RATIONALE: Imaging procedures, such as PET scans, may determine the extent of cancer and help doctors plan radiation therapy. Radiation therapy uses high-energy x-rays to kill tumor cells. Giving radiation therapy that uses a 3-dimensional image of the tumor to help focus thin beams of radiation directly on the tumor, and giving radiation therapy in higher doses over a shorter period of time, may kill more tumor cells and have fewer side effects. Specialized radiation therapy that delivers a high dose of radiation directly to the tumor may kill more tumor cells and cause less damage to normal tissue.

PURPOSE: This clinical trial is studying PET scans to see how well they work in patients with head and neck cancer who are undergoing 3-dimensional conformal radiation therapy and intensity-modulated radiation therapy.

OBJECTIVES:

Primary

• To assess the value of pre-treatment PET in determining the target volume in patients with head and neck cancer undergoing three-dimensional conformational radiotherapy and intensity-modulated radiotherapy.

Secondary

• To evaluate variations in weekly fludeoxyglucose F 18 PET imaging during the first 5 weeks of treatment.
• To determine the relationship between changes in tumor metabolism during radiotherapy and control tumor at 3 months and at 1 year post-treatment.

OUTLINE: This is a multicenter study.

Patients undergo fludeoxyglucose F18 PET (FDG-PET) in addition to conventional imaging at baseline. Patients undergo standard three-dimensional conformational radiotherapy and intensity-modulated radiation therapy 5 days a week for 5 weeks.

Some patients also undergo weekly FDG-PET during treatment.

DISEASE CHARACTERISTICS:

• Histologically confirmed head and neck cancer

  • No nasopharyngeal or paranasal sinus cancer
  • Locally advanced disease (T3 or T4)
  • Not in complete remission

• Planning to undergo curative radiotherapy (minimum dose of 66 Gy), with or without standard treatment (i.e., platinum-based chemotherapy or biological therapy/rituximab)

• Measurable tumor according to RECIST criteria

PATIENT CHARACTERISTICS:

• WHO performance status 0-2

• Not pregnant or nursing

• Able to lie still for 1 hour

• No history of progressive neoplastic disease

• No known hypersensitivity to fludeoxyglucose F18 or any of its excipients

• No severe or uncontrolled systemic disease, including any of the following:

  • Kidney disease
  • Liver disease
  • Cardiac disease
  • Unstable or uncompensated respiration
  • Uncontrolled diabetes (i.e., glucose ≥ 1.5 g/L)

• No geographical, social, or psychological conditions that make follow-up impossible

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• No prior surgery
• No concurrent experimental agents