The sensitivity of ArcCHECK‐based gamma analysis to manufactured errors in helical tomotherapy radiation delivery
| Autor: | James C.H. Chu, Alistair Templeton, Julius V. Turian |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Male
Quality Assurance Health Care Computer science medicine.medical_treatment tomotherapy Radiation Sensitivity and Specificity Tomotherapy DQA medicine Radiation Oncology Physics Humans Radiology Nuclear Medicine and imaging ArcCHECK Head and neck Closing (morphology) Radiometry Instrumentation Simulation business.industry Radiotherapy Planning Computer-Assisted Gamma ray Prostatic Neoplasms Radiotherapy Dosage Gamma analysis Gamma Rays Head and Neck Neoplasms gamma analysis Radiotherapy Intensity-Modulated business Nuclear medicine Quality assurance Sensitivity (electronics) |
| Zdroj: | Journal of Applied Clinical Medical Physics |
| ISSN: | 1526-9914 |
| Popis: | Three‐dimensional measurement arrays are an efficient means of acquiring a distribution of data for patient plan delivery QA. However, the tie between plan integrity and traditional gamma‐based analysis of these data are not clear. This study explores the sensitivity of such analysis by creating errors in Helical Tomotherapy delivery and measuring the passing rates with an ArcCHECK cylindrical diode array. Errors were introduced in each of the couch speed, leaf open time, and gantry starting position in increasing magnitude while the resulting gamma passing rates were tabulated. The error size required to degrade the gamma passing rate to 90% or below was on average a 3% change in couch speed, 5° in gantry synchronization, or a 5 ms in leaf closing speed for a 3%/3 mm Van Dyk gamma analysis. This varied with plan type, with prostate plans exhibiting less sensitivity than head and neck plans and with gamma analysis criteria, but in all cases the error magnitudes were large compared to actual machine tolerances. These findings suggest that the sensitivity of ArcCHECK‐based gamma analysis to single‐mode errors in tomotherapy plans is dependent upon plan and analysis type and at traditional passing thresholds unable to detect small defects in the plan. PACS number: 87.55.Qr |
| Databáze: | OpenAIRE |
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