LASSO-based NTCP model for radiation-induced temporal lobe injury developing after intensity-modulated radiotherapy of nasopharyngeal carcinoma.

We investigated the incidence of temporal lobe injury (TLI) in 132 nasopharyngeal carcinoma (NPC) patients who had undergone intensity-modulated radiotherapy (IMRT) in our hospital between March 2005 and November 2009; and identified significant dosimetric predictors of TLI development. Contrast-enhanced lesions or cysts in the temporal lobes, as detected by magnetic resonance imaging (MRI), were regarded as radiation-induced TLIs. We used the least absolute shrinkage and selection operator (LASSO) method to select Dmax (the maximum point dose) and the D1cc (the top dose delivered to a 1-mL volume) from 15 dose-volume-histogram-associated and four clinically relevant candidate factors; the Dmax and the D1cc were the most significant predictors of TLI development.

A new index comparable to BED for evaluating the biological efficacy of hypofractionated radiotherapy schemes on early stage non-small cell lung cancer: analysis of data from the literature.

Background And Purpose: Hypofractionated radiotherapy has been the principal curative treatment option for early stage NSCLC patients who are medically inoperable or those who refuse surgery and achieved favorable clinical outcomes. Evidence demonstrated that the linear quadratic model widely used in normally fractionated radiotherapy cannot work well to fit outcome data by use of BED to predict the effect of hypofractionation schemes. New models and the related metrics need to be developed to quantify the effect of high-dose ablative regimens for early stage NSCLC.