Introduction: Laser induced thermal therapy (LITT) is a novel, minimally invasive method of treating intracranial neoplasms. Minimal data exists on which imaging methods are ideal for post-ablation imaging. The purpose of this project is to determine which MRI protocol gives the most concordance in volume assessment after MRI-guided LITT for intracranial neoplasms.
Methods: 20 patients who received LITT at our institution were included in our study. 3 reviewers were trained for volumetric analysis. Tumors were independently demarcated by each reviewer on post-procedural axial SPGR, axial FLAIR, axial DWI, and axial GRE sequences. The volume rating data was then analyzed using Pearson Correlation Analysis between rater pairs to determine which protocol had the most concordance amongst the three raters. The closer the correlation is to 1, the more concordant the MRI protocol was amongst the three raters.
Results: Post-contrast SPGR sequences were shown to be the most concordant in our study, with an average correlation between raters of .946. DWI (correlation = .88) was the next-most concordant imaging sequence, followed by GRE (correlation = .75). Demarcation of lesions on the FLAIR sequence (correlation = .71) was least concordant in our study.
Conclusions: This study described for the first time the relationship between MRI protocols and imaging of patients post-LITT. Our data shows that the SPGR-post contrast protocol tends to provide the most inter-observer concordance when evaluating tumor appearance and volumetrics post-LITT, with DWI following closely behind. In summary, our data suggests that post-contrast SPGR imaging allows for the most concordant measurement of post-LITT follow up of tumor planes when patients require follow-up imaging.
Patient Care: This research is one of the first steps to improving post-operational care for LITT patients. It does so by helping to determine which imaging modality has the most utility for examining volumetric changes after the procedure has been performed.
Learning Objectives: By the conclusion of this session, participants should be able to: 1)Describe the laser induced thermal therapy procedure 2)Understand the volumetric analysis procedure employed in this project 3) Discuss why the SPGR protocol was determined to be the most effective