Having a look at the publications (unfortunately, I have access to most academic journal databases due to my background..) around the clinical trial for chemoradiotherapy as a means of controlling advanced H&N cancer, it looks like the clinical trials conducted to determine the efficacy of the treatment used the '3 Big Bag Cisplatin' approach which is why most doctors recommend this.

It was reassuring to know that there was significant improvements in overall outcome for patients who had chemotherapy along with radiotherapy if the cancer was considered high risk (multiple lymph nodes, Extra-capsular spread) and that the extra strain on the body of having these toxins administered was justified..

However, it does state that the long-term side effects for this type of treatment are significantly worse hence why most patients treating earlier stages of cancer are only administered Radiotherapy.