头发对头颈部肿瘤精确放疗摆位误差影响

Effect of hair on placement error in precise radiotherapy of head and neck tumors

目的精确放疗已成为目前头颈部肿瘤主要的治疗方式。由于头颈部肿瘤毗邻脊髓、脑干等多个危及器官(organ at risk,OAR),放疗时对定位和摆位的精确度要求更高。本研究旨在探讨头颈部位原发和继发肿瘤精确放疗中头发对摆位误差的影响。方法选取2015-06-01-2017-03-31江苏大学附属徐州肿瘤医院放疗患者48例,其中男24例(留发组与去发组各12例),女24例(留发组与去发组各12例)。年龄28~70岁,中位年龄55岁。其中鼻咽癌16例,下咽癌5例,喉癌4例,口腔癌3例,垂体瘤2例,食管癌、乳腺癌和肺癌颈椎转移、脑转移18例。组间临床资料有可比性。热塑头颈肩膜固定,1次/周原CT-Sim校位。以颅骨右茎突尖足方向末层中心点为原点,以CT-Sim床的左右、进出、升降(x、y、z)为三维方向(3D)建立坐标系,分析左茎突尖足方向末层中心点、定位坐标系原点在上述坐标系中的位移。两骨性标记间、坐标系原点与骨性标记间三维摆位误差分别定义为绝对摆位误差、传统摆位误差。结果 x、y、z三维绝对摆位误差:无发组低于留发组,差异有统计学意义(t值分别为-3.45、-2.71、-6.32,均P<0.05)。无发组3D绝对摆位误差分别为x(0.67±0.30)mm、y(0.98±0.68)mm、z(0.81±0.48)mm,留发组分别为x(1.38±0.79)mm,y(1.85±1.19)mm,z(2.48±0.98)mm。女无发组低于女留发组,差异有统计学意义(t值分别为-3.57、-3.81、-7.05,均P<0.05)。女无发组3D绝对摆位误差分别为x(0.69±0.38)mm、y(0.99±0.69)mm、z(0.82±0.45)mm,女留发组分别为x(1.66±0.84)mm、y(1.96±1.27)mm、z(2.69±1.14)mm。男性无发组低于男留发组,但差异无统计学意义,P>0.05。x、y、z三维传统摆位误差:无发组低于留发组,差异有统计学意义(t值分别为-2.81、-4.12、-5.11,均P<0.05)。无发组3D传统摆位误差分别为x(0.71±0.38)mm、y(0.50±0.68)mm、z(0.72±0.15)mm,留发组分别为x(1.29±0.76)mm、y(1.88±1.19)mm、z(1.34±0.50)mm。女无发组低于留发组,差异有统计学意义(t值分别为-2.99、-5.01、-5.78,均P<0.05)。女无发组3D传统摆位误差分别为x(0.70±0.42)mm、y(0.47±0.73)mm、z(0.72±0.11)mm,女留发组分别为x(1.36±0.85)mm、y(1.92±1.23)mm、z(1.52±0.56)mm。男无发组低于男留发组,但差异无统计学意义,P>0.05。结论头颈部肿瘤精确放疗中头发可致绝对摆位误差和传统摆位误差,建议无(去)发放疗。

OBJECTIVE Precise radiation therapy has become the main treatment for head and neck cancer. The head and neck tumor is adjacent to the spinal cord,brain stem and many other organ at risk（OAR）,radiotherapy must be more accurate in localizing and positioning. This research is to investigate the effect of hair on the placement error in pre- cise radiotherapy of head and neck tumors（including primary and secondary）. METHODS Totally 48 patients with radio- therapy from 2015-6-1 to 2017-3-31 who were from Xuzhou Tumor Hospital Affiliated to Jiangsu University participating in the prospective cohort study,including 16 cases of nasopharyngeal carcinoma,5 cases of hypopharyngeal cancer,4 cases of laryngeal cancer, 3 cases of oral cancer, 2 cases of pituitary tumor, and 18 cases of cervical metastasis and brain metasta- sis of esophageal cancer,breast cancer and lung cancer. Aged 28--70 years（median age 55）, 24 male cases（keep hair or not,12 cases respectively）, 24 female cases （keep hair or not, 12 cases respectively）. The clinical data between the two groups were comparable. Thermoplastic head and neck shoulder membrane fixed, 1 time/W original CT-Sim school position. In skull styloid process pointed foot right direction layer at the end of the center for the origin,establishing in pa- tients with left and right side, head and foot, dorsoventral（x, y, z） for the direction of the 3-dimensional coordinate system, analyze the direction of left styloid process,pointed at the end of the center layer, positioning the displacement coordinate system origin in the above. The error of the 3-dimensional placement error between the origin of the coordinate system and the bone mark was defined as the absolute placement error and the traditional palcement error. RESULTS Absolute posi- tioning error： （1）no hair group 〈 retention hair group, the difference had statistical significance （t=- 3.45,--2. 71, -6.32,P〈0.05）. The 3D absolute positioning error of no hair group was respectively （0. 67±0. 30） ram, （0.98±0.68） mm, （0. 81! 0. 48） mm, and the retention hair group was （1. 38±0. 79） mm,（1. 85±1. 19） mm,（2. 48±0.98） mm. （2） there was no statistical significance （t = - 3.57, - 3.81, --7.05, P〈0.05）. The absolute positioning error of the female no hair group was （0.69±0.38） mm,（0.99±0.69） mm,（0. 82±0. 45） ram,and the female retention hair group （1.66±0.84） ram,（1.96±1.27） mm,（2.69±l. 14） mm. （3）the male no hair group 〈 retention hair group,but the difference was not statistically significant （P〉0.05）. Traditional positioning error： （1）no hair group 〈 retention hair group, the difference has statistical significance （t = - 2.81, - 4.12, - 5.11, P〈0.05）. The 3 D traditional positioning er- rors of no hair group were （0.71± 0.38） mm, （0. 50±0. 68） mm, （0. 72 i- 0. 15） mm, and the retention groups were （1.29±0.76） mm, （1.88±1.19） mm, （1.34±0.50） mm. （2）the female no hair group 〈 retention hair group,the differ- ence was statistically significant （t=- 2.99,--5.01,--5.78, P〈O. 05）. The traditional positioning errors of female no hair group were （0. 70 ± 0.42） ram, （0. 47±0. 73） mm, （0. 72 ± 0. 11） mm, and female retention groups （1. 36± 0.85） mm,（1.92±l. 2g） mm,（1.52±0.56） mm. （3）the male no hair group retention hair group,but the difference was not statistically significant （P〉0.05）. CONCLUSIONS In the accurate radiotherapy of head and neck tumor,the hair can cause absolute placement error and traditional placement error. According to our study no hair treatment is recommended.