Laser Interstitial Thermal Therapy for Ultra-Early, Pre-Radiotherapy Glioblastoma Recurrence

Background:

GBM is frequent and still has a poor prognosis. Standard therapy consists of complete resection of enhancing tumor (CRET) followed by RT and CT. At the institution, patients planned for RT undergo a pre-radiotherapy planning MRI. As recently published, >40% of patients exhibit contrast-enhancing tumor recurrence in the short interval between early postoperative MRI and pre-RT MRI, despite CRET in the initial surgery. This ultra-early recurrence is strongly associated with shorter OS: in the cohort, median overall survival (OS) was 13.3m and 24.4m for patients with and without recurrence in pre-RT MRI, respectively. Hence, pre-radiation GBM recurrence is a frequent event with detrimental consequences for patients.

Reoperation in this setting is rarely performed as it delays adjuvant treatment, which worsen prognosis further. LITT is an established, minimally invasive treatment form for brain lesions such as glioblastoma recurrences and metastases. LITT may offer a solution to this dilemma as its minimal invasiveness enables to ablate the recurrent tumor without delaying treatment. As an additional benefit, LITT may work as a potent sensitizer to subsequent RT and CT.

A key challenge in the implementation of LITT in this setting is the tight scheduling window (maximum 1 week) between pre-radiotherapy planning MRI and start of radiotherapy. In order not to delay adjuvant treatment, LITT should optimally be performed within this time window. To be feasible, both planning and execution of LITT, including coordination of intraoperative MRI and engineering support, must occur within this short timeframe. This feasibility study aims to prospectively investigate whether LITT can be integrated into the existing care pathway without postponing of adjuvant treatment. This may lay the groundwork for future clinical trials.

Objective: