Department of Radiation Oncology, University Medical Center Freiburg, Robert-Koch-Str. 6, 79106, Freiburg, Germany.
German Cancer Consortium, Partner Site Freiburg (DKTK), Freiburg, Germany.
Radiat Oncol. 2018 Feb 20;13(1):28. doi: 10.1186/s13014-018-0974-5.
Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors occurring in various anatomic regions. Although diagnostic criteria and treatment management are not established, current treatment options consist of surgery and chemotherapy including mTOR inhibitors. Stereotactic body radiation therapy (SBRT) is a non-invasive ablative treatment which has shown excellent control rates for more common types of unresectable liver tumors and metastases. In this report we present a rare case of PEComa of the liver that was treated by stereotactic radiotherapy followed by resection. Staging and evaluation of treatment response was done by FDG-PET/CT. This case highlights the potential of SBRT as a neoadjuvant treatment even for rare liver malignancies. It is the first case of liver PEComa treated by SBRT and resection.
A 52-year-old woman presented at an external hospital with abdominal pressure and pain in the right upper abdominal quadrant. A CT scan showed a 700 cm liver lesion in segment IV. In repeated biopsy in July 2015 histopathological workup showed a pleomorphic epitheloid tumor with small to medium sized cells expressing vimentin and melan-A while being negative for cytokeratin establishing the diagnosis of PEComa of the liver. To achieve high, ablative doses a stereotactic body radiotherapy (SBRT) technique was chosen consisting of 60Gy (biologically effective dose 105Gy) in 8 fractions of 7.5Gy. Radiotherapy planning was based on MRI resulting in a planning target volume (PTV) of 1944 cm. Treatment toxicity was limited to a slight elevation of transaminases (grade 1 and 3). A complete resection was performed 21 weeks after radiotherapy confirmed by negative surgical margins. At last follow-up 21 months after therapy, MRI showed neither local nor distant tumor recurrence. The patient was in stable condition (ECOG 1) and without late radiation toxicity.
This is the first documented case of liver PEComa treated by SBRT and resection. A favorable post-treatment course demonstrates that SBRT is a potential neoadjuvant treatment that is capable of reducing an inoperable rare liver tumor to a resectable lesion.
血管周上皮样细胞瘤（PEComa）是一种罕见的间叶性肿瘤，可发生于多个解剖部位。尽管尚未建立诊断标准和治疗管理方法，但目前的治疗选择包括手术和化疗，包括 mTOR 抑制剂。立体定向体部放射治疗（SBRT）是一种非侵入性的消融治疗方法，已显示出对更常见的不可切除肝肿瘤和转移瘤非常优异的控制率。在本报告中，我们介绍了一例罕见的肝脏 PEComa 病例，该病例采用立体定向放疗联合手术治疗。通过 FDG-PET/CT 进行分期和评估治疗反应。该病例强调了 SBRT 作为新辅助治疗的潜力，甚至对于罕见的肝恶性肿瘤也是如此。这是首例采用 SBRT 和手术治疗的肝脏 PEComa 病例。
一名 52 岁女性因腹部不适和右上腹疼痛在外院就诊。CT 扫描显示肝 IV 段有一处 700cm 的病灶。2015 年 7 月的重复活检组织学检查显示，一种多形性上皮样肿瘤，具有小至中等大小的细胞，表达波形蛋白和黑色素-A，而细胞角蛋白阴性，确立了肝脏 PEComa 的诊断。为了实现高消融剂量，选择了立体定向体部放疗（SBRT）技术，包括 60Gy（生物有效剂量 105Gy），共 8 次，每次 7.5Gy。放射治疗计划基于 MRI，计划靶区（PTV）为 1944cm。治疗毒性仅限于转氨酶轻度升高（1 级和 3 级）。放疗 21 周后进行了完全切除术，手术切缘阴性。在治疗后 21 个月的最后一次随访中，MRI 显示既无局部也无远处肿瘤复发。患者病情稳定（ECOG 1），无晚期放射毒性。
这是首例采用 SBRT 和手术治疗的肝脏 PEComa 病例。良好的治疗后病程表明，SBRT 是一种潜在的新辅助治疗方法，能够将不可切除的罕见肝肿瘤缩小至可切除病灶。
