tailieunhanh - Báo cáo khoa học: "A comparison of dose-response characteristics of four NTCP models using outcomes of radiationinduced optic neuropathy and retinopathy"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài: A comparison of dose-response characteristics of four NTCP models using outcomes of radiationinduced optic neuropathy and retinopathy. | Moiseenko et al. Radiation Oncology 2011 6 61 http content 6 1 61 RADIATION ONCOLOGY RESEARCH Open Access A comparison of dose-response characteristics of four NTCP models using outcomes of radiation-induced optic neuropathy and retinopathy Vitali Moiseenko1 William Y Song2 Loren K Mell2 and Niranjan Bhandare3 Abstract Background Biological models are used to relate the outcome of radiation therapy to dose distribution. As use of biological models in treatment planning expands uncertainties associated with the use of specific models for predicting outcomes should be understood and quantified. In particular the question to what extent model predictions are data-driven or dependent on the choice of the model has to be explored. Methods Four dose-response models-logistic log-logistic Poisson-based and probit-were tested for their ability and consistency in describing dose-response data for radiation-induced optic neuropathy RION and retinopathy RIRP . Dose to the optic nerves was specified as the minimum dose Dmin received by any segment of the organ to which the damage was diagnosed by ophthalmologic evaluation. For retinopathy the dose to the retina was specified as the highest isodose covering at least 1 3 of the retinal surface D33 that geometrically covered the observed retinal damage. Data on both complications were modeled separately for patients treated once daily and twice daily. Model parameters D50 and g and corresponding confidence intervals were obtained using maximumlikelihood method. Results Model parameters were reasonably consistent for RION data for patients treated once daily D50 ranging from to Gy and gfrom to . Similar consistency was seen for RIRP data which span a broad range of complication incidence with D50 from to Gy and gfrom to for patients treated twice daily Gy and for patients treated once daily. However large variations were observed for RION in patients .