- Détails du magazine
- Format
- Magazine
- eISSN
- 1898-0309
- Première publication
- 30 Dec 2008
- Période de publication
- 4 fois par an
- Langues
- Anglais
Chercher
- Accès libre
Effect of the thermoplastic masks on dose distribution in the build-up region for photon beams
Pages: 1 - 4
Résumé
The aim of the study was to investigate the influence of thermoplastic masks material (Klarity Medical&Equipment Co., Guangzhou, China) with different diameters of holes (ϕ 0.25 cm and ϕ 0.40 cm) on the dose distribution in the build-up region for photon beams. Measurements were made for external radiation beams produced by the linear accelerator (TrueBeam, Varian Medical Systems, Inc., Palo Alto, CA, USA) using the Markus parallel plane ionization chamber and the Unidos electrometer (both from PTW, Freiburg, Germany). Measurements were made in a solid water phantom for two photon energies 6 MV and 15 MV, at 90 cm source to skin distance, for four fields of 5 cm × 5 cm, 10 cm × 10 cm, 15 cm × 15 cm and 20 cm × 20 cm. Compared to the open field, the maximum dose with mask was closer to the surface of the phantom by about 1.4 mm and 1.2 mm for 6 MV and 15 MV X-Rays, respectively. The surface dose increase from 10% to 42% for 6 MV and from 5% to 28% for 15 MV X-Rays.
Mots clés
- radiotherapy
- thermoplastic mask
- X-ray
- percentage depth dose
- AAPM TG 176
- Accès libre
Qualitative analysis of irregular fields delivered with dual electron multileaf collimator: A Monte Carlo study
Pages: 5 - 9
Résumé
The use of a dual electron multileaf collimator (eMLC) to collimate therapeutic electron beam without the use of cutouts has been previously shown to be feasible. Further Monte Carlo simulations were performed in this study to verify the nature and appearance of the isodose distribution in water phantom of irregular electron beams delivered by the eMLC. Electron fields used in this study were selected to reflect those used in electron beam therapy. Results of this study show that the isodose distribution in a water phantom obtained from the simulation of irregular electron beams through the eMLC conforms to the pattern of the eMLC used in the delivery of the beam. It is therefore concluded that the dual eMLC could deliver isodose distributions reflecting the pattern of the eMLC field that was used in the delivery of the beam.
Mots clés
- irregular fields
- Monte Carlo
- electron multileaf collimator
- cut-out
- applicator
- Accès libre
Dosimetric study of the protection level of the bone marrow in patients with cervical or endometrial cancer for three radiotherapy techniques - 3D CRT, IMRT and VMAT. Study protocol.
Pages: 11 - 15
Résumé
Mots clés
- gynaecological cancer
- hematologic toxicity
- radiotherapy
- 3D printing
- Bayesian networks
- deformable image registration