作者：张殿波 荣荥 王旭东 徐兵 宋万江 戴志学
【摘要】 目的 分析宫颈癌中子刀(252锎)放射治疗前后的MRI表现，探讨MRI对宫颈癌中子刀(252锎)放射治疗后的诊断价值。 方法 对100例经病理证实的宫颈癌患者在中子刀(252锎)放射治疗前及放疗后不同时间段行MRI扫描。每次MRI扫描均用相同的扫描方法。在MRI图像上观察肿瘤中子刀(252锎)放射治疗前后的大小、信号改变及其周围结构的变化，进行对比分析。 结果 放疗结束时，局部控制率100%;78例肿瘤消失;22例肿瘤明显缩小，缩小率&>85%。肿瘤信号改变：放疗结束后，78例肿瘤信号消失，T2WI及STIR无异常信号改变，22例T2WI及STIR见有肿瘤信号;T1WI增强，78例无异常信号改变或轻微强化，22例不均匀强化;放疗后2年内，97例无异常信号改变;T1WI增强成像后，90例无异常信号改变，3例轻微强化。7例T2WI及STIR仍见有不均匀肿瘤信号，但较前期信号明显降低，T1WI增强，肿瘤呈不均匀强化。放疗后盆腔内脏器的表现：并发直肠炎性改变5例，肠壁增厚(6mm~-9.5mm)，T1WI呈等信号，T2WI及STIR呈高信号;膀胱炎性改变3例，膀胱壁增厚(6.2mm)，T1WI呈等信号，T2WI及STIR呈高信号;子宫颈限局性改变3例，T1WI呈低信号，T2WI及STIR呈高信号。放疗后2年内，上述改变恢复正常或轻微纤维化。 结论 MRI检查可反映中子刀(252锎)对肿瘤的疗效，是评价宫颈癌中子刀(252锎)放射治疗疗效及预后的最佳检查手段。放疗结束后，肿瘤缩小程度、T2WI上的信号改变及T1WI增强扫描瘤内有无强化区是预测中子刀(252锎)放射治疗效果的重要观测指标。
【关键词】 子宫颈癌;中子刀(252锎); 放射治疗;磁共振成像
Clinical value in evaluating of cervical cancer to neutron-knife radiation therapyZHANG Dianbo， RONG Xing， WANG Xu-dong， et al. Department of MRI， the Hospital of Heilongjiang Farm ， Harbin China[Abstract] Objective To analysis the image of MRI and discuss 0the diagnostic value of MRI in evaluating of cervical cancer to neutron-knife radiation therapy . Methods 100cases were checked by MRI before and after radiation therapy that were confirmed by pathology with cervical cancer . Same scan methods were done . We compared and discussed the changing of image in size ， signal and surrounding of tumor befor and after neutron-knife radiation therapy . Results At the end of radiation therapy ， rate of partial control was 100% . Among them ，tumors was disappear in 78 cases ，tumors got smaller obviously in 22 cases ，small rate was more than 85% . Signal changing of tumors : At the end of radiation therapy ， signal were disappear in 78 cases ， no abnormal signal changing were seen at T2WI and STIR . Tumors signal were seen in 22 cases . In T1WI enhancement ， no signal changing or slight enhancement were in 78 cases ， uneven enhancement were in 22 cases . In two years after radiation therapy ， no abnormal signal changing were in 97 cases . After T1WI enhancement ， no abnormal signal changing were in 90 cases ， slight enhancement were in 3 cases . Uneven tumors signal were seen in 7 cases at T2WI and STIR . Signals was lower than before . In T1WI enhancement ， uneven enhancement were seen in tumors . Pelvis organs image after radiation therapy : inflammation and thickness of rectal were in 5 cases ， T1WI was even signal ， T2WI and STIR was high signal ; inflammation and thickness of bladder were 3 cases . T1WI was even signal ， T2WI and STIR weres high signal . Changing of cervical were 3 cases ， T1WI was low signal ， T2WI and STIR were high signal . In 2 years after radiation therapy ， the changing was normal or slight fiber . Conclusion Image of MRI can evaluate of cervical cancer of neutron-knife radiation therapy and is good method to do so . After radiation therapy ， it is an important evaluating tool in size of tumors ， changing of signals and enhancement .
[Key words] uterus cervical cancer; neutron-nife (Californium-252); radiation therapy; magnetic resonance imaging.
对中晚期(Ⅱb以上)的子宫颈癌(uterus cervical cancer ，UCC)，放射治疗(简称放疗)是首选的治疗方法。国内外多采用192Ir或137Cs高剂量率γ射线腔内后装治疗。而中子刀(252锎)近距离治疗妇科恶性肿瘤始于20世纪60年代后期[1、2、3]，已取得了很好疗效。有关UCC放疗前后MRI的研究文献，国内已有诸多报道，表明MRI是UCC放疗后判断疗效及预后的最佳检查方法。但MRI对中子刀(252锎)腔内放射治疗UCC后诊断的研究，国内外少有报道。笔者搜集100例经病理证实UCC中子刀(252锎)放疗前后的MRI资料，系统观察UCC经中子刀(252锎)治疗后的MRI表现，结合文献及临床随访资料分析总结如下。
材料与方法
1、临床资料 选取2003年8月～2008年12月，未接受过任何治疗的100例原发性宫颈癌患者均经活检确诊，年龄21-76岁，平均Clinical value in evaluating of cervical cancer to neutron-knife radiation therapy
ZHANG Dianbo， RONG Xing， WANG Xu-dong， et al. Department of MRI， the Hospital of Heilongjiang Farm ， Harbin China
[Abstract] Objective To analysis the image of MRI and discuss 0the diagnostic value of MRI in evaluating of cervical cancer to neutron-knife radiation therapy . Methods 100cases were checked by MRI before and after radiation therapy that were confirmed by pathology with cervical cancer . Same scan methods were done . We compared and discussed the changing of image in size ， signal and surrounding of tumor befor and after neutron-knife radiation therapy . Results At the end of radiation therapy ， rate of partial control was 100% . Among them ，tumors was disappear in 78 cases ，tumors got smaller obviously in 22 cases ，small rate was more than 85% . Signal changing of tumors : At the end of radiation therapy ， signal were disappear in 78 cases ， no abnormal signal changing were seen at T2WI and STIR . Tumors signal were seen in 22 cases . In T1WI enhancement ， no signal changing or slight enhancement were in 78 cases ， uneven enhancement were in 22 cases . In two years after radiation therapy ， no abnormal signal changing were in 97 cases . After T1WI enhancement ， no abnormal signal changing were in 90 cases ， slight enhancement were in 3 cases . Uneven tumors signal were seen in 7 cases at T2WI and STIR . Signals was lower than before . In T1WI enhancement ， uneven enhancement were seen in tumors . Pelvis organs image after radiation therapy : inflammation and thickness of rectal were in 5 cases ， T1WI was even signal ， T2WI and STIR was high signal ; inflammation and thickness of bladder were 3 cases . T1WI was even signal ， T2WI and STIR weres high signal . Changing of cervical were 3 cases ， T1WI was low signal ， T2WI and STIR were high signal . In 2 years after radiation therapy ， the changing was normal or slight fiber . Conclusion Image of MRI can evaluate of cervical cancer of neutron-knife radiation therapy and is good method to do so . After radiation therapy ， it is an important evaluating tool in size of tumors ， changing of signals and enhancement .
[Key words] uterus cervical cancer; neutron-nife (Californium-252); radiation therapy; magnetic resonance imaging.
对中晚期(Ⅱb以上)的子宫颈癌(uterus cervical cancer ，UCC)，放射治疗(简称放疗)是首选的治疗方法。国内外多采用192Ir或137Cs高剂量率γ射线腔内后装治疗。而中子刀(252锎)近距离治疗妇科恶性肿瘤始于20世纪60年代后期[1、2、3]，已取得了很好疗效。有关UCC放疗前后MRI的研究文献，国内已有诸多报道，表明MRI是UCC放疗后判断疗效及预后的最佳检查方法。但MRI对中子刀(252锎)腔内放射治疗UCC后诊断的研究，国内外少有报道。笔者搜集100例经病理证实UCC中子刀(252锎)放疗前后的MRI资料，系统观察UCC经中子刀(252锎)治疗后的MRI表现，结合文献及临床随访资料分析总结如下。
材料与方法
[Abstract] Objective To analysis the image of MRI and discuss 0the diagnostic value of MRI in evaluating of cervical cancer to neutron-knife radiation therapy . Methods 100cases were checked by MRI before and after radiation therapy that were confirmed by pathology with cervical cancer . Same scan methods were done . We compared and discussed the changing of image in size ， signal and surrounding of tumor befor and after neutron-knife radiation therapy . Results At the end of radiation therapy ， rate of partial control was 100% . Among them ，tumors was disappear in 78 cases ，tumors got smaller obviously in 22 cases ，small rate was more than 85% . Signal changing of tumors : At the end of radiation therapy ， signal were disappear in 78 cases ， no abnormal signal changing were seen at T2WI and STIR . Tumors signal were seen in 22 cases . In T1WI enhancement ， no signal changing or slight enhancement were in 78 cases ， uneven enhancement were in 22 cases . In two years after radiation therapy ， no abnormal signal changing were in 97 cases . After T1WI enhancement ， no abnormal signal changing were in 90 cases ， slight enhancement were in 3 cases . Uneven tumors signal were seen in 7 cases at T2WI and STIR . Signals was lower than before . In T1WI enhancement ， uneven enhancement were seen in tumors . Pelvis organs image after radiation therapy : inflammation and thickness of rectal were in 5 cases ， T1WI was even signal ， T2WI and STIR was high signal ; inflammation and thickness of bladder were 3 cases . T1WI was even signal ， T2WI and STIR weres high signal . Changing of cervical were 3 cases ， T1WI was low signal ， T2WI and STIR were high signal . In 2 years after radiation therapy ， the changing was normal or slight fiber . Conclusion Image of MRI can evaluate of cervical cancer of neutron-knife radiation therapy and is good method to do so . After radiation therapy ， it is an important evaluating tool in size of tumors ， changing of signals and enhancement .
[Key words] uterus cervical cancer; neutron-nife (Californium-252); radiation therapy; magnetic resonance imaging.
对中晚期(Ⅱb以上)的子宫颈癌(uterus cervical cancer ，UCC)，放射治疗(简称放疗)是首选的治疗方法。国内外多采用192Ir或137Cs高剂量率γ射线腔内后装治疗。而中子刀(252锎)近距离治疗妇科恶性肿瘤始于20世纪60年代后期[1、2、3]，已取得了很好疗效。有关UCC放疗前后MRI的研究文献，国内已有诸多报道，表明MRI是UCC放疗后判断疗效及预后的最佳检查方法。但MRI对中子刀(252锎)腔内放射治疗UCC后诊断的研究，国内外少有报道。笔者搜集100例经病理证实UCC中子刀(252锎)放疗前后的MRI资料，系统观察UCC经中子刀(252锎)治疗后的MRI表现，结合文献及临床随访资料分析总结如下。
材料与方法
1、临床资料 选取2003年8月～2008年12月，未接受过任何治疗的100例原发性宫颈癌患者均经活检确诊，年龄21-76岁，平均年龄48.5岁。治疗前分期采用国际妇产科协会(intemational federation of gynecology and obstetrics ，FIGO)分类法，结合MRI检查判定[1、4]。本组ⅡB28例，ⅢA20例，ⅢB46例，ⅣA6例;89例为宫颈鳞癌，中分化52例，低分化26例，高分化12例;腺癌10例。
2、治疗方法 应用中子刀(252锎)腔内后装治疗配合8MVX或10MVX直线加速器同时行全盆腔照射治疗。首先行252锎中子腔内治疗，A点剂量8～10Gy/次，1次/W，4～5次/疗程。参考A点的剂量达36～40Gy。中子治疗的第2周，全盆腔行8MVX或10MVX直线加速器采用前后野对穿外照射，外照射总剂量为40～50Gy，平均45Gy，2Gy/次，4次/W，当剂量达到20～30Gy时，盆腔中央扫4cm厚铅块。
3、MRI检查 采用GE Signa Profil/I 0.2T 永磁型开放式磁共振成像仪。检查前适量饮水，带金属节育环者，取出节育环后进行检查。所有病例放疗前后均行以下序列和方位的盆腔扫描：①轴位SE T1WI 序列，TR440ms，TE13ms，激励次数(NEX)5;②轴位、矢状位和/或冠状位快速自旋回波(FSE)T2WI序列，TR3300～4000ms，TE132ms，回波链长度(ETL)10～11，激励次数6;③轴位频带预饱和反转恢复法脂肪抑制技术(spectral saturation inversion recovery ，STIR);④钆喷酸葡胺(0.2ml/kg 体重)静脉注射后行轴位、矢状位及冠状位化学位移成像(out of phave )扫描。所有扫描序列视野(FOV)26，层厚6mm，层间距2mm，扫描矩阵256×160。
100例患者，放疗前MRI检查1次，放疗后2年内不同时间段做2～5次不等的MRI扫描。每次MRI检查后，对肿瘤消失者，均做宫颈刮片或行组织活检。
结 果
1、宫颈癌放疗后肿瘤的MRI表现 (1)肿瘤大小形态变化：中子刀(252锎)放射治疗前肿瘤大小为7.4cm3～16.5cm3;规则形43例，不规则形57例。放疗结束时，局部控制率100%，78例肿瘤消失，12例肿瘤明显缩小(图1)，缩小率〉85%(图2，3);(2)肿瘤信号变化：放疗结束后，78例肿瘤信号消失，T2WI及STIR无异常信号改变，22例T2WI及STIR见有肿瘤信号;T1WI增强，78例无异常信号改变或轻微强化(图1)，22例不均匀强化(图2，3);放疗后2年内，97例无异常信号改变;T1WI增强成像后，90例无异常信号改变，3例轻微强化(图1、2，3)。7例T2WI及STIR仍见有不均匀肿瘤信号，但较前期信号明显降低，T1WI增强，肿瘤呈不均匀强化(图3)。
2、放疗后盆腔内脏器的MRI表现 放疗结束后，并发直肠炎性改变5例，肠壁增厚(6mm～9.5mm)，T1WI呈等信号，T2WI及STIR呈高信号(图2);膀胱炎性改变3例，膀胱壁增厚(6.2mm)，T1WI呈等信号，T2WI及STIR呈高信号(图1);子宫颈限局性改变3例，T1WI呈低信号，T2WI及STIR呈高信号。放疗后2年内，上述改变恢复正常或轻微纤维化。
讨 论
宫颈腺癌特别是恶性程度较高的腺癌，对一般的低LETγ射线(如60钴、137铯、192铱等γ射线)不甚敏感，但中子射线属于高LET射线，对高分化及低分化腺癌均较敏感，故应用中子刀(252锎)放射治疗UCC，大大提高了局部控制率及生存率，文献研究报道，平均肿块直径达52mm，3年局部控制率达97.4%，3年总生存率达81.8%;5年存活率可达70～80%[2、5、6、7、8]。本组50例2年局部控制率达100%，2年总生存率100%。
MRI具有高的组织分辨率和多方位、多序列成像方法及无损伤的独特优势，能清晰显示子宫颈、子宫(可显示子宫浆膜层、肌层及粘膜层，这是其他影像检查方法无法比拟的)及盆腔其他脏器、盆腔内间隙及盆腔的解剖层次。
有关UCC放疗前后MRI的研究文献，国内已有诸多报道[9、10、11、12、13、14]，表明MRI是UCC放疗后判断疗效及预后的最佳检查方法。但中子刀(252锎)治疗UCC后的MRI表现，国内外文献少有报道。笔者对100例UCC患者经中子刀(252锎)治疗后的MRI表现研究分析，得出以下结论：①由于中子射线独特的放射生物学特性，无论是宫颈鳞癌或腺癌，中子刀(252锎)放射治疗UCC后肿块可消失或明显缩小(缩小率达85%以上)至消失，且疗后并发症的发生率。②具有独特优势的MRI可直观地显示中子刀(252锎)放射治疗UCC后肿瘤大小和信号的变化情况。尤其是T2WI及T1WI增强扫描信号变化不仅可反应残留的肿瘤组织，亦可反映放疗[4、15]。放疗结束时肿瘤缩小程度、T2WI上的信号改变及T1WI增强扫描瘤内有无强化区是预测中子刀(252锎)放射治疗效果的重要观测指标。
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