同步加量调强放疗在转移瘤姑息治疗中的应用

目的 探讨同步加量调强放疗(SIB-IMRT)在转移瘤姑息治疗中的价值.方法 45例转移瘤患者采取SIB-IMRT,大体肿瘤靶区(GTV)处方剂量2.0～5.0 Gy/次,计划靶区(PTV)处方剂量1.8～3.0 Gy/次,共治疗10 ～28次.并制定三维适形放疗(3D-CRT)计划作为比较.放疗结束后1个月及以后每3个月进行疗效及不良反应评价.结果 除1例患者因治疗期间出现严重的肝脓肿未能完成治疗外,其余患者均顺利完成治疗.其中19例患者同步静脉或口服化疗或靶向药物治疗.不良反应及分级:38.64％ (17/44)的患者无不良反应发生,Ⅰ～Ⅱ级消化道或骨髓抑制等不良反应发生率为56.82％ (25/44),仅3例患者(6.82％)出现Ⅲ级骨髓抑制,无Ⅲ级及以上的胃肠道反应和任何Ⅳ级不良反应发生.放疗计划评估:SIB-IMRT与3D-CRT计划GTV平均受量分别为(5556.1±925.6) cGy和(4491.5±881.4)cGy,提高了23.7％,差异有统计学意义(=15.492,P=0.000).危及器官的比较:共评估了包括肺、小肠、脊髓、肾脏、肝脏等167个危及器官,其中有72个危及器官的受量SIB-IMRT较3D-CRT减小,减小0.50％～77.43％,平均19.71％;95个危及器官的受量增加,增加0.59％～86.71％,平均18.13％;总平均为增加0.86％.因此,SIB-IMRT计划可以接受.临床疗效评估:中位随访时间10个月(5 ～ 26个月),失访2例,照射野内无复发生存率为95.23％(40/42).结论 采用SIB-IMRT可显著提高肿瘤区的照射剂量,正常组织受量有增有减,增加的幅度较小,且患者耐受性良好.

Appliation of simultaneous integrated boost-intensity modulated radiotherapy for metastatic malignancies palliative care

Objective To study the effect and feasibility of simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) for metastatic malignancies palliative care patients with metastatic malignant cancer.Methods Forty-five patients with metastatic malignant cancer were treated with SIB-IMRT for 10 to 28 fractions.The gross target volume (GTV) was 2.0-5.0 Gy per fraction,and the marginal dose of the planning target volume (PTV) was 1.8-3.0 Gy per fraction.For comparing the different delivering techniques,the three dimensional-conformal radiotherapy (3D-CRT) plan for each patient was optimized.The effects and adverse effects were evaluated in the first month's follow-up and every three months thereafter.Results All patients completed the radiation therapy except for one who developed severe hepatic abscess.Nineteen patients received concurrent intravenous or oral chemotherapy or targeted drug therapies.The proportion of patients without adverse reaction was 38.64％ (17/44),and the incidence rate of grade Ⅰ-Ⅱ digestive tract or bone marrow suppression was 56.82％ (25/44).Only 3 patients (6.82％) occurred grade Ⅲ bone marrow suppression,and no grade Ⅲ gastrointestinal reaction and Ⅳ adverse reaction occurred.The mean doses of GTV were (5556.1 ±925.6) cGy for SIB-IMRT and (4491.5 ± 881.4) cGy for 3D-CRT,with 23.7％ increase (t =15.492,P =0.00).One hundred and sixty-seven organs at risk (OARs) including lungs,intestine,spine,kidneys and liver were evaluated.Seventy-two OARs had decreased irradiation dose with SIB-IMRT compared with 3D-CRT,the range of the decrease ratio was 0.50％-77.43％,with a mean value of 19.71％.Ninety-five OARs had elevated irradiation dose with SIB-IMRT compared with 3D-CRT,the range of the increase ratio was 0.59％-86.71％,with a mean value of 18.13％.The total mean value was increased 0.86％.So the SIBIMRT was acceptable.The median follow-up duration was 10 months (5-26 months).Two patients dropped out.The relapse-free rate within the radiation field was 95.23％ (40/42).Conclusion SIB-IMRT can significantly increase radiation doses of the tumor fields.The doses of OARs with SIB-IMRT are increased or some decreased,and the range of the increased dose is indistinctive,and the patients are well tolerated.