1.Wearable robots can better improve the balance and walking of stroke survivors
Lan ZHANG ; Jianhua HE ; Zhen YANG ; Shantao TANG ; Zhenping DING ; Longjun TAN
Chinese Journal of Physical Medicine and Rehabilitation 2024;46(6):529-533
Objective:To explore the clinical efficacy of a wearable robot for improving the balance and walking function of stroke survivors.Methods:Eighty stroke survivors were randomly divided into an observation group and a control group, each of 40. Both groups were given routine rehabilitation, but the observation group additionally received 20 minutes of training assisted by a wearable robot six days a week for 4 weeks. Before and after the experiment, both groups were evaluated using the Berg Balance Scale (BBS) and functional ambulation categories (FACs). Their movement distance and ellipse area were measured using a Prokin balance instrument, and their step length and pace on the affected side were recorded.Results:Significant improvement in the average BBS and FAC scores, exercise length, ellipse area, and step length and speed on the affected side was observed in both groups. On average, the experimental group′s results were significantly better than those of the control group.Conclusion:Supplementing conventional rehabilitation with wearable robot assistance can significantly improve the balance and walking function of stroke survivors.
2.A multicenter study on the prediction of gamma passing rate based on radiomic features
Luqiao CHEN ; Qianxi NI ; Yu WU ; Huan REN ; Jinmeng PANG ; Jianfeng TAN ; Longjun LUO ; Zhili WU ; Jinjia CAO
Chinese Journal of Radiological Medicine and Protection 2024;44(12):1027-1033
Objective:To construct classification prediction models for gamma passing rate using radiomics-based machine learning approaches and data from multiple radiotherapy institutions and evaluate the models′ performance.Methods:The data from 572 volumetric-modulated arc therapy (VMAT) patients across three radiotherapy institutions (514 for training and 58 for testing)were retrospectively collected. Additionally, 45 VMAT plans were collected from a single institution as an independent external validation set. For all the data, a three-dimensional dose validation approach based on actual measurements of phantoms was utilized, and gamma analysis was performed at the 3%/2 mm criterion using a dose threshold of 10%, absolute doses, and global normalization. After radiomic features were extracted from dose files, feature selection was performed using the random forest (RF) method and RF combined with Shapley Additive exPlanation (SHAP). Then, feature subsets of varying sizes (10, 20, 30, 40, and 50) were selected based on feature rankings. Using these subsets as inputs, data training was conducted using the Extreme Gradient Boosting (XGBoost) algorithm. Finally, the models′ classification performance was assessed using the area under the curve (AUC) values and F1-score.Results:Under the 3%/2 mm criterion, all models performed the best in the case of 20 feature subsets. The optimal prediction model established based on the feature selection using RF exhibited AUC and F1-score of 0.88 and 0.89, respectively on the testing set and 0.82 and 0.90, respectively, on the validation set. The optimal prediction model built based on the feature selection using RF combined with SHAP yielded AUC and F1-score of 0.86 and 0.92 on the testing set and 0.87 and 0.89, respectively, on the validation set, along with superior robustness. Therefore, the second model possessed certain advantages over the first model.Conclusions:For multicenter dose verification result, it is feasible to construct a machine learning prediction model with high classification performance using radiomic features derived from dose files, combined with feature selection based on SHAP. This approach can assist in advancing the clinical applications and implementation of gamma passing rate prediction models.
3.A multicenter study on the prediction of gamma passing rate based on radiomic features
Luqiao CHEN ; Qianxi NI ; Yu WU ; Huan REN ; Jinmeng PANG ; Jianfeng TAN ; Longjun LUO ; Zhili WU ; Jinjia CAO
Chinese Journal of Radiological Medicine and Protection 2024;44(12):1027-1033
Objective:To construct classification prediction models for gamma passing rate using radiomics-based machine learning approaches and data from multiple radiotherapy institutions and evaluate the models′ performance.Methods:The data from 572 volumetric-modulated arc therapy (VMAT) patients across three radiotherapy institutions (514 for training and 58 for testing)were retrospectively collected. Additionally, 45 VMAT plans were collected from a single institution as an independent external validation set. For all the data, a three-dimensional dose validation approach based on actual measurements of phantoms was utilized, and gamma analysis was performed at the 3%/2 mm criterion using a dose threshold of 10%, absolute doses, and global normalization. After radiomic features were extracted from dose files, feature selection was performed using the random forest (RF) method and RF combined with Shapley Additive exPlanation (SHAP). Then, feature subsets of varying sizes (10, 20, 30, 40, and 50) were selected based on feature rankings. Using these subsets as inputs, data training was conducted using the Extreme Gradient Boosting (XGBoost) algorithm. Finally, the models′ classification performance was assessed using the area under the curve (AUC) values and F1-score.Results:Under the 3%/2 mm criterion, all models performed the best in the case of 20 feature subsets. The optimal prediction model established based on the feature selection using RF exhibited AUC and F1-score of 0.88 and 0.89, respectively on the testing set and 0.82 and 0.90, respectively, on the validation set. The optimal prediction model built based on the feature selection using RF combined with SHAP yielded AUC and F1-score of 0.86 and 0.92 on the testing set and 0.87 and 0.89, respectively, on the validation set, along with superior robustness. Therefore, the second model possessed certain advantages over the first model.Conclusions:For multicenter dose verification result, it is feasible to construct a machine learning prediction model with high classification performance using radiomic features derived from dose files, combined with feature selection based on SHAP. This approach can assist in advancing the clinical applications and implementation of gamma passing rate prediction models.
4.Gamma pass rate classification prediction and interpretation based on SHAP value feature selection
Luqiao CHEN ; Qianxi NI ; Jinmeng PANG ; Jianfeng TAN ; Xin ZHOU ; Longjun LUO ; Degao ZENG ; Jinjia CAO
Chinese Journal of Radiation Oncology 2023;32(10):914-919
Objective:To explore the feasibility and validity of constructing an intensity-modulated radiotherapy gamma pass rate prediction model after combining the SHAP values with the extreme gradient boosting tree (XGBoost) algorithm feature selection technique, and to deliver corresponding model interpretation.Methods:The dose validation results of 196 patients with pelvic tumors receiving fixed-field intensity-modulated radiotherapy using modality-based measurements with a gamma pass rate criterion of 3%/2 mm and 10% dose threshold in Hunan Provincial Tumor Hospital from November 2020 to November 2021 were retrospectively analyzed. Prediction models were constructed by extracting radiomic features based on dose files and using SHAP values combined with the XGBoost algorithm for feature filtering. Four machine learning classification models were constructed when the number of features was 50, 80, 110 and 140, respectively. The area under the receiver operating characteristic curve (AUC), recall rate and F1 score were calculated to assess the classification performance of the prediction models.Results:The AUC of prediction model constructed with 110 features selected based on the SHAP-valued features was 0.81, the recall rate was 0.93 and the F1 score was 0.82, which were all better than the other 3 models.Conclusion:For intensity-modulated radiotherapy of pelvic tumor, SHAP values can be used in combination with the XGBoost algorithm to select the optimal subset of radiomic features to construct predictive models of gamma pass rates, and deliver an interpretation of the model output by SHAP values, which may provide value in understanding the prediction by machine learning-dependent models.

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