Table of Contents
ISRN Pulmonology
Volume 2013 (2013), Article ID 519602, 13 pages
http://dx.doi.org/10.1155/2013/519602
Review Article

Respiratory Gating for Radiotherapy: Main Technical Aspects and Clinical Benefits

1Department of Radiation Oncology, Paris Descartes University, European Georges Pompidou Hospital, 75015 Paris, France
2Department of Radiation Oncology, Centre Intégré de Cancérologie de Laval (CICL), Hôpital de la Cité-De-La-Santé, 1755 Boulevard René-Laennec, Laval, QC, Canada H7M 3L9

Received 8 January 2013; Accepted 29 January 2013

Academic Editors: A. S. Melani, C. Owen, and B. A. Rybicki

Copyright © 2013 Philippe Giraud and Annie Houle. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Respiratory-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast, and liver tumors. An increased conformality of irradiation fields leading to decreased complication rates of organs at risk is expected. Five main strategies are used to reduce respiratory motion effects: integration of respiratory movements into treatment planning, forced shallow breathing with abdominal compression, breath-hold techniques, respiratory gating techniques, and tracking techniques. Measurements of respiratory movements can be performed either in a representative sample of the general population, or directly on the patient before irradiation. Reduction of breathing motion can be achieved by using either abdominal compression, breath-hold techniques, or respiratory gating techniques. Abdominal compression can be used to reduce diaphragmatic excursions. Breath-hold can be achieved with active techniques, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily breath-holds. Respiratory gating techniques use external devices to predict the phase of the breathing cycle while the patient breathes freely. Another approach is tumor-tracking technique, which consists of a real-time localization of a constantly moving tumor. This work describes these different strategies and gives an overview of the literature.