Nine-year Experience: Prophylactic Cranial Irradiation in Extensive Disease Small-cell Lung Cancer

In 2007, a European Organization for Research and Treatment of Cancer (EORTC) study demonstrated a beneficial effect on overall survival (OS) with the use of prophylactic cranial irradiation (PCI) in extensive disease small-cell lung cancer. Nevertheless, debate is ongoing regarding the role of PCI, because the patients in that trial did not undergo imaging of the brain before treatment. Also, a recent Japanese randomized trial showed a detrimental effect of PCI on OS in patients with negative pretreatment brain magnetic resonance imaging findings. Of our patients, 87% underwent brain imaging before PCI. In the present retrospective analysis, we found that PCI leads to a nearly doubled median OS compared with the irradiation arm of the EORTC trial, with a 2-month prolonged median OS compared with the irradiation arm of the Japanese trial. Background: In 2007, the European Organization for Research and Treatment of Cancer (EORTC) study (ClinicalTrials. gov identifier, NCT00016211) demonstrated a beneficial effect on overall survival (OS) with the use of prophylactic cranial irradiation (PCI) for extensive disease (ED) small-cell lung cancer (SCLC). Nevertheless, debate is ongoing regarding the role of PCI, because the patients in that trial did not undergo magnetic resonance imaging (MRI) of the brain before treatment. Also, a recent Japanese randomized trial showed a detrimental effect of PCI on OS in patients with negative pretreatment brain MRI findings. Materials and Methods: We examined the medical records of 136 patients with ED SCLC who had initially responded to chemotherapy and undergone PCI from 2007 to 2015. The outcomes, radiation toxicity, neurologic progression-free survival, and OS after PCI were analyzed. Survival and correlations were calculated using log-rank and univariate Cox proportional hazard ratio analyses. Results: The median OS and the median neurologic progression-free survival after PCI was 12 and 19 months, respectively. No significant survival difference was seen for patients who had undergone MRI before PCI compared with patients who had undergone contrast-enhanced computed tomography (P = .20). Univariate analysis for OS did not show a statistically significant effect for known cofactors. Conclusion: In the present cohort, PCI was associated with improved survival compared with the PCI arm of the EORTC trial, with a nearly doubled median OS period. Also, the median OS was prolonged by 2 months compared with the irradiation arm of the Japanese trial.