Ponce Sara Beltrán, Chhabra Saurabh, Hari Parameswaran, Firat Selim
Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin.
Division of Hematology/Oncology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin.
Adv Radiat Oncol. 2022 Apr 10;7(5):100964. doi: 10.1016/j.adro.2022.100964. eCollection 2022 Sep-Oct.
Allogeneic hematopoietic cell transplantation (HCT) serves as the only curative treatment option for patients with myelofibrosis and other myeloproliferative neoplasms. Splenomegaly commonly manifests in patients with myeloproliferative neoplasms and can lead to delayed or poor engraftment, increased transfusion burden, and worse survival. Methods to decrease the effect of splenomegaly include splenectomy and splenic irradiation. We sought to report on clinical outcomes for patients treated with splenic irradiation as part of their transplant conditioning.
Patients with splenomegaly measuring greater than 22 cm were referred for splenic irradiation. They received radiation to the entire spleen to 10 Gy in 5 fractions using 3-dimensional conformal radiation with anteroposterior/posteroanterior or opposed tangent fields. Blood counts were monitored closely on treatment. Changes in splenic size were measured using first and last treatment image guided radiation therapy and pre- and posttransplant diagnostic imaging.
Seventeen patients completed pretransplant splenic irradiation between 2012 and 2021. Median platelet, white blood cell, and hemoglobin levels decreased on treatment. One patient required platelet transfusion and 3 required packed red blood cell transfusions. Mean decrease in spleen size during radiation was -8.5% in the craniocaudal dimension. Prolonged decreases, measured 2 to 12 months after transplant, averaged 14.64%. All patients engrafted. Fourteen (82.4%) were alive at time of analysis with median follow-up of 4.2 years from hematopoietic cell transplantation.
Splenic irradiation offers a safe method of managing significant splenomegaly as part of transplant conditioning. Transplant outcomes in this series were excellent. Prospective data may be beneficial to determine the absolute benefit of this addition to pretransplant conditioning in this patient population.
异基因造血细胞移植（HCT）是骨髓纤维化和其他骨髓增殖性肿瘤患者唯一的治愈性治疗选择。脾肿大在骨髓增殖性肿瘤患者中常见，可导致移植延迟或不佳、输血负担增加及生存率降低。减轻脾肿大影响的方法包括脾切除术和脾脏照射。我们试图报告接受脾脏照射作为移植预处理一部分的患者的临床结局。
脾肿大超过22 cm的患者被转诊接受脾脏照射。他们使用三维适形放疗，采用前后/后前或对穿切线野，将整个脾脏分5次照射至10 Gy。治疗期间密切监测血细胞计数。使用首次和末次治疗的图像引导放射治疗以及移植前后的诊断成像测量脾脏大小的变化。
17例患者在2012年至2021年间完成了移植前脾脏照射。治疗期间血小板、白细胞和血红蛋白水平中位数下降。1例患者需要输注血小板，3例需要输注红细胞悬液。放疗期间脾脏头足径平均缩小8.5%。移植后2至12个月测量的持续缩小平均为14.64%。所有患者均实现造血植入。分析时14例（82.4%）存活，自造血细胞移植后的中位随访时间为4.2年。
脾脏照射作为移植预处理的一部分，为处理显著脾肿大提供了一种安全的方法。本系列的移植结局良好。前瞻性数据可能有助于确定在该患者群体中，将此方法添加到移植预处理中的绝对益处。
