PURPOSE Meningiomas have an excellent survival prognosis, and radiotherapy (RT) is a central component of interdisciplinary treatment. During treatment planning, the definition of the target volume remains challenging using MR and CT imaging alone. This is the first study to analyze the impact of additional PET-imaging on local control (LC) and overall survival (OS) after high-precision RT. METHODS We analyzed 339 meningiomas treated between 2000 and 2018. For analyses, we divided the patients in low-grade (n = 276) and high-grade (n = 63) cases. We performed RT in an adjuvant setting due to subtotal resection or later due to recurrent tumor growth. The target volumes were delineated based on diagnostic CT and MRI and, if available, additional PET-imaging (low-grade: n = 164, 59.4%; high-grade: n = 39, 61.9%) with either 68Ga-Dotanoc/Dotatoc, 18F-fluoroethyltyrosine or 11C-methionine tracer. Patients were treated with fractionated stereotactic RT with a median total dose and dose per fraction of 54 Gy and 1.8 Gy, respectively. RESULTS Median follow-up was 5.6 years. For low-grade meningiomas, mean OS was 15.6 years and mean LC was 16.9 years; for high-grade cases mean OS was 11.6 years, and mean LC was 11.1 years. In univariate analyses, PET-imaging had a significant impact on OS (p = 0.035) and LC (p = 0.041) for low-grade meningiomas and remained significant (p = 0.015) for LC in the multivariate analysis. For high-grade cases, PET did not influence both OS and LC. Further prognostic factors could be identified. CONCLUSIONS For low-grade meningiomas, we showed that the addition of PET-imaging for target volume definition led to a significantly enhanced LC. Thus, PET improves the detection of tumor cells and helps distinguish between healthy tissue and meningioma tissue, especially during the treatment planning process.

中文翻译：

---

将PET成像整合到低度脑膜瘤的放射治疗计划中可改善结局。

目的脑膜瘤具有良好的生存预后，放疗（RT）是跨学科治疗的重要组成部分。在治疗计划期间，仅使用MR和CT成像很难确定目标体积。这是第一项分析额外的PET成像对高精度RT后局部控制（LC）和总生存期（OS）的影响的研究。方法我们分析了2000年至2018年治疗的339例脑膜瘤。为进行分析，我们将患者分为低度（n = 276）和高度（n = 63）病例。由于次全切除术或后来由于复发性肿瘤生长，我们在辅助治疗中进行了放疗。根据诊断性CT和MRI以及（如果有的话）使用68Ga-Dotanoc / Dotatoc进行的额外PET成像（低度：n = 164，59.4％;高度：n = 39，61.9％）来确定目标体积，18F-氟乙基酪氨酸或11C-蛋氨酸示踪剂。患者接受分级立体定向RT治疗，中位总剂量和每分剂量分别为54 Gy和1.8 Gy。结果中位随访时间为5.6年。对于低度脑膜瘤，平均OS为15.6年，平均LC为16.9年。对于高级病例，平均OS为11.6年，平均LC为11.1年。在单变量分析中，对于低度脑膜瘤，PET成像对OS（p = 0.035）和LC（p = 0.041）有显着影响，而在多变量分析中，对于LC仍然显着（p = 0.015）。对于高级情况，PET不会同时影响OS和LC。可以确定进一步的预后因素。结论对于低度脑膜瘤，我们表明为靶体积定义增加PET成像可显着增强LC。因此，