Analysis of dose comparison techniques for patient‐specific quality assurance in radiation therapy

Purpose Gamma evaluation is the most commonly used technique for comparison of dose distributions for patient‐specific pretreatment quality assurance in radiation therapy. Alternative dose comparison techniques have been developed but not widely implemented. This study aimed to compare and evaluate...

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Bibliographic Details
Published in:	Journal of applied clinical medical physics Vol. 20; no. 11; pp. 189 - 198
Main Authors:	Yu, Liting, Tang, Timothy L. S., Cassim, Naasiha, Livingstone, Alexander, Cassidy, Darren, Kairn, Tanya, Crowe, Scott B.
Format:	Journal Article
Language:	English
Published:	United States John Wiley & Sons, Inc 01-11-2019 John Wiley and Sons Inc
Subjects:	Agreements Algorithms dose comparison technique gamma evaluation Gamma Rays Humans Methods Neoplasms - radiotherapy Organs at Risk - radiation effects PSQA Quality Assurance, Health Care - standards Quality control Radiation therapy Radiotherapy Dosage Radiotherapy Planning, Computer-Assisted - methods Radiotherapy, Intensity-Modulated - methods Radiotherapy, Intensity-Modulated - standards Studies Technical Note Technical Notes gamma evaluation dose comparison technique PSQA radiation therapy
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Summary:	Purpose Gamma evaluation is the most commonly used technique for comparison of dose distributions for patient‐specific pretreatment quality assurance in radiation therapy. Alternative dose comparison techniques have been developed but not widely implemented. This study aimed to compare and evaluate the performance of several previously published alternatives to the gamma evaluation technique, by systematically evaluating a large number of patient‐specific quality assurance results. Methods The agreement indices (or pass rates) for global and local gamma evaluation, maximum allowed dose difference (MADD) and divide and conquer (D&C) techniques were calculated using a selection of acceptance criteria for 429 patient‐specific pretreatment quality assurance measurements. Regression analysis was used to quantify the similarity of behavior of each technique, to determine whether possible variations in sensitivity might be present. Results The results demonstrated that the behavior of D&C gamma analysis and MADD box analysis differs from any other dose comparison techniques, whereas MADD gamma analysis exhibits similar performance to the standard global gamma analysis. Local gamma analysis had the least variation in behavior with criteria selection. Agreement indices calculated for 2%/2 mm and 2%/3 mm, and 3%/2 mm and 3%/3 mm were correlated for most comparison techniques. Conclusion Radiation oncology treatment centers looking to compare between different dose comparison techniques, criteria or lower dose thresholds may apply the results of this study to estimate the expected change in calculated agreement indices and possible variation in sensitivity to delivery dose errors.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	1526-9914 1526-9914
DOI:	10.1002/acm2.12726