Glioblastoma Treated With Magnetic Resonance Imaging-Guided Laser Interstitial Thermal Therapy: Safety, Efficacy, and Outcomes

Abstract

Background: Despite the multitude of available treatments, glioblastoma (GBM) remains an aggressive and uniformly fatal tumor. Laser interstitial thermal therapy (LITT) is a novel, minimally invasive treatment that holds promise for treating patients with GBM who are not candidates for traditional open craniotomy. However, due to the recent introduction of LITT into clinical practice, large series that evaluate safety and long-term outcomes after LITT are lacking.

Objective: To present our institution's series of over 50 GBM patients treated with LITT, with regard to safety, efficacy, and outcomes.

Methods: We performed a retrospective descriptive study of patients with histologically proven GBM who underwent LITT. Data collected included demographics, tumor location and volume, tumor genetic markers, treatment volume, perioperative complications, and long-term follow-up data.

Results: We performed 58 LITT treatments for GBM in 54 patients over 5.5 yr. Forty-one were recurrent tumors while 17 were frontline treatments. Forty GBMs were lobar in location, while 18 were in deep structures (thalamus, insula, corpus callosum). Average tumor volume was 12.5 ± 13.4 cm3. Average percentage of tumor treated with the yellow thermal damage threshold (TDT) line (dose equivalent of 43°C for 2 min) was 93.3% ± 10.6%, and with the blue TDT line (dose equivalent of 43°C for 10 min) was 88.0% ± 14.2%. There were 7 perioperative complications (12%) and 2 mortalities (3.4%). Median overall survival after LITT for the total cohort was 11.5 mo, and median progression-free survival 6.6 mo.

Conclusion: LITT appears to be a safe and effective treatment for GBM in properly selected patients.

Keywords: Brain tumors; GBM; Glioblastoma; LITT; Laser ablation; Laser interstitial thermal therapy; MRI; Thermoablation.

Graphical Abstract

FIGURE 1.

TDT lines. Image during laser ablation, demonstrating tumor volume (constructed manually on Monteris® [Plymouth, Minnesota] proprietary software at the time of surgery) and yellow and blue thermal damage threshold (TDT) lines (derived from real-time MRI thermometry).

FIGURE 2.

Lesion locations. Pre- and postoperative imaging demonstrating successful radiographic response for tumors in A, left posterior thalamic and B, left frontal locations. Magnetic resonance-safe metal artifact is noted on the patient's right side in B.

FIGURE 3.

A, Overall and B, PFS in primarily treated vs recurrent GBM after LITT. OS for primarily treated vs recurrent GBM was 9.1 and 11.8 mo, respectively; PFS was 3.6 and 7.3 mo, respectively. There were no statistically significant differences.

FIGURE 4.

OS in primarily treated vs recurrent GBM from time of histologic diagnosis. OS for the primarily treated group was 9.1 mo, and for the recurrent group, 22.3 mo (P < 0.0001).

FIGURE 5.

A and B, Overall and PFS by MGMT promoter status, and C and D, EGFR amplification status. OS for the MGMT-methylated vs MGMT-unmethylated group was 11.6 and 11.1 mo, respectively; PFS was 6 and 6.3 mo, respectively. There were no statistically significant differences. OS for the EGFR amplified vs EGFR nonamplified group was 11.4 and 8.6 mo, respectively; PFS was 6.7 and 4.4 mo, respectively. There were no statistically significant differences.