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Identifying MRI markers associated with early response following laser ablation for neurological disorders: preliminary findings.

Tiwari P, Danish S, Madabhushi A - PLoS ONE (2014)

Bottom Line: Although highly promising, the long-term effects of laser ablation as a viable treatment option for neurological disorders have yet to be rigorously studied and quantified.In this work, we present a quantitative framework for monitoring per-voxel thermal-induced changes post-LITT over time on multi parametric MRI.On a cohort of six GBM studies we found that (a) it may be important for the initial treatment-related changes to subside to more reliably capture MRI markers relating to tumor recurrence, and (b) T1w MRI and T2-GRE may better differentiate changes that may correspond to tumor recurrence from patients with no recurrence, as compared to T2w-MRI, and FLAIR.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States of America.

ABSTRACT
There is a renewed interest in MR-guided laser interstitial thermal therapy (LITT) as a minimally invasive alternative to craniotomy for local treatment of various brain tumors and epilepsy. LITT allows for focused delivery of laser energy monitored in real time by MRI, for precise ablation of the lesion. Although highly promising, the long-term effects of laser ablation as a viable treatment option for neurological disorders have yet to be rigorously studied and quantified. In this work, we present a quantitative framework for monitoring per-voxel thermal-induced changes post-LITT over time on multi parametric MRI. We demonstrate that voxel-by-voxel quantification of MRI markers over time can enable a careful and accurate (a) characterization of early LITT-related changes (if and when they are exaggerated and when they subside), and (b) identification and monitoring of MRI markers that potentially allow for better quantification of response to LITT therapy. The framework was evaluated on two distinct cohorts of patients (GBM, epilepsy), who were monitored post-LITT at regular time-intervals via multi-parametric MRI. On a cohort of six GBM studies we found that (a) it may be important for the initial treatment-related changes to subside to more reliably capture MRI markers relating to tumor recurrence, and (b) T1w MRI and T2-GRE may better differentiate changes that may correspond to tumor recurrence from patients with no recurrence, as compared to T2w-MRI, and FLAIR. Similarly, our preliminary analysis of four epilepsy studies suggests that (a) early LITT changes (attributed to swelling, edema) appear to subside within 4-weeks post-LITT, and (b) ADC may be more reflective of early treatment changes (up to 1 month), while T1w may be more reflective of early delayed treatment changes (1 month, 3 months), while T2-w and T2-FLAIR appeared to be more sensitive to late treatment related changes (6-months post-LITT) compared to the other MRI protocols under evaluation.

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Related in: MedlinePlus

Original T2-w MRI images for (a) baseline (pre-LITT), (b) 24-hour, (c) 1-month, (d) 3-month, (e) 6 month post-LITT.Figs. 6(f) , (g) , (h) , and (i)  correspond to difference maps for T2-w MRI acquired at each of , , , and  with respect to . Fig. 6(j) shows temporal profiles of every MR protocol , , reflecting the changes in imaging markers at different time-points with respect to baseline scan.
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pone-0114293-g006: Original T2-w MRI images for (a) baseline (pre-LITT), (b) 24-hour, (c) 1-month, (d) 3-month, (e) 6 month post-LITT.Figs. 6(f) , (g) , (h) , and (i) correspond to difference maps for T2-w MRI acquired at each of , , , and with respect to . Fig. 6(j) shows temporal profiles of every MR protocol , , reflecting the changes in imaging markers at different time-points with respect to baseline scan.

Mentions: Fig. 6(a) shows a pre-LITT T1w MRI image, while Figs. 6(b)–(e) show multiple time-points post-LITT for time-points at 24-hours, 2-months, 4-months, 7-months, and 11-months respectively for a GBM study identified as successful treatment. The corresponding color maps for time-point 1 to time-point 4 with respect to pre-LITT T1w MRI are shown in Figs. 6(f), (g), (h), and (g) respectively. Fig. 6 seems to suggest that (a) changes in MR parameters are enhanced at 24-hours post-LITT, and (b) intensity values decrease across time-points post-LITT after initial enhancement (at 24-hours) for successful treatment.


Identifying MRI markers associated with early response following laser ablation for neurological disorders: preliminary findings.

Tiwari P, Danish S, Madabhushi A - PLoS ONE (2014)

Original T2-w MRI images for (a) baseline (pre-LITT), (b) 24-hour, (c) 1-month, (d) 3-month, (e) 6 month post-LITT.Figs. 6(f) , (g) , (h) , and (i)  correspond to difference maps for T2-w MRI acquired at each of , , , and  with respect to . Fig. 6(j) shows temporal profiles of every MR protocol , , reflecting the changes in imaging markers at different time-points with respect to baseline scan.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263602&req=5

pone-0114293-g006: Original T2-w MRI images for (a) baseline (pre-LITT), (b) 24-hour, (c) 1-month, (d) 3-month, (e) 6 month post-LITT.Figs. 6(f) , (g) , (h) , and (i) correspond to difference maps for T2-w MRI acquired at each of , , , and with respect to . Fig. 6(j) shows temporal profiles of every MR protocol , , reflecting the changes in imaging markers at different time-points with respect to baseline scan.
Mentions: Fig. 6(a) shows a pre-LITT T1w MRI image, while Figs. 6(b)–(e) show multiple time-points post-LITT for time-points at 24-hours, 2-months, 4-months, 7-months, and 11-months respectively for a GBM study identified as successful treatment. The corresponding color maps for time-point 1 to time-point 4 with respect to pre-LITT T1w MRI are shown in Figs. 6(f), (g), (h), and (g) respectively. Fig. 6 seems to suggest that (a) changes in MR parameters are enhanced at 24-hours post-LITT, and (b) intensity values decrease across time-points post-LITT after initial enhancement (at 24-hours) for successful treatment.

Bottom Line: Although highly promising, the long-term effects of laser ablation as a viable treatment option for neurological disorders have yet to be rigorously studied and quantified.In this work, we present a quantitative framework for monitoring per-voxel thermal-induced changes post-LITT over time on multi parametric MRI.On a cohort of six GBM studies we found that (a) it may be important for the initial treatment-related changes to subside to more reliably capture MRI markers relating to tumor recurrence, and (b) T1w MRI and T2-GRE may better differentiate changes that may correspond to tumor recurrence from patients with no recurrence, as compared to T2w-MRI, and FLAIR.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States of America.

ABSTRACT
There is a renewed interest in MR-guided laser interstitial thermal therapy (LITT) as a minimally invasive alternative to craniotomy for local treatment of various brain tumors and epilepsy. LITT allows for focused delivery of laser energy monitored in real time by MRI, for precise ablation of the lesion. Although highly promising, the long-term effects of laser ablation as a viable treatment option for neurological disorders have yet to be rigorously studied and quantified. In this work, we present a quantitative framework for monitoring per-voxel thermal-induced changes post-LITT over time on multi parametric MRI. We demonstrate that voxel-by-voxel quantification of MRI markers over time can enable a careful and accurate (a) characterization of early LITT-related changes (if and when they are exaggerated and when they subside), and (b) identification and monitoring of MRI markers that potentially allow for better quantification of response to LITT therapy. The framework was evaluated on two distinct cohorts of patients (GBM, epilepsy), who were monitored post-LITT at regular time-intervals via multi-parametric MRI. On a cohort of six GBM studies we found that (a) it may be important for the initial treatment-related changes to subside to more reliably capture MRI markers relating to tumor recurrence, and (b) T1w MRI and T2-GRE may better differentiate changes that may correspond to tumor recurrence from patients with no recurrence, as compared to T2w-MRI, and FLAIR. Similarly, our preliminary analysis of four epilepsy studies suggests that (a) early LITT changes (attributed to swelling, edema) appear to subside within 4-weeks post-LITT, and (b) ADC may be more reflective of early treatment changes (up to 1 month), while T1w may be more reflective of early delayed treatment changes (1 month, 3 months), while T2-w and T2-FLAIR appeared to be more sensitive to late treatment related changes (6-months post-LITT) compared to the other MRI protocols under evaluation.

Show MeSH
Related in: MedlinePlus