67 Limited-stage small cell lung cancer – how to address the high risk of intracranial metastases?

Abstract Introduction Small cell lung cancer (SCLC) accounts for approximately 15% of lung cancers and is characterised by rapid proliferation, early dissemination and poor prognosis. It has a strong predilection for brain metastases, with around 10% of patients presenting with intracranial disease. Current standard of care recommends prophylactic cranial irradiation (PCI) for patients with limited-stage (LS) SCLC who respond to initial therapy. However, scrutiny of practice in the modern era does not necessarily reflect this. Method A retrospective review was conducted of all patients diagnosed with LS SCLC between January 2019 and July 2024 at Imperial College Healthcare NHS Trust. Seven patients (20%) completed PCI. Eighteen patients did not undergo PCI, and nine experienced progression, died, or declined treatment prior to consideration. Results Among patients receiving PCI (mean age 65 years), three had died and four were alive at analysis. All deaths in the PCI group were associated with intracranial progression. Of surviving PCI patients, 75% had no evidence of intracranial progression. All intracranial progression events occurred within 12 months of PCI. In the non-PCI group (mean age 71 years), 44% were alive without intracranial progression at follow-up, while 56% had died; of those who died, 40% experienced intracranial progression. Conclusions Many patients managed without PCI remain alive and free from intracranial progression, demonstrating favourable real-world outcomes. With recent trials failing to replicate survival benefits previously reported and in the modern era of MRI surveillance, avoiding PCI may spare patients long-term neurocognitive and quality-of-life sequelae. Advances in radiotherapy, including stereotactic radiosurgery and systemic therapies with immunotherapy, further challenge PCI’s traditional role. These findings reflect evolving practice and suggest selected patients may achieve favourable outcomes with initial surveillance.