Autor(es): Duarte, Mónica ; Rodrigues, Vanessa ; Caetano, Marco ; Fernandes, Paulo ; Bak, Bartos
Data: 2022
Identificador Persistente: http://hdl.handle.net/10400.21/15142
Origem: Repositório Científico do Instituto Politécnico de Lisboa
Assunto(s): Left breast cancer; Radiotherapy; Free-breathing; Deep inspiration breath-hold; Left ventricle; Cancro mama esquerda; Radioterapia; Respiração livre; Inspiração forçada; Ventrículo esquerdo
ABSTRACT: Introduction – Radiotherapy (RT) is a therapeutic approach for the treatment of left breast cancer. However, different breathing techniques free breathing (FB) and deep inspiration breath-hold (DIBH) can be used. Objectives – To identify which of the breathing techniques, DIBH or FB, has obtained better irradiation of the planning target volume (PTV) and a lower dose at the organs at risk (OAR). Check if the DIBH technique allows a dose reduction in the left ventricle. Methodology – Twenty female patients with pathology in the left breast were selected. In computed tomography, the contours of PTV and OAR were made. We obtained dosimetric data for each patient, with each of the two types of breathing techniques. Dosimetric data for all patients were compared for both respiratory techniques. Results – The DIBH technique reduced the mean dose (Dmean) and V20% in the left lung, only being higher in four patients. In the left ventricle, there was a decrease in Dmean and V30% in all patients. The spinal cord in either DIBH or FB did not reach the reference limit, however, there was an improvement when using DIBH. Conclusions – The DIBH technique presents lower doses in the organs at risk, improvements in PTV dose coverage, as well as conformity, homogeneity, and quality indexes when compared to the FB technique.
