A new approach to radiochromic film dosimetry based on non-local means
| Autor: | Alfonso López-Fernández, Cesar Briso Rodriguez, Diego García-Pinto |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Film Dosimetry
Computer science medicine.medical_treatment Square (algebra) 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Optics medicine Dosimetry Radiology Nuclear Medicine and imaging Radiochromic film Protocol (science) Artifact (error) Dosimeter Radiological and Ultrasound Technology business.industry Noise (signal processing) Uncertainty Non-local means Radiation therapy 030220 oncology & carcinogenesis Calibration Ionization chamber Artifacts business Algorithms |
| Zdroj: | Physics in Medicine & Biology. 65:225019 |
| ISSN: | 1361-6560 0031-9155 |
| DOI: | 10.1088/1361-6560/abb71b |
| Popis: | Radiochromic film in conjunction with flatbed scanners are frequently employed as dosimeters for advanced techniques in radiotherapy. Their strengths are as follows: light element composition, low energy dependence, near biological tissue equivalence and high spatial resolution. However, they have some weaknesses as well: non-uniformities, read out noise, and scanning artifacts. Several processing protocols have been proposed intending to correct the perturbations these weaknesses produce. The aim of this paper is to present a new processing protocol for radiochromic film dosimetry based on a non-local means denoising algorithm. Three dose distributions of open square fields and a spatial combination of these fields using different angles of incidence and monitor units have been employed to validate the protocol. The dose distributions are traceable to ionization chamber measurements. Additionally, a real dose distribution of a treatment was used to simulate scanning data with noise and scanning lateral artifact, and to study how the protocol behaves under these perturbations. The same measured raw data have been processed by means of an implementation of the multichannel protocol (multigaussian method). It has been found that the proposed protocol reduces dose uncertainty even though it uses fewer scans than the multichannel protocol. |
| Databáze: | OpenAIRE |
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