Major De-escalation to 30 Gy for Select Human Papillomavirus Associated Oropharyngeal Carcinoma

All subjects on Cohort A and the first 100 subjects accrued to Cohort B will undergo a pre-treatment F-FMISO scan PET/CT scan pretreatment. For both Cohort A and Cohort B, FMISO scan will be repeated between the 5th-10th RT day if pre-treatment scan is hypoxic. If the repeat 18F-FMISOscan PET/CT demonstrates hypoxia, the subject will receive 70Gy concurrent with 2 cycles of chemotherapy. All subjects accrued onto Cohort B after 100 accruals will undergo only one 18F-FMISO scan done 5-10 treatment days after start of radiation therapy.

Treatment will be delivered as one fraction per day on a standard 5 day per week schedule (excluding weekends and holidays), total of 30 Gy over 3 weeks at 2 Gy per fraction each day. The gross nodes, the primary/postoperative bed if applicable, all subclinical areas at risk for disease will receive the same dose at 30Gy.

Cycle 1 (week 1): At the start of week 1 of IMRT, subjects will receive cisplatin 100 mg/m2 intravenously. They may be given for 2 consecutive days (50 mg/m2 each day for a total dose 100 mg/m2), typically on days 1 and 2, or as a single dose, typically on day 1.

If cisplatin cannot be given at 100 mg/m2 for either cycle 1 or cycle 2, the investigator may use a regimen with carboplatin and 5-Fluorouracil in its place. Carboplatin will be given at a dose of AUC 1.25 intravenously daily x 4 days starting on day 1 of the cycle (total dose of AUC 5). Cycle 2 (Week 4): After the three weeks of radiation at week 4 when the subject no longer is receiving radiation therapy, subjects will receive cisplatin 100 mg/m2 intravenously. The may be given for 2 consecutive days (50 mg/m2 each day for a total dose 100 mg/m2), typically on days 22 and 23, or as a single dose, typically on day 22.

If cisplatin cannot be given at 100 mg/m2 for either cycle 1 or cycle 2, the investigator may use a regimen with carboplatin and 5-Fluorouracil in its place. 5-Fluorouracil will be given at a dose of 600 mg/m2 intravenous infusion over 24 hours daily x 4 days (total dose of 2400 mg/m2 intravenous infusion over 96 hours).

Proton beam using pencil beam delivery either with the Varian or IBA delivery systems will be allowed for Cohort B. Proton beam therapy will be given at the New York Proton Center in New York City, where MSKCC has a well-established business associate agreement and cooperative research agreement with, respectively. If treatment at NYPC is not feasible, patients may be referred to ProCure in Somerset, NJ.