Comparison of different fractionation regimens for early-stage nasopharyngeal carcinoma using radiobiological model(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2019年第6期
- Page:
- 626-631
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Comparison of different fractionation regimens for early-stage nasopharyngeal carcinoma using radiobiological model
- Author(s):
- LU Jiayang; HUANG Baotian; LI Mei; ZHANG Jiyong
- Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou 515000, China
- Keywords:
- ; Keywords: radiobiological model; nasopharyngeal carcinoma; volumetric modulated arc therapy; dosimetry
- PACS:
- R811.1；R730.55
- DOI:
- DOI:10.3969/j.issn.1005-202X.2019.06.002
- Abstract:
- Abstract: Objective To provide a theoretical reference for selecting a preferable fractionation regimen (FR) for radiotherapy of early-stage nasopharyngeal carcinoma by comparing radiobiological and dosimetric responses of tumor to different FR. Methods A total of 24 patients were enrolled in this study, and 3 volumetric modulated arc therapy (VMAT) plans with different FR (70 Gy/30 Fr, 70 Gy/33 Fr and 70 Gy/35 Fr) were designed for each patient. Webb-Nahum radiobiological model considering the repopulation and hypoxia of tumor clonogenic cells was used to predict tumor control probability (TCP), and Lyman-Kutcher-Burman model was utilized to estimate the normal tissue complication probability (NTCP) for organs-at-risk. Subsequently, TCP was combined with NTCP to calculate uncomplicated TCP (UTCP). The UTCP, TCP, NTCP and dosimetric parameters of VMAT plans with different FR were compared and analyzed. Results Among 3 different VMAT plans, the VMAT plan with 70 Gy/30 Fr had the highest UTCP (80.6%), while the VMAT plan with 70 Gy/35 Fr had the lowest UTCP (78.0%) (P<0.05). The VMAT plan with 70 Gy/30 Fr increased TCP by up to 7.3%, and meanwhile maintained or slightly increased NTCP, only with a maximum increase of 2.2% (P<0.05). No significant dosimetric difference was found among 3 different FR. Conclusion Based on the radiobiological model analysis, the VMAT with 70 Gy/30 Fr for early-stage nasopharyngeal carcinoma provides the maximal therapeutic gain and improves improving local control rate of tumor, without significantly increasing the toxicity of normal tissues. However, more clinical trials are needed to validate the conclusion.
Last Update: 2019-06-25