Underdosing of the maxillary sinus for small fields used in newer radiotherapy techniques: Comparison of thermoluminescent dosimeter and Monte Carlo data.
J Cancer Res Ther
; 14(2): 351-356, 2018.
Article
en En
| MEDLINE
| ID: mdl-29516918
ABSTRACT
AIMS:
To evaluate the underdosing of the maxillary sinus at its distal end produced by air cavity in the path of the 6 MV photon beam. MATERIALS ANDMETHODS:
A cubic solid water slab phantom of dimensions 18 cm × 18 cm × 18 cm with 4 cm × 4 cm × 4 cm air cavity 3 cm away from its anterior surface was used in this study. The percentage depth dose (PDD) for 6 MV X-rays along the central axis of the cubical air cavity was measured using thermoluminescent dosimeter-100 chips. The EGSnrc/DOSXYZnrc Monte Carlo (MC) code was used to estimate the PDD values in both homogeneous and inhomogeneous conditions. The dose data were generated for 1 cm × 1 cm, 2 cm × 2 cm, 3 cm × 3 cm, and 5 cm × 5 cm field sizes.RESULTS:
Average percentage dose reductions at 1 mm beyond the distal surface of the maxillary sinus for the field sizes 1 × 1, 2 × 2, and 3 × 3 cm2 are 42.4%, 39.5%, and 29.4%, respectively. However, for 5 cm × 5 cm field size, there is a dose enhancement (i.e., overdosing) at 1 mm from the distal surface of the maxillary sinus and the average percentage dose enhancement is 5.9%. Also, beyond 1 cm from the air-water interface, there is dose enhancement for all the field sizes.CONCLUSION:
This study showed that the significant dose reduction occurs near the air-water interface for the treatment techniques using small photon fields such as intensity-modulated radiotherapy or other newer techniques. MC-based treatment planning calculation predicts realistic dose distribution while using small photon fields in the treatment of maxillary sinus.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Radioterapia
/
Dosificación Radioterapéutica
/
Dosimetría Termoluminiscente
/
Método de Montecarlo
/
Dosimetría in Vivo
/
Seno Maxilar
Tipo de estudio:
Health_economic_evaluation
Límite:
Humans
Idioma:
En
Revista:
J Cancer Res Ther
Asunto de la revista:
NEOPLASIAS
/
TERAPEUTICA
Año:
2018
Tipo del documento:
Article
País de afiliación:
India