CT图像重建视野大小对放射治疗计划剂量计算及体积评估的影响
CT도상중건시야대소대방사치료계화제량계산급체적평고적영향
Volumetric and dosimetric variations in radiation treatment planning using CT images based on different reconstructed field-of-view
  • 万方数据
    中华放射医学与防护杂志 중화방사의학여방호잡지
    Chinese Journal of Radiological Medicine and Protection
    2010年 3期 303-306 ,共4页

    陆中杰%严森祥%卜路懿%周进淇

    륙중걸%엄삼상%복로의%주진기

    CT%鼻咽癌%视野%剂量%放射治疗 CT%鼻嚥癌%視野%劑量%放射治療
    CT%비인암%시야%제량%방사치료
    Computed tomography%Nasopharyngeal carcinoma%Field-of-view%Dose%Radiation therapy
    目的 探讨CT图像重建视野(FOV)大小对放射治疗计划剂量计算及体积评估可能存在的影响.方法 对16例鼻咽癌患者的CT原始扫描数据分别行45 cm常规FOV和65 cm扩展视野(EFOV)重建并传输至放射治疗计划系统,所有病例均在常规FOV重建的CT图像上勾画肿瘤体积(GTV)、临床靶区(CTV)及脑干、晶体、腮腺、脊髓等危及器官,并制定7野等角动态调强放射治疗计划(GTV处方剂量70 Gy).两种重建方法图像按照医学数字影像通信3.0标准(DICOM 3.0)坐标方式融合后,拷贝常规FOV图像上的靶区及危及器官至EFOV图像,并将治疗计划移植至EFOV图像,治疗计划中心为两种重建方法图像的同一DICOM坐标,利用剂量体积直方图(DVH)工具计算两种重建方法图像上GTV、CTV和脑干、晶体、腮腺、脊髓的体积、最大剂量(Dmax)、平均剂量(Dmean)及最小剂量(Dmin).将入组病例的每个治疗计划7野分别导入常规45 cm FOV和65 cmEFOV重建的二维通量图验证设备Mapchek 1175的模体,距离通过协议(DTA)分析5 cm深度平面绝对剂量的计算和实测结果通过率.结果 两种重建方法图像上的靶区和危及器官的体积差异具有统计学意义,所有入组病例靶区和危及器官在常规FOV图像上的体积均大于EFOV图像上的体积.较小体积的晶体最大剂量Dmax常规FOV与EFOV图像之间差异有统计学意义(t=-3.14,P<0.007),其余靶区及危及器官的最大剂量Dmax差异无统计学意义.CTV和GTV平均剂量Dmean在EFOV图像上大于FOV图像,差异有统计学意义(t=-6.45、-5.65,P<0.001),危及器官的平均剂量Dmean和靶区及危及器官最小剂量Dmin差异均无统计学意义.两种重建方法图像上治疗计划的7野通过率之间差异无统计学意义.结论 在放射治疗CT模拟定位过程中图像重建FOV的大小对于靶区及部分危及器官的体积及剂量计算结果和治疗计划的评价存在影响;观察和验证二维通 量图通过率,两者之间的差异并不显著.
    목적 탐토CT도상중건시야(FOV)대소대방사치료계화제량계산급체적평고가능존재적영향.방법 대16례비인암환자적CT원시소묘수거분별행45 cm상규FOV화65 cm확전시야(EFOV)중건병전수지방사치료계화계통,소유병례균재상규FOV중건적CT도상상구화종류체적(GTV)、림상파구(CTV)급뇌간、정체、시선、척수등위급기관,병제정7야등각동태조강방사치료계화(GTV처방제량70 Gy).량충중건방법도상안조의학수자영상통신3.0표준(DICOM 3.0)좌표방식융합후,고패상규FOV도상상적파구급위급기관지EFOV도상,병장치료계화이식지EFOV도상,치료계화중심위량충중건방법도상적동일DICOM좌표,이용제량체적직방도(DVH)공구계산량충중건방법도상상GTV、CTV화뇌간、정체、시선、척수적체적、최대제량(Dmax)、평균제량(Dmean)급최소제량(Dmin).장입조병례적매개치료계화7야분별도입상규45 cm FOV화65 cmEFOV중건적이유통량도험증설비Mapchek 1175적모체,거리통과협의(DTA)분석5 cm심도평면절대제량적계산화실측결과통과솔.결과 량충중건방법도상상적파구화위급기관적체적차이구유통계학의의,소유입조병례파구화위급기관재상규FOV도상상적체적균대우EFOV도상상적체적.교소체적적정체최대제량Dmax상규FOV여EFOV도상지간차이유통계학의의(t=-3.14,P<0.007),기여파구급위급기관적최대제량Dmax차이무통계학의의.CTV화GTV평균제량Dmean재EFOV도상상대우FOV도상,차이유통계학의의(t=-6.45、-5.65,P<0.001),위급기관적평균제량Dmean화파구급위급기관최소제량Dmin차이균무통계학의의.량충중건방법도상상치료계화적7야통과솔지간차이무통계학의의.결론 재방사치료CT모의정위과정중도상중건FOV적대소대우파구급부분위급기관적체적급제량계산결과화치료계화적평개존재영향;관찰화험증이유통 량도통과솔,량자지간적차이병불현저.
    Objective To analyze the volumetric and dosimetric variations in radiation treatment planning(RTP) using CT images based on normal and extended reconstructed field-of-view(FOV). Methods Original data of CT scans from 16 cases of nasopharyngeal carcinomas were reconstructed to form 2 sets of CT images with Dermal(45 cm)and EFOV(65 cm),which were then exposed to RTP. Contouring of targets/OAR including GTV(gross tumor volume),CTV(clinical target volume,CTV),brain stem, lens, parotids and cord was made on normsl FOV CT set.A 7-field equi-angular IMRT (intensity modulated radiation Therapy)plan was generated with prescribed GTV dose of 70 Gy.Two sets 0f CT images were fused in DICOM coordinate system and targets/OARs on normal FOV CT were copied to EFOV CT.IMRT plans were then transplanted from normal FOV to EFOV CT,with the same isocenter on DICOM coordinates.Volumetric and dosimetrie variations including GTV,CTV brain stem,lens, parotids and cord were calculated on dose-volume-histogram(DVH).For dosimetric verification,IMRT plans were input into fluence maps of Mapcheck 1175 phantom based on normal FOV and EFOV, and DTA(distance to agreement)was used to analyze the passing rate of calculated/measured absolute doses at 5 cm depth.Paired-t test was used to compare the passing rate of field 1-7 of IMRT plans based on 2 CT sets.Results Volumes of targets and OARs on 2 CT sets of different FOVs were statistically different.with larger calculated volume on norlual FOV in all cases.There was no statistic difference in the maximal(Dmax) doses received by all targets and OARs except the small-volume lens, in which the dose was higher on normal CT than that on EFOV CT(t=-3.14,P<0.007).The mean doses(Dmean)to the CTV(clinical target volume)and GTV(gross tumor volume)were higher on EFOV than normal FOV CT(t=-6.45,-5.65,P<0.001).There was no statistic difference in Dmean received by OARs and the minimal dose (Dmin)by all targets and OARs(P>0.05).There was also no statistic difference in the passing rate of field 1-7 of IMRT plans based on 2 CT sets.Conclusions There were volumetric and dosimetric variations as evaluated on DVH using different reconstructed FOV during CT simulation,though the difference between the passing rates as verified in 2 dimensional fluence map was not significant.
    원문보기 원문다운로드 사이트로이동
저자의 최근 논문