Can the radiotherapy dose be reduced in patients with head and neck cancer who have a complete response to induction/neoadjuvant chemotherapy?

Agree with Dr. Kimple, and some more comments:

While the prognosis of patients with HNC achieving CR after induction chemo is better than of those who do not achieve CR, there is no level III evidence that reducing RT intensity in those achieving CR is safe. Randomized studies of induction followed with RT (or chemo-RT) vs RT (or chemo-RT) alone in HNC did not result in improved outcome in the induction arms, despite achieving a high rate of clinical CR post-induction. The reason for this failure...

Beating a drum here, but again, I would not do this unless in the setting of a clinical trial until we have more (any) data to support its safety and efficacy.

At this time, the only area I would consider this would be a patient with a small primary tumor who has an oncologic resection demonstrating a pathologic CR after comprehensive sectioning and who would not have likely warranted adjuvant RT in the first place.

My read of the induction chemotherapy literature as it relates to head and neck ...

Agree with both @Dr. First Last and @Dr. First Last. As explained in @Dr. First Last’s comment, imaging is not a surrogate for complete clonigenic cell kill.