Determination of small-field output factors for beam-matched linear accelerators using various detectors and comparison of detector-specific output correction factors using IAEA Technical Report Series 483 protocol.
| Autor: | Kannan M; Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Bengaluru, Karnataka, India., Saminathan S; Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Bengaluru, Karnataka, India., Chandraraj V; Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Bengaluru, Karnataka, India., Gowtham Raj D; Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Bengaluru, Karnataka, India., Ganesh KM; Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Bengaluru, Karnataka, India. |
|---|---|
| Jazyk: | angličtina |
| Zdroj: | Reports of practical oncology and radiotherapy : journal of Greatpoland Cancer Center in Poznan and Polish Society of Radiation Oncology [Rep Pract Oncol Radiother] 2023 Jun 26; Vol. 28 (2), pp. 241-254. Date of Electronic Publication: 2023 Jun 26 (Print Publication: 2023). |
| DOI: | 10.5603/RPOR.a2023.0024 |
| Abstrakt: | Background: Beam matching is widely used to ensure that linear accelerators used in radiotherapy have equal dosimetry characteristics. Small-field output factors (OF) were measured using different detectors infour beam-matched linear accelerators and the measured OFs were compared with existing treatment planning system (TPS) Monte Carlo algorithm calculated OFs. Materials and Methods: Three Elekta Versa HD TM and one Elekta Infinity TM linear accelerators with photon energies of 6 MV flattening filter (FF), 10 MVFF, 6 MV flattening filter free (FFF) and 10 MVFFF were used in this study. All the Linac'swere beam-matched, Dosimetry beam data were ± 1% compare with Reference Linac. Ten different type of detectors (four ionizationchambers and six diode detectors) were used for small-field OF measurements. The OFs were measured for field sizes of 1 × 1 to 10 × 10 cm 2 , and normalized to 10 × 10 cm 2 field size. The uncorrected and corrected OFs were calculated from these measurements. The corrected OF was compare with existing treatment planning system (TPS) Monte Carlo algorithm calculated OFs. Results: The small-field corrected and Uncorrected OF variations among the linear accelerators was within 1% for all energies and detectors. An increase in field size led to a reduction in the difference between OFs among the detectors, which was the case for all energies. The RSD values decreased with increasing field size. The TRS 483 provided Detector-specificoutput-correction factor (OCF) reduced uncertainty in small-field measurements. Conclusion: It is necessary to implement the OF-correction of small fields in a TPS. Special care must be taken to incorporate the corrected small-field OF in a TPS. Competing Interests: Conflict of interest None declared. (© 2023 Greater Poland Cancer Centre.) |
| Databáze: | MEDLINE |
| Externí odkaz: |
|