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

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• 作者：Miranda E.M.C. Christianen^a ; Arjen van der Schaaf^a ; Hans Paul van der Laan^a ; Irma M. Verdonck-de Leeuw^b ; Patricia Doornaert^c ; Olga Chouvalova^a ; Roel J.H.M. Steenbakkers^a ; Charles René ; Leemans^b ; Sjoukje F. Oosting^d ; Bernard F.A.M. van der Laan^e ; Jan L.N. Roodenburg^f ; Ben J. Slotman^c ; Hendrik P. Bijl^a ; Johannes A. Langendijk^a ; ^{j.a.langendijk@umcg.nl" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Radiotherapy ; Head and neck cancer ; Swallowing sparing IMRT ; Model based approach
• 刊名：Radiotherapy and Oncology
• 出版年：2016
• 出版时间：February 2016
• 年：2016
• 卷：118
• 期：2
• 页码：298-303
• 全文大小：643 K

文摘

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 SWAL_M6 (ΔNTCP_SWALM6 = NTCP_standard − NTCP_SW-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 ΔNTCP_SWALM6 was 4.9% (range 0.01–17.3%), with a significant lower mean predicted NTCP_SW-IMRT of 22.6% (95% CI 20.2–24.9%), compared to NTCP_standard of 27.5% (95% CI 24.9–29.9%) (p < 0.001). There was a perfect correspondence of NTCP_SW-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.