Yang David D, Brennan Victoria S, Huynh Elizabeth, Williams Christopher L, Han Zhaohui, Ampofo Nicole, Vastola Marie E, Sangal Paavni, Singer Lisa, Mak Raymond H, Leeman Jonathan E, Cagney Daniel N, Huynh Mai Anh
Harvard Radiation Oncology Program, Boston, Massachusetts.
Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
Int J Radiat Oncol Biol Phys. 2022 Dec 1;114(5):941-949. doi: 10.1016/j.ijrobp.2022.05.016. Epub 2022 May 19.
Stereotactic body radiation therapy can be an effective treatment for oligometastases. However, safe delivery of ablative radiation is frequently limited by the proximity of mobile organs sensitive to high radiation doses. The goal of this study was to determine the feasibility, safety, and disease control outcomes of stereotactic magnetic resonance-guided adaptive radiation therapy (SMART) in patients with abdominopelvic oligometastases.
We identified 101 patients with abdominopelvic oligometastases, including 20 patients enrolled on phase 1 protocols, who were consecutively treated with SMART on a 0.35T magnetic resonance linear accelerator (MR linac) at a single institution from October 2019 to September 2021. Local control and overall survival were analyzed using the Kaplan-Meier method.
Overall, 114 tumors were treated. The most common histology was prostate adenocarcinoma (60 tumors [53.5%]), and 65 sites (57.0%) were centered in the pelvis. Ninety-one sites (79.8%) were treated to 8 Gy × 5, and 49 (43.0%) were treated with breath-hold respiratory gating. Online adaptation resulted in a clinically significant improvement in coverage or organ sparing in 86.6% of delivered fractions. The median time required for adaptation was 24 minutes, and the median time in the treatment room was 58 minutes. With median follow-up of 11.4 months, the 12-month local control was 93% and was higher for prostate adenocarcinoma versus other histologies (100% vs 84%; P = .009). The 12-month overall survival was 96% and was higher for prostate adenocarcinoma versus other histologies (100% vs 91%; P = .046). Three patients (3.0%) developed grade 3 toxic effects (colonic hemorrhage at 3.4 months and urinary tract obstructions at 10.1 and 18.4 months, respectively).
In this study, SMART was feasible, safe, and effective for delivering ablative radiation therapy to abdominopelvic metastases. Adaptive planning was necessary in the large majority of cases. The advantages of SMART warrant its further investigation as a standard option for the treatment of abdominopelvic oligometastases.
立体定向体部放射治疗对寡转移瘤可能是一种有效的治疗方法。然而，消融性放疗的安全实施常常受到对高辐射剂量敏感的活动器官的位置限制。本研究的目的是确定立体定向磁共振引导自适应放射治疗（SMART）在腹盆腔寡转移瘤患者中的可行性、安全性和疾病控制效果。
我们纳入了101例腹盆腔寡转移瘤患者，其中20例入组1期方案，于2019年10月至2021年9月在单一机构使用0.35T磁共振直线加速器（MR直线加速器）对这些患者连续进行SMART治疗。采用Kaplan-Meier法分析局部控制率和总生存率。
总共治疗了114个肿瘤。最常见的组织学类型是前列腺腺癌（60个肿瘤[53.5%]），65个部位（57.0%）位于盆腔。91个部位（79.8%）接受8Gy×5的治疗，49个部位（43.0%）采用屏气呼吸门控技术治疗。在线自适应调整使86.6%的照射野在靶区覆盖或器官保护方面有了临床上显著的改善。自适应调整所需的中位时间为24分钟，在治疗室的中位时间为58分钟。中位随访11.4个月，12个月的局部控制率为93%，前列腺腺癌的局部控制率高于其他组织学类型（100%对84%；P = 0.009）。12个月的总生存率为96%，前列腺腺癌的总生存率高于其他组织学类型（100%对91%；P = 0.046）。3例患者（3.0%）出现3级毒性反应（分别在3.4个月时发生结肠出血，在10.1个月和18.4个月时发生尿路梗阻）。
在本研究中，SMART对于腹盆腔转移瘤进行消融性放射治疗是可行、安全且有效的。在大多数情况下，自适应计划是必要的。SMART的优势使其有必要作为腹盆腔寡转移瘤治疗标准选择进行进一步研究。
