Objective To investigate the impact of two different algorithms, AAA and AXB, on the dose distribution of postoperative radiotherapy for left-sided breast cancer after breast-conserving surgery. Methods A total of 96 target volumes from patients who underwent breast-conserving surgery for left-sided breast cancer were selected for dose verification using a two-dimensional matrix system. The planned dose distributions were simulated using both AAA and AXB algorithms. Dosimetric differences in organs at risk and the target volumes were then compared to identify the algorithm that could reduce the radiation dose to organs at risk without compromising the dose distribution to the target volume. Dose verification was performed on the plans generated by both algorithms, and the pass rates of plans for each target volume using both algorithms were compared to provide a quantitative basis for the precise selection of subsequent radiotherapy plans. Results Both AAA and AXB plans met the radiotherapy requirements. The AXB algorithm demonstrated significant advantages in the D₉₈, D₂, homogeneity index, and conformity index for the planning target volume, as well as in the V₅ and V₂₀ for the left lung. The AXB algorithm showed advantages in the V₃₀ for the heart and the maximum and mean doses for the skin. With the 2 mm/2% criterion in dose verification, the gamma pass rate was higher for the AXB algorithm. Conclusion Through a comparative analysis of the two algorithms, this study revealed that the AXB algorithm offers certain advantages in the dose distribution of radiotherapy after breast-conserving surgery for left-sided breast cancer. These findings provide an important reference for the rational selection of algorithms in clinical practice and are expected to improve radiotherapy efficacy and patient prognosis.

Objective To explore the influence of 3D printed individualized tissue compensators on the dose of the radiotherapy target area and the radiotherapy accuracy in intensity-modulated radiotherapy for vul-var carcinoma.Methods Twenty patients with vulvar cancer who visited this hospital from December 2022 to December 2024 were selected as the research subjects and divided into the control group and 3D group accord-ing to the random number table method,10 cases in each group.The control group used the conventional tis-sue compensators,while the 3D group used the 3D printed individualized tissue compensators.The dosimetric results of the target area and normal tissues were compared between the two groups.Results Compared with the control group,the maximum dose[(5 501.00+22.12)cGy vs.(5 659.60+84.59)cGy],average dose[(5 203.60+52.45)cGy vs.(5 258.70+42.95)cGy]and dose of 2％target volume[(5 360.30+63.70)cGy vs.(5 408.90+91.90)cGy]in the 3D group were lower,and the homogeneity index(0.12+0.01 vs.0.13+0.02)and conformity index(1.16+0.05 vs.1.23+0.04)were better,and the differences were statistically significant(P＜0.05).There was no statistically significant difference in dose of 30％clinical target volume of the bladder and rectum between the two groups(P＞0.05).During and after radiotherapy,among 20 cases,4 cases presented with grade 3 skin reactions,which were wet peeling,with 2 cases in each of the two groups.The remaining 16 cases had the grade 1 to 2 skin reactions.Conclusion In intensity-modulated radiotherapy for vulvar carcinoma,the dose distribution of 3D-printed personalized tissue compensators is superior to that of conventional organizational compensators.

Objective:To compare the dosimetric difference between 3D-printed multi-channel applicator and conventional vaginal single-channel applicator for brachytherapy, aiming to provide guidance for patients receiving brachytherapy after cervical cancer surgery.Methods:From January 2019 to November 2020, 25 cervical cancer patients complicated with VAIN Ⅲ receiving 192Ir high-dose-rate brachytherapy after cervical cancer surgery were selected. Each patient was located by CT scanning with 3D-printed multi-channel applicator and conventional vaginal single-channel applicator, and corresponding plan and evaluation were carried out. The dose volume histogram (DVH) was obtained by inverse dose optimization algorithm. The dosimetric differences of high-risk clinical target volume (HRCTV), bladder and rectum during brachytherapy were compared with those of source applicators. The optimal treatment plan was selected. Results:D 90%, D 100%, V 100% and V 150% of the plans designed by 3D-printed individual multi-channel applicator had no significant differences compared with those designed by conventional single-channel applicator (all P>0.05). The bladder and rectal D 2cm 3 designed by 3D-printed multi-channel applicator were significantly lower than those using conventional single-channel applicator, and the differences were statistically significant (both P<0.05). Conclusion:The multi-channel individual applicator target made by 3D-printing technology has good conformal property, properly protects the bladder and rectum and possesses treatment advantages over conventional single-channel applicator.