Impact of respiratory motion on breast tangential radiotherapy using the field-in-field technique compared to irradiation using physical wedges

  • Hidekazu Tanaka Gifu University Hospital
  • Shinya Hayashi Gifu University Hospital
  • Kazuhiro Ohtakara Gifu University Hospital
  • Hiroaki Hoshi Gifu University Hospital

Abstract

Background: This study aimed to evaluate whether the field-in-field (FIF) technique is more vulnerable to the impact of respiratory motion than irradiation using physical wedges (PWs).

Patients and methods: Ten patients with early stage breast cancer were enrolled. Computed tomography (CT) was performed during free breathing (FB). After the FB-CT data set acquisition, 2 additional CT scans were obtained during a held breath after light inhalation (IN) and light exhalation (EX). Based on the FB-CT images, 2 different treatment plans were created for the entire breast for each patient and copied to the IN-CT and EX-CT images. The amount of change of in the volume of the target receiving 107%, 95%, and 90% of the prescription dose (V107%, V95%, and V90%, respectively), on the IN-plan and EX-plan compared with the FB-plan were evaluated.

Results: The V107%, V95%, and V90% were significantly larger for the IN-plan than for the FB-plan in both the FIF and PW plans. While the amount of change in the V107% was significantly smaller in the FIF than in the PW plan, the amount of change in the V95% and V90% was significantly larger in the FIF plan. Thus, the increase in the V107% was smaller while the increases in the V95% and V90% were larger in the FIF than in the PW plan.

Conclusions: The amount of change in dose parameters due to respiratory motion was smaller with the FIF technique than with irradiation using PWs, within an acceptable range.

Author Biographies

Hidekazu Tanaka, Gifu University Hospital
Shinya Hayashi, Gifu University Hospital
Kazuhiro Ohtakara, Gifu University Hospital
Hiroaki Hoshi, Gifu University Hospital
Published
2014-02-03
How to Cite
Tanaka, H., Hayashi, S., Ohtakara, K., & Hoshi, H. (2014). Impact of respiratory motion on breast tangential radiotherapy using the field-in-field technique compared to irradiation using physical wedges. Radiology and Oncology, 48(1). Retrieved from https://radioloncol.com/index.php/ro/article/view/1525
Section
Clinical oncology