Radiolabeled cetuximab plus whole-brain irradiation (WBI) for the treatment of brain metastases from non-small cell lung cancer (NSCLC)

Background and Purpose: The addition of systemic drugs to whole-brain irradiation has not improved the survival of patients with multiple brain metastases, most likely because the agents did not readily cross the blood-brain barrier (BBB). Radiolabeling of cetuximab was performed to investigate whether this antibody crosses the BBB. Case Report: A patient with multiple brain lesions from non-small cell lung cancer was investigated. The largest metastasis (40 × 33 × 27 mm) was selected the reference lesion. On day 1, 200 mg/m² cetuximab (0.25% hot and 99.75% cold antibody) were given. On day 3, 200 mg/m² cetuximab (cold antibody) were given. Weekly doses of 250 mg/m² cetuximab were administered for 3 months. Results: The reference lesion showed enhancement of radiolabeled cetuximab ( ¹²³I-Erbi) on scintigraphy; ¹²³I-Erbi crossed the BBB and accumulated in the lesion. The reference lesion measured 31 × 22 × 21 mm at 4 months. Enhancement of contrast medium was less pronounced. Conclusion: This is the first demonstration of cetuximab crossing the BBB and accumulating in brain metastasis.