Role of Stereotactic Radiotherapy in Cranial Metastases of Small Cell Lung Cancer
Naciye IŞIK1,Gökhan YAPRAK1,Cengiz GEMİCİ1,Özüm ATASOY1
1Department of Radiation Oncology, Kartal Dr. Lütfi Kırdar Training and Research Hospital, İstanbul-Turkey DOI : 10.5505/tjo.2019.2206 OBJECTIVE
Brain metastasis can be seen in small cell lung cancer patients despite cranial radiotherapy. Incase of intracranial recurrence after cranial radiotherapy, treatment choices are restricted. Cranial reirradiation may be an option. In our study, the role of stereotactic radiotherapy after relapse in patients undergoing whole brain radiotherapy for prophylaxis or metastasis was investigated.

Thirty-six small cell lung cancer patients who had intracranial recurrence after total cranial irradiation and who were treated with salvage SRT in our clinic between June 2010 and January 2019 were evaluated retrospectively. The patients were treated with frameless robotic radiosurgery system (CyberKnife -Accuray, CA, USA). Median 20 Gy (10-24 Gy) was administered in 1 to 4 fractions depending on the volume and relation of the tumor with critical structures.

Whole brain radiotherapy was performed with cranial prophylaxis in 16 patients (44.5%) and brain metastasis in 20 patients (55.5%), in which patients underwent stereotactic radiotherapy (SRT) with recurrence/metastasis. Median follow-up time after SRT was 5.5 months. Median one and two years survivals after SRT were %33 and %6.6, and median survival was 4,1 months. After SRT, one and two-year cranial control rates were 57% and 15%, and the median cranial control duration was 12.8 months. In multivariate analysis, only time interval between WBRT and SRT was found to be significant for survival after SRT p=0.014 (HR: 2.66 95% CI:1.21-5.82).

SRT should be considered as a treatment alternative especially in patients with long time intracranial control after whole brain radiotherapy and in patients with systemic disease control. Keywords : Brain metastasis re-irradiation; small cell lung cancer; stereotactic radiotherapy