Introduction: MRI-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive procedure that is increasingly used to treat deep-seated brain tumors. Combining MRgLITT and diffusion tensor imaging (DTI) for real-time operative planning can enhance maximal, safe ablation.
Methods: We performed a retrospective analysis of prospectively collected patient data at the University of Texas MD Anderson Cancer Center. DTI was fused with LITT navigational images and used with T1 subtraction scans for intraoperative thermography data.
Results: 18 patients (n = 13 high-grade glioma, n = 5 metastasis,) with brain tumors in close proximity to white matter tracts (WMTs) were included in our study. Mean patient age was 55 years, median length of follow-up was 3.65 months, and median hospital stay was 2 days. Median tumor volume was 4.67 cm3, median pre-procedure Karnofsky Performance Scale (KPS) score was 90 and median post-procedure KPS score was 85. Patient age and tumor volume were not found to significantly affect change in KPS. Median distance between tumor and WMTs was 1.85 mm, while the median distance from ablation cavity to WMTs was 1.2 mm. Median untreated tumor volume was 0.10 cm3 and complete ablation was performed in 7 patients (39%). Median temperature was 41.3 C (range 6.6 – 54.9). 4 patients (22%) experienced worsened or new-onset post-operative hemiparesis that persisted on last follow-up. 5 patients (28%) experienced recurrence. There were 2 deaths (11%). In 7 patients (39%) the ablation cavity partially overlapped WMTs. In this subgroup, the median temperature was 46 C (range 41.3 – 54.9) and 2 of the 7 patients experienced complications (hemiparesis) still observed on last follow-up. Temperature was not found to be a predictor of complications in this subgroup.
Conclusions: DTI tractography and real-time temperature maps during MRgLITT for brain tumors proximal to WMTs enhance complication avoidance.
Patient Care: Our study provides preliminary evidence for a novel method of using MRgLITT in tandem with DTI to treat brain tumors adjacent to white matter tracts. This can aid the surgeon in planning the safest treatment option that maximizes tumor removal for this patient population.
Learning Objectives: 1. Describe the importance of LITT with DTI in brain tumor treatment.
2. Discuss when to use this treatment modality as an alternative to surgical resection.
3. Identify the importance of considering alternatives such as LITT or LITT with DTI in comparison to surgical resection for brain tumors located in regions adjacent to white matter tracts or deep-seated locations.