Whole-Brain Radiation Therapy Plus Sequential or Simultaneous Integrated Boost for the Treatment of Finite Number of Brain Metastases in Non-Small Cell Lung Cancer

Abstract

There has been no definitive regimens on how to integrate whole brain radiotherapy (WBRT) and local boost for brain metastatas (BMs). To compare the therapeutic effect and cerebral cognitive dysfunction in non-small cell lung cancer patients with finite number of BMs (≤10) treated by WBRT plus sequential integrated boost (SEB) or simultaneous integrated boost(SIB). A total of 52 non-small cell lung cancer patients with finite number of BMs who underwent IMRT from January 2013 to December 2016 were retrospectively analyzed. Twenty cases in group A were irradiated by WBRT+ SEB (first 3Gy*10Fx for WBRT then 4Gy*3Fx for BMs) and 32 case in group B were irradiated by WBRT+SIB (3Gy*10Fx for WBRT and the same 4Gy*10Fx for BMs). The clinical efficacy and differences in cognitive impairment were compared between 2 groups. The Cumulative survival rates of 1, 2 and 3 years in 52 patients were 52.5%, 28.6% and 14.3%, respectively. The median survival time was 13 months. The Cumulative 1, 2 and 3-year survival rates of group A were 60.0%, 41.1%, 27.4%, respectively. The median survival time was 15 months. The 1,2 and 3-year survival rates of group B were 47.8%, 19.1%, 0%, respectively. The median survival time was 10 months. The effect diffrence between group A and B was significant (P=0.046). Subgroup analysis revealed that 1, 2 and 3 years survival rate and median survival time of group A were significantly superior to group B, especially to those patients with 1-2 BMs, male or age <59 years old (P <0.05). MMSE scores at the end of radiation and at 1 month after radiation were not significantly different from those before treatment in both group (p> 0.05), however, the scores at 3 or 6 months after radiation were lower than before radiation, the difference was significant(p<0.05). There was no significant difference in MMSE scores in the 2 group before radiation, at the end of radiation, at 1 month after radiation and at 6 months after radiation (P> 0.05) .The scores of group A at 3 months after radiation was higher than that of group B (p <0.05). Certainly, group A had longer radiotherapy time and more cost than group B (p<0.005). For finite number of BMs in non-small cell lung cancer, WBRT+SEB is likely to be better thanWBRT+SIB, especially to 1-2 metastases, male or aged <59 years patients. The decline of cognitive function in both groups occurred after 3 months of radiation, and WBRT+SEB group seems to be less impairment of brain cognitive function than that WBRT+SIB group. It is worth further study to verify Which boost scheme will be better.