The effect of geometrical optimisation on some parameters of dose distribution as exemplified by brachytherapy applied in patients with breast cancer

Abstract

Purpose

The analysis of the dose distribution parameters for two-plane implants in the breast using geometrical optimisation.

Material and methods

The analysis was carried out on dose distribution parameters, and on the dose distribution quality index (QI) for 20 two-plane applications administered in our clinical practice. The toliowing parameters were determined: the reference volume V₁₀₀, the irradiated volume V₅₀, and the high dose volume V₅₀. These parameters were analysed both in the case of geometrical optimisation of dose distribution, and in the case without optimisation.

Conclusions

Geometrical optimisation leads to an increase in the reference volume V₁₀₀. As contrasted with the conventional non-optimised implant, in accordance with the Paris System of interstitial brachyterapy, the above system of optimisation makes it possible to limit the active length of the implant which does not extend beyond the target area, which has its advantage when, in breast implants, the target area is bordering the skin.