Immobilization techniques' influence on treatment plan results in postmastectomy radiotherapy.

Abstract

To compare different immobilization devices used for chest wall and nodal irradiation in breast cancer dosimetrically. All patients with left-sided breast cancer received chest wall and lymphatic irradiation. Treatment plans were created for radiotherapy in single arm (SA) lift board, double arm (DA) lift board, and wing board (WB) positions. Dose-volum e histograms (DVH) were used for evaluation based on planning target volume (PTV) coverage and organs at risk (OARs). One-way analysis of variance (ANOVA) test was performed to identify the dose-volume differences among different immobilization techniques. Clinically acceptable plans were generated with all immobilization boards. Significantly lower doses in the body except target volumes were found in the SA lift board group compared to other groups (P < 0.05). No relevant differences were observed among the plans according to the other dose parameters of target volumes and OARs. SA board is an immobilization device that can be used safely for three-dimensional conformal radiotherapy in young left-sided breast cancer with an unfavorable anatomy as it significantly reduces low-dose exposure.