Intensity-modulated radiation therapy (IMRT) in head and neck (H&N) cancer has the capability to generate steep dose gradients, leading to an improved therapeutic index. IMRT plans are typically based on a pretreatment computed tomography scan that provides a snapshot of the patient's anatomy. Nevertheless, interfractional patient variations may occur because of setup error and anatomical modifications. Therefore, the accuracy of IMRT delivery for H&N cancer may be compromised during the treatment course, potentially affecting the therapeutic index. In this framework, adaptive radiotherapy is a potential solution, which consists of “the explicit inclusion of the temporal changes in anatomy during the imaging, planning, and delivery of radiotherapy.” Adaptive radiotherapy has brought an additional dimension to the management of patients with H&N cancer and has the potential to counteract the effects of positioning errors and anatomical changes. This article reviews the causes and discusses potential solutions to circumvent the discrepancies between the planned dose and the actual dose received by patients treated for H&N malignancies.
Department of Radiation Oncology, Center for Molecular Imaging and Experimental Radiotherapy (IMRE), Université catholique de Louvain, St-Luc University Hospital, Brussels, Belgium
Address reprint requests to Vincent Grégoire, MD, PhD, FRCR, Department of Radiation Oncology, Cliniques Universitaires Saint-Luc, Avenue Hippocrate 10, B-1200 Brussels, Belgium
This work is supported by a grant from the Belgian Federation against Cancer (convention Number SCIE 2003-23FR), by a grant from the “Cancéropôle du Nord-Ouest (France),” by a grant (Painter) from the Région wallonne (Belgium), by the “Fonds J. Maisin” of the Université catholique de Louvain and by grants from the European Community (Biocare EC Research Program # LSHC-CT-2004-505785; Maestro EC project # LSHC-CT-2004-503564).
The authors have no financial relationship with the organizations that sponsored the research.
John A. Lee and Xavier Geets are postdoctoral fellows with the FNRS (Fonds National de la Recherche Scientifique).
Financial support: Pierre Castadot is a research fellow with the FNRS (Fonds National de la recherche Scientifique).
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