Impact of prophylactic cranial irradiation in adenocarcinoma of the lung.

Out of 148 patients who had metastatic adenocarcinoma of the lung and were referred to Chang Gung Memorial Hospital for treatment from 1979 to 1987, 20% had symptomatic brain metastases. We have attempted to determine the subset of high-risk patients who might benefit from prophylactic cranial irradiation. In 25 patients with a complete remission, 36% (n = 9) eventually developed brain metastases after a minimum follow-up of 24 months. Patients with initial mediastinal node metastases showed a higher incidence of brain metastases (75%) than those harboring only hilar node metastases (25%, p = 0.03). Age, sex, tumor location and clinical staging had no significant correlation in the prognosis of brain metastases. Since the median recurrence-free survival rate of six months for patients with brain metastases was significantly shorter than for those without (14 months), we recommend that prophylactic cranial irradiation be conducted in complete responders with mediastinal nodal lesions to see if such treatment will prolong patients' recurrence-free survival via a reduction in brain metastases, thus improving their quality of life.