Assessing Heterogeneity Effects on Points A, B, and Organs at Risk Doses in High-dose-Rate Brachytherapy for Cervical Cancer - A Comparison of 192Ir and 60Co Sources Using Monte Carlo N-Particle 5.
J Med Phys
; 49(2): 294-303, 2024.
Article
in En
| MEDLINE
| ID: mdl-39131438
ABSTRACT
Purpose:
The present article deals with investigating the effects of tissue heterogeneity consideration on the dose distribution of 192Ir and 60Co sources in high-dose-rate brachytherapy (HDR-BT). Materials andMethods:
A Monte Carlo N-Particle 5 (MCNP5) code was developed for the simulation of the dose distribution in homogeneous and heterogeneous phantoms for cervical cancer patients. The phantoms represented water-equivalent and human body-equivalent tissues. Treatment data for a patient undergoing HDR-BT with a 192Ir source were used as a reference for validation, and for 60Co, AAPM Task Group 43 methodology was also applied. The dose values were calculated for both source types in the phantoms.Results:
The results showed a good agreement between the calculated dose in the homogeneous phantom and the real patient's treatment data, with a relative difference of less than 5% for both sources. However, when comparing the absorbed doses at critical points such as Point A right, Point A left, Point B right, Point B left, bladder International Commission on Radiation Units and Measurement (ICRU) point, and recto-vaginal ICRU point, the study revealed significant percentage differences (approximately 5.85% to 12.02%) between the homogeneous and heterogeneous setups for both 192Ir and 60Co sources. The analysis of dose-volume histograms (DVH) indicated that organs at risk, notably the rectum and bladder, still received doses within recommended limits.Conclusions:
The study concludes that 60Co and 192Ir sources can be effectively used in HDR-BT, provided that careful consideration is given to tissue heterogeneity effects during treatment planning to ensure optimal therapeutic outcomes.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Med Phys
Year:
2024
Document type:
Article
Affiliation country:
Irán
Country of publication:
India