Dosimetric Comparison of Postmastectomy Radiotherapy Plans for Synchronous Bilateral Breast Cancer, Including Regional Lymph Node Irradiation.
Technol Cancer Res Treat
; 22: 15330338231214449, 2023.
Article
em En
| MEDLINE
| ID: mdl-37964574
ABSTRACT
BACKGROUND:
To investigate the optimal radiotherapy plans for synchronous bilateral breast cancer (SBBC) patients receiving postmastectomy radiotherapy (PMRT), including regional lymph node irradiation (RNI).METHODS:
For 10 SBBC patients who underwent bilateral mastectomy and received bilateral PMRT with RNI, 3 integrally optimized plans with a single isocenter were designed for each patient in this retrospective study intensity-modulated radiation therapy (IMRT) with 9 fixed beams (9F-IMRT), volumetric-modulated arc therapy (VMAT) with 2 pairs of half arcs (2F-VMAT), VMAT with 2 pairs of outer tangential arcs and 1 pair of 200-degree arcs (3F-VMAT). The paired t-test (in the case of normal variables) and Friedman's test (in the case of nonnormal variables) were applied to compare the planning target volumes (PTVs) and organs at risk (OARs) values of the 3 techniques.RESULTS:
The 3 techniques provided adequate target dose coverage and comparable results for PTVs. For OARs, 3F-VMAT yielded the lowest mean or median values of the left lung (15.02 ± 1.57â Gy) and right lung (14.91 ± 1.14â Gy), heart (6.19 (1.96)â Gy), coronary artery (15.96 ± 5.76â Gy) and liver (8.10 ± 2.70â Gy) which were significantly different from those of 9F-IMRT and 2F-VMAT. The percentages of volume at various doses (V5, V10, V20, and V30) of 3F-VMAT plans were also lower than or comparable with those of 9F-IMRT and 2F-VMAT. The monitor units (MUs) of 3F-VMAT were 31% higher than those of 9F-IMRT and comparable with those of 2F-VMAT; however, there were time savings and halved beam-on times (BOTs) compared to 9F-IMRT.CONCLUSIONS:
The 3F-VMAT plan yielded comparable target coverage compared with 9F-IMRT and 2F-VMAT, was superior in dose sparing of normal tissues and enabled shorter BOTs, improving treatment efficiency. In our research, 3F-VMAT was the optimal radiotherapy technique for SBBC patients receiving PMRT including RNI.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Mama
/
Radioterapia de Intensidade Modulada
Limite:
Female
/
Humans
Idioma:
En
Revista:
Technol Cancer Res Treat
Assunto da revista:
NEOPLASIAS
/
TERAPEUTICA
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
China