Normal tissue complication probability modeling for cochlea constraints to avoid causing XXXX after head-and-neck intensity-modulated radiation therapy.

@entity1 @entity135 @entity137 @entity8527 @entity5 @entity1109 @entity392
BACKGROUND: Radiation-induced @entity392 is a side effect of radiotherapy in the inner ear for @entity5 of the head and neck. Effective dose constraints for protecting the cochlea are under-reported. The aim of this study is to determine the cochlea dose limitation to avoid causing @entity392 after @entity135 ( @entity135 ) intensity-modulated radiation therapy (IMRT). METHODS: In total 211 @entity1 with @entity135 were included; the side effects of radiotherapy were investigated for 422 inner ears in the cohort. Forty-nine of the four hundred and twenty-two samples (11.6  %) developed grade 2+ @entity1109 after IMRT, as diagnosed by a clinician. The Late Effects of Normal Tissues-Subjective, Objective, Management, Analytic (LENT-SOMA) criteria were used for @entity392 evaluation. The logistic and Lyman-Kutcher-Burman (LKB) normal tissue complication probability (NTCP) models were used for the analyses. RESULTS: The NTCP-fitted parameters were @entity8527 50    =   46.31  Gy (95  % CI, 41.46-52.50), y 50    =   1.27 (95  % CI, 1.02-1.55), and @entity8527 50    =   46.52  Gy (95  % CI, 41.91-53.43), m   =   0.35 (95  % CI, 0.30-0.42) for the logistic and LKB models, respectively. The suggested guideline @entity8527 20 for the tolerance dose to produce a 20  % complication rate within a specific period of time was @entity8527 20    =   33.62  Gy (95  % CI, 30.15-38.27) (logistic) and @entity8527 20    =   32.82  Gy (95  % CI, 29.58-37.69) (LKB). CONCLUSIONS: To maintain the incidence of grade 2+ @entity392 @entity137 <20  % in IMRT, we suggest that the mean dose to the cochlea should be <32  Gy. However, models should not be extrapolated to other @entity1 populations without further verification and should first be confirmed before clinical implementation.
