锥形束CT在线调整大分割放射治疗椎体转移癌  

Study of Hypo-Fractionated Image-Guided Intensity Modulated Radiotherapy (IG-IMRT) for Treating Spinal Metastasis Using Cone-Beam Computed Tomography (CBCT)

作　　者：郭雷鸣[1] 朱中秀[1] 赵雅琴[1] 徐庆丰[1] 王辛[1] 钟仁明[1] 何银波[1] 柏森[1] 许峰[1] 

机构地区：[1]四川大学华西医院肿瘤中心腹部肿瘤科,成都市610041

出　　处：《中国肿瘤临床》2010年第24期1450-1454,共5页Chinese Journal of Clinical Oncology

基　　金：四川省科技攻关计划课题资助(编号:03SG022-008)~~

摘　　要：目的:评价锥形束CT(CBCT)在线调整技术在大分割治疗椎体转移瘤中的应用价值。评价分次间摆位误差及治疗过程中靶区位移对治疗的影响。方法:2008年12月至2009年08月,应用医科达Synergy系统治疗椎体转移瘤10例,每次照射前、调整后及治疗后获取CBCT图像,将获取图像和计划CT图像匹配,获得靶中心X(左右)、Y(头脚)、Z(前后)方向的位移及旋转角度误差,分析误差及分布规律。应用逆向调强放射治疗技术,靶区剂量63Gy/9次,隔日照射。随访6个月。结果:10例患者共10个靶区CBCT扫描269次。首次摆位在X、Y、Z方向位移误差分别为(-0.90±4.20)mm、(-0.40±4.90)mm、(-2.50±3.40)mm,旋转角度误差分别为(-0.20±1.65)°、(-1.12±1.84)°、(0.22±1.48)°。调整后其位移误差分别为±0.80mm、±0.90mm、(-0.10±0.80)mm;治疗后分别为(-0.10±1.30)mm、±1.80mm、(0.10±1.40)mm。调整后角度误差分别为(-0.21±1.06)°、(-0.72±0.96)°、(0.33±0.85)°;治疗后分别为(-0.15+1.27)°、(-0.64±1.39)°、(0.62±1.18)°。调整前PTV外扩值范围为8.40～11.00mm,调整后缩小为1.20～1.50mm。10例患者疼痛缓解,未发现放疗副作用。治疗6个月后复查骨扫描提示核素浓聚减少。结论:CBCT在线调整能纠正摆位误差,既满足靶区剂量的提升也有效降低了脊髓受量。高剂量大分割图像引导调强放疗技术是治疗椎体转移瘤的一种安全、有效的新方法。Objective： To evaluate the applicability and effectiveness of hypo-fractionated image-guided intensity modulated radiotherapy （IG-IMRT） in treating spinal metastasis and to investigate the interfractional and intrafractional radiotherapy setup errors for spinal metastasis using kV-CBCT. Methods： From October 2008 to August 2009, 10 patients with spinal metastasis were treated with the Elekta Synergy TM system. All patients received kilovoltage cone beam computed tomography （kV-CBCT） before receiving radiation treatment, after correction and treatment. The acquired X-ray volumetric images （XVl） which were co-registered with planning CT and errors of isocenter position on left-right （LR）, superior-inferior （SI） and anterior-posterior （AP） axes X, Y, and Z and angle of rotation were obtained and analyzed. The dose prescribed to metastatic lesions was 63 Gy! 9f, with the mean spinal cord dose limited to 〈 34.2 Gy and per fraction dose 〈 3.8 Gy. Patients were followed up for 6 months for pain relief and bone lesion resolution. Results： Ten patients were treated and received a total of 269 CBCT scans. Before set-up correction, the translational positioning errors （means ＋ SD） in the left-right （X）, superior-inferior （Y） and anterior-posterior （Z） axes were （-0.90 ± 4.20）, （-0.40 ±4.90） and （-2.50 ±3.40） mm, respectively; the rotation errors were （-0.20 ±1.65）, （-1.12 ± 1.84） and （0.22±1.48） degrees, respectively. After correction, those errors were （0.00 ± 0.80）, （0.00 ± 0.90）, （-0.10 ± 0.80） mm and （-0.21 ± 1.06）, （-0.72 ± 0.96）, （0.33 ± 0.85） degrees, respectively. The pre-correction PTV margins were from 8.40 to 11.00 ram, while the post-correction margins were from 1.20 mm to 1.50 mm. All patients requested pain relief. After 6 months, all patients were rechecked with a bone scan showing significantly decreased nuclide accumulation. There was no radiation-induced toxicity detected clinically during a medi

关 键 词：图像引导放射治疗 锥形束CT 分次间误差 分次内误差 大分割放射治疗 

分 类 号：R738[医药卫生—肿瘤]