腹膜后淋巴结转移的宫颈癌PET-CT与CT定位放疗计划比较研究

目的 评估对腹膜后淋巴结转移的Ⅱ_B—Ⅳ_A期宫颈癌患者采用PET-CT体外放疗定位、制定计划的可行性。方法 疗前采用PET-CT诊断分期同时定位,利用PET-CT融合图像制定针对转移淋巴结区加量的3DRT计划,并与同期CT计划进行比较,配对t检验或非参数检验差异。结果PET-CT计划与CT计划比较:GTV_nd、PGTV_nd、CTV、PTV均增加(P=0.012、0.010、0.018、0.018);小肠V₄₀、V₅₀、D_{1 cm³} 相近(P=0.744、0.588、0.423),V₂₀、V₃₀、D_mean均降低(68.1%:74.5%,P=0.020;36.1%:39.6%,P=0.016;2546.1 Gy:2761.4 Gy,P=0.036);肾脏V₂₀增高(9.4%∶5.7%,P=0.006),D_mean也增加(877.0 cGy∶733.8 cGy,P=0.005),V₃₀、V₄₀相近(P=0.089、0.341)。直肠、膀胱、结肠、骨盆骨、骨髓、股骨头D_mean均未增加(P=0.406、0.107、0.178、0.397、0.285、0.743)。结论 利用PET-CT融合图像制定体外3DRT计划,可精确定位转移淋巴结并提高放疗剂量,具有可行性;但应特别注意对小肠和肾脏保护。

A comparative study of positron emission tomography-computed tomography and computed tomography image-guided radiotherapy for cervical cancer with retroperitoneal node metastasis

Objective To evaluate the feasibility of using positron emission tomography-computed tomography (PET-CT) to guide lesion localization and radiotherapy planning for stage ⅡB-ⅣA cervical cancer with retroperitoneal node metastasis.Methods Before treatment,PET-CT was used for staging and lesion localization.Three-dimensional radiotherapy (3DRT) plans with boost doses for metastatic lymph nodes were made based on the fused PET-CT images.The obtained plans were compared with CT image-guided plans within the same period.Comparison was made by paired t test or non-parametric test.Results The PET-CT plans had significantly larger GTVnd,pGTV nd,CTV,and PTV than the CT plans (P =0.012,0.010,0.018,0.018).There were no significant differences in V40,V50,or D1 cm3 for the small intestine between the two plans (P=0.744,0.588,0.423).The PET-CT plans had significantly lower V20,V30,and Dmean for the small intestine than the CT plans (68.1％ vs.74.5％,P=0.020;36.1％ vs.39.6％,P=0.016;2 546.1 vs.2 761.4 Gy,P=0.036).Moreover,the PET-CT plans had significantly larger V20 and Dmean for the kidney than the CT plans (9.4％ vs.5.7％,P=0.006;877.0 vs.733.8 Gy,P=0.005).There were no significant differences in V30 and V40 for the kidney or Dmean for the rectum,bladder,colon,pelvic bone,bone marrow,and femoral head between the two plans (P=0.089,0.341,0.406,0.107,0.178,0.397,0.285,0.743).Conclusions It is feasible to use fused PET-CT images to guide external 3DRT plans,which can accurately localize the metastatic lymph nodes and elevate the radiation dose.However,the protection of the small intestine and kidney should be taken into account.