Clinical study of the treatment of multiple brain metastases from adenocarcinoma of the lung by simultaneous integrated boost intensity-modulated radiotherapy

Abstract

Objective: To investigate the effects of simultaneous integrated boost intensity-modulated radiotherapy (SIB) and sequential boost conformal radiotherapy (CRT) in treatment of multiple brain metastases from lung adenocarcinoma. Methods: Forty-two patients with multiple brain metastases from lung adenocarcinoma were analyzed. The epidermal growth factor (EGFR) mutations were negative, ECOG (Eastern Cooperative Oncology Group) were not more than two, the diameters of brain metastases were from 0.5cm to 3.0cm and the numbers of brain metastases were from three to five. The target volume of radiotherapy included whole brain and brain metastatic tumor. The radiation models were divided into SIB in 26 cases and CRT in 16 cases. The median radiation dose of whole brains in SIB and CRT groups were 40Gy, and the brain metastases tumor were 55Gy, 60Gy respectively, and the median number of radiotherapy for 22 times, 30 times. Thirty one patients followed by pemetrexed maintenance chemotherapy (PMC) or docetaxel maintenance chemotherapy (DMC) and 11 patients received no maintenance chemotherapy (NMC). Results: The 1-, 3-, and 5-year survival rates of whole group were 92.8%, 23.8%, and 4.8%, respectively. The median survival time of SIB and CRT groups were 36 months, 29 months, respectively. The SIB group was better than CRT group, and PMC was better than DMC or NMC. Multiple factors analyses showed ECOG, dose and times of brain metastatic tumor radiotherapy, and cycles of PMC were independent risk factors for survival time. The late main adverse reaction was hypomnesia. Conclusion: SIB was superior to CRT, and PMC could improve survival time.