Inclusion Criteria:

- Biopsy-proven SCC of the oropharynx (tonsil, base of tongue, pharyngeal wall or
palate).

- Tumor positive for infection with HPV virus type 16 or other types (section 8.0).

- T stage: 1, 2. T3 tumors are allowed if the tumor is arising from the tonsillar fossa
and/or is exophytic based on both clinical exam and CT; Surgery of the primary tumor
is limited to incisional or excisional biopsies (i.e tonsillectomy) even without
macroscopic disease left. Positive resection margins and/or gross residual disease at
the primary site are allowed.

- Any N stage, but resectable; lymph nodes in both sides of the neck are at risk of
metastatic disease, according to clinical judgment, and require irradiation;
pre-treatment surgery in the neck in the forms of incisional/excisional biopsy or a
multilevel neck dissection is allowed only if there is gross tumor left at the
primary site.

- No other malignancy except for non-melomatous skin cancer, early stage prostate
cancer (T<2a and PSA<10 and GLS<7) or a carcinoma not of head and neck origin disease
free for > 5 yrs.

- Cannot have distant metastasis (M0)

- ECOG performance status 0-1.

- Patient's nutritional and general physical condition must be considered compatible
with the proposed radiotherapeutic treatment.

- Patient is judged to be mentally reliable to follow instructions and to keep
appointments.

- Patient is on no other treatment for head and neck cancer.

- Signed study-specific informed consent prior to registration.

Exclusion Criteria:

- Evidence of distant metastases.

- Absence of macroscopic disease after upfront surgery, i.e., TxNx and TxN0. TxN+ and
T1-3Nx are eligible if the T/N stage categories meet the criteria of 3.1.1.

- Previous irradiation for head and neck tumor; concurrent chemotherapy other than the
treatment per protocol; previous chemotherapy ≤ 3 months from start of RT.

- Active untreated infection.

- Major medical or psychiatric illness, which in the investigators' opinions would
interfere with either completion of therapy and follow-up or with full and complete
understanding of the risks and potential complications of the therapy.

- Prophylactic use of amifostine or pilocarpine is not allowed.