CAJ | 학술논문

目的观察鼻咽癌IMRT中OAR实际受量估算值与计划剂量的差异.方法选取13例拟接受IMRT鼻咽癌患者,在放疗第10、20、30次时重新CT扫描,并勾画脑干、脊髓、左右腮腺和颌下腺,观察其体积在放疗中的变化.将放疗前治疗计划复制到每个新的CT图像上,计算整个放疗中估算增加的剂量(实际受量估算值减去物理计划剂量).结果放疗第10、20、30次时左、右腮腺及颌下腺体积在放疗过程呈进行性下降(P值均为0.000).与计划剂量相比,整个放疗过程脑干、脊髓的Dmax分别平均增加3.76、3.68 Gy (P=0.000、0.000),左、右腮腺的D50分别平均增加5.11、3.54Gy(P=0.001、0.023),左、右颌下腺的D50分别平均增加0.49、0.75Gy(P =0.220、0.230).结论鼻咽癌放疗过程后腮腺和颌下腺体积明显缩小.脑干、脊髓和腮腺实际受量较计划剂量显著增加,而颌下腺受量变化不明显.
목적 관찰비인암IMRT중OAR실제수량고산치여계화제량적차이.방법 선취13례의접수IMRT비인암환자,재방료제10、20、30차시중신CT소묘,병구화뇌간、척수、좌우시선화합하선,관찰기체적재방료중적변화.장방료전치료계화복제도매개신적CT도상상,계산정개방료중고산증가적제량(실제수량고산치감거물리계화제량).결과 방료제10、20、30차시좌、우시선급합하선체적재방료과정정진행성하강(P치균위0.000).여계화제량상비,정개방료과정뇌간、척수적Dmax분별평균증가3.76、3.68 Gy (P=0.000、0.000),좌、우시선적D50분별평균증가5.11、3.54Gy(P=0.001、0.023),좌、우합하선적D50분별평균증가0.49、0.75Gy(P =0.220、0.230).결론 비인암방료과정후시선화합하선체적명현축소.뇌간、척수화시선실제수량교계화제량현저증가,이합하선수량변화불명현.
Objective To investigate the dosimetric difference of organ at risk (OAR) for planning and actual estimated during intensity-modulated radiotherapy (IMRT) for patients with nasopharyngeal carcinoma.Methods Thirteen patients were enrolled to accept full course of IMRT.CT scans were acquired in the 10th,20th,and 30th fractions during radiotherapy,respectively.OAR,including brain stem,spinal cord,parotid gland and submandibular gland,were delineated on repeated CT scans.The volume change of OAR were investigated.After that,the plans were copied to the new CT image to calculate the escalated average dose of OAR during radiotherapy (Actual estimated receiving dose minus planning dose).Results The change trend of volume was decreasing gradually for parotid gland and submandibular gland during the 10th,20th,and 30th times radiotherapy (all P =0.000).The maximum dose (Dmax) of brain stem and spinal cord and the 50％ volume receiving dose (D50) of parotid gland increased significantly in the 10th,20th,and 30th times during radiotherapy,respectively.The escalated average dose were 3.76 and 3.68 Gy for Dmax of brain stem and spinal cord (P =0.000,0.000),5.11 and 3.54 Gy for D50 of left and right parotid (P =0.001,0.023),and 0.49 and 0.75 Gy for D50 of left and right submandibular gland (P =0.220,0.230),respectively.Conclusions The volume of parotid gland and submandibular gland significantly decreased after radiotherapy The actual receiving dose of brain stem,spinal cord,and parotid gland increased significantly during radiotherapy.However,there was no significant change for the actual receiving dose of submandibular gland.