Matsui Jennifer K, Jackson Scott, Fang Judy, Mohler David G, Steffner Robert J, Avedian Raffi S, Charville Gregory W, Rijn Matt van de, Million Lynn, Chin Alexander L, Hiniker Susan M, Kalbasi Anusha, Moding Everett J
The Ohio State University College of Medicine, Columbus, Ohio.
Department of Radiation Oncology, Stanford University, Stanford, California.
Adv Radiat Oncol. 2025 Jan 15;10(3):101718. doi: 10.1016/j.adro.2025.101718. eCollection 2025 Mar.
Synovial sarcoma (SS) is a rare, aggressive soft tissue malignancy that is divided into biphasic and monophasic histologic subtypes. In addition to surgical resection, radiation therapy (RT) improves local control in patients at higher risk of recurrence. This study aimed to investigate the impact of histologic subtype on radiation response and survival outcomes in patients treated with RT as part of definitive management.
We retrospectively identified patients with SS treated with RT and surgical resection from 1997 to 2020 at Stanford Medical Center. We assessed the association between histologic subtypes (biphasic vs monophasic) and response to preoperative RT based on imaging and pathology. Volumetric response was calculated using the pre-RT and post-RT/preoperative postcontrast T1-weighted magnetic resonance imaging images. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Univariable and multivariable analyses were conducted using Cox regression models. Variables for univariable and multivariable analyses included age, histologic subtypes, tumor location, tumor size, margin status, chemotherapy, and performance status.
In our study, 50 patients met the inclusion criteria. The median age was 34.8 years at diagnosis, and 36% (n = 18) received concurrent chemotherapy. Biphasic (n = 18, 36%) and monophasic (n = 32, 64%) tumors exhibited significant differences in negative margin status (94% vs 66%, = .036). Of the 22 patients who underwent preoperative RT, 15 patients had pre-RT and post-RT imaging to assess volumetric changes. Biphasic tumors demonstrated less necrosis at the time of surgical resection but a significantly greater volumetric decrease with preoperative RT (42% vs 5%, = .004). PFS and OS were superior in biphasic tumors ( = .003 and = .009, respectively). Multivariable analyses identified histologic subtypes (monophasic vs biphasic) as a significant factor impacting PFS (HR, 5.65; 95% CI, 1.78-17.91; = .003).
Biphasic tumors exhibit an improved volumetric response to preoperative RT and improved outcomes. These findings underscore the importance of considering histology when tailoring treatment for patients with SS.
滑膜肉瘤（SS）是一种罕见的侵袭性软组织恶性肿瘤，分为双相型和单相型组织学亚型。除手术切除外，放射治疗（RT）可改善复发风险较高患者的局部控制。本研究旨在探讨组织学亚型对接受RT作为确定性治疗一部分的患者放射反应和生存结果的影响。
我们回顾性地确定了1997年至2020年在斯坦福医疗中心接受RT和手术切除的SS患者。我们根据影像学和病理学评估了组织学亚型（双相型与单相型）与术前RT反应之间的关联。使用放疗前和放疗后/术前增强T1加权磁共振成像图像计算体积反应。采用Kaplan-Meier方法估计无进展生存期（PFS）和总生存期（OS）。使用Cox回归模型进行单变量和多变量分析。单变量和多变量分析的变量包括年龄、组织学亚型、肿瘤位置、肿瘤大小、切缘状态、化疗和体能状态。
在我们的研究中，50例患者符合纳入标准。诊断时的中位年龄为34.8岁，36%（n = 18）接受了同步化疗。双相型（n = 18，36%）和单相型（n = 32，64%）肿瘤在阴性切缘状态方面存在显著差异（94%对66%，P = .036）。在22例接受术前RT的患者中，15例患者有放疗前和放疗后的影像学检查以评估体积变化。双相型肿瘤在手术切除时坏死较少，但术前RT后体积减少明显更大（42%对5%，P = .004）。双相型肿瘤的PFS和OS更好（分别为P = .003和P = .009）。多变量分析确定组织学亚型（单相型与双相型）是影响PFS的一个重要因素（HR，5.65；95%CI，1.78 - 17.91；P = .003）。
双相型肿瘤对术前RT表现出更好的体积反应和更好的结果。这些发现强调了在为SS患者制定治疗方案时考虑组织学的重要性。
