Objective To evaluate the dosimetric impact of interfractional bladder fullness variation in volumetric modulated arc therapy for cervical cancer using artificial intelligence-assisted cone-beam CT(CBCT)image segmentation,and propose an imaging-based quantitative assessment criterion for bladder fullness,providing an objective basis for assessing bladder filling status during clinical treatment.Methods Fifty patients receiving volumetric modulated arc therapy for cervical cancer were selected.The criterion for determining bladder fullness was as follow:if the bladder longitudinal diameter measured on the CBCT mid-sagittal plane was greater than half of the bladder longitudinal diameter measured on the localizable CT,it was defined as≥50%bladder fullness;otherwise,it was defined as<50%bladder fullness.Based on this criterion,two CBCT images were selected for each patient(representing fractions with≥50%and<50%fullness,respectively).Borui auto-contouring system was applied to re-contour the target areas and organs at risk,followed by dose recalculation.Results Compared with≥50%bladder fullness group,<50%bladder fullness group had significantly increased bladder V40,and small bowel Dmax,Dmean,V55,V45,V40(P<0.05),indicating that during interfractional radiotherapy,a CBCT-measured bladder longitudinal diameter less than half of the bladder longitudinal diameter measured on the localizable CT could serve as a predictor for significantly increased radiation dose to the bladder and small bowel.Correlation analysis revealed that bladder volume change showed a positive correlation with bladder Dmax change(R=0.45),a significant negative correlation with bladder V30(R=-0.37),and negative correlations with small bowel Dmax,Dmean,V55,V45,V40(R=-0.31,-0.41,-0.39,-0.49,-0.61).The correlation results indicate that increasing bladder fullness could reduce the radiation dose to the bladder and small bowel.Conclusion Artificial intelligence-assisted segmentation confirms that in interfractional radiotherapy for cervical cancer,when the CBCT-measured bladder longitudinal diameter is less than half of the longitudinal diameter measured on the localizable CT,there is a significant increase in radiation dose to OAR.Maintaining an ideal state of bladder fullness contributes to reducing the radiation dose to the bladder and small bowel.It is crucial to provide patients with adequate bladder management education before treatment and implement strict bladder volume management strategies during treatment fractions.

Objective To evaluate the dosimetric impact of interfractional bladder fullness variation in volumetric modulated arc therapy for cervical cancer using artificial intelligence-assisted cone-beam CT(CBCT)image segmentation,and propose an imaging-based quantitative assessment criterion for bladder fullness,providing an objective basis for assessing bladder filling status during clinical treatment.Methods Fifty patients receiving volumetric modulated arc therapy for cervical cancer were selected.The criterion for determining bladder fullness was as follow:if the bladder longitudinal diameter measured on the CBCT mid-sagittal plane was greater than half of the bladder longitudinal diameter measured on the localizable CT,it was defined as≥50%bladder fullness;otherwise,it was defined as<50%bladder fullness.Based on this criterion,two CBCT images were selected for each patient(representing fractions with≥50%and<50%fullness,respectively).Borui auto-contouring system was applied to re-contour the target areas and organs at risk,followed by dose recalculation.Results Compared with≥50%bladder fullness group,<50%bladder fullness group had significantly increased bladder V40,and small bowel Dmax,Dmean,V55,V45,V40(P<0.05),indicating that during interfractional radiotherapy,a CBCT-measured bladder longitudinal diameter less than half of the bladder longitudinal diameter measured on the localizable CT could serve as a predictor for significantly increased radiation dose to the bladder and small bowel.Correlation analysis revealed that bladder volume change showed a positive correlation with bladder Dmax change(R=0.45),a significant negative correlation with bladder V30(R=-0.37),and negative correlations with small bowel Dmax,Dmean,V55,V45,V40(R=-0.31,-0.41,-0.39,-0.49,-0.61).The correlation results indicate that increasing bladder fullness could reduce the radiation dose to the bladder and small bowel.Conclusion Artificial intelligence-assisted segmentation confirms that in interfractional radiotherapy for cervical cancer,when the CBCT-measured bladder longitudinal diameter is less than half of the longitudinal diameter measured on the localizable CT,there is a significant increase in radiation dose to OAR.Maintaining an ideal state of bladder fullness contributes to reducing the radiation dose to the bladder and small bowel.It is crucial to provide patients with adequate bladder management education before treatment and implement strict bladder volume management strategies during treatment fractions.

Objective To analyze the individualized CTV-to-PTV margin dose and positioning errors in radiotherapy for esophageal cancer for improving the treatment accuracy while meeting dose requirements.Methods Fifty-four esophageal cancer patients admitted to Sun Yat-sen University Cancer Center at Huangpu District from June 2021 to June 2022 were enrolled.All of the patients underwent CBCT scans in each fraction,and a total of 1283 CBCT images were collected.The image registration between CBCT image before radiotherapy and planning CT image was carried out to obtain errors in vertical(VRT),longitudinal(LNG),lateral(LAT),Roll,Pitch,and YAW directions.The mean values of six-dimensional positioning errors in the first 5 fractions were calculated,and the results were compared with the total fractional errors using the single sample t-test method for determining the differences.The CTV-to-PTV margin was calculated with the formula(margin=2.5∑+0.7δ),and the calculated margins were divided into 5 groups:Group A(5 mm expansion in all directions),Group B(7.9 mm expansion in LAT direction,and 5 mm expansion in other directions),Group C(11.03 mm expansion in LNG direction,and 5 mm expansion in the other directions),Group D(6.36 mm expansion in VRT direction,and 5 mm expansion in the other directions),and Group E(7.9 mm expansion in LAT direction,11.03 mm expansion in LNG direction,and 6.36 mm expansion in VRT direction).Simulation planning was conducted for 10 patients.Results The proportions of differences between the mean values of six-dimensional errors in the first 5 fractions and the total fractional errors in 54 patients were analyzed.There was no significant difference in 192 out of the 324 directions in 54 patients,accounting for 59.26%(P>0.05).Among them,the LAT,LNG,VRT,Pitch,Roll and YAW directions accounted for 64.81%,57.41%,51.85%,64.81%,57.41%and 59.26%of the total cases.The calculated CTV-to-PTV margin was 7.90,11.03 and 6.36 mm in LAT,LNG and VRT directions.The statistical analysis showed that the differences in the coverage rates of organs-at-risk and target areas among the 5 groups of CTV-to-PTV margins were trivial(P>0.05).Conclusion Using the positioning errors in the first 5 fractions of radiotherapy for esophageal cancer to predict subsequent positioning errors is feasible.The reasonable individualized margin in radiotherapy for esophageal cancer can reduce the inter-fractional off-target rate without increasing the dose delivered to organs-at-risk.The study provides a reference for the target volume margin of esophageal cancer and an important basis for precision treatment.

Objective To study the forensic application of G oldeneyeTM D N A ID 26Y K it in the She na-tionality. Methods Through capillary electrophoresis, the genotype of 26 Y-STR loci were analyzed in 53 unrelated m ale individuals from Fujian She nationality. The population genetics param eters such as allele frequency and haplotype diversity were calculated. The com parisons am ong the She nationality and the other nationalities were analyzed. Results A total of 126 alleles were observed on the 26 Y-STR loci of 53 unrelated m ale individuals. The allele frequencies and G D value ranged from 0.010 1 to 0.886 8 and 0.211 2 to 0.846 2, respectively. The G D value w as greater than 0.5 in the 19 loci. A total of 47 hap-lotypes were observed. B ased on RST, m ultidim ensional scaling plot indicated that the genetic relationship am ong Fujian She nationality and M innan H an nationality w as closest, follow ed by Southern C hina H an nationality and N orthern C hina nationality. Conclusion G oldeneyeTM D N A ID 26Y K it including 26 Y-STR loci has good polym orphism in the She nationality. A s an additional system , it has forensic appli-cation value in som e special cases.