Objective To analyze the correlation between three evaluation methods of middle cerebral artery occlu -sion and focal cerebral ischemia , and to explore a new method and standard for the evaluation of the model .Method Thirty healthy adult male SD rats were randomly divided into a sham-operated group ( n=20 ) and model group .According to Zea-Longa procedure ,we established the disease model to detect the changes in cerebral blood flow before and after sur -gery.The resulted cerebral infarction area was taken as gold standards .Then we analyzed the correlation between the standards and the changes in cerebral blood flow .Results The changes of infarction area ratio were positively correlated with the changes of cerebral blood flow in the model rats .Conclusions The changes of rat cerebral blood flow can be used to evaluate whether the cerebral ischemia model is successful or not .

Objective:To investigate the radiation field and dose selection of patients with isolated chest wall recurrence (ICWR) after modified radical mastectomy, and analyze the prognostic factors related to subsequent chest wall recurrence.Methods:Clinical data of 201 patients with ICWR after mastectomy admitted to the Fifth Medical Center, Chinese PLA General Hospital from 1998 to 2018 were retrospectively analyzed. None of the patients received postoperative adjuvant radiotherapy. After ICWR, 48 patients (73.6%) underwent surgery and 155 patients (77.1%) received radiotherapy. Kaplan-Meier method was used to calculate the post-recurrence progression-free survival (PFS) rates and the difference was compared by log-rank test. Multivariate analysis was performed using Cox regression model. Competing risk model was adopted to estimate the subsequent local recurrence (sLR) rates after ICWR and the difference was compared with Gray test. Multivariate analysis was conducted using F&G analysis. Results:With a median follow up of 92.8 months after ICWR, the 5-year PFS rate was 23.2%, and the 5-year sLR rate was 35.7%. Multivariate analysis showed that patients with surgery plus radiotherapy and recurrence interval o F>12 months had a lower sLR rate. Patients with recurrence interval o F>48 months, local plus systemic treatment and surgery plus radiotherapy had a higher PFS rate. Among the 155 patients who received chest wall radiotherapy after ICWR, total chest wall irradiation plus local boost could improve the 5-year PFS rate compared with total chest wall irradiation alone (34.0% vs. 15.4%, P=0.004). Chest wall radiation dose (≤60 Gy vs.>60 Gy) exerted no significant effect upon the sLR and PFS rates (both P>0.05). In the 53 patients without surgery, the 5-year PFS rates were 9.1% and 20.5%( P=0.061) with tumor bed dose ≤60 Gy and>60 Gy, respectively. Conclusions:Local radiotherapy is recommended for patients with ICWR after modified radical mastectomy of breast cancer, including total chest wall radiation plus local boost. The radiation dose for recurrence should be increased to 60 Gy, and it should be above 60 Gy for those who have not undergone surgical resection. In addition, patients with ICWR still have a high risk of sLR, and more effective treatments need to be explored.

Objective: To analyze the failure patterns of locoregional recurrence (LRR) and investigate the range of radiotherapy in T_1-2N₁ breast cancer patients undergoing modified radical mastectomy. Methods: From September 1997 to April 2015, 2472 women with T_1-2N₁ breast cancer after modified radical mastectomy without neoadjuvant systemic therapy were treated in our hospital. 1898 patients who did not undergo adjuvant radiotherapy were included in this study. The distribution of accumulated LRR was analyzed. The LR and RR rates were estimated by the Kaplan-Meier method, and the prognostic factors were identified in univariate analyses with Log-rank test. Multivariate analysis was performed using Cox logistic regression analysis. Results: With a median follow-up of 71.3 months (range 1.1-194.6), 164 patients had LRR, including supraclavicular/infraclavicular lymph nodes in 106(65%), chest wall in 69(42%), axilla in 39(24%) and internal mammary lymph nodes (IMNs) in 19 patients (12%). In multivariate analysis, age (>45 years vs.≤45 years), tumor location (other quadrants vs. inner quadrant), T stage (T₁ vs. T₂), the number of positive axillary lymph nodes (1 vs. 2-3), hormone receptor status (positive vs. negative) were significant prognostic factors for both LR and RR. Conclusions In patients with T_1-2N₁ breast cancer after modified radical mastectomy, the most common LRR site is supraclavicular/infraclavicular nodal region, followed by chest wall. The axillary or IMN recurrence is rare. The prognostic factors for LR and RR are similar, which indicates that supraclavicular/infraclavicular and chest wall irradiation should be considered for postmastectomy radiotherapy.

Currently, radiotherapy has been found to induce lymphopenia in multiple solid tumors, which has been proven to be associated with poor prognosis. Radiation-induced lymphopenia (RIL) is associated with age, baseline lymphocyte count, tumor size and location and radiotherapy regimens (radiation fractionation, field size and technique), etc. In addition, several drugs and cytokines may help restore lymphocytes. Exploration of effective strategies to prevent or treat RIL may be an important future direction to improve prognosis of cancer patients.

Radiotherapy has improved the locoregional control and overall survival for patients with breast cancer. Breast/chest wall and supraclavicular fossa are the common sites of irradiation. During radiotherapy, the thyroid gland will be inevitably irradiated at a certain dose, which might increase the risk of hypothyroidism in the long-term survivors. The irradiation dose to the thyroid gland cannot be evaluated by traditional two-dimensional radiation technique. The hypothyroidism induced by radiation has been largely ignored. With the development of radiotherapy and application of three-dimentional conformal radiotherapy and intensity-modulated radiotherapy in breast cancer, how to choose appropriate radiation technique and how to limit the dose irradiated to the thyroid gland remain to be urgently resolved. This review systematically summarized the clinical characteristics, pathogenesis, risk factors and monitoring of hypothyroidism induced by radiotherapy, aiming to help clinicians to make the optimal decision in radiation technique selection and treatment plan evaluation.

Objective:To analyze the prognosis of patients with isolated regional recurrence (RR) after mastectomy, and evaluate the efficacy of radiotherapy and identify the optimal radiation target volumes.Methods:Clinical data of 144 patients with first isolated RR after mastectomy between 2001 and 2018 were retrospectively analyzed. All patients had not received post-mastectomy radiotherapy. The primary endpoints consisted of the subsequent locoregional recurrence (sLRR), distant metastasis (DM), progression-free survival (PFS) and overall survival (OS).Results:With a median follow-up of 82.5 months after RR, the 5-year sLRR, DM, PFS and OS rates for the entire group were 42.1%, 71.9%, 22.9% and 62.6%, respectively. Local plus systemic therapy was an independent favorable prognostic factor for sLRR ( P<0.001) and PFS ( P=0.013). The sLRR rate in the surgery plus radiotherapy group was the lowest ( P<0.001). Surgery plus radiotherapy significantly reduced the 5-year risk of recurrence within the initially involved nodal regions ( P<0.001). Patients with chest wall irradiation obtained the 5-year subsequent chest wall recurrence rate of 12.1% compared to 14.8%( P=0.873) for those without chest wall irradiation. The subsequent supraclavicular recurrence rate was lower in patients with prophylactic supraclavicular irradiation than that without prophylactic supraclavicular irradiation (9.9% vs. 23.8%, P=0.206). The incidence rates of initially uninvolved axillary and internal mammary nodal recurrence were below 10% regardless of prophylactic irradiation or not. Conclusions:Patients with RR alone have an optimistic 5-year OS in the contemporary era. Comprehensive locoregional treatment including surgery and radiotherapy combined with systemic therapy is recommended. The chest wall, axillary and internal mammary nodal prophylactic irradiation should not be routinely performed for all patients with RR. The value of supraclavicular prophylactic irradiation remains to be evaluated.

Objective:To describe a prospective study of pre-operative tumor-bed boost performed at the 1.5 T MR-Linac in combination with adjuvant whole breast irradiation, and a first case, with an accentuation on clinical feasibility and safety.Methods:A phase II, single arm study recruiting early stage patients follows a paradigm that first boosts the tumor bed and then undergoes breast conservative surgery in 2 weeks, and last irradiates the whole breast in 6 weeks. The primary endpoint is ≥ grade 2 acute breast toxicity. A 43 years old patient affected by a breast carcinoma, not special type of the right-sided lateral quadrant, staged cT 2N 0M 0, was planned and treated. The dose, 8 Gy for one time, was calculated by Monaco on CT simulation images. Both the air electron stream effect (ESE) and the electron return effect (ERE) at the presence of 1.5 T magnetic field were evaluated. During the pre-treatment evaluation, we carried out adaptation-to-position adjustment. Results:The normal organ dosimetry is within toleration. The Dmax to the skin, the chin and the right upper arm was 8.44 Gy, 28.5 cGy and 17.8 cGy, respectively. There was no increased toxicity from ERE and ESE, and the treatment was well tolerated without > grade 1 acute toxicity. The patient received breast conservative surgery on day 7 without delayed wound healing.Conclusions:This is the first case successfully treated within a clinical trial by pre-operative tumor-bed boost under 1.5 T MR-Linac in our institution. More participants are needed to validate and optimize the paradigm.

Objective:To analyze locoregional recurrence (LRR) pattern of patients with pT 1-2N 1 breast cancer after modified radical mastectomy, with and without adjuvant radiotherapy (RT). Methods:A total of 5442 eligible patients with breast cancer from 12 Chinese centers were included. The LRR sites and the effect of RT at different sites on recurrence in patients with and without RT were analyzed. The Kaplan-Meier method was used to calculate the cumulative LRR rate, and the difference was compared by the log-rank test.Results:With a median follow-up time of 63.8 months for the entire cohort, 395 patients developed LRR. The chest wall and supraclavicular fossa were the most common LRR sites, regardless of RT or molecular subtypes. The 5-year chest wall recurrence rates for patients with and without chest wall irradiation were 2.5% and 3.8%( P=0.003); the 5-year supraclavicular lymph nodal recurrence rates for patients with and without supraclavicular fossa irradiation were 1.3% and 4.1%( P<0.001); the 5-year axillary recurrence-free rates for patients with and without axillary irradiation were 0.8% and 1.5%( HR=0.31, 95% CI: 0.04-2.23, P=0.219); and the 5-year internal mammary nodal recurrence-free rates for patients with and without internal mammary nodal irradiation were 0.8% and 1.5%( HR=0.45, 95% CI: 0.11-1.90, P=0.268). Conclusions:The chest wall and supraclavicular fossa are the most common LRR sites of patients with pT 1-2N 1 breast cancer after modified radical mastectomy, which is not affected by adjuvant RT or molecular subtypes. The chest wall and supraclavicular fossa irradiation significantly reduce the risk of recurrence in the corresponding area. However, axillary and internal mammary nodal irradiation has no impact on the risk of recurrence in the corresponding area.

Objective:To analyze the efficacy of chest wall boost radiotherapy in stage T 4 breast cancer patients after modified radical mastectomy. Methods:A retrospective analysis was performed on the data of 148 stage T 4 breast cancer patients who were admitted from 2000 to 2016 and received radiotherapy after modified radical mastectomy. There were 57 cases in the chest wall boost radiotherapy group and 91 cases in the conventional dose group. Radiotherapy was performed by conventional+ chest wall electron beam, three-dimensional conformal+ chest wall electron beam, intensity modulated radiotherapy+ chest wall electron beam irradiation. EQD 2 at the boost group was >50Gy. All patients received neoadjuvant chemotherapy. Kaplan-Meier method was used to analyze survival; Logrank was used to test differences; and Cox model was used to do multivariate prognostic analysis. Results:The median follow-up time was 67.2 months. The 5-year rates of chest wall recurrence (CWR), locoregional recurrence (LRR), disease-free survival (DFS), and overall survival (OS) were 9.9%, 16.2%, 58.0%, and 71.4%, respectively. The 5-year rates of CWR, LRR, DFS, and OS with and without chest wall boost radiotherapy were 14% vs. 7%, 18% vs. 15%, 57% vs. 58%, 82% vs. 65%( P>0.05), respectively. Multivariate analysis showed that chest wall boost radiotherapy had no significant effect on prognosis ( P>0.05). Among 45 patients in the recurrent high-risk group, boost radiotherapy seemed to have higher OS rate ( P=0.058), DFS rate ( P=0.084), and lower LRR rate ( P=0.059). Conclusions:Stage T 4 breast cancer patients had strong heterogeneity. Chest wall boost radiotherapy did not apparently benefit all patients. For patients with 2-3 high risk factors including positive vascular tumor embolus, pN 2-N 3, and hormone receptor negative, chest wall boost radiotherapy showed a trend of improving efficacy.

Colorectal cancer (CRC), a malignant tumor worldwide consists of microsatellite instability (MSI) and stable (MSS) phenotypes. Although SHP2 is a hopeful target for cancer therapy, its relationship with innate immunosuppression remains elusive. To address that, single-cell RNA sequencing was performed to explore the role of SHP2 in all cell types of tumor microenvironment (TME) from murine MC38 xenografts. Intratumoral cells were found to be functionally heterogeneous and responded significantly to SHP099, a SHP2 allosteric inhibitor. The malignant evolution of tumor cells was remarkably arrested by SHP099. Mechanistically, STING-TBK1-IRF3-mediated type I interferon signaling was highly activated by SHP099 in infiltrated myeloid cells. Notably, CRC patients with MSS phenotype exhibited greater macrophage infiltration and more potent SHP2 phosphorylation in CD68⁺ macrophages than MSI-high phenotypes, suggesting the potential role of macrophagic SHP2 in TME. Collectively, our data reveals a mechanism of innate immunosuppression mediated by SHP2, suggesting that SHP2 is a promising target for colon cancer immunotherapy.