Cranial irradiation in cancer of the lung of all cell types. Prophylactic cranial irradiation for lung cancer patients at high risk for development of cerebral metastasis: results of a prospective randomized trial conducted by the Radiation Therapy Oncology Group. Role of elective brain irradiation during combined chemoradiotherapy for limited disease non-small cell lung cancer.
The Veterans Administration Lung Group conducted a prospective study of irradiation for subclinical brain metastases in patients with inoperable carcinoma of the lung between 1975 and 1978. Patients were randomized to receive whole-brain irradiation (2,000 rads in two weeks) or no brain treatment, and to receive one of two regimens of thoracic irradiation. Three hundred twenty-three patients with normal radionuclide brain scans were able to be evaluated. The rate of clinical brain metastasis was 26% for patients with small cell carcinoma vs 10% for the "non-small-cell" group. A statistically insignificant decrease in the rate of brain metastasis was found among irradiated patients with small cell carcinoma. The frequency of brain metastasis in the non-small-cell patients was reduced from 13% to 6% by irradiation. Prophylactic cranial irradiation can decrease morbidity from non-small-cell carcinoma of the lung. Beginning in February 1984, 187 evaluable patients with adenocarcinoma or large cell carcinoma of the lung clinically confined to the chest were randomized to receive either conventionally fractionated thoracic irradiation alone or thoracic irradiation with concurrent, prophylactic cranial irradiation. The study population included 161 patients treated for medically or surgically inoperable primary cancers, and 26 patients undergoing adjuvant postoperative mediastinal irradiation following attempted curative resection of primary cancers found to have metastasized to hilar or mediastinal lymph nodes. Elective brain irradiation was not effective in preventing the clinical appearance of brain metastases, although the time to develop brain metastases appears to have been delayed. Eighteen of 94 patients (19%) randomized to chest irradiation alone have developed brain metastases as opposed to 8/93 patients (9%) randomized to receive prophylactic cranial irradiation (p = .10). No survival difference was observed between the treatment arms. Among the 26 patients undergoing prior resection of all gross intrathoracic disease, brain metastases were observed in 3/12 patients (25%) receiving adjuvant chest irradiation alone, compared to none of 14 receiving prophylactic cranial irradiation (p = .06). In the absence of fully reliable therapy for the primary disease, and without effective systemic therapy preventing dissemination to other, extrathoracic sites, prophylactic cranial irradiation for inoperable non-small cell lung cancer cannot be justified in routine clinical practice. Further investigation in the adjuvant, postoperative setting may be warranted. We have studied the clinical impact of elective brain irradiation (EBI) in patients with locally advanced, non-small cell lung cancer (LA-NSC). All patients received combination chemotherapy (cyclophosphamide + doxorubicin (Adriamycin) + cisplatin = CAP) or CAP plus radiotherapy as the initial treatment for their active tumor or as an adjuvant therapy. Of 97 evaluable patients, 46 were randomized to receive EBI (3 000 rad in 10 fractions given over two weeks). The characteristics of both groups were comparable by sex, age, performance status, pretherapy weight loss, histologic cell type, clinical staging, and type of prior therapy. EBI significantly decreased the incidence of central nervous system (CNS) metastasis in the treated group compared to the control group (4% vs 27%, p = .002). CNS involvement occurred in the treated group after failure at other sites whereas 12 of 14 control patients had CNS metastases as the first site of relapse. EBI decreased the incidence of CNS metastasis in all prognostic categories. Using multivariate analysis, the beneficial effect was shown to be significant in females, patients with good performance status, weight loss less than 6%, squamous cell histology, state III disease or no prior therapy. EBI significantly increased CNS metastasis-free interval with a beneficial effect that was significant in males, patients with weight loss less than 6%, squamous cell histology or responders. Although no survival benefit was observed for the treated group because of the adverse effect from other relapses, EBI will become more important as better treatment programs are developed.(ABSTRACT TRUNCATED AT 250 WORDS)
This update of the review published in 2005 does not contain any new trials published in full. One new trial that has only been published as an abstract, does not show any benefit in overall survival in patients receiving prophylactic cranial irradiation. There is insufficient evidence to support the use of PCI in clinical practice. Where possible, patients should be offered entry into a clinical trial.