La Rosa Alonso, Mittauer Kathryn E, Rzepczynski Amy E, Chuong Michael D, Bassiri-Gharb Nema, McAllister Nicole C, Hall Matthew D, Press Robert H, Gutierrez Alonso N, Tolakanahalli Ranjini, Mehta Minesh P, Kotecha Rupesh
Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, 1R203, 8900 N Kendall Drive, Miami, FL, 33176, USA.
Department of Radiation Oncology, Hospital Universitario La Paz, Madrid, Spain.
J Neurooncol. 2025 Apr 29. doi: 10.1007/s11060-025-05060-7.
Glioblastoma (GBM) management post maximal-safe resection consists of concurrent chemoradiation (CRT) and adjuvant chemotherapy. MRIs are historically performed post-operatively and/or at treatment planning. Continuous interfractional changes during CRT have not been adequately characterized. MR-guided radiation therapy (MRgRT) allows for detailed imaging of tumor volumes during the course of treatment. This is a preliminary initial report evaluating temporal and spatial changes that occur in GBM, in order to model tumor dynamics.
Five GBM patients enrolled onto an institutional biorepository registry underwent treatment with our 0.35T MRgRT workflow. Target volumes were delineated based on T2/FLAIR (GTV_46Gy) and T1 gadolinium-enhanced MR (GTV_14Gy) sequences. Weekly post-contrast MRIs were performed during CRT with the 0.35T magnet to monitor target volume dynamics.
Thirty-five MR scans were evaluated. The median time from surgery to CRT was 32 days (range: 28-40), with a median of 13 days (range: 12-14) from simulation to CRT. We found median volume reductions of 40.0% (range: 8.3-86.5%), and 37.1% (range: 15.0-67.5%) for GTV_46Gy and GTV_14Gy, respectively. The bulk of these changes occurred early, within the first 3 weeks of the 6-week treatment, with significant reductions observed between baseline and week 1 -32.6% for GTV_46Gy and 17.9% for GTV_14Gy. Separately, statistically significant volume reductions for the cavity volume (F = 59.43, p < 0.05) were observed. Compared to baseline, centroid migrations of the target volumes were also noted: the median GTV_46Gy centroid migration was 7.4 mm (range: 2.0-10.8 mm) and the median GTV_14Gy centroid migration was 3.6 mm (range: 1.3-8.8 mm).
Our pilot study suggests that weekly MRgRT imaging for GBM patients undergoing long course CRT reveals significant GTV reductions and centroid migrations, especially during the first 3 weeks of treatment. A more detailed understanding of which patients are at highest risk for tumor change and migration is needed to best apply these imaging parameters to clinical practice.
胶质母细胞瘤（GBM）在进行最大安全切除术后的治疗包括同步放化疗（CRT）和辅助化疗。传统上，MRI检查是在术后和/或治疗计划时进行。CRT期间连续的分次间变化尚未得到充分描述。磁共振引导放射治疗（MRgRT）能够在治疗过程中对肿瘤体积进行详细成像。这是一份初步的初始报告，旨在评估GBM中发生的时间和空间变化，以便建立肿瘤动力学模型。
五名登记在机构生物样本库的GBM患者接受了我们的0.35T MRgRT治疗流程。根据T2/FLAIR序列（GTV_46Gy）和T1钆增强MR序列（GTV_14Gy）勾画靶区体积。在CRT期间，使用0.35T磁体每周进行一次增强MRI检查，以监测靶区体积的动态变化。
共评估了35次MR扫描。从手术到CRT的中位时间为32天（范围：28 - 40天），从模拟到CRT的中位时间为13天（范围：12 - 14天）。我们发现GTV_46Gy和GTV_14Gy的中位体积分别减少了40.0%（范围：8.3 - 86.5%）和37.1%（范围：15.0 - 67.5%）。这些变化大多发生在早期，即在6周治疗的前3周内，基线与第1周之间观察到显著减少——GTV_46Gy减少32.6%，GTV_14Gy减少17.9%。另外，观察到空洞体积有统计学意义的减少（F = 59.43，p < 0.05）。与基线相比，还注意到靶区体积的质心迁移：GTV_46Gy的质心中位迁移为7.4毫米（范围：2.0 - 10.8毫米），GTV_14Gy的质心中位迁移为3.6毫米（范围：1.3 - 8.8毫米）。
我们的初步研究表明，对于接受长疗程CRT的GBM患者，每周进行MRgRT成像可显示出GTV的显著减少和质心迁移，尤其是在治疗的前3周。需要更详细地了解哪些患者发生肿瘤变化和迁移的风险最高，以便将这些成像参数更好地应用于临床实践。
