Two 21-day cycles of pemetrexed (500 milligrams per square meter [mg/m2] intravenous [IV] infusion) and carboplatin (target area under the curve [AUC] 5 IV infusion) followed by two 21-day cycles of pemetrexed (500 mg/m2 IV infusion) and carboplatin (target AUC 5 IV infusion) with concurrent radiotherapy (2 Gray [Gy] per fraction, 5 fractions per week, up to a dose of 50 Gy is administered).