I had 70Gy IMRT radiation alone, and it did not kill the cancer, it recurred. To eradicate SCCC you need more than 50Gy, but more like 70Gy or higher. especially those areas difficult to treat, likely to recur like BOT. It is shown in studies that by adding chemo improves outcome up to 20 present or so, depending on the type of chemo or tagged therapy. NCCN is just a guideline not set in stone. and each doctor, patient is different. All I can say is you do not want a recurrence, and should do it right the first time.