Dosimetric evaluation of four adaptive IMRT strategies for head-neck cancer
Tan Shuhui,Li Yufeng,Huang Pu,Lou Jingjiao,Li Hongsheng,Yin Yong,Li Dengwang
Shandong Provincial Key Laboratory of Medical Physics Image Processing Technology,Institute of Biomedical Sciences,School of Physics and Electronics,Shandong Normal University,Ji’nan 250014,China (Tan SH,Huang P,Luo JJ,Li DW);Rizhao People′s Hospital of Shandong Province,Rizhao 276826,China (Li YF);Department of Radiation Oncology,Shandong Cancer Hospital,Ji’nan 250117,China (Li HS,Yin Y)
Abstract：Objective To investigate the effects of numerous re-planning strategies on the anatomic and dosimetric outcomes of target volume and organs at risk (OARs) in patients with head and neck cancer receiving fractionated radiotherapy.Methods From 2015 to 2016,28 patients with head and neck cancer were enrolled in this study with Shandong Cancer Hospital,consisting of 19 patients with nasopharyngeal carcinoma, 4 patients with laryngocarcinoma, and 5 patients with carcinoma of the maxillary sinus. All of them received conventionally fractionated radiotherapy. Each patient had six weekly cone-beam CT (CBCT) scans, which were performed on the first day of every week, to obtain reference images. A virtual CT image was generated by registration of planning CT and each weekly CBCT image. The four re-planning strategies were used for the reconstruction of re-planned dose, while the initial planning was used as a reference. The weekly doses calculated using virtual CT were summed together to obtain the actual dose. The actual and initial planned doses were evaluated. The nonparametric Friedman test was used to evaluate the differences between multiple groups, and the differences between any two groups were analyzed by paired t test. Results The sizes of planning target volume, clinical target volume, and left/right parotid glands (PGs) changed significantly within the six weeks (P=0.041, 0.046, 0.024, and 0.017, respectively).For these four re-planning strategies, there were significant differences between the actual dose and the initial planned dose to the PGs (all P<0.05), with average values decreased by 5.02%, 11.17%, 12.08%, and 13.19%, respectively, compared with that in the reference strategy. Conclusions Re-planning during treatment course could ensure the sparing of OARs and allow for sufficient dose to the target volume. The higher the number of re-planning strategies, the more the actual dose is close to the initial planed dose;the efficiency of two re-planning strategies is the highest.
Tan Shuhui,Li Yufeng,Huang Pu et al. Dosimetric evaluation of four adaptive IMRT strategies for head-neck cancer[J]. Chinese Journal of Radiation Oncology, 2017, 26(5): 560-564.
[1] Ezzell GA,Galvin JM,Low D,et al. Guidance document on delivery,treatment planning,and clinical implementation of IMRT:report of the IMRT subcommittee of the AAPM radiation therapy committee[J].Med Phys,2003,30(8):2089-2115.DOI:10.1118/1.1591194. [2] 冯梅,范子煊,黎杰,等.582例鼻咽癌IMRT 5年远期疗效及预后分析[J].中华放射肿瘤学杂志,2011,20(5):369-373.DOI:10.3760/cma.j.issn.1004-4221.2011.05.003. Feng M,Fan ZX,lI J,et al. The analysis of 5 years of long-term curative effect and prognosis of.582 patients with nasopharyngeal carcinoma IMRT[J].Chin J Radiat Oncol,2011,20(5):369-373.DOI:10.3760/cma.j.issn.1004-4221.2011.05.003. [3] 曹建忠,罗京伟,徐国镇,等.鼻咽癌调强放疗中解剖及剂量学改变再次计划必要性研究[J].中华放射肿瘤学杂志,2008,17(3):161-164.DOI:10.3321/j.issn:1004-4221.2008.03.001. Cao JZ,Luo JW,Xu GZ,et al. The change of anatomy and dosimetry or necessity of replanning during IMRT of nasopharyngeal carcinoma in[J].Chin J Radiat Oncol,2008,17(3):161-164.DOI:10.3321/j.issn:1004-4221.2008.03.001. [4] Lee C,Langen KM,Lu W,et al. Assessment of parotid gland dose changes during head and neck cancer radiotherapy using daily megavoltage computed tomography and deformable image registration[J].Int J Radiat Oncol Bio Phys,2008,71(5):1563-1571.DOI:10.1016/j.ijrobp.2008.04.013. [5] Joseph Wee,Eng Huat Tan,Bee Choo Tai,et al. Randomized trial of radiotherapy versus concurrent chemoradiotherapy followed by adjuvant chemotherapy in patients with American Joint Committee on Cancer/International Union against cancer stage Ⅲ and Ⅳ nasopharyngeal cancer of the endemic variety[J].J Clin Oncol,2005,23(27):6730-6738.DOI:10.1200/JCO.2005.16.790. [6] Dial C,Weiss E,Siebers JV,et al. Benefits of adaptive radiation therapy in lung cancer as a function of replanning frequency[J].Med Phys,2016,43(4):1787-1794.DOI:10.1118/1.4943564. [7] Castelli J,Simon A,Louvel G,et al. Impact of head and neck cancer adaptive radiotherapy to spare the parotid glands and decrease the risk of xerostomia[J].Radiat Oncol,2015,10:6.DOI:10.1186/s13014-014-0318-z. [8] Wu QW,Chi YW,Chen PY,et al. Adaptive replanning strategies accounting for shrinkage in head and neck IMRT[J].Int J Radiat Oncol Biol Phys,2009,75(3):924-932.DOI:10.1016/j.ijrobp.2009.04.047. [9] Hansen EK,Bucci MK,Quivey JM,et al. Repeat CT imaging and replanning during the course of IMRT for head-and-neck cancer[J].Int J Radiat Oncol Bio Phys,2006,64(2):355-362.DOI:10.1016/j.ijrobp.2005.07.957. [10] Duma MN,Kampfer S,Schuster T,et al. Adaptive radiotherapy for soft tissue changes during helical tomotherapy for head and neck cancer[J].Strahlenther Onkol,2012,188(3):243–247.DOI:10.1007/s00066-011-0041-8. [11] Yang HH,Hu W,Wang W,et al. Replanning during intensity modulated radiation therapy improved quality of life in patients with nasopharyngeal carcinoma[J].Int J Radiat Oncol Bio Phys,2013,85(1):e47-54.DOI:10.1016/j.ijrobp.2012.09.033. [12] Richter A,Hu QQ,Steglich D,et al. Investigation of the usability of conebeam CT data sets for dose calculation[J].Radiat Oncol,2008,3:42.DOI:10.1186/1748-717X-3-42. [13] Yu G,Yang GY,Li BS,et al. Accelerated gradient-based free form deformable registration for online adaptive radiotherapy[J].Phys Med Biol,2015,60(7):2765-2783.DOI:10.1088/0031-9155/60/7/2765. [14] 黄劭敏,邓小武,赵充,等.鼻咽癌调强放疗中解剖结构改变对剂量分布影响研究[J].中华放射肿瘤学杂志,2010,19(5):404-408.DOI:10.3760/cma.j.issn.1004-4221.2010.05.005. Huang SM,Deng XW,Zhao C,et al. The impact of anatomical changes on dose distribution for nasopharyngeal carcinoma with IMRT[J].Chin J Radit Oncol,2010,19(5):404-408.DOI:10.3760/cma.j.issn.1004-4221.2010.05.005. [15] 张勇乾,张富利,王雅棣,等.头颈部肿瘤HT剂量学研究[J].中华放射肿瘤学杂志,2014,23(6):519-522.DOI:10.3760/cma.j.issn.1004-4221.2014.06.016. Zhang YQ,Zhang FL,Wang YD,et al. Dosimetric study of HT for head and neck cancer[J].Chin J Radit Oncol,2014,23(6):519-522.DOI:10.3760/cma.j.issn.1004-4221.2014.06.016. [16] Barker Jr J,Garden AS,Ang AK,et al. Quantification of volumetric and geometric changes occurring during fractionated radiotherapy for head-and-neck cancer using an integrated CT/linear accelerator system[J].Int J Radiat Oncol Biol Phys,2004,59(4):960-970.DOI:10.1016/j.ijrobp.2003.12.024.
2017, Vol. 26 
