Postoperative Intensity Modulated Radiotherapy with 5-Fields for Parotid Cancer

doi:10.3969/j.issn.1005-4979.2014.01.011

Abstract

Abstract: Objective: The study was designed to clarify the appropriate field number for better dosimetric results and delivery efficiency of RT for postoperative patients with parotid glands cancer. Methods: The efficiency of dosimetry of intensity-modulated radiotherapy (IMRT) with 5-fields IMRT versus 7-fields, 9-fields and 11-fields IMRT were compared. The dose-volume-histgram （DVH）were used to evaluate different fields IMRT plans in 5 postoperative patients with parotid cancer. The percent volumes with ≥95% prescribed radiation dose (V95), ＞110% prescription dose (V110), conformity index (CI) and homogeneous index (HI) in the planning target volume (PTV), maximum dose in brain stem and spinal cord , mean dose in contralateral parotid glands and ipsilateral middle ears, monitor units (MU) and times of RT of 5-fields and more than 5-fields IMRT were compared statistically. Results: There were no differences for V95、V110、CI、HI in PTV and the mean dose in ipsilateral middle ears (P>0.05), for the comparison between 5-fields IMRT and 7-, 9-, and 11-fields. The maximum dose in brain stem of 11-fields IMRT was the lowest(P<0.05), and the maximum dose in spinal cord of 5-fields IMRT was the lowest (P<0.05), but all doses of the groups were safety. The maximum dose in contralateral parotid glands, MU and times of RT of 5-fields IMRT were superior than that of 7-, 9-, and 11-fields IMRT（P<0.05）. Conclusion: The 5-fields IMRT for postoperative patients with parotid glands cancer can offer good dosimetric results and lower MU and total treatment time. The more than 5-fields IMRT can not provide better dosimetric results, but will increase MU and total treatment time.

Key words: parotid gland cancer; , postoperative intensity-modulated radiotherapy (IMRT); , dosimetry

摘要： 目的：对5、7、9、11野的腮腺癌调强放射治疗进行剂量学评估，优选达到良好剂量分布和治疗效率的放射野数目。方法：用容积剂量图（dose-volume-histgram, DVH）对5例不同放射野数调强放疗患者，分别行剂量学研究，比较不同数量放射野放疗计划靶区（planningl target volume，PTV)的以下指标。≥95%处方剂量的体积百分比 (V95)、＞110%处方剂量的体积百分比 (V110)、适形指数（conformal index，CI）和均匀指数（homogeneous index HI）；脑干和脊髓的最大剂量（D maximum）、对侧腮腺和同侧中耳的平均剂量（D mean）、跳数（monitor units, MU）和治疗时间均值，并行统计学分析。结果： 5野调强放疗与更多野（7、9、11野）技术相比，靶区V95、V110、CI、HI和同侧中耳平均剂量均未见明显统计学差异（P>0.05）；脊髓最大剂量以5野调强放疗最低（P<0.05）；脑干最大剂量以11野调强放疗最低（P<0.05）,但5~11野调强均在安全剂量范围内；对侧腮腺平均剂量、MU和总治疗时间均以5野调强放疗明显优于更多野技术（P<0.05）。结论：腮腺癌术后5野调强放疗，具有良好的剂量分布和治疗效率，采用更多野调强技术对剂量分布未见明显改善，但会增加MU和总治疗时间。

关键词: , 腮腺癌, , , 术后调强放疗, , , 剂量学

CLC Number:

R739.87

SHI Hui-feng，HU Hai-sheng, WANG Zhong-he. Postoperative Intensity Modulated Radiotherapy with 5-Fields for Parotid Cancer[J]. 《Journal of Oral and Maxillofacial Surgery》, 2014, 24(1): 52-.

石慧烽，胡海生，王中和. 腮腺癌术后5放射野调强放射治疗的临床观察[J]. 《口腔颌面外科杂志》, 2014, 24(1): 52-.

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URL: https://journal06.magtech.org.cn/Jweb_joms/EN/10.3969/j.issn.1005-4979.2014.01.011

https://journal06.magtech.org.cn/Jweb_joms/EN/Y2014/V24/I1/52

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