基于螺旋断层治疗的儿童全骨髓全淋巴照射临床研究

Clinical study of total marrow and lymphatic irradiation in children using helical tomotherapy

目的评价基于螺旋断层治疗的全骨髓全淋巴照射（TMLI）的预处理方案的可行性。方法选取7例急性淋巴细胞白血病与再生障碍性贫血儿童患者作为研究对象，中位年龄为7岁。处方剂量方案12 Gy分6次，2次／d。比较TMLI方案与基于螺旋断层治疗的全身照射技术（TBI）的靶区和危及器官受量，并对7例患者进行急性不良反应分级。结果相比TBI方案，TMLI方案危及器官的平均剂量减少4．2％-40．6％。肾脏平均剂量减少最大。只有1-2级不良反应被观察到，其中2例恶心，5例呕吐，1例厌食，1例红斑，3例腹泻，1例口腔黏膜炎。结论证实TMLI方案可行。与TBI方案相比，相同剂量TMLI方案的平均治疗时间并没有增加。TMLI方案的危及器官剂量减小。预测发病率减少，为清髓性预处理方案提供了一种策略。但TMLI方案的远期不良反应需要进一步临床评估。

Objective To evaluate the feasibility of total marrow and lymphatic irradiation （TMLI） with helical tomotherapy as a conditioning regimen before hematopoietic stem cell transplantation （HSCT）. Methods Seven children with acute lymphoblastic leukemia and aplastic anemia were recruited as study subjects. The median age was 7 years old. The prescribed dose was 12 Gy/6 fractions twice daily. The exposure dose of the target and the organs at risk between helical helical tomotherapy-based TMLI regimen and total body irradiation （TBI） regimen were statistically compared, and acute toxicity grading was performed for all patients. Results Compared with the TBI regimen, the average exposure dose reduction for organs at risk after the TMLI regimen was ranged from 4. 2% to 40. 6%.The average exposure dose reduction for the kidney was the largest among all organs. The acute toxicities experienced by all patients were graded and recorded including 2 cases of nausea,5 cases of vomiting, 1 case of anorexia, 1 case of eryhema,3 cases of diarrhea,and 1 case of oral mucositis. Only grade 1-2 toxicities were observed,and no grade 3-4 toxicities occurred. Conclusions The findings in this study confirm the feasibility of helical helical tomotherapy-based TMLI regimen. Compared with the TBI regimen, the mean duration of treatment for the TMLI regimen with an equivalent dose is not increased. The exposure dose experienced by organs at risk is reduced and the predicted incidence rate is decreased when the TMLI regimen is employed, which provides a myeloablative pretreatment strategy. However, the long-term toxicity of TMLI regime remains to be evaluated by clinical trials.