Dosimetric comparison between RapidArc and Novalis Knife in stereotactic radiosurgery for multiple brain metastases(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2020年第10期
- Page:
- 1242-1247
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Dosimetric comparison between RapidArc and Novalis Knife in stereotactic radiosurgery for multiple brain metastases
- Author(s):
- DAI Peng; ZHANG Ping; LUO Longhui; DENG Guanhua; LAI Mingyao; SHAN Changguo; HUANG Qing; CAI Linbo
- Department of Oncology, Guangdong Sanjiu Brain Hospital, Guangzhou 510510, China
- Keywords:
- Keywords: multiple brain metastases stereotactic radiosurgery RapidArc Novalis Knife dosimetric comparison
- PACS:
- R815.6；R739.41
- DOI:
- DOI:10.3969/j.issn.1005-202X.2020.10.006
- Abstract:
- Abstract: Objective To compare the dosimetric differences between two techniques, namely RapidArc based on multi-leaf collimator and Novalis Knife based on circular cone, in the stereotactic radiosurgery for multiple brain metastases. Methods Ten patients treated by Novalis Knife were enrolled in the study. Each patient had 3 to 5 brain metastases, and there were 37 brain metastases in total. The treatment plans of these cases were replanned with a single-isocenter and 4 non-coplanar RapidArc (RapidArc SRS plans), with the prescription dose for target areas standardized to 16 Gy. Dosimetric parameters, including the conformity index and homogeneity index of target areas, gradient index around target areas, the V16, V12, V9, V6 and V3 of normal brain tissues and monitor units were compared between Novalis Knife plans and RapidArc SRS plans. Results Compared with Novalis Knife plans, RapidArc SRS plans had a higher conformity index (0.79±0.10 vs 0.50±0.22, P=0.000), lower homogeneity index (0.07±0.01 vs 0.15±0.07, P=0.000) and higher gradient index (15.92[±]12.43 vs 5.05[±]3.53, P=0.000). The V16 of normal brain tissues in RapidArc SRS plans was obviously lower than that in Novalis Knife plans (P=0.005). There was no significant difference between two kinds of plans in the V12 and V9 of normal brain tissues (P=0.445, 0.059). However, the V6 and V3 of normal brain tissues in RapidArc SRS plans were significantly higher than those in Novalis Knife plans (P=0.005, 0.005). Moreover, compared with Novalis Knife plans, RapidArc SRS plans were associated with markedly reduced monitor units (P=0.005). Conclusion RapidArc SRS plans can achieve the simultaneous treatment of multiple brain metastases by setting a single-isocenter, with higher conformity index and lower homogeneity index of target area but compared with Novalis Knife plans, RapidArc SRS plans have a worse gradient index and a larger low-dose coverage range. The patients with multiple brain metastases who have poor adherence to treatment can be treated by RapidArc which is more efficient, and fractional dose mode should be adjusted according to the clinical situation, thereby reducing the risk of radiation injuries.
Last Update: 2020-10-29