Progress of Research on Radiotherapy Combined with Immunotherapy for Brain Metastases from Non-small Cell Lung Cancer / 肿瘤防治研究

Lung cancer is the second most common cancer worldwide, and 40% of patients with non-small cell lung cancer may develop brain metastases. Radiotherapy is a classic treatment for brain metastases, and immunotherapy has emerged for advanced non-small cell lung cancer. This article discusses the theoretical bases, clinical efficacy and safety, and the optimum timing of radiotherapy combined with immunotherapy for brain metastases from non-small cell lung cancer to provide reference for clinical practice and scientific research.

Precision thoracic radiotherapy in limited-stage small cell lung cancer: a network meta-analysis / 中华放射肿瘤学杂志

Objective:To systematically evaluate the efficacy and safety of precision thoracic radiotherapy (TRT) in the limited-stage small cell lung cancer (LS-SCLC) patients by network meta-analysis.Methods:Randomized controlled trials (RCTs) of TRT regimes in the LS-SCLC were electronically searched from PubMed, Web of Science, The Cochrane Library, CNKI and Wanfang Data from inception to September 1 st, 2021. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Statistical analysis was performed by Stata 17 and R 4.1.1 software. Results:A total of 6 RCTs involving 1730 patients with six radiation regimens including hyperfractionated radiotherapy (HFRT): HFRT 45(45 Gy/30 F) and HFRT 60(60 Gy/40 F); conventional fractionated radiotherapy (CFRT): CFRT 70(70 Gy/35 F) and CFRT 66(66 Gy/33 F); moderately hypofractionated radiotherapy (MHFRT): MHFRT 65(65 Gy/26 F) and MHFRT 42(42 Gy/15 F) were included. The network meta-analysis showed that: in terms of improving progression-free survival and overall survival, there was no statistically significant difference among the six radiotherapy regimens. The probabilistic ranking results were: MHFRT 65> HFRT 60>CFRT 66>CFRT 70>MHFRT 42>HFRT 45, and HFRT 60>MHFRT 65>CFRT 66>CFRT 70>HFRT 45>MHFRT 42, respectively. The HFRT 60 regimen was superior to other regimens in reducing the incidence of grade ≥3 pneumonia, and there was no difference between the regimens in causing grade ≥3 radiation esophagitis, and the results of ranking probability were: HFRT 60> MHFRT 42>CFRT 66>CFRT 70>HFRT 45>MHFRT 65, and HFRT 60>CFRT 70>CFRT 66>HFRT 45>MHFRT 42>MHFRT 65, respectively. Conclusions:HFRT 60 radiotherapy regimen may be more effective and safer in the treatment of LS-SCLC patients as a priority choice for LS-SCLC TRT. Limited by the number and quality of included studies, the above conclusions need to be verified by more high-quality studies.

Application of linac-based fractionated stereotactic radiation therapy in treatment of oligo brain metastases / 肿瘤研究与临床

Brain metastases are common in oncologic patients. Stereotactic radiosurgery (SRS) is an effective treatment for oligo brain metastases. However, SRS is not suitable for large metastatic lesions. Fractionated stereotactic radiation therapy (FSRT) is a new option for the treatment of brain metastases. It can deliver high doses of radiation to tumor while protecting the normal tissues and organs outside the irradiation field as much as possible and maintaining good local control rate of tumors. This article reviews the dose-response relationship and adverse reactions of FSRT with different fractionated dose schemes, and the progress of FSRT combined with targeted therapy and immunotherapy.

Impacts of endostatin on expression of vascular endothelial growth factor receptor-2 in non-small cell lung cancer cells and mechanisms underlying its radiosensitizing effect / 中华放射肿瘤学杂志

Objective To determine the effects of endostatin on the expression of vascular endothelial growth factor receptor?2 ( VEGFR?2 ) in non?small cell lung cancer cells ( human A549 lung adenocarcinoma cells and human Calu?1 lung carcinoma cells) , and to investigate the possible mechanisms underlying its radiosensitizing effect. Methods The CCK8 method was used to determine the inhibitory effect of endostatin on cell proliferation and calculate the drug concentration that caused a 20% reduction in cell proliferation within 24 h ( IC20 ) . RT?PCR and Western blot assays were used to assess the mRNA and protein expression of VEGFR?2, proteins within its related signaling pathways, and HIF?1α, respectively. The radiosensitivity of cells in each group was determined by colony formation assay;cell apoptosis and cell cycle distribution were determined by flow cytometry. Comparison of mean values between multiple samples was made by one?way analysis of variance, and comparison of mean values between two samples was made by t test. Results Endostatin significantly inhibited the proliferation of Calu?1 cells ( F=50?36,P<0?01) with an IC20 of 296?5 μg/ml;the mRNA and protein expression of VEGFR?2 and HIF?1α was also significantly inhibited in endostatin?treated Calu?1 cells ( F=25?43,10?44, all P<0?05) . Moreover, the phosphorylation of Akt, ERK 1/2, and p38 was significantly reduced in endostatin?treated Calu?1 cells ( F=2?89,0?24, 1?09, all P<0?05) . The radiosensitivity enhancement ratios for Calu?1 cells and A549 cells were 1?38 and 1?09, respectively. Endostatin significantly induced apoptosis ( F=44?15, P<0?01) and G2/M blockage ( F= 104?24, P< 0?01 ) in Calu?1 cells. Conclusions Endostatin induces apoptosis and enhances radiosensitivity in Calu?1 cells with high expression of VEGFR?2, but it has a limited impact on A549 cells with low expression of VEGFR?2.