PET/CT在放射治疗中的应用价值

正电子发射断层扫描仪／计算机体层扫描（positron emission tomography／computed tomography，PET／CT）同机融合是1种先进的影像诊断系统，它可更精确地确定原发肿瘤、区域转移淋巴结以及远处转移病灶的位置和范围，对肿瘤放疗前治疗计划的制定、放疗疗效的评价、放疗后复发或残留的鉴别以及放疗后预后的评估等方面均具有重要作用。     

PET-CT图像融合在食管癌精确放疗中的应用

目的探讨PET-CT融合图像勾画靶区的食管癌三维适形放疗计划的优势。方法对16例食管癌病例分别进行CT、PET同机扫描,图像重建后传输至三维治疗计划系统(3D-Treatment planning system,TPS),进行自动图像融合,由同一临床医师分别在CT、PET-CT融合图像上勾画出,同一物理师分别设计优化TPS计划,给予常规处方剂量2.0Gy×30次,每个计划采用5个方向照射野来实现较好的靶区剂量分布,并达到周围正常组织保护的目的。计算各计划的靶区体积并显示剂量体积直方图(dose-volume histogram,DVH),比较2个计划的全肺平均受量(mean lung dose,MLD)、双肺受照超过20Gy的体积占全肺体积的百分比(V20)、气管平均受量、心脏平均受量、脊髓最大受量。结果CT勾画的GTV体积均值为67.10cm3,大于PET-CT融合图像下勾划的GTV均值60.82cm3,包括MLD、全肺V20、气管平均受量、心脏平均受量、脊髓最大受量在内的各项DVH参数的比较显示,均以PET-CT勾画靶区的计划明显优于CT勾画靶区的计划。结论PET-CT图像融合基础上勾画靶区制定放疗计划,可更有效的保护周围正常组织和器官。     

原发性肝癌三维适形放疗114例疗效评价

观察三维适形放射治疗（three-dimensional conformal radiotherapy,3DCRT）原发性肝癌的临床疗效.对114 例原发性肝癌患者在CT 定位下以3～5 mm层厚连续扫描,静脉双期碘造影剂增强扫描,精确定位治疗靶区并制定3DCRT计划,使90%等剂量曲线包绕计划靶体积（planning target volume,PTV）.以Varian 2100C 直线加速器实施放疗计划照射剂量1.8～2 Gy/次,5次/周,总剂量50～66 Gy,总疗程5～7周.治疗后1个月33例部分缓解,3个月42例部分缓解,6个月53例部分缓解.1、2和3年生存率分别为52.6%、35.1%和 28.9%.初步研究结果提示,3DCRT是原发性肝癌的有效无创治疗手段.     

3D-CRT结合同步化疗治疗Ⅲ期非小细胞肺癌的随机分组研究

[目的]研究三维适形放射治疗（3D-CRT）大剂量分割同步给予铂类为主的化学药物治疗不能切除的Ⅲ期非小细胞肺癌（NSCLC）的可行性。[方法]自2000年8月至2003年6月，将90例符合入选条件的Ⅲ期非小细胞肺癌患者随机分为3组，1组30例，以铂类为主的化疗＋3D-CRT常规分割组；2组30例，为单纯3D-CRT常规分割组；3组30例，以铂类为主的化疗＋3D-CRT大剂量分割组。1、2组分割剂量1．8—2Gy／次，5次/周，总剂量66～66．6Gy／6～8周，3组4．5～5Gy／次，3次/周，总剂量45Gy／4～5周.[结果]1、2、3组的3年总生存率和无病生存率分别为33.3％、20．0％、36．6％和23.3％、16．6％、23．3％，中位生存期分别为31、20、32个月。1、3组明显好于2组（1组和2组比较．Х^2=3．87．P=0．0492；2组和3组比较，Х^2=4．28．P=0．0387）．2组的中位转移时间为22个月，与1组的31．5个月、3组的30．5个月比较，有显著性统计学意义（1组和2组比较Х^2=4．71，P=0．0301；2、3组比较Х^2=4．02，P=0．0449）。1、2、3组的中位复发时间分别为27．5、32、28个月，无显著性统计学差异（1、2组比较Х^2=0．42，P=0．5177；1、3组比较Х^2=0．001，P=0．9636；2、3组比较Х^2=0．44，P=0．5066）。急性放射性食管炎：1、2、3组的发生半分别为46．7％、43．3％、63．3％。1、2、3组发生放射性肺炎的例数接近（Х^2=1．440，P=0．487），以Ⅰ级反应为主。[结论]3D-CRT联合化疗降低了Ⅲ期非小细胞肺癌患者的远处转移率，提高了总生存率和无病生存率。大剂量分割结合同步化疗可缩短疗程．提高局部控制率．但发生早期和晚期放射性损伤的概率增加．     

18F-FDG PET/CT显像监测胃癌术后复发转移的价值

Objective PET with 18F-fluorodeoxyglucose (FDG) has been used to beth detect and stage a variety of malignancies. The aim of this retrospective study was to evaluate the clinical value of 18F-FDG PET/CT for recurrence and metastasis in gastric carcinoma patients after total gastrectomy. Methods A total of 45 gastric carcinoma patients who underwent total gastrectomy were included. PET/CT scans were obtained for restaging. The " gold standard" of 18F-FDG PET/CT diagnostic accuracy was based on either histopathology or clinical follow-up. By using the t-test from SPSS 11.5, the cut-off of maximum standard-ized uptake values (SUVmax) from 18F-FDG to differentiate benign from malignant lesion at stomach were determined and calculated. Results (1) Of the 45 patients, 22 were suspicion recurrent lesion at stomach. Of the 22 patients, 12 were confirmed to have recurrent lesions. The diagnostic accuracy were 100.0% (12/ 12) for sensitivity, 70.0% (7/10) for specificity, and 86.4% (19/22) for accuracy, respectively. A higher SUVmax in malignant than benign lesion was noted (6.27 ± 3.42 vs 3.92 ± 2.24), though not reached to the significance (t = 1. 862, P > 0.05). (2) For extra-gastric lesion detection, the sensitivity, specificity, and accuracy for region lymph nodes were 78.9% (15/19), 92.3% (24/26), and 86.7% (39/ 45), for peritoneal spreading were 6/9, 97.2% (35/36), 91. 1% (41/45), and for distant sites were 86.7%(13/15), 93.3% (28/30), 91.1% (41/45). (3) False positive were found in eight sites. All were either inflammatory or physiological uptake at intestine. False negative were found in nine sites. Either due to small in size (less than 1.0 cm in diameter), well differentiation of the tumor cell or with a nature of signet ring. Conclusion 18F-FDG PET/CT had a potential to detect local, regional, and distant metastasis in gastric cancer.     

实体肿瘤脑膜转移32例临床分析

脑膜转移瘤由Eberth于1870年首先提出，多见于血液肿瘤，如急性白血病。但实体肿瘤也有发生，且随生存期的延长和诊断技术的提高发病率正在上升。2000年4月至2003年8月经MRI和（或）脑脊液诊断的实体瘤脑膜转移32例，现报道如下。     

18F-FDG PET/CT显像监测胃癌术后复发转移的价值

Objective PET with 18F-fluorodeoxyglucose (FDG) has been used to beth detect and stage a variety of malignancies. The aim of this retrospective study was to evaluate the clinical value of 18F-FDG PET/CT for recurrence and metastasis in gastric carcinoma patients after total gastrectomy. Methods A total of 45 gastric carcinoma patients who underwent total gastrectomy were included. PET/CT scans were obtained for restaging. The " gold standard" of 18F-FDG PET/CT diagnostic accuracy was based on either histopathology or clinical follow-up. By using the t-test from SPSS 11.5, the cut-off of maximum standard-ized uptake values (SUVmax) from 18F-FDG to differentiate benign from malignant lesion at stomach were determined and calculated. Results (1) Of the 45 patients, 22 were suspicion recurrent lesion at stomach. Of the 22 patients, 12 were confirmed to have recurrent lesions. The diagnostic accuracy were 100.0% (12/ 12) for sensitivity, 70.0% (7/10) for specificity, and 86.4% (19/22) for accuracy, respectively. A higher SUVmax in malignant than benign lesion was noted (6.27 ± 3.42 vs 3.92 ± 2.24), though not reached to the significance (t = 1. 862, P > 0.05). (2) For extra-gastric lesion detection, the sensitivity, specificity, and accuracy for region lymph nodes were 78.9% (15/19), 92.3% (24/26), and 86.7% (39/ 45), for peritoneal spreading were 6/9, 97.2% (35/36), 91. 1% (41/45), and for distant sites were 86.7%(13/15), 93.3% (28/30), 91.1% (41/45). (3) False positive were found in eight sites. All were either inflammatory or physiological uptake at intestine. False negative were found in nine sites. Either due to small in size (less than 1.0 cm in diameter), well differentiation of the tumor cell or with a nature of signet ring. Conclusion 18F-FDG PET/CT had a potential to detect local, regional, and distant metastasis in gastric cancer.     

自由与主动呼吸控制状态下乳腺癌调强放疗位移EPID误差比较

目的:应用电子射野影像系统测量自由呼吸状态(FB)和主动呼吸控制状态(ABC)下的相对位移,并对比其差别。方法:选择29例接受保留乳房术后调强放疗的乳腺癌患者,16例在FB下13例在ABC下接受放疗。患者在每次放疗前拍电子射野影像片(EPI),ABC的8例在每次放疗前拍2次。依据胸壁和乳腺表面轮廓将EPI和数字重建图像(DRR)进行配准,计算出每次配准时垂直和水平方向的差异。结果:FB组水平和垂直方向的平均位移分别为1.93和0.99mm,ABC组分别为1.97和1.14mm。位移>5mm的<4%。ABC组之间在水平和垂直方向的位移差异无统计学意义,P值分别为0.778和0.142。其中8例每次放疗前拍2次EPI的ABC患者,在水平和垂直方向差异无统计学意义,P值分别为0.220和0.862。结论:尽管从理论上ABC可减少呼吸运动,但在减少由摆位误差和呼吸运动造成的混合位移方面并无优势。乳腺癌放疗时从临床靶区到计划靶区外放5mm的边界是合理的。     

肺癌放疗后放射性肺损伤CT分级与正常组织并发症概率的关系

目的 探讨非小细胞肺癌 (NSCLC)三维适形放疗(3DCRT)后放射性肺损伤的CT分级与正常组织并发症概率(NTCP)的关系。方法 将3DCRT治疗后CT随访6个月以上的169例Ⅰ～Ⅲ期NSCLC患者按随访CT放射性肺损伤的表现分级并分为CT阳性组(2～4级)和CT阴性组(0、1级),复习全部病例的治疗计划,按全肺NTCP和患侧肺的NTCP分布各分为5组,对比分析放射性肺损伤CT分级与NTCP的关系。结果 不同CT分级的全肺和患侧肺NTCP值差异有统计学意义(全肺P=0.004,患侧肺P=0.000);全肺NTCP分组和患侧肺NTCP分组研究均显示患侧肺CT分级阳性率组间差异有统计学意义(全肺P=0.003,患侧肺P=0.000)。结论 NSCLC行3DCRT后放射性肺损伤的CT分级与NTCP密切相关。