Study [references] Duration study conducted Radiation techniques Mean Radiation doses Sample size (n) Follow up period Loco- regional Control Freedom From Distant Metastasis Overall survival Grade 3 Acute  toxicity incidence Grade 3 Late toxicity Schwartz DL [7] 1996-2005 74→3DCRT 57→IMRT 60Gy/30fr 131 4 years 79% 76% 73% NA 2% Rosenbluth BD[8] 2001-2004 IMRT 63Gy/30fr 20 2 years 85% 46% 60% 50% None Urbano TG [9] 2005-2006 IMRT 58.8Gy/28fr 13 2 years 90% 87% NA 8-31% NA Turaka A [10] 2001-2008 IMRT 60Gy/30fr 10 2years 90% 87% 80% 10-30% None Our study 2007-2011 IMRT 66Gy/33fr 18 4 years 88.9% 83.2% 89.4% 5.5% None 3DCRT= Three dimensional conformal Radiation therapy, IMRT= Intensity modulated Radiation Therapy, Gy=Grays, NA= not available

Table 4: Comparison various studies using IMRT of locoregional control, distant metastasis control and overall survival rates.