Dosimetric comparison in sparing normal tissue dosage by using auto-SBRT planning in oligo liver tumors

Shu Zhang; Weiyi Zhan; Ni Zeng; Jiangping Yang; Maoqi Xiong; Wenjun Liao; Nianyong Chen; Jianghong Xiao

doi:10.3389/fonc.2023.1273042

Dosimetric comparison in sparing normal tissue dosage by using auto-SBRT planning in oligo liver tumors

Front Oncol. 2023 Nov 9:13:1273042. doi: 10.3389/fonc.2023.1273042. eCollection 2023.

Authors

Shu Zhang^{1

2}, Weiyi Zhan³, Ni Zeng¹, Jiangping Yang¹, Maoqi Xiong⁴, Wenjun Liao⁵, Nianyong Chen^{1

2}, Jianghong Xiao⁶

Affiliations

¹ Head and Neck Oncology Department, Cancer Center, West China Hospital, Sichuan University, Chengdu, China.
² Department of Radiation Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu, China.
³ Cancer Center, West China Hospital, Sichuan University, Chengdu, China.
⁴ West China Clinical Skills Training Center, West China School of Medicine/West China Hospital, Sichuan University, Chengdu, China.
⁵ Department of Radiation Oncology, Radiation Oncology Key Laboratory of Sichuan Province, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, Affiliated Cancer Hospital of University of Electronic Science and Technology of China, Chengdu, China.
⁶ Radiotherapy Physics and Technology Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, China.

Abstract

Purpose: The study aimed to compare the dosimetric distribution of VMAT plans by increasing the number of half arcs in liver SBRT and investigate the effect by using automatic plan software in plan optimization.

Method: Thirty-one patients with oligo liver tumors were randomly selected. VMAT treatment plans with different numbers of coplanar half arcs were generated.

Result: Adding arcs significantly increased the PTV, D_2%, D_50%, and CI, but sacrificed the plan homogeneity. It also decreased the maximum dose of normal tissues such as the stomach, duodenum, and spinal cord and reduced D_mean, D_500cc, and D_700cc for the liver. Nevertheless, the diminishing effect gradually decayed into three arcs. Meanwhile, the addition of arcs substantially extended the beam-on time.

Conclusion: In the context of SBRT for oligo liver tumors, increasing the number of coplanar half arcs will improve PTV conformity and offer better protection for OARs, albeit at the expense of increased treatment duration. Considering the trade-off between plan quality and treatment efficiency, a three-arc plan may be more suitable for clinical implementation.

Keywords: auto-planning; dose sparing; liver cancer; number of half arcs; stereotactic body radiation therapy; volumetric-modulated arc therapy.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work is supported by the National Nature Science Foundation of China (NSFC 62071314, NSFC 82203197), the Sichuan Science and Technology Program (23ZDYF0638), and the New Technology Program, West China Hospital, Sichuan University (2022-377).