Fushe yanjiu yu fushe gongyi xuebao (Oct 2022)

Dosimetric analysis of the Varian Edge accelerator for long-size tumor treatment

  • FENG Weigui,
  • GUO Yixiao,
  • ZHANG Lijuan,
  • CAI Hongyi,
  • DU Wen

DOI
https://doi.org/10.11889/j.1000-3436.2022-0012
Journal volume & issue
Vol. 40, no. 5
pp. 48 – 55

Abstract

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Among the cervical cancer treatments for patients with long-size tumors using the varian edge linear accelerator, we compared the newly designed plan (NewPlan) with the AutoPlan, which was automatically generated by the treatment planning system, and explored the dosimetric difference between the two plans for a more beneficial treatment. According to the accelerator's multi-leaf collimator characteristics, 11 cases of cervical cancer treatment plans using the simultaneous volumetric modulated arc therapy were selected. Based on the Eclipse 13.6.23 version of the planning system, the SPSS 19.0 statistical software was used to analyze the data, and the GraphPad prism 9.0 software was used to produce statistical graphs. The dose distribution difference between the NewPlan and conventional AutoPlan in the target area and organs at risk was analyzed. The results showed that the two plans met the dosimetry requirements. There were significant differences in the D98%, D50%, Dmean, target coverage, and heterogeneity index (HI) of the PGTVnd in the high dose area (p<0.05). There was no significant difference in the target area CTV (p>0.05). There were significant differences in the D2%,D98%, D50%, Dmean, and HI of PTV in the planned target area (p<0.05). The differences of the Dmean V30, and V40 of the bladder and rectum were statistically significant (p<0.05). The volume percentage of the bladder and rectum in the NewPlan was lower compared with that of the AutoPlan at the same dose. There was no statistical difference in the dosimetry parameters of the bilateral femoral head and small intestine (p>0.05). The comparison of the two plans reveals that the NewPlan can reduce cold and hot spots in the target area, improve the therapeutic dose in the tumor area, and reduce the dose of the organs at risk, which is conducive to improving the efficacy. Based on the varian edge accelerator, the NewPlan design is feasible for the treatment of patients with long-size tumors.

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