Dosimetric study on photon optimization algorithm and progressive resolution optimization algorithm in volumetric modulated arc therapy plan for nasopharyngeal carcinoma(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2019年第8期
- Page:
- 872-876
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Dosimetric study on photon optimization algorithm and progressive resolution optimization algorithm in volumetric modulated arc therapy plan for nasopharyngeal carcinoma
- Author(s):
- LIU Zhibin; SHI Jinping; ZHANG Liwen; XIE Qiuying; TENG Jianjian; LI Yinghui
- Department of Radiation Oncology, Cancer Center, the First People’s Hospital of Foshan (Affiliated Foshan Hospital of Sun Yat-sen University), Foshan 528000, China
- Keywords:
- ; Keywords: nasopharyngeal carcinoma; volumetric modulated arc therapy; photon optimization algorithm; progressive resolution optimization; dosimetric analysis
- PACS:
- R811.1；R739.6；R312
- DOI:
- DOI:10.3969/j.issn.1005-202X.2019.08.002
- Abstract:
- Abstract: Objective To compare the dosimetric differences between photon optimization (PO) algorithm and progressive resolution optimization (PRO) algorithm of Eclipse planning system in volumetric modulated arc therapy plan for nasopharyngeal carcinoma. Methods The CT images of 20 patients who were treated with radiotherapy for nasopharyngeal carcinoma were imported into the planning system, and then target areas and organs-at-risk were delineated. Two different RapidArc plans were generated with different algorithm, namely PO algorithm and PRO algorithm. The dosimetric distributions, monitor units, gamma passing rates and optimization time of the two kinds for treatment plans were compared. Results No significant difference was found between PO plan and PRO plan in the D2%, Dmean, D98%, target coverage, conformity index and homogeneity index of PGTVnx (P>0.05). However, the D98% and Dmean of PGTVnd, PTV1 and PTV2 in PO plan were higher than those in PRO plan (P<0.05). There was no statistical difference between two plans in the doses of bilateral lenses, bilateral parotid glands, bilateral temporal lobes and bilateral optic nerves (P>0.05). Compared with those in PO plan, the D1% and Dmean of brainstem, D1% of spinal cord and Dmean of larynx were lower in PRO plan, with statistical differences (P<0.05). The gamma passing rates of both two plans met treatment requirements, and the gamma passing rates (3 mm/3% and 2 mm/3%) of PO were (99.13±0.81)% and (97.77±1.31)%, respectively, superior to (98.62±0.84)% and (96.84±1.31)% of PRO plan. Moreover, the average monitor units of PRO plan were increased to 1.13 times of that of PO plan (P=0.000), and the average optimization time was 1.66 times of that of PO plan (P=0.000). Conclusion Both of PO plan and PRO plan can qualify clinical requirements. PO plan is advantageous in the dose distribution of target area, but PRO plan has more advantages in the protection of brainstem, spinal cord and larynx. PO algorithm is recommended for volumetric modulated arc therapy plan for nasopharyngeal carcinoma, because the plan generated by PO algorithm can greatly reduce monitor units and shorten optimization time.
Last Update: 2019-08-26