The most frequent grade @-@ adverse events were dysphagia ( @ -LSB- @ % -RSB- of @ patients in the chemoradiotherapy group vs @ -LSB- @ % -RSB- of @ in the panitumumab plus chemoradiotherapy group ) , mucosal inflammation ( @ -LSB- @ % -RSB- vs @ -LSB- @ % -RSB- ) , and radiation skin injury ( eight -LSB- @ % -RSB- vs @ -LSB- @ % -RSB- ) .