TY - JOUR
T1 - Geometric Image Biomarker Changes of the Parotid Gland Are Associated With Late Xerostomia
AU - van Dijk, Lisanne V.
AU - Brouwer, Charlotte L.
AU - van der Laan, Hans Paul
AU - Burgerhof, Johannes G. M.
AU - Langendijk, Johannes A.
AU - Steenbakkers, Roel J. H. M.
AU - Sijtsema, Nanna M.
N1 - Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Purpose: To identify a surrogate marker for late xerostomia 12 months after radiation therapy(Xer12m), according to information obtained shortly after treatment.Methods and Materials: Differences in parotid gland (PG) were quantified in image biomarkers (ΔIBMs) before and 6 weeks after radiation therapy in 107 patients. By performing stepwise forward selection, ΔIBMs that were associated with Xer12m were selected. Subsequently other variables, such as PG dose and acute xerostomia scores, were added to improve the prediction performance. All models were internally validated.Results: Prediction of Xer12m based on PG surface reduction (ΔPG-surface) was good (area under the receiver operating characteristic curve, 0.82). Parotid gland dose was related to ΔPG-surface (P<.001, R2 = 0.27). The addition of acute xerostomia scores to the ΔPG-surface improved the prediction of Xer12m significantly, and vice versa. The final model including ΔPG-surface and acute xerostomia had outstanding performance in predicting Xer12m early after radiation therapy (area under the receiver operating characteristic curve, 0.90).Conclusions: Parotid gland surface reduction was associated with late xerostomia. The early posttreatment model with ΔPG-surface and acute xerostomia scores can be considered as a surrogate marker for late xerostomia.
AB - Purpose: To identify a surrogate marker for late xerostomia 12 months after radiation therapy(Xer12m), according to information obtained shortly after treatment.Methods and Materials: Differences in parotid gland (PG) were quantified in image biomarkers (ΔIBMs) before and 6 weeks after radiation therapy in 107 patients. By performing stepwise forward selection, ΔIBMs that were associated with Xer12m were selected. Subsequently other variables, such as PG dose and acute xerostomia scores, were added to improve the prediction performance. All models were internally validated.Results: Prediction of Xer12m based on PG surface reduction (ΔPG-surface) was good (area under the receiver operating characteristic curve, 0.82). Parotid gland dose was related to ΔPG-surface (P<.001, R2 = 0.27). The addition of acute xerostomia scores to the ΔPG-surface improved the prediction of Xer12m significantly, and vice versa. The final model including ΔPG-surface and acute xerostomia had outstanding performance in predicting Xer12m early after radiation therapy (area under the receiver operating characteristic curve, 0.90).Conclusions: Parotid gland surface reduction was associated with late xerostomia. The early posttreatment model with ΔPG-surface and acute xerostomia scores can be considered as a surrogate marker for late xerostomia.
KW - INTENSITY-MODULATED RADIOTHERAPY
KW - MULTIVARIABLE PREDICTION MODEL
KW - CT-BASED DELINEATION
KW - QUALITY-OF-LIFE
KW - NECK-CANCER
KW - SUBMANDIBULAR-GLANDS
KW - INDIVIDUAL PROGNOSIS
KW - CONSENSUS GUIDELINES
KW - COMPUTED-TOMOGRAPHY
KW - DIAGNOSIS TRIPOD
U2 - 10.1016/j.ijrobp.2017.08.003
DO - 10.1016/j.ijrobp.2017.08.003
M3 - Article
C2 - 28939226
SN - 0360-3016
VL - 99
SP - 1101
EP - 1110
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 5
ER -