The 90 % isodose volume was covered by the entire CTV with 3-5 beams , in a conventionally fractionated RT at 1.8-2 .0 Gy/d for the first two thirds of treatment course to a dose of about 50-50 .4 Gy followed by LCAHFR using reduced fields ( 2 cm extended margin at both ends of the lesion ) , twice daily at 1.5 Gy per fraction ( with aminimal interval of 6 h between fractions ) to a dose of 18-21 Gy .
