中华放射肿瘤学杂志
中華放射腫瘤學雜誌
중화방사종류학잡지
CHINESE JOURNAL OF RADIATION ONCOLOGY
2010年
3期
263-266
,共4页
高云生%常熙%周莉钧%胡伟刚%王孝深%朱国培%吴永如%胡超苏
高雲生%常熙%週莉鈞%鬍偉剛%王孝深%硃國培%吳永如%鬍超囌
고운생%상희%주리균%호위강%왕효심%주국배%오영여%호초소
脑肿瘤%头颈肿瘤%体层摄影术,X线计算机,锥形束%摆位误差
腦腫瘤%頭頸腫瘤%體層攝影術,X線計算機,錐形束%襬位誤差
뇌종류%두경종류%체층섭영술,X선계산궤,추형속%파위오차
Brain neoplasms%Head and neck neoplasms%Tomography,X-ray computed,cone-beam%Set-up error
目的 分析兆伏锥形束CT(MVCBCT)引导的头颈部肿瘤精确放疗中摆位误差.方法 头颈部肿瘤共22例(鼻咽癌15例,腮腺癌4例,脑胶质瘤术后3例),其中接受三维适形放疗7例、调强放疗15例,照射剂量为56.0~70.4 Gy分28~32次6~7周完成.19例用头颈肩面罩固定,3例头部面罩固定.所有患者均行CT模拟,勾画靶区和危及器官.每周治疗前拍1次MVCBCT图像,每位患者接受4~7次MVCBCT.分析相对于计划CT上中心在头脚、垂直、左右方向上的摆位误差.结果 左右、前后和头脚方向中任一方向>0.3 cm 28次,>0.4 cm 15次,>0.5 cm 9次,头脚方向要比左右、前后方向超过近0.1 cm.头脚和左右中心偏移方向的频次差别不大,而在垂直方向则更多的向后偏移达4:1.相对来说头脚方向摆位误差较左右、前后方向大,随着放疗时间延长各方向偏移的平均值均有增大趋势.结论 头颈部肿瘤精确放疗时CTV至PTV边界外扩并不需均匀外放,垂直方向上治疗中心向前偏移概率明显超过向后,头脚方向比左右、前后方向摆位误差大;随着放疗的进行3个方向上的摆位误差都有增大趋势.
目的 分析兆伏錐形束CT(MVCBCT)引導的頭頸部腫瘤精確放療中襬位誤差.方法 頭頸部腫瘤共22例(鼻嚥癌15例,腮腺癌4例,腦膠質瘤術後3例),其中接受三維適形放療7例、調彊放療15例,照射劑量為56.0~70.4 Gy分28~32次6~7週完成.19例用頭頸肩麵罩固定,3例頭部麵罩固定.所有患者均行CT模擬,勾畫靶區和危及器官.每週治療前拍1次MVCBCT圖像,每位患者接受4~7次MVCBCT.分析相對于計劃CT上中心在頭腳、垂直、左右方嚮上的襬位誤差.結果 左右、前後和頭腳方嚮中任一方嚮>0.3 cm 28次,>0.4 cm 15次,>0.5 cm 9次,頭腳方嚮要比左右、前後方嚮超過近0.1 cm.頭腳和左右中心偏移方嚮的頻次差彆不大,而在垂直方嚮則更多的嚮後偏移達4:1.相對來說頭腳方嚮襬位誤差較左右、前後方嚮大,隨著放療時間延長各方嚮偏移的平均值均有增大趨勢.結論 頭頸部腫瘤精確放療時CTV至PTV邊界外擴併不需均勻外放,垂直方嚮上治療中心嚮前偏移概率明顯超過嚮後,頭腳方嚮比左右、前後方嚮襬位誤差大;隨著放療的進行3箇方嚮上的襬位誤差都有增大趨勢.
목적 분석조복추형속CT(MVCBCT)인도적두경부종류정학방료중파위오차.방법 두경부종류공22례(비인암15례,시선암4례,뇌효질류술후3례),기중접수삼유괄형방료7례、조강방료15례,조사제량위56.0~70.4 Gy분28~32차6~7주완성.19례용두경견면조고정,3례두부면조고정.소유환자균행CT모의,구화파구화위급기관.매주치료전박1차MVCBCT도상,매위환자접수4~7차MVCBCT.분석상대우계화CT상중심재두각、수직、좌우방향상적파위오차.결과 좌우、전후화두각방향중임일방향>0.3 cm 28차,>0.4 cm 15차,>0.5 cm 9차,두각방향요비좌우、전후방향초과근0.1 cm.두각화좌우중심편이방향적빈차차별불대,이재수직방향칙경다적향후편이체4:1.상대래설두각방향파위오차교좌우、전후방향대,수착방료시간연장각방향편이적평균치균유증대추세.결론 두경부종류정학방료시CTV지PTV변계외확병불수균균외방,수직방향상치료중심향전편이개솔명현초과향후,두각방향비좌우、전후방향파위오차대;수착방료적진행3개방향상적파위오차도유증대추세.
Objective To evaluate set-up errors by megavoltage cone-beam CT in head and neck cancers treated with precision radiotherapy. Methods From April 2007 to March 2008, 22 patients with nasopharyngeal carcinoma (15 patients) ,parotid carcinoma (4 patients) and brain glioma (3 patients) were enrolled, among whom 7 patients underwent three-dimensional conformal radiotherapy (3DCRT) and 15 received intensity modulated radiotherapy (IMRT). The radiation dose was 56. 0 -70.4 Gy in 28 -32 fractions within 6 -7 weeks. Megavoltage cone-beam scan was performed weekly before treatment. The isocenter displacement was calculated by comparing megavoltage cone-beam CT and planning CT in left-right (LR), cranio-caudal (CC), and anterior-posterior (AP) directions. Results Totally 129 sets of megavoltage cone-beam CT images were obtained for 22 patients. The frequency of isocenter shift more than 0. 3 cm,0. 4 cm and 0. 5 cm were 28,15 and 9, respectively. The maximum mean set-up error was found in CC, which was about 0. 1 cm more than that in LR and AP. The frequency of isocenter shift direction was almost identical in LR and CC, which was more frequent (about 75%) in the posterior direction. Conclusions During the course of radiation of brain tumor and head and neck cancer, the enlarging tendency of set-up errors has been found in all the three directions. The isocenter shift in AP was more frequent to the posterior direction.