Watchful Observation of Patients With Limited Small Cell Lung Cancer Instead of the PCI - Prospective, Multi-center One-arm Study

Prophylactic cranial irradiation (PCI) is a current standard of care after confirmed response to radical chemoradiotherapy for limited disease small cell lung cancer (LD-SCLC). This standard is mostly based on results of old randomized studies when brain imaging with magnetic resonance (MRI) was not available. Survival benefit of PCI in extended SCLC was recently challenged by results of randomized phase III study from Japan. We propose to carefully follow LD-SCLC patients with MRI instead of PCI in order to apply modern brain irradiation [stereotactic radiotherapy (SRT) in eligible patients or whole brain radiation therapy (WBRT)] to patients who develop metastases and to eliminate long terms neurocognitive deficits caused by PCI in patients who would never develop brain metastases.

Methods and analysis This is a prospective multi-centre one-arm trial. A total of 80 patients diagnosed with LD-SCLC after confirmed response to standard of care radical chemoradiotherapy will be enrolled. Patients will be followed-up by brain MRI every 3 months up to 3 years. Neurocognitive function tests will be performed at baseline and after 12 and 24 months. Patients who develop brain metastases during observation will be irradiated. In case of limited number and volume of metastases SRT will be offered to patients; others will be treated with WBRT. The primary endpoint of the trial is overall survival. We have assumed that our approach will not compromise overall survival of treated patients. 2-year survival will be at least 50% in our trial compared to 36% for a group of 138 patients LD-SCLC from our institution treated in 2003-2006 with radical chemoradiotherapy and PCI. The secondary endpoints were designed to asses the risk of developing brain metastases without PCI; to assess the efficacy of radiotherapy of early detected brain metastases, including the feasibility and efficacy of SRT; to assess neurocognitive functions and QoL in the studied cohort. QLQ-C30 questionnaire and the California Verbal Learning Test (CVLT), Color connection test (CTT), Benton visual memory test (BNRT) and Verbal fluency test (VFT) will be carried out by the certified psychologist.

Ethics and dissemination The trial received ethical approval from the local medical university Bioethical Review Board (Komisja Bioetyczna Collegium Medicum Uniwersytet Warmińsko-Mazurski w Olsztynie). The results of the trial will be disseminated through peer-reviewed publications and conference presentations.