The Role of Thoracic 3-Dimensional Radiation Therapy for Non-Small Cell Lung Cancer Patients With Bone Oligometastases

Purpose/Objective(s): To evaluate the role of three-dimensional radiation therapy for Non-Small Cell Lung Cancer (NSCLC) patients with bone metastasis. Materials/Methods: Clinical data of 95 NSCLC patients with bone metastases were collected, all patients received radiation to thoracic primary tumor and 2 cycles chemotherapy. The Kaplan-Meier method was used to calculate the OS. The log-rank test was used to compare the survival curves. Multivariate Cox regression analysis was used to test independent significant prognostic factors for OS. Results: For these 95 patients, 47 patients had only bone metastasis, 48 had bone concur with other organ metastasis. The median survival time (MST) was 11.0 months (95% CI, 8.5-13.5), and the 1-, 2and 3-year overall survival rate was 43.6%, 16.8% and 8.5%, respectively. The MST was 15.0 months for patients received radiation dose to primary tumor 63 Gy, whereas 9.0 months for those with dose <63 Gy (chi-squareZ 11.038, p Z 0.001). Patients with treatment response (CR + PR) to primary tumor had longer median OS time than those without response (SD + PD) (13.0 months vs 7.0 months, chi-square Z 4.364, p Z 0.037). Overall survival was significantly prolonged in patients with received 4 cycles chemotherapy vs <4 cycles, the MSTwas 14.0 months vs 8.0 months (chi-square Z 6.800, p Z 0.009), radiation to metastatic sites was not correlated with OS. Radiation dose to primary tumor 63 Gy remained significance when patients with bone metastasis only and those had bone intercurrent with other organ metastasis were analyzed separately. For patients with bone metastasis only, patients with T1-2 tumors had longer OS than those with T3-4 tumors, the 1-, 2and 3-year overall survival rate was 50.0% vs 39.5%, 27.8% vs 9.3%, 18.5% vs 2.3% (chi-square Z 3.912, p Z 0.048), respectively; radiation to metastatic sites was marginally significant correlated with OS (chi-squareZ 2.757, pZ 0.097); and patients received 4 cycles chemotherapy and <4 cycles had similar survival times, the MST was 14.0 months vs 12.0 months (chi-square Z 0.756, p Z 0.385). On multivariate analysis, radiation dose 63 Gy, and bone metastasis only were independent prognostic factors for better OS. Conclusions: Radiation dose to primary tumor 63 Gy and bone metastasis only are associated with better overall survival in NSCLC patients with bone metastasis. For patients with bone metastasis only, besides radiation dose, T status was also correlated with OS, whereas the number of chemotherapy cycles was not, aggressive thoracic radiation play an important role in improving OS. Author Disclosure: S. Su: None. B. Lu: None. W. Ouyang: None. Q. Li: None. Y. Hu: None. Z. Ma: None. H. Li: None.