Efficacy of Prophylactic Cranial Irradiation According to the Risk of Extracranial Recurrence in Limited-Stage Small Cell Lung Cancer

• Published in: Cancer research and treatment Vol. 55; no. 3; pp. 875 - 884
• Main Authors: Lee, Tae Hoon, Chung, Joo-Hyun, Wu, Hong-Gyun, Kim, Suzy, Lee, Joo Ho, Keam, Bhumsuk, Kim, Jin-Soo, Kim, Ki Hwan, Kim, Byoung Hyuck, Kim, Hak Jae
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Cancer Association 01.07.2023; 대한암학회
• Subjects: Adult; Aged; Aged, 80 and over; Brain Neoplasms - prevention & control; Brain Neoplasms - radiotherapy; Cranial Irradiation; Female; Humans; Lung Neoplasms - pathology; Magnetic Resonance Imaging; Male; Middle Aged; Neoplasm Metastasis; Neoplasm Recurrence, Local; Original; Positron-Emission Tomography; Retrospective Studies; Small Cell Lung Carcinoma - pathology; 의학일반; Prophylactic cranial irradiation; Brain metastases; Small cell lung carcinoma; Competing risk regression
• ISSN: 1598-2998; 2005-9256; 2005-9256
• DOI: 10.4143/crt.2022.1583

Purpose We aimed to evaluate the effectiveness of prophylactic cranial irradiation (PCI) for “early brain metastasis”, which occurs before extracranial recurrence (ECR), and “late brain metastasis”, which occurs after ECR, in limited-stage small cell lung cancer (LS-SCLC).Materials and Methods We retrospectively analyzed 271 LS-SCLC patients who underwent definitive chemoradiation. All patients were initially staged with brain magnetic resonance imaging and positron emission tomography. Intracranial recurrence (ICR), ECR, progression-free rate (PFR), and overall survival (OS) were analyzed as clinical endpoints. The competing risk of the first recurrence with ICR (ICRfirst) was evaluated. Significantly associated variables in multivariate analysis of ECR were considered as ECR risk factors. Patients were stratified according to the number of ECR risk factors.Results The application of PCI was associated with higher PFR (p=0.008) and OS (p=0.045). However, PCI was not associated with any of the clinical endpoints in multivariate analysis. The competing risk of ICRfirst was significantly decreased with the application of PCI (hazard ratio, 0.476; 95% confidence interval, 0.243 to 0.931; p=0.030). Stage III disease, sequential, and stable disease after thoracic radiation were selected as ECR risk factors. For patients without these risk factors, the application of PCI was significantly associated with increased OS (p=0.048) and a decreased risk of ICRfirst (p=0.026).Conclusion PCI may play a role in preventing early brain metastasis rather than late brain metastasis after ECR, suggesting that only patients with a low risk of ECR may currently benefit from PCI.