Swallowing sparing intensity modulated radiotherapy (SW-IMRT) in head and neck cancer: Clinical validation according to the model-based approach

Miranda E. M. C. Christianen, Arjen van der Schaaf, Hans Paul van der Laan, Irma M. Verdonck-de Leeuw, Patricia Doornaert, Olga Chouvalova, Roel J. H. M. Steenbakkers, Charles Rene Leemans, Sjoukje F. Oosting, Bernard F. A. M. van der Laan, Jan L. N. Roodenburg, Ben J. Slotman, Hendrik P. Bijl, Johannes A. Langendijk*

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

39 Citaten (Scopus)
68 Downloads (Pure)


Purpose: The aim of this study was to clinically validate a multivariable normal tissue complication probability (NTCP) model for grade 2-4 swallowing dysfunction at 6 months after radiotherapy or chemoradiation (SWAL(M6)) in head and neck cancer patients treated with swallowing sparing intensity modulated radiotherapy (SW-IMRT) and to test if SW-IMRT resulted in a reduction of the prevalence of SWAL(M6).

Materials and methods: The primary endpoint was SWAL(M6). For all 186 patients, a standard IMRT (parotid sparing) and a SW-IMRT plan (additional constraints for swallowing organs at risk) was created. The difference in NTCP for SWALM6 (Delta NTCPSWALM6 = NTCPstandard - standard NTCPSW-IMRT) was calculated. Patients were treated with SW-IMRT. The external validation of the NTCP model was analyzed by comparing performance measures.

Results: The mean Delta NTCPSWALM6 was 4.9% (range 0.01-17.3%), with a significant lower mean predicted NTCPSW-IMRT of 22.6% (95% CI 20.2-24.9%), compared to NTCPstandard standard of 27.5% (95% CI 24.9-29.9%) (p <0.001). There was a perfect correspondence of NTCPSW-IMRT with the observed prevalence of SWAL(M6) (22.6%). The overall model performance, discrimination and 'goodness of fit' were good.

Conclusion: We externally validated the multivariable NTCP model for SWAL(M6) in SW-IMRT treated patients, showing reduced swallowing dysfunction by reducing the dose parameters included in this NTCP model. (C) 2015 The Authors. Published by Elsevier Ireland Ltd.

Originele taal-2English
Pagina's (van-tot)298-303
Aantal pagina's6
TijdschriftRadiotherapy and Oncology
Nummer van het tijdschrift2
StatusPublished - feb-2016

Citeer dit