宫颈癌三维适形近距离治疗膀胱体积变化对正常组织受量影响

Effect of bladder volume change on normal tissue doses in 3D conformal brachytherapy for cervical cancerEffect of bladder volume change on normal tissue doses in 3D conformal brachytherapy for cervical cancer

目的 比较宫颈癌患者三维适形近距离治疗中膀胱体积改变对正常组织受量影响.方法 2012-2013年本院行宫颈癌根治性外照射＋三维适形近距离治疗患者56例.行三维适形近距离治疗中分别将膀胱排空和充盈50、100、150 ml,比较不同膀胱充盈状态下直肠、小肠、乙状结肠及膀胱D0.1cm3、D1.0cm3、D2.0cm3并行配对t检验.结果 直肠D0.1cm3在膀胱充盈50、100 ml后较排空状态明显减少（P =0.000、0.000）;小肠D0.1cm3和D1.0cm3及D2.cm3在膀胱充盈50、100、150 ml较排空状态明显减少（P=0.008、0.000、0.000和0.000、0.000、0.000及0.000、0.000、0.000）;膀胱D0.1cm3和D1.0cm3及D2.0cm3充盈100、150 ml后较排空状态明显增加（P=0.000、0.000和0.000、0.000及0.000、0.000）.结论 膀胱充盈状态改变了膀胱、小肠受量,对直肠、乙状结肠剂量影响较小;膀胱体积增加有利于降低小肠受量.在不改变膀胱受量前提下膀胱充盈50 nd较充盈100、150 ml更利于降低小肠受量.

Objective To evaluate the effect of bladder volume change on the doses to normal tissues in cervical cancer patients undergoing external three-dimensional conformal radiotherapy （3DRT）plus 3D conformal brachytherapy （3DCBT）.Methods The study included 56 patients with cervical cancer who were admitted to our hospital from 2012 to 2013 and received radical external 3DRT and 3DCBT.During 3DCBT,the doses to 0.1,1.0,and 2.0 cm3（D0.1 cm3,D1.0cm3,and D2.0cm3,respectively） for the rectum,small intestine,sigmoid colon,and bladder under different bladder filling status （empty,50,100,and 150 ml） were compared and analyzed by paired t-test.Results The rectum D0.1cm3 with bladder volumes of 50and 100 ml were significantly reduced compared with that with an empty bladder （P =0.000,0.000）.The D0.1 cm3,D1.0cm3,and D2.0cm3 for the small intestine with bladder volumes of 50,100,and 150 ml were significantly reduced compared with those with an empty bladder （P =0.008,0.000,0.000 and 0.000,0.000,0.000 or 0.000,0.000,0.000）.The D0.1 cm3,D1.0cm3,and D2.0cm3 for the bladder with bladder volumes of 100 and 150 ml were significantly increased compared with those with an empty bladder （P =0.000,0.000 and 0.000,0.000 or 0.000,0.000）.Conclusions The doses to the bladder and small intestine are influenced by different bladder filling status,but the doses to the rectum and sigmoid colon show no significant variation.The increase in bladder volume is helpful in reducing the dose to the small intestine.Without any change in the bladder dose,the bladder volume of 50 ml is more beneficial to reduce the dose to the small intestine than those of 100 and 150 ml.