Nearly 40-60% patients fail on LPP and predicting this failure before spares these patients of unnecessary chemoradiation and its toxicities, trauma of recurrent disease and complications of salvage surgery. Mutation of the p53 gene has been found to regulate cell proliferation and chemosensitivity. LP is significantly higher in the group of patients whose tumors over expressed p53 but it does not predict survival. A retrospective study nested within the VA study reported that T stage, p53 over-expression and elevated proliferating cell nuclear antigen index were independent predictors of successful LP . Success of RT depends on killing all clonogenic cells that increases linearly with tumor volume (TV). Lesions are classified as T3 or T4 despite a wide variation in TV if one were to perform volumetric analysis for all. TV is one of the most precise and most relevant predictors of RT outcome. This inverse relationship may be explained on the basis of hypoxia due to central tumor necrosis that is detrimental for CT as well as RT. Cartilage invasion, soft tissue extension, volume, extensive nodal involvement, pre epiglottic space invasion, paraglottic space invasion and arytenoids infiltration are some of the radiological parameters that can predict poor outcome to RT.