Fast neutron treatment for squamous cell carcinoma of the head and neck: final report of Edinburgh randomised trial.

OBJECTIVE To compare neutron treatment and megavoltage (photon) radiotherapy in locally advanced squamous cell carcinoma of the head and neck. DESIGN Randomised trial of patients stratified by site of primary tumour and presence or absence of lymph node metastases. Follow up of patients after treatment. SETTING Department of clinical oncology, Western General Hospital, Edinburgh. PATIENTS 165 Patients with untreated, histologically proved squamous cell carcinoma of the oral cavity, oropharynx, larynx, or hypopharynx. All patients completed treatment, and no patient was lost to follow up. INTERVENTION Treatment with either neutrons or photons. MAIN OUTCOME MEASURES Disease state and morbidity (scored with the system of the European Organisation for Research on Treatment of Cancer) at each visit during follow up. RESULTS Of the 165 patients, 85 were randomised to receive neutron treatment and 80 to receive photon treatment. Minimum follow up was five years. Local control of cancer remained similar in the two groups, being achieved in 37 (44%) patients after neutron treatment and 36 (45%) after photon treatment. Five year and actuarial 10 year survival rates were 24% (20/85) and 14% respectively in the group treated with neutrons and 34% (27/80) and 30% respectively in the group treated with photons. Five year survival rates without local disease were 19% (16/85) and 30% (24/80) respectively. Necrosis was more common after neutron treatment than after photon treatment. Seven patients in the neutron group who developed necrosis died whereas no deaths were associated with photon treatment. CONCLUSION Rates of long term local control were similar in the two groups. Necrosis related to radiation was more common in patients treated with neutrons, and the mortality related to treatment was significantly higher in these patients.