Hedman Mattias, Rossi Elia, Dalqvist Emmy, Karlsson Kristin, Linder-Stragliotto Christina
Department of Radiation Oncology, Karolinska University Hospital, Stockholm, Sweden.
Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden.
Radiat Oncol. 2025 Sep 8;20(1):139. doi: 10.1186/s13014-025-02719-3.
Stereotactic Body Radiotherapy (SBRT) has been proven to be a safe and effective alternative to surgery in patients with metastatic primary sarcoma. However, data describing tumor response in relation to the given radiotherapy dose is lacking. Therefore, this study aims at analyzing efficacy and dose-response relationship in a retrospective cohort.
Patients with metastatic sarcoma treated with ablative SBRT and followed up at the Karolinska University Hospital between 2008 and 2021 were included. SBRT was delivered using an inhomogeneous dose distribution resulting in higher median doses within the planning target volume (PTV) than the dose prescribed. Local control (LC), progression-free survival (PFS), overall survival (OS), adverse events and dose-response relationship were assessed. Statistical analysis was performed to identify variables that correlate to outcome.
Forty-three patients with a total of 83 lesions were treated. The most frequent histology was leiomyosarcoma (44%). The most common site of metastases was the lung (84%), followed by the liver (11%). The median prescription dose was 45 Gy (range 30-56 Gy) delivered in 3 fractions (range 2-8) with a planned median CTV mean dose of 309 Gy in EQD with α/β = 3 Gy. The local control at 1-year, 2-year and 5-year from SBRT treatment was 97, 93 and 84%, respectively. For tumors with a planned mean CTV dose above EQD 278.8 Gy (corresponding to 60.3 Gy in 3 fractions) the 1, 2 and 5-year local control was 100, 100 and 93%, respectively. Tumors planned with a lower dose than EQD 278.8 Gy (α/β = 3 Gy) had a 1, 2 and 5-year local control of 90, 70 and 52%, respectively. The difference in local control between the high dose and low dose groups was statistically significant (p < 0.001). The median OS for all patients was 43 months. When respecting dose constraints, there were only limited number of mild side effects.
In this analysis a strongly significant dose-response relationship with excellent LC rates and limited side effects for patients with metastatic lesions of sarcoma were seen. These results could be related to the inhomogeneous dose distribution of SBRT treatments utilized in this study.
立体定向体部放射治疗（SBRT）已被证明是转移性原发性肉瘤患者手术的一种安全有效的替代方法。然而，缺乏关于肿瘤反应与给定放疗剂量关系的数据。因此，本研究旨在分析回顾性队列中的疗效和剂量反应关系。
纳入2008年至2021年在卡罗林斯卡大学医院接受消融性SBRT治疗并随访的转移性肉瘤患者。SBRT采用不均匀剂量分布，导致计划靶体积（PTV）内的中位剂量高于处方剂量。评估局部控制（LC）、无进展生存期（PFS）、总生存期（OS）、不良事件和剂量反应关系。进行统计分析以确定与结局相关的变量。
共治疗43例患者，共83个病灶。最常见的组织学类型是平滑肌肉瘤（44%）。最常见的转移部位是肺（84%），其次是肝（11%）。中位处方剂量为45 Gy（范围30 - 56 Gy），分3次给予（范围2 - 8次），计划CTV平均中位剂量在α/β = 3 Gy的等效剂量下为309 Gy。SBRT治疗后1年、2年和5年的局部控制率分别为97%、93%和84%。对于计划平均CTV剂量高于等效剂量278.8 Gy（相当于3次分割60.3 Gy）的肿瘤，1年、2年和5年的局部控制率分别为100%、100%和93%。计划剂量低于等效剂量278.8 Gy（α/β = 3 Gy）的肿瘤，1年、2年和5年的局部控制率分别为90%、70%和52%。高剂量组和低剂量组之间的局部控制差异具有统计学意义（p < 0.001）。所有患者的中位总生存期为43个月。当遵守剂量限制时，只有少数轻度副作用。
在本分析中，对于肉瘤转移性病变患者，观察到显著的剂量反应关系，局部控制率良好且副作用有限。这些结果可能与本研究中使用的SBRT治疗的不均匀剂量分布有关。
