support vector machine artificial intelligence neural networks National Center for Biotechnology Information NCBI NLM MEDLINE review humans pubmed abstract nih national institutes of health national library of medicine pmid:26581149 doi:10.1016/j.ijrobp.2015.07.2286 john kang russell schwartz sushil beriwal esophagitis / etiology logistic models lung neoplasms / radiotherapy machine learning* / statistics & numerical data machine learning* / trends models statistical computer* prognosis radiation oncology* radiation pneumonitis / etiology radiotherapy dosage radiotherapy* / statistics & numerical data reproducibility of results treatment outcome xerostomia / etiology