Prophylactic Cranial Irradiation in Extensive Disease Small Cell Lung Cancer

Summary

Percutaneous cranial irradiation (PCI) has had benefit for patients with limited disease small cell lung cancer (SCLC). The findings of a study now indicate that PCI also has benefit in the setting of extensive disease-SCLC, where the risk of brain metastases is high. This article discusses the findings of a study in which PCI led to a significant reduction in the risk of symptomatic brain metastases and a significant prolongation of survival.

  • Respiratory Cancers
  • Cancer Clinical Trials

Percutaneous cranial irradiation (PCI) has had benefit for patients with limited disease small cell lung cancer (SCLC). The findings of a study now indicate that PCI also has benefit in the setting of extensive disease (ED)-SCLC, where the risk of brain metastases is high.

Ben Slotman, MD, PhD, VU University Medical Center, Amsterdam, the Netherlands, reported the findings of a study in which PCI led to a significant reduction in the risk of symptomatic brain metastases and a significant prolongation of survival.

The trial involved 286 patients with ED-SCLC who had a response to standard chemotherapy. The patients were randomly assigned to the PCI group (143 patients) or to the control group (143 patients). Persistent primary disease was present in approximately 75% of the patients in each group. Approximately 70% of patients had persistent metastases to lymph nodes, bone, lung, or other sites after completion of chemotherapy. Radiotherapy was usually given as 20 Gy in 5 fractions. Other radiotherapy schemes included 24–30 Gy in 8–12 fractions and 30 Gy in 10 fractions.

Dr. Slotman said that symptomatic brain metastases was defined as the radiographic evidence of brain metastases and the presence of one or more key symptoms. These symptoms included signs of increased intracranial pressure, headache, nausea and/or vomiting, cognitive and/or affective disturbances, seizures, or focal symptoms.

At 1 year, the rate of symptomatic brain metastases was significantly lower for patients in the PCI group than for patients in the control group (Table 1). One-year overall survival was also significantly better for patients treated with PCI. Dr. Slotman reported that PCI had no significant effect on extracranial disease progression. However, the treatment extended failure-free survival (Table 1). Symptomatic brain metastases was the first event in 9% of patients in the PCI group compared with 35% of patients in the control group.

Table 1.

Comparison of Outcomes for PCI Group and Control Group.

PCI was well tolerated and had no adverse effects on the quality of life. Headache was the most common side effect. The only grade 3 adverse event was headache, which occurred in 4% of patients. Late radiation effects were rare. Grade 3 late effects (severe headache or severe central nervous system dysfunction) developed in approximately 2% of patients.

Dr. Slotman concluded, “Patients with extensive disease-small cell lung cancer who respond to chemotherapy should now routinely be offered PCI.”

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