Intensity-Modulated Radiation Therapy or 3-Dimensional Conformal Radiation Therapy in Decreasing Hearing Loss in Patients Who Have Undergone Surgery for Parotid Tumors

A Multicenter Randomized Study of Cochlear Sparing Intensity Modulated Radiotherapy Versus Conventional Radiotherapy in Patients With Parotid Tumors

RATIONALE: Radiation therapy uses high-energy x-rays to kill tumor cells. 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. Giving radiation therapy after surgery may kill any tumor cells that remain after surgery. It is not yet known whether intensity-modulated radiation therapy or 3-dimensional conformal radiation therapy is more effective in decreasing hearing loss in patients undergoing radiation therapy for parotid gland cancer.

PURPOSE: This randomized phase III trial is studying intensity-modulated radiation therapy to see how well it works compared with 3-dimensional conformal radiation therapy in decreasing hearing loss in patients who have undergone surgery for parotid tumors.

OBJECTIVES:

Primary

• To determine the potential of cochlear-sparing intensity-modulated radiotherapy (IMRT) versus conventional radiotherapy comprising 3-dimensional conformal radiotherapy in reducing the incidence of sensory-neural hearing loss in patients with parotid tumors undergoing radiotherapy to the parotid region.

Secondary

• To describe and compare the impact of both IMRT and conventional radiotherapy on physical, social and emotional well-being including generic functional and symptom aspects as well as disease-specific issues relevant to audiometry.

OUTLINE: This is a multicenter study. Patients are stratified according to center and radiotherapy dose. Patients are randomized to 1 of 2 treatment arms after surgical resection.

• Arm I (cochlear-sparing intensity-modulated radiotherapy [IMRT]): Patients undergo cochlear-sparing IMRT using the local planning system once daily, 5 days per week, for 6 weeks (total of 30 fractions) at a total dose of 60 Gy (65 Gy if macroscopic residual disease). Patients may undergo elective neck irradiation of the uninvolved lymph node areas once daily, 5 days per week, for 6 weeks.
• Arm II (conventional radiotherapy): Patients undergo conventional radiotherapy comprising 3-dimensional conformal radiotherapy once daily, 5 days per week, for 6 weeks (total of 30 fractions) at a total dose of 60 Gy (65 Gy if macroscopic residual disease). Patients may undergo elective neck irradiation of the uninvolved lymph node areas once daily, 5 days a week, for 5 weeks.

Patients complete quality-of-life questionnaires (EORTC QLQC30 v.3.0, the head and neck module H&N35, and a modified version of the Glasgow Hearing Aid Benefit profile) at baseline and at 6,12, 24, 36, 48, and 60 months after completion of study therapy. Patients also undergo audiological and vestibular assessment at 6 and 12 months following radiotherapy and then annually thereafter for up to 5 years.

After completion of study treatment, patients are followed up at 3, 6, 12, 18, and 24 months and then annually thereafter for up to 5 years (annually for recurrence for at least 10 years).

Peer Reviewed and Funded or Endorsed by Cancer Research UK.

DISEASE CHARACTERISTICS:

• Histologically confirmed malignant tumors of the parotid glands
• Adjuvant radiotherapy planned post-surgery
• No parotid tumors requiring primary radiotherapy
• No benign tumors requiring postoperative radiotherapy
• No metastases from squamous cell carcinoma of the head and neck to the parotid gland
• At high-risk of radiation-induced sensory-neural hearing loss with conventional radiotherapy due to the irradiation of the parotid bed to a dose equivalent of 60 Gy in 2 Gy/fraction with photon beams, using the wedge-pair technique

PATIENT CHARACTERISTICS:

• WHO performance status 0-1
• No hearing loss > 60 dB
• No previous or concurrent illness that, in the investigator's opinion, would interfere with either completion of therapy or follow-up
• Suitable to attend regular follow-up and undergo audiograms and toxicity monitoring and be available for long term follow-up

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• No prior radiotherapy to the head and neck region
• No concurrent chemotherapy