Comparative analysis of an image-guided versus a non-image-guided setup approach in terms of delivered dose to the parotid glands in head-and-neck cancer IMRT.

Duma, MN; Kampfer, S; Wilkens, JJ; Schuster, T; Molls, M; Geinitz, H

doi:10.1016/j.ijrobp.2009.09.047

journal article

Titel:: Comparative analysis of an image-guided versus a non-image-guided setup approach in terms of delivered dose to the parotid glands in head-and-neck cancer IMRT.
Dokumenttyp:: Journal Article
Autor(en):: Duma, MN; Kampfer, S; Wilkens, JJ; Schuster, T; Molls, M; Geinitz, H
Abstract:: PURPOSE: To assess the impact of interfractional variations of shape and setup uncertainties on the dose to the parotid glands (PGs) in head-and-neck cancer intensity-modulated radiotherapy and image-guided radiotherapy (IGRT). METHODS AND MATERIALS: Two scenarios were analyzed retrospectively for 10 head-and-neck cancer patients, treated with helical TomoTherapy (TomoTherapy Inc., Madison, WI): the IGRT scenario and the non-IGRT scenario. The initial dose-volume histograms derived from the planning computed tomography (PCT) scan and 120 recalculated dose-volume histograms of the PGs of each scenario and of corresponding fractions were compared. Setup errors, cumulative median doses (CMDs) for 6 fractions, overall volumes of the PGs, and volumes that received less than 1 Gy or more than 1.6 Gy per fraction were analyzed. RESULTS: The mean decrease in the PG volume was 0.13 cm(3)/d. There was a significantly higher CMD than initially predicted (mean increase for 6 fractions, 1.13 Gy for IGRT and 0.96 Gy for non-IGRT). The volume that received less than 1 Gy per fraction decreased (mean difference to PCT, 1.36 cm(3) for IGRT [p = 0.003] and 1.35 cm(3) for non-IGRT [p = 0.003]) and the volume that received more than 1.6 Gy per fraction increased with increasing fraction number (mean difference to PCT, 1.14 cm(3) for IGRT [p = 0.01] and 1.16 cm(3) for non-IGRT [p = 0.006]). There was no statistically significant difference between the two scenarios (CMD, p = 0.095; volume that received <1 Gy per fraction, p = 0.896; and volume that received >1.6 Gy per fraction, p = 0.855). CONCLUSIONS: In the analyzed group the actual delivered dose to the PGs does not differ significantly between an IGRT and a non-IGRT approach. However, IGRT in head-and-neck cancer intensity-modulated radiotherapy is strongly recommended to improve patient setup.
Zeitschriftentitel:: Int J Radiat Oncol Biol Phys
Jahr:: 2010
Band / Volume:: 77
Heft / Issue:: 4
Seitenangaben Beitrag:: 1266-73
Sprache:: eng
Volltext / DOI:: doi:10.1016/j.ijrobp.2009.09.047
PubMed:: http://view.ncbi.nlm.nih.gov/pubmed/20350787
Print-ISSN:: 0360-3016
TUM Einrichtung:: Institut für Medizinische Statistik und Epidemiologie; Klinik und Poliklinik für RadioOnkologie und Strahlentherapie
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