Radiotherapy Dose De-escalation for the Treatment of HPV-Associated Cancers of the Oropharynx

PRIMARY OBJECTIVE:

I. To determine 2-year progression-free survival in patients with HPV-associated oropharyngeal cancer treated with definitive chemoradiation with dose de-escalation based on tumor standardized uptake value maximum (SUVmax) on intra-treatment fludeoxyglucose F-18 (18FDG)-PET/CT performed after 20 Gy.

SECONDARY OBJECTIVES:

I. To evaluate locoregional progression-free survival, distant disease-free survival, and overall survival in patients using the above approach.

II. To validate the association between intra-treatment tumor SUVmax and progression-free survival.

III. To assess the toxicity profile (both acute and long-term) of dose de-escalated radiation therapy and chemotherapy.

OUTLINE:

Patients receive standard of care treatment consisting of radiation therapy daily, five days per week, and cisplatin intravenously (IV) once weekly (QW) for 2 weeks in the absence of disease progression or unacceptable toxicity. Patients then receive 18FDG IV and undergo PET/CT. Patients are then assigned to 1 of 2 groups based on results of PET/CT.

DE-ESCALATED RADIATION DOSE: Patients with a favorable response after PET/CT receive radiation therapy and cisplatin for an additional 4 weeks in the absence of disease progression or unacceptable toxicity.

STANDARD RADIATION DOSE: Patients determined to have an inadequate response after PET/CT receive radiation therapy and cisplatin for an additional 5 weeks in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up at 1, 3, 6, 12 and 24 months.