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 investigate the effects of RNA interference(RNAi)-mediated silencing of Peroxiredoxin 1(PRDX1)gene on the invasion and migration of human colorectal cancer SW480 cells.Methods: Lentiviruses negative control vector and PRDX1 RNAi were transfected respectively into colorectal cancer SW480 cells.The transfected cells were divided into PRDX1 silencing group(si-PRDX1)and negative control group(Vector).The expressions of PRDX1 mRNA and protein in SW480 cells were exa mined by quantitative real-time PCR(qRT-PCR)and immunoblotting(Western blot),respectively.The cell migration and invasion capabilities were evaluated with transwell chamber assay and transwell chamber,respectively.The protein expressions of TIMP-2,MMP-2 and MMP-9 were detected by Western blot.Results: Compared with control group,the expressions of PRDX1 mRNA and protein were significantly decreased in PRDX1 silencing group(P<0.01),PRDX1 gene silencing cell line was successfully constructed.The levels of invasion and migration capacities of SW480 cells transfected with si-PRDX1 were lower than those in the cells transfected with control-siRNA(vector)(P<0.01).The expression of TIMP-2 was significantly increased,while the expressions of MMP-2 and MMP-9 were significantly decreased(P<0.05).Conclusion: Silencing of PRDX1 inhibits the invasion,migration and metastasis of human colorectal cancer SW480 cells by regulating the expressions of TIMP-2,MMP-2 and MMP-9.