Magnetic resonance imaging-guided focused laser interstitial thermal therapy for intracranial lesions: single-institution series

Abstract

Background: Surgical treatments for deep-seated intracranial lesions have been limited by morbidities associated with resection. Real-time magnetic resonance imaging-guided focused laser interstitial thermal therapy (LITT) offers a minimally invasive surgical treatment option for such lesions.

Objective: To review treatments and results of patients treated with LITT for intracranial lesions at Washington University School of Medicine.

Methods: In a review of 17 prospectively recruited LITT patients (34-78 years of age; mean, 59 years), we report demographics, treatment details, postoperative imaging characteristics, and peri- and postoperative clinical courses.

Results: Targets included 11 gliomas, 5 brain metastases, and 1 epilepsy focus. Lesions were lobar (n = 8), thalamic/basal ganglia (n = 5), insular (n = 3), and corpus callosum (n = 1). Mean target volume was 11.6 cm, and LITT produced 93% target ablation. Patients with superficial lesions had shorter intensive care unit stays. Ten patients experienced no perioperative morbidities. Morbidities included transient aphasia, hemiparesis, hyponatremia, deep venous thrombosis, and fatal meningitis. Postoperative magnetic resonance imaging showed blood products within the lesion surrounded by new thin uniform rim of contrast enhancement and diffusion restriction. In conjunction with other therapies, LITT targets often showed stable or reduced local disease. Epilepsy focus LITT produced seizure freedom at 8 months. Preliminary overall median progression-free survival and survival from LITT in tumor patients were 7.6 and 10.9 months, respectively. However, this small cohort has not been followed for a sufficient length of time, necessitating future outcomes studies.

Conclusion: Early peri- and postoperative clinical data demonstrate that LITT is a safe and viable ablative treatment option for intracranial lesions, and may be considered for select patients.

Figures

FIGURE 1

Magnetic resonance imaging (MRI)–guided Neuroblate focused laser interstitial thermal therapy. A, tripod base affixed to surface with laser probe visible. B, rendering of Neuroblate probe with laser emerging orthogonally to tip. C, trajectory strategy, treatment, and cell death areas, and thermometry measurements. The target region was defined preoperatively based on MRI (green sphere, on left and green lines). Intraoperative axial images show enhancing lesion within target region (green line), 45°C thermal dose line (yellow), and 52°C thermal dosage line (blue). Thermometry measurements (right) in degrees Celsius are plotted in space relative to the MRI within the region of thermometry monitoring (light green). A thermometry temperature color key is shown at bottom.

FIGURE 2

Magnetic resonance imaging (MRI) showing a thalamic glioblastoma treated with focused laser interstitial thermal therapy (LITT). A, preoperative T1-weighted MRI with gadolinium and T2-weighted MRI showing a 3.5 × 4.0-cm left thalamic lesion. B, intraoperative coronal T1-weighted MRI with contrast showing the probe targeting the tumor. Diffusion-weighted image (C) and T1-weighted MRI with gadolinium and T2-weighted MRI (D) were performed on postoperative day 1. T1-weighted MRI with gadolinium and T2-weighted MRI 3 (E), 7 (F), and 15 (G) months postoperatively. Arrow in B indicates LITT probe.

FIGURE 3

Magnetic resonance imaging (MRI) showing a recurrent glioblastoma treated with focused laser interstitial thermal therapy. A, preoperative T1-weighted MRI with gadolinium and T2-weighted MRI showing a 1.3 × 0.8-cm left frontal lesion. T1-weighted MRI with gadolinium and T2-weighted MRI on postoperative days 1 (B) and 5 (C) and 11 months (D) postoperatively.

FIGURE 4

Magnetic resonance imaging (MRI) showing a melanoma metastasis treated with focused laser interstitial thermal therapy (LITT). A, preoperative T1-weighted MRI with gadolinium and T2-weighted MRI showing a 2.5 × 2.1-cm right frontal lesion. B, intraoperative sagittal and axial T1-weighted MRI with contrast showing the probe targeting the tumor. T1-weighted MRI with gadolinium and T2-weighted MRI (C) were performed on postoperative day 1. T1-weighted MRI with gadolinium and T2-weighted MRI 1 (D) and 3 (E) months postoperatively. Arrow in B indicates LITT probe.

FIGURE 5

Magnetic resonance imaging (MRI) showing architectural distortion in the left subinsular region that corresponded to an abnormality on the ictal and interictal single-photon emission computed tomography (SPECT) study and was treated with focused laser interstitial thermal therapy. A, preoperative coronal fluid-attenuated inversion recovery MRI and T2-weighted MRI showing a 2.5 × 2.1-cm left subinsular lesion. B, preoperative ictal SPECT study showing increased activity in left insula and temporal lobe. T1-weighted MRI with gadolinium and T2-weighted MRI on postoperative day 1 (C) and 5 months postoperatively (D).

FIGURE 6

Local control of brain tumors after focused laser interstitial thermal therapy (LITT). Histogram shows volumetric analysis of postoperative imaging binned into 5 and 10 months after treatment relative to preoperative baseline volume.

FIGURE 7

Kaplan-Meier curves for focused laser interstitial thermal therapy (LITT) tumor patients including total cohort, gliomas, and metastases. Recurrence-free survival (A), survival after LITT (B), and survival after intracranial diagnosis (C) are displayed. Patient 2 was excluded from this analysis. The number of patients (n) at risk are below the curves at listed monthly intervals.

Figure

No available caption