Ive only seen this with one other patient and that was just within the past week or two.
For oral cancer, chemo alone is used only as a palliative measure. You will sometimes see chemo used alone when a patient has a recurrence. Is this some type of clinical trial?
Im sure the doctors have their reasons behind doing the chemo. If I were you I would question the doctors in depth about it.
Here is a link to the NCCN guidelines for head and neck cancers. Its what the treating physicians should be going by when treating a patient with h&n cancer.
NCCN H&N Guidelines Best wishes!