Correlation between the setting of gating window width and setup accuracy in left breast cancer radiotherapy based on deep inspiration breath hold.

Personalized precision irradiation of patients with left-sided breast cancer is possible by examining the setup errors of 3- and 4-mm gated window widths for those treated with deep inspiration breath-hold (DIBH) treatment. An observational study was performed via a retrospective analysis of 250 cone-beam computed tomography (CBCT) images of 60 left-breast cancer patients who underwent whole-breast radiotherapy with the DIBH technique between January 2021 and 2022 at our hospital. Among them, 30 patients had a gated window width of 3 mm, while the remaining 30 had a gated window width of 4 mm; both groups received radiotherapy using DIBH technology. All patients underwent CBCT scans once a week, and the setup errors in the left-right (x-axis), inferior-superior (y-axis), and anterior-posterior (z-axis) directions were recorded. The clinical-to-planning target volume (CTV-PTV) margins of the two gating windows were calculated using established methods. The setup error in the Y direction was 1.69 ± 1.33 mm for the 3-mm - wide gated window and 2.42 ± 3.02 mm for the 4-mm - wide gated window. The two groups had statistically significant differences in the overall mean setup error (Dif 0.7, 95% CI 0.15-1.31, t = 2.48, p= 0.014). The Z-direction setup error was 2.32 ± 2.12 mm for the 3-mm - wide gated window and 3.15 ± 3.34 mm for the 4-mm - wide gated window. The overall mean setup error was statistically significant between the two groups (Dif 0.8, 95% CI 0.13-1.53, t= 2.34, p = 0.020). There was no significant difference in the X-direction setup error (p > 0.05). Therefore, the CTV-PTV margin values for a 3-mm gated window width in the X, Y, and Z directions are 5.51, 5.15, and 7.28 mm, respectively; those for a 4-mm gated window width in the X, Y, and Z directions are 5.52, 8.16, and 10.21 mm, respectively. The setup errors of the 3-mm - wide gating window are smaller than those of the 4-mm - wide gating window in the three dimensions. Therefore, when the patient's respiratory gating window width is reduced, the margin values of CTV-PTV can be reduced to increase the distance between the PTV and the organs at risk (OARs), which ensures adequate space for the dose to decrease, resulting in lower dose exposure to the OARs (heart, lungs, etc.), thus sparing the OARs from further damage. However, some patients with poor pulmonary function or unstable breathing amplitudes must be treated with a slightly larger gating window. Therefore, this study lays a theoretical basis for personalized precision radiotherapy, which can save time and reduce manpower in the delivery of clinical treatment to a certain extent. Another potential benefit of this work is to bring awareness to the potential implications of a slightly larger gating window during treatment without considering the resulting dosimetric impact.

Effects of deep learning- versus atlas-based automatic contouring methods on the contouring of organs-at-risk in rectal cancer / 中国基层医药

Objective:To investigate the effects of deep learning-based AiContour ??versus atlas-based Raystation ?? automatic contouring methods on the contouring of organs-at-risk on CT images of patients with rectal cancer who undergo radiotherapy, providing evidence for clinical application. Methods:Fifty patients with rectal cancer who received treatment during January to June 2020 in Zhejiang Provincial People's Hospital (Affiliated Hospital of Hangzhou Medical College) were included in this study. The CT images from 20 patients with rectal cancer that had been contoured by experienced radiotherapist were selected as target images and automatically contoured using the data template library of AiContour ?? and Raystation ?? automatic contouring methods. Hausdorff distance, mean distance to agreement, dice similarity coefficient, Jaccard coefficient were used to quantitatively evaluate the accuracy of the volume of contour of organs-at-risk automatically sketched by the two methods. Results:There was no significant difference in Hausdorff distance in left femoral head [(6.81 ± 2.66) vs. (7.24 ± 2.10)], right femoral head [(7.38 ± 3.91) vs. (8.14 ± 3.71)], pelvis [(24.00 ± 9.01) vs. (24.66 ± 9.67)] between AiContour ?? and Raystation ?? automatic contouring methods ( tleft femoral head = -0.831, tright femoral head = -0.821, tpelvis = -0.357, all P > 0.05). Significant differences were observed in mean distance to agreement, dice similarity coefficient and Jaccard coefficient of organs-at-risk (all P < 0.05). The mean values of dice similarity coefficient automatically sketched by AiContour ?? method were > 0.7. The DSC of left kidney, right kidney, rectum and bladder automatically sketched by Raystation ?? method were < 0.7, and the dice similarity coefficient values of other organs-at-risk automatically sketched by Raystation ?? method were > 0.7. In addition, Hausdorff distance, mean distance to agreement and Jaccard coefficient values of organs-at-risk automatically sketched by AiContour ?? method were superior to those automatically sketched by Raystation ??. Conclusion:After slight modification, the organs-at-risk automatically sketched by AiContour ?? and Raystation ?? methods can meet clinical requirement. The contouring effects provided byAiContour ?? method were superior to those provided by Raystation ?? method.

Changes of CD4(+) CD25 (+) regulatory T cells in peripheral blood in patients with hepatocellular carcinoma before and after TACE / 华中科技大学学报（医学）（英德文版）

This study investigated the changes of CD4(+) CD25(+) regulatory T cells (Tregs) in peripheral blood of patients with hepatocellular carcinoma before and after transcatheter arterial chemoembolization (TACE). The proportion of CD4(+) CD25(+) Tregs among CD4(+) T lymphocytes in peripheral blood of 33 patients with hepatocellular carcinoma was determined by flow cytometry before, 1 week and 1 month after TACE. And 25 healthy volunteers served as control. One month after TACE, the patients were divided into two groups: 22 in group A, who were in stable condition or getting better; and 10 in group B, who were deteriorating. One patient died and was excluded. The results showed that the percentage of CD4(+)CD25(+) Tregs among CD4(+) T lymphocytes did not significantly change in the 33 patients 1 week after TACE as compared with that before TACE, however, the difference was significant (P<0.01) between the patients with hepatocellular carcinoma and the healthy subjects. The percentage of CD4(+) CD25(+) Tregs among CD4(+) T lymphocytes in group A 1 month after TACE was decreased significantly in comparison with that before and 1 week after TACE (P<0.01), whereas, that in group B was increased significantly 1 month after TACE (P<0.01). It was concluded that patients with hepatocellular carcinoma had a higher proportion of CD4(+)CD25(+) Tregs in peripheral blood. TACE did not significantly affect the level of CD4(+) CD25(+) Tregs within short time (such as 1 week). The proportion of CD4(+)CD25(+) Tregs in peripheral blood 1 month after TACE was related to the prognosis of hepatocellular carcinoma.