Objective:To evaluate the protective effects of hydrogel implantation in prostate cancer patients for radiotherapy.Methods:A search was performed in PubMed, Web of Science, Cochrane Library, Embase, CNKI and VIP to collect controlled clinical research literature concerning hydrogel implantation in prostate cancer for radiotherapy. The Revman 5.3 software was used to perform meta-analyses of rectal V70, rectal D2 cm 3, rectal toxicity effects and bowel symptoms. Results:The review included ten controlled clinical trials involving 1 360 patients (690 in the hydrogel group and 670 in the control group). The result of Meta-analysis showed that the rectal V70 and rectal D2 cm 3 of prostate cancer patients in the hydrogel group were significantly lower than those in the control group( MD=-4.5, 95% CI -7.11 to -1.90, P<0.001; MD=-19.78, 95% CI -25.92 to -13.63, P<0.001), early and late G1 rectal toxic effects in the hydrogel group were significantly lower than those in the control group ( OR=0.64, 95% CI 0.45-0.90, P=0.01; OR=0.28, 95% CI 0.13-0.60, P=0.001)and the late bowel quality of life in the hydrogel group was significantly improved compared with the control group( MD=5.13, 95% CI 3.29-6.98, P<0.001). However, there were no statistically significant differences in early and late ≥G2 rectal toxic effects( OR=0.46, 95% CI 0.17-1.25, P=0.13; OR=0.44, 95% CI 0.09-2.17, P=0.31)and the early bowel symptoms( MD=2.30, 95% CI -1.31-5.91, P=0.21)between the two groups. Conclusions:Hydrogel implantation inprostate cancer for radiotherapy can reduce rectal V70 and rectal D2 cm 3, lower the early and late G1 rectal toxic effects, and reduce improve the late bowel symptoms.

Objective To apply 3D printing technology to fabricate patient-specific silicone tissue compensators for the chest wall and compare the advantages and clinical characteristics between conventional bolus and 3D-printed PLA materials. Methods The chest wall data of two breast cancer patients undergoing mastectomy were obtained based upon the CT images. A patient-specific 3D printing silicone rubber bolus (3D-SRB) was designed and fabricated. The conformability of 3D-SRB,3D-PLA and conventional bolus to the chest wall were validated. Ecipse8. 6 planning system was adopted to statistically compare the dosimetric parameters of virtual plan with those after using three tissue compensators. Results The 3D-SRB was successfully designed and fabricated with a similar hardness to conventional bolus. During the process of validating conformability and radiotherapy planning,3D-SRB and 3D-PLA were superior to conventional bolus in terms of conformability to chest wall and planning dosimetric distribution.3D-SRB was advantageous in repeatability, conformability and comfortable experience compared with 3D-PLA. Regarding dosimetric parameters,3D-SRB yielded the highest repeatability with the virtual plan, followed by 3D-PLA and conventional bolus. Conclusion It is applicable to utilize 3D-SRB as the patient-specific compensators for the chest wall,which is of significance in clinical practice.