Dose-effect relationship of stereotactic body radiotherapy in non-small cell lung cancer patients

Objective: To establish the dose effect relationship between the dose parameters of stereotactic body radiation therapy (SBRT) for early non-small cell lung cancer (NSCLC) and the local tumor control rate. Materials and methods: A comprehensive literature search was conducted using PubMed, the Web of Science and the Cochrane databases to determine the articles treated with SBRT in early-stage NSCLC. Original studies with complete prescription dose information, tumor local control rate and other important parameters were screened and reported. Probit model in XLSTAT 2016 was used for regression analysis, and P < 0.05 was set as a statistically significant level. Results: After literature screening, 22 eligible studies were included in probit model regression analysis, involving 1861 patients. There is no significant dose effect relationship between nominal BED10 and peripheral BED10 versus 3 years local control probability. There were significant dose effect relationships between the center BED10 and the average BED10 versus the 3 years local control probability, with P values are 0.001 and < 0.0001, respectively. According to the results of this model, the 3 years local control rate of 90.5% (87.5-92.1%) and 89.5% (86.7-91.0%) can be expected at the center BED10 of 180 Gy or the average BED10 of 140 Gy, prospectively. Conclusions: For NSCLC treated with SBRT, more attention should be paid to the central dose and average dose of PTV. A set of clear definition in the dose prescription should be established to ensure the effectiveness and comparability of treatment.