ABSTRACT
Metformin is the basic drug for type 2 diabetes mellitus. More and more studies have shown that metformin has anti-tumor effect, and its radiosensitization effect has been gradually found. Metformin can increase the radiosensitivity of tumor cells by improving hypoxia, increasing reactive oxygen species, inhibiting DNA damage repair, inducing cell cycle arrest and regulating immune microenvironment. However, several recently published randomized controlled trials have not confirmed that metformin can increase the efficacy of chemoradiotherapy. In this review, the mechanism and clinical results of metformin radiosensitization were summarized. The dose of metformin will be an important factor for basic and clinical research in the future.
ABSTRACT
Objective@#To analyze the spatial distribution of brain metastases in EGFR-mutant lung cancer and the risk of hippocampal metastasis.@*Methods@#Patients with lung cancer brain metastases diagnosed and treated in the Shanghai Cancer Center Fudan University from 2006 to 2016 were enrolled. The brain metastasis with positive mutation of EGFR gene was screened. The magnetic resonance images of the patients were reviewed and the distribution characteristics of brain metastasis were analyzed.@*Results@#A total of 920 lung cancer patients with brain metastases were screened, 266 of whom had EGFR gene mutation detection, and 131(49%) were identified as EGFR gene mutations. Excluding 17 patients who did not have a head magnetic resonance examination in our hospital, a total of 114 patients and 738 lesions were enrolled in this study. The proportion of brain metastases distributed in each brain region was 22.8%, 19.5%, 22.0%, 13.4%, 3.3%, 16.7%, and 2.2% for frontal, temporal, parietal, occipital lobe, insula, cerebellum, and brainstem, respectively. The number of metastases and cases located in the hippocampus, <5 mm from the hippocampus, <10 mm from the hippocampus, and<15 mm from the hippocampus were 6(0.8%), 10(1.3%), 11(1.4%), and 14(1.8%), 5 cases (4.4%), 8 cases (7.0%), 9 cases (7.9%), and 11 cases (9.6%), respectively.@*Conclusion@#EGFR-mutant lung cancer brain metastasis is low risk in the hippocampus and its surrounding 15 mm.
ABSTRACT
Objective To explore the differences in the hippocampal delineation among different radiologists and to evaluate the impact of the delineating guideline training upon improving the accuracy of target area.Methods In this prospective study,20 patients scheduled to receive whole brain radiation therapy were selected.Before and after the delineating guideline training,three physicians from Department of Radiation Oncology delineated the hippocampal targets three times for each patient.One physician from Department of Imaging Diagnosis delivered the delineating guideline training and delineated the hippocampus of 20 patients as the standard target area.The delineating targets before and after the training were statistically compared among different physicians.Results The conformity indexes with the standard target of three physicians before and after the training were 0.66±0.04 and 0.77±0.02,0.62±0.04 and 0.76± 0.02,0.49±0.05 and 0.74±0.04,respectively.The conformity indexes were all statistically increased after the training (all P＜ 0.05).The inter-observer variability significantly differed among different physicians before and after training (all P＜0.05).The coefficient of variance of hippocampal volume before and after training were 0.16±0.06 and 0.08±0.04 with statistical significance (all P＜0.05).Compared with all targets before training,the consistency of each physician was significantly improved after training (all P＜0.05).Conclusion Hippocampal delineation guideline training can improve the accuracy of delineation.
ABSTRACT
Regulatory T cells ( Treg) play important role in immune homeostasis in physics and hamper the anti-tumor immunity. Depletion of intra-tumor Treg is a critical step to boost the anti-tumor effect in immune therapy. Radiotherapy can induce secretion of TGF-βand IL33 from tumor cells and then increase Treg proliferation and recruitment into tumor through Langerhans cell. Depletion of Treg could increase the local control and abscopal effect of radiotherapy.
ABSTRACT
Background and purpose:Radiotherapy is one of the main treatment methods for brain tumor patients, but neurotoxicity was observed frequently. Because of the confounding factors in clinical data, it’s hard to summarize the characteristic of neurological changes after brain irradiation. This study used the brain irradiation injury model of rats to test whether brain irradiation change the mood and memory.Methods:Whole brain of SD rats (6-8 weeks old) was exposed to 22 Gy radiation. Open ifeld and elevated plus maze was used to assess the anxiety of rats, passive avoidance was used to assess the mood memory, and novel place recognition was used to assess the spatial memory at 1 month or 10 months after brain irradiation.Results:At 1 month post irradiation, rats moved with less distance and entrance to the central zone of open ifeld with less time, explored the open and closed arms with less time and the exploration of open arms also decreased, entered the darkroom more rapidly during the test phase of passive avoidance, and lose the interest to explore the novel place during novel place recognition. At 10 months post irradiation, rats exhibited similarly with control group during open ifeld and elevated plus maze test, but still entered the darkroom more rapidly during the test phase of passive avoidance, and lose the interest to explore the novel place during novel place recognition.Conclusion:Brain irradiation could decrease the locomotor activity, increase the anxiety mood, reduce the mood and spatial memory; mood dysfunction induced by brain irradiation could restore, but memory impairments would be long-standing.