Whole Brain Radiation Therapy With Local Simultaneous Integrated Boost Conformal Radiation Therapy in the Treatment for Patients With 1-3 Brain Metastases

Abstract

To evaluate the feasibility whole brain radiation therapy (WBRT) with local simultaneous integrated boost conformal radiation therapy (SIB-CR) in the patients with one to three brain metastases. Twenty-one patients with one to three brain metastases confirmed by enhanced MRI/CT were prospectively collected and treated by whole brain radiation therapy with local SIB-CR. The prescribed dose of whole brain was 40 Gy/22 fractions and GTV to 55 Gy/22 fractions simultaneously in about 4.5 weeks. The acute radiation toxicities were recorded from the start of treatment to four weeks after the end of treatment. The late toxicities were evaluated. The tumor response was evaluated at 4 weeks after the end of radiation therapy. The overall survival (OS) and intracranial progression-free survival (PFS) time were calculated from the day of treatment until death, intracranial progression or the last follow-up date. There were 11 male and 10 female patients in this group. The median age was 52 years (range, 39-72 years). Fourteen patients received radiation therapy alone while 7 cases received chemoradiation therapy. There were 2 patients with complete response, 16 patients with partial response and 3 patients with stable disease. The overall tumor response rate was 85.7% (18/21). The median follow-up time was 7 months (range, 1-12.5 months). To the follow-up cut-off time, five patients were dead, including 3 cases died of intracranial lesions and 2 of unknown causes. The rate of overall brain control was 85.7% (18/21), the local control rate 90.5% (19/21). The overall median survival time was 7 months. The 6-month OS and intracranial PFS rates were 76.6% and 61.3%, respectively. The 1-year OS and intracranial PFS rates were 61.3% and 65.6%, respectively. The 1-year survival rate of patients treated with radiation therapy alone and chemoradiation therapy was 69.3% and 85.7%, respectively (p = 0.253). Multivariate analysis showed that the RPA classification was correlated with survival. Survival rates among the patients with different RPA scores showed that the median survival period of RPA 1, 2 and 3 level were 9, 8 and 5 months, respectively (p = 0.021). Whole brain irradiation with SIB-CR technique is effective in patients with one to three brain metastases with a higher tumor response and shorter radiation therapy duration and is well tolerated. SIB-CR technique is an effective option for these patients.