Swallowing sparing intensity modulated radiotherapy (SW-IMRT) in head and neck cancer: Clinical validation according to the model-based approachChristianen, M. E. M. C., van der Schaaf, A., van der Laan, H. P., Verdonck-de Leeuw, I. M., Doornaert, P., Chouvalova, O., Steenbakkers, R. J. H. M., Leemans, C. R., Oosting, S. F., van der Laan, B. F. A. M., Roodenburg, J. L. N., Slotman, B. J., Bijl, H. P. & Langendijk, J. A., Feb-2016, In : Radiotherapy and Oncology. 118, 2, p. 298-303 6 p.
Research output: Contribution to journal › Article › Academic › peer-review
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.
|Number of pages||6|
|Journal||Radiotherapy and Oncology|
|Publication status||Published - Feb-2016|
- Radiotherapy, Head and neck cancer, Swallowing sparing IMRT, Model based approach, QUALITY-OF-LIFE, OROPHARYNGEAL CANCER, VOLUME PARAMETERS, PREDICTION MODELS, DYSPHAGIA, IMPACT, PERFORMANCE, DYSFUNCTION, DEPENDENCE, TOXICITY