基于非线性变换法提高平扫头颅CT的灰白质对比度

目的 采用矩阵实验室(MATLAB)图像处理技术构建一种非线性变换法,用以提高平扫头颅CT图像的脑灰、白质对比度.方法 使用西门子definition型双源CT采集38例(女16例,男22例)在本院就诊怀疑脑部病变的患者脑正常平扫图像数据,测量脑灰、白质的平均CT值,并计算对应的像素值,对各例DICOM图像行MATLAB后处理.通过频域内的圆形滤波器,实现图像的高、低通滤波分离.采用基于灰度值调整的非线性变换法,以脑灰质和脑白质的平均灰度值为两个转折点,对图像的灰度进行拉伸,以增强图像的灰白质对比.结果 38例患者的正常脑平扫图像,经灰度值非线性变换法处理后,两转折点处灰度值差值较原始图像增加了1.5个像素值(0＜△p≤3);脑灰质和脑白质对比度也明显提高;灰白质分界更加清楚;且处理后图像与原始图像保持接近.结论 基于MATLAB图像处理软件的灰度值非线性变换法,能够在不增加噪声的前提下,有效增强平扫头颅CT图像的灰白质对比度,适用于任何CT机型采集的DICOM图像数据.     

简单调强高剂量或常规剂量放射治疗伴淋巴结转移的食管癌疗效分析

目的 探讨简单调强放疗技术(sIMRT)并同期化疗治疗颈段及胸上段食管癌,并予转移淋巴结高剂量放疗的可行性.方法 44例患者随机分为2组,高剂量组20例,常规剂量组24例.对颈及胸上段食管癌的原发灶和预防照射区进行sIMRT计划设计.定义3个靶区:PGTVnd为转移淋巴结靶区,高剂量组患者给予68.1 Gy,每次2.27 Gy,共30次;常规剂量组患者给予60 Gy,每次2.0 Gy,共30次.PTV1为需要加量照射的原发灶靶区,高剂量组给予63.9 Gy,每次2.13 Gy,共30次;常规剂量组60 Gy,每次2.0 Gy,共30次.PTV2为预防照射区,高剂量组和常规剂量组均给予54 Gy,每次1.8 Gy,共30次.放疗中顺铂(DDP)+5-氟尿嘧啶(5-FU)方案第1～5天和第29～33天同期化疗2个周期,放疗结束后28 d原方案重复2个疗程.结果 所有患者均完成了治疗计划,治疗中仅1例发生Ⅲ级放射性气管炎.高剂量组与常规剂量组淋巴结病灶达完全缓解(CR)者分别为75%(15/20)与45.8%(11/24),差异有统计学意义(x2=3.84,P＜0.05);1、2、3年无进展生存率分别为60%、40%、25%和41.7%、25%、8.3%(x2=4.11,P＜0.05);原发病灶近期疗效和1、2、3年生存率差异无统计学意义;不良反应主要为Ⅰ～Ⅱ级白细胞下降.结论 sIMRT计划治疗颈及胸上段食管癌,急性放射反应可耐受,给予转移淋巴结高剂量放疗可以提高患者的无复发生存率.

Abstract：

Objective To investigate the feasibility of simplified intensity-modulated radiotherapy (sIMRT) and concurrent chemotherapy against neck and upper thoracic esophageal carcinoma with lymph node metastasis.Methods sIMRT plans were designed for 44 patients of neck and upper thoracic esophageal carcinoma with lymph node metastasis, 20 of which underwent high dose sIMRT (hsIMRT group) and 24 underwent conventional dose sIM RT (csIMRT group).Three target volumes were defined:PGTVnd, target volume of lymph node lesion, irradiated to 68.1 Gy ( 2.27 Gy × 30 fractions ) for the hsIMRT group, and 60 Gy (2.0 Gy ×30 fractions) the csIMRT group; PTV1, the target volume of primary lesion, to be irradiate to 63.9 Gy (2.13 Gy × 30 fractions) for the hsIMRT group and 60 Gy (2.0 Gy × 30fractions) for the csIMRT group; PTV2 , the prophylacticly irradiated volume, to be irradiated to 54 Gy (1.8 Gy ×30) for both groups.The sIMRT plan included 5 equiangular coplanar beams.All patients received DDP + 5-FU regimen concurrently with radiotherapy at 1 -5 d and 29- 33 d, respectively.Chemotherapy was repeated for two cycles 28 days after the radiotherapy was finished.Results The treatment was completed for all patients within 6 weeks.During the treatment only one patient with grade 3 acute bronchitis was observed in the hsIMRT group.The complete response (CR) rate for the lymph node lesion of the hsIMRT group was 75% ( 15/20 ), significantly higher than that of the csIMRT group [45.8% ( 11/24), x2 = 3.84, P ＜ 0.05].The 1-, 2-, and 3-year progression-free survival rates of the hsIMRT group were 60%, 40%, and 25% , respectively,all significantly higher than those of the csIMRT group (41.7%, 25%, and 8.3% respectively, x2 = 4.11,P ＜ 0.05).However, there were not significant differences in the total survival rate, and the CR and PR of the esophageal lesion between these 2 groups.The major toxicity observed was grade Ⅰ -Ⅱ leukoctyopenia.Conclusions sIMRT generates desirable dose distribution for neck and upper thoracic esophageal carcinoma.hsIMRT has a better short-term efficacy than csIMRT.High dose radiotherapy toward metastatic lymph nodes helps increase progression-free survival.     

食管癌术后纵隔转移灶同时加量调强放射治疗分析

目的:探讨食管癌根治术后纵隔转移灶同时加量调强放疗的意义和效果.方法:39例食管癌根治术后发生纵隔转移患者,设定原发灶和预防照射区进行SIB-IMRT(simultaneous integrated boost intensity-modulated radiation therapy)计划设计.定义2个靶区:PTV1为需要加量照射的淋巴结靶区,给予69Gy(2.3×30次);PTV2为预防照射区,给予54Gy(1.8×30次)的剂量,设计等角度5野调强计划.结果:5野调强获得了满意的剂量分布,患者可在6周内完成治疗计划,所有患者完成了放疗,治疗后3个月复查CT,病灶达CR(complete response)占66.7%(36/54),PR(partial response)占 33.3%(18/54),总有效率(CR+PR)达到100.0%.结论:食管癌根治术后纵隔转移患者进行同时加量调强放射治疗物理学优势明显,可以明显提高局部控制率,急性放射治疗反应可耐受,具有良好的应用前景.     

宫颈癌术后调强放疗与常规4野计划剂量学比较及放射反应分析

目的:研究宫颈癌术后7野调强放疗计划与常规4野放疗计划(4野箱式照射)对危及器官的保护,并分析比较两种计划所产生的急性放射反应?方法:选取本院50例患者,其中25例为已行调强放疗,确定为调强组;另25例为已行常规放疗,确定为常规组?调强组同时设计常规4野模拟计划,与调强计划进行比较,做剂量学研究;同时,调强组与常规组进行急性反应的比较研究?结果:调强计划中达到46 Gy剂量包含临床靶区(CTV)体积显著>常规4野计划(P < 0.05)?调强计划46 Gy包绕小肠?直肠?膀胱及骨髓的体积显著<4野计划(P < 0.05)?调强组的1?2级恶心呕吐(P = 0.002)?腹泻(P = 0.048)?白细胞下降(P = 0.02)?血红蛋白下降(P = 0.005)明显少于4野常规组?结论:调强计划较常规计划对保护危及器官具有明显剂量学优势,可以明显减少急性放射损伤?