keyword(s):  
Radiation Therapy ◽  
Helical Tomotherapy ◽  
Intensity Modulated Radiation Therapy ◽  
Calibration Procedure ◽  
Dose Verification ◽  
Radiographic Film ◽  
Intensity Modulated
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