Multi-site evaluation of the Razor stereotactic diode for CyberKnife small field relative dosimetry.
Phys Med
; 65: 40-45, 2019 Sep.
Article
em En
| MEDLINE
| ID: mdl-31430585
ABSTRACT
PURPOSE:
The aims of this study were (i) to validate in a multi-site context the suitability of the IBA Razor silicon diode detector for CyberKnife relative dosimetry. (ii) to fit the multi-center experimental data into a function relating the field output factors to the effective field size (EFS). METHODS AND MATERIALS Ratio of detector readings in clinical and reference field (OFdet) and beam profiles were acquired on five CyberKnife units for fixed collimator diameters (range 5-60â¯mm), using both Razor and PTW 60017 diodes. Measured OFdet were corrected using published MonteCarlo correction factors to get field output factors ΩQclin,Qmsrfclin,fmsr. Profiles were analyzed in terms of penumbra and EFS. ΩQclin,Qmsrfclin,fmsr obtained in four centers were fitted as a function of EFS, while the data of the 5th center were used to validate the fitting curve.RESULTS:
Differences between Razor and PTW60017 ΩQclin,Qmsrfclin,fmsr were within 1.5% over all centers down to 7.5â¯mm aperture and within 3.5% for the 5â¯mm diameter. The fit showed a coefficient of determination R2â¯=â¯0.997. The mean deviation of measured points from the predictive curve was within 0.5%. Data of the 5th center showed a mean deviation of 0.4% from the curve, with maximum differences within 2.5% for the 7.5â¯mm aperture.CONCLUSIONS:
The results confirmed the suitability of Razor detector for CyberKnife dosimetry by comparison to the PTW 60017 diode which has been well characterized and is in widespread use. The proposed mathematical relation between ΩQclin,Qmsrfclin,fmsr and EFS is a robust predictive model applicable to different CyberKnife systems and detectors.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Radiometria
/
Radiocirurgia
/
Equipamentos e Provisões Elétricas
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Phys Med
Assunto da revista:
BIOFISICA
/
BIOLOGIA
/
MEDICINA
Ano de publicação:
2019
Tipo de documento:
Article