RATIONALE: Radiation therapy uses high-energy x-rays to damage tumor cells. It is not yet known which radiation therapy regimen is more effective in preventing brain metastases in patients with limited-stage small cell lung cancer while taking into account chronic neurotoxicity from radiation therapy.

PURPOSE: This randomized phase II trial compares the incidence of chronic neurotoxicity between three different brain irradiation regimens. The corresponding phase III component addressing the prevention of brain metastases was run by EORTC and reported separately (NCT00005062).

OBJECTIVES:

• Compare the incidence of chronic neurotoxicity in patients treated with these regimens.
• Compare quality of life of patients treated with these regimens. (phase III closed to accrual as of 12/31/05)

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to age (60 and under vs over 60) and time since induction therapy (90 days or less vs 91-180 days vs 181-240 days). Patients are randomized to 1 of 3 treatment arms.

• Arm I: Patients undergo prophylactic cranial irradiation (PCI) once daily 5 days a week. Treatment continues for 2 weeks in the absence of unacceptable toxicity.
• Arm II: Patients undergo PCI once daily 5 days a week. Treatment continues for 2.6 weeks in the absence of unacceptable toxicity.
• Arm III: Patients undergo PCI twice daily 5 days a week. Treatment continues for 3.4 weeks in the absence of unacceptable toxicity.

Quality of life is assessed at baseline, every 6 months for 1 year, and then annually for 3 years.

Patients are followed every 6 months for 1 year and then annually for 3 years.

PROJECTED ACCRUAL: A total of 264 patients will be accrued for this study within 3.5 years.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed small cell lung cancer by fine needle aspiration, biopsy, or 2 positive sputa

  • Limited stage (I-IIIB)

    • Confined to 1 hemithorax
    • No T4 based on malignant pleural effusion, or N3 disease based on contralateral hilar or contralateral supraclavicular involvement

• Complete response after induction chemotherapy (with or without thoracic radiotherapy)

• Consolidative chest radiotherapy may be initiated before study

• No radiographic evidence of any of the following:

  • Brain metastases

    • Normal brain CT scan or MRI less than 1 month before study

  • Ipsilateral lung metastases

  • Malignant pleural effusion

    • Minimal pleural effusion by chest CT scan allowed, but not by chest x-ray

PATIENT CHARACTERISTICS:

Age

• Not specified

Performance status

• Zubrod 0-1

Life expectancy

• Not specified

Hematopoietic

• Absolute granulocyte count at least 1,500/mm^3
• Platelet count at least 75,000/mm^3
• Hemoglobin at least 10.0 g/dL^

Hepatic

• Not specified

Renal

• Not specified

Pulmonary

• See Disease Characteristics

Other

• Not pregnant or nursing
• Fertile patients must use effective contraception
• Neurological function class 1 or 2
• No epilepsy requiring permanent oral medication
• No other malignancy within the past 5 years except nonmelanoma skin cancer or carcinoma in situ of the cervix
• No other serious medical or psychiatric condition that would preclude study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• See Disease Characteristics
• At least 1 week since prior chemotherapy
• No concurrent chemotherapy

Endocrine therapy

• Not specified

Radiotherapy

• See Disease Characteristics
• No prior external beam radiotherapy to the head or neck, including stereotactic radiotherapy
• Concurrent thoracic radiotherapy allowed

Surgery

• Not specified

Other

• No concurrent antitumor agents

PI's are required to abide by the sponsor's publication guidelines which require review by coauthors and subsequent review and approval by the sponsor.