According to results recently presented at the 2007 annual meeting of the American Society of Clinical Oncology (ASCO), prophylactic cranial radiation following treatment with chemotherapy doubles survival at one year and reduces the risk of developing brain metastasis among patients with extensive-disease small cell lung cancer (SCLC). 

Approximately two-thirds of patients with SCLC have extensive disease at the time of diagnosis. A large portion of these patients ultimately develop brain metastasis, so the use of prophylactic radiation to destroy micrometastasis in the brain could potentially reduce the growth of these metastasis. 

Dutch researchers recently conducted a trial to evaluate prophylactic cranial radiation among patients with extensive disease SCLC. This trial included 286 patients who demonstrated a response to 4-6 cycles of chemotherapy; 70% of patients had disease that had spread outside the lung. Patients were randomized to prophylactic cranial radiation consisting of 20 to 30 Gy administered in five to 12 fractions or observation following chemotherapy.  

• At one year, symptomatic brain metastases occurred in 14.6% of patients treated with cranial radiation compared with 40.4% of patients in the observation group.
• Survival was doubled at one year for patients treated with cranial radiation compared to those in the observation group (27.1% versus 13.3%, respectively) (p=0.003).
• Radiation was well tolerated; the most common side effects were headache, nausea and vomiting and fatigue.  

These results indicate that prophylactic cranial radiation appears to significantly improve survival at one year and reduce the risk of developing brain metastasis among patients with extensive-disease SCLC who respond to chemotherapy. Furthermore, cranial radiation did not significantly reduce quality of life among these patients. Dr. Slotman, the lead investigator of this trial stated that “Prophylactic cranial irradiation should now routinely be offered to all responding SCLC patients with extensive disease."  

Reference: Slotman B, Faivre-Finn C, Kramer G, et al. A Randomized Trial of Prophylactic Cranial Irradiation (PCI) Versus no PCI in Extensive Disease Small Cell Lung Cancer After a Response to Chemotherapy (EORTC 08993-22993). Proceedings from the American Society of Clinical Oncology Conference. Chicago/IL. 2007.  Abstract # 4.