Objective:To compare the impact of the AlignRT-based optical guidance method with the traditional marker line method on the accuracy of positioning, and explore the effect of patient′s different thoracic characteristic parameters on the precision of optical guidance positioning.Methods:A total of sixty breast cancer patients who received post breast-conserving radiotherapy at Anhui Cancer Hospital from July 2022 to September 2023 were retrospectively selected. Then these patients were equally divided into traditional cross hairs set-up (marker line group) and surface-guided set-up (SGRT group). The cone-beam CT scanning results were used as the gold standard, the three-dimensional set-up errors and the CTV-PTV target area external radiotherapy boundaries of two groups were studied comparatively. Multiple patient′s thoracic characteristic parameters were defined and the correction between each parameter and set-up error of SGRT was analyzed.Results:The mean value of three-dimensional set-up errors in the SGRT group and the marker line group was within 0.2 cm and 0.5 cm, respectively. The differences in three-dimensional set-up errors and total displacements between two groups were statistically significant ( z=-2.93, -3.21, -2.59, -4.76, P<0.05). The SGRT group reduced the CTV-PTV boundary from 0.5 cm of conventional marker line group to 0.3 cm. The thoracic aspect ratio H/W, the affected side pinch angle α1, and the healthy side pinch angle α2 were positively correlated with the x-direction posing error ( r=0.49, 0.59, 0.71, P<0.05); whereas, the affected side and the healthy side mammary gland heights D1 and D2 were negatively correlated with the z-direction posing error ( r=-0.46, -0.49, P<0.05). Conclusions:For breast-conserving postoperative radiotherapy patients, SGRT can obtain a more accurate radiotherapy set-up than the traditional marker line method, and can effectively reduce the target area externally expanded range. Meanwhile, the monitoring accuracy of SGRT is affected by the patient′s thoracic characteristic parameters, and clinical attention should be paid to breast-conserving radiotherapy patients with thick body shape, narrow body width, and small breast glands.

Objective:To compare the impact of the AlignRT-based optical guidance method with the traditional marker line method on the accuracy of positioning, and explore the effect of patient′s different thoracic characteristic parameters on the precision of optical guidance positioning.Methods:A total of sixty breast cancer patients who received post breast-conserving radiotherapy at Anhui Cancer Hospital from July 2022 to September 2023 were retrospectively selected. Then these patients were equally divided into traditional cross hairs set-up (marker line group) and surface-guided set-up (SGRT group). The cone-beam CT scanning results were used as the gold standard, the three-dimensional set-up errors and the CTV-PTV target area external radiotherapy boundaries of two groups were studied comparatively. Multiple patient′s thoracic characteristic parameters were defined and the correction between each parameter and set-up error of SGRT was analyzed.Results:The mean value of three-dimensional set-up errors in the SGRT group and the marker line group was within 0.2 cm and 0.5 cm, respectively. The differences in three-dimensional set-up errors and total displacements between two groups were statistically significant ( z=-2.93, -3.21, -2.59, -4.76, P<0.05). The SGRT group reduced the CTV-PTV boundary from 0.5 cm of conventional marker line group to 0.3 cm. The thoracic aspect ratio H/W, the affected side pinch angle α1, and the healthy side pinch angle α2 were positively correlated with the x-direction posing error ( r=0.49, 0.59, 0.71, P<0.05); whereas, the affected side and the healthy side mammary gland heights D1 and D2 were negatively correlated with the z-direction posing error ( r=-0.46, -0.49, P<0.05). Conclusions:For breast-conserving postoperative radiotherapy patients, SGRT can obtain a more accurate radiotherapy set-up than the traditional marker line method, and can effectively reduce the target area externally expanded range. Meanwhile, the monitoring accuracy of SGRT is affected by the patient′s thoracic characteristic parameters, and clinical attention should be paid to breast-conserving radiotherapy patients with thick body shape, narrow body width, and small breast glands.

Objective To evaluate the efficacy of Gateway balloon dilation in the treatment of symptomatic severe stenosis of middle cerebral artery.Methods The clinical data and imaging materials of 98 patients with severe symptomatic stenosis of the middle cerebral artery,who were admitted to the Second Affiliated Hospital of Nanchang University of China from May 2019 to August 2022 to receive Gateway balloon dilation,were retrospectively analyzed.The diameter of the narrowed artery before and after Gateway balloon dilation treatment,peak systolic blood flow velocity(PSV),end-diastolic blood flow velocity(EDV),Mori classification of stenosis lesion,operation-related complications,imaging manifestations and clinical follow-up results were analyzed.Results Of the 98 patients,Mori type A was seen in 83(84.69％)and Mori type Bin 15(15.31％).Successful Gateway balloon dilation procedure was accomplished in all patients.After surgery,the symptoms were improved or stabilized to varying degrees.The mean residual lumen diameter of the stenosis lesion was significantly increased from preoperative(2.01±0.13)mm to postoperative(2.33±0.25)mm,the stenosis ratio was remarkably decreased from preoperative(81.28±15.17)％to postoperative(50.24±12.83)％,the PSV and EDV were strikingly decreased from preoperative(251.01±60.13)cm/s and(104.28±32.25)cm/s to postoperative(155.33±53.28)cm/s and(70.24±36.33)cm/s respectively,the differences were statistically significant(all P＜0.05).Seven patients developed surgical complications,which were improved in short time.The patients were followed up for 10 months,modified Rankin Scale(mRS)score of ≤2 points was obtained in 88 patients(89.79％),indicating that the patients had a good quality of life as well as a good functional recovery.Conclusion For the treatment of symptomatic severe stenosis of middle cerebral artery,Gateway balloon dilation carries a significant long-term therapeutic effect with fewer surgical complications.Therefore,Gateway balloon dilation is an effective treatment for this type of disease.