Comparison of 2D and 3D dosimetry parameters for breast planning

Autor: Louise Fahy, James Murphy, Maryam Alanazi
Rok vydání: 2018
Předmět:
Zdroj: Physica Medica. 52:176
ISSN: 1120-1797
DOI: 10.1016/j.ejmp.2018.06.052
Popis: Historically, external beam radiotherapy (EBRT) breast/chest wall treatment planning was a 2D process using breast contour and X-ray imaging, and the depth of the lung or heart in the treatment field was used to estimate the risk to these organs. Over the last two decades, the use of 3D CT imaging for breast treatment planning has become widespread but many centres still use Depth-in-Field for organ at risk (OAR) estimation. This is a retrospective study of breast cancer patients treated at our centre. The DVH parameters for lung and heart will be compared with the depth in the treatment field to investigate which of these parameters should be used in the clinic for plan evaluation. The treatment plans of 60 left-breast cancer patients treated with a prescription dose of 50 Gy in 25 fractions were reviewed. The results illustrated that there was a strong correlation between DVH parameters for the heart and the depth in field. Also, there was a strong correlation between DVH parameters and the lung depth in two field tangential plans. However, no correlation existed for plans with a third field to treat the supraclavicular area. There was not enough data to analyse the relation between the V107% of prescription dose and the depth in the treatment field. Moreover, comparing the results with clinical trials indicated that the mean dose and V20 Gy for heart and mean dose and V40 Gy for lung are valid parameters to look at when estimating the risk to heart and lung.
Databáze: OpenAIRE
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