Dosimetric evaluation of dynamical conformal arc and rapid arc in stereotactic body radiotherapy for lung metastases(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2022年第8期
- Page:
- 929-935
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Dosimetric evaluation of dynamical conformal arc and rapid arc in stereotactic body radiotherapy for lung metastases
- Author(s):
- ZHENG Fang; CHEN Hongtao; CHEN Weisi; SHI Yabin; GAO Yan; LIANG Xiaomin; ZHONG Heli
- Department of Radiation Oncology, Shenzhen Peoples Hospital/the Second Clinical Medical College, Jinan University/the First Affiliated Hospital, Southern University of Science and Technology, Shenzhen 518020, China
- Keywords:
- Keywords: dynamical conformal arc rapid arc stereotactic body radiotherapy lung metastasis
- PACS:
- R734；R811
- DOI:
- DOI:10.3969/j.issn.1005-202X.2022.08.002
- Abstract:
- Abstract: Objective To compare dosimetric differences between dynamic conformal arc (DCA) and rapid arc (RA) in stereotactic body radiotherapy (SBRT) for lung metastases, and to evaluate their advantages and clinical application value. Methods Twenty cases of lung metastases were selected retrospectively, and two kinds of SBRT plans were generated using RA and DCA techniques, separately. Based on the RTOG0813 protocol criteria, the plan metrics such as PTV dosimetric parameters and organs-at-risk doses were compared between two groups of SBRT plans. In addition, the execution efficiency was evaluated by planning time, MU and delivery time. Results All RA and DCA plans met the PTV coverage requirements in the RTOG0813 protocol. RA plans performed better than DCA plans in conformity index, intermediate dose spillage R50% and D2 cm(0.998±0.039 vs 1.357±0.138, 4.90±0.93 vs 6.04±1.09, 47.3%±6.7% vs 54.5%±10.8% P<0.05). Compared with DCA plans, RA plans provided a lower V12.5 Gy, V13.5 Gy, V20 Gy to lungs, and less Dmax, V30 Gy to the chest wall ［(148.60±114.24) cm3 vs (176.25±152.16) cm3, (135.52±107.25) cm3 vs (162.10±141.21) cm3, 2.83%±3.38% vs 3.52%±4.29%, (3 734.42±1 229.7) cGy vs (4 230.31±1 510.60) cGy, (0.51±0.81) cm3 vs (0.93±1.25) cm3 P<0.05］. There was no statistical difference between the two kindsof plans in the dosimetric parameters of the heart, spinal cord, esophagus, vessels and skin (P>0.05). The comparison of execution efficiency showed that DCA plans saved 81.1% planning time, reduced 41.1% MU and 56.5% delivery time than RA plans. Conclusion Compared with DCA plan, RA plan has better conformability and can better control the dose drop gradient outside the target area, and it is more beneficial in protecting organs-at-risk close to the target area.Compared with RA plan, DCA plan can significantly improve the planning and treatment efficiencies while overcoming the interaction effect between the moving target area and the blade. When the difference in dose distribution between them is trivial, attention should be paid to the improvement of treatment efficiency, and DCA technique can be regarded as an effective treatment alternative to RA.
Last Update: 2022-09-05