Di DengFollow

Date of Award

January 2019

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Veronica Chiang


This thesis describes a three-part study on the use of Laser Thermal Ablation (LTA) for brain metastases demonstrating radiological progression after failed stereotactic radiosurgery: (1) A retrospective review of 30 patients across 4 centers, (2) a clinical trial with 42 patients across 6 centers, and (3) a single institution retrospective review of 75 lesions comparing LTA to craniotomy for these patients.

LTA was demonstrated in all three studies to be an effective treatment of brain metastases radiographically re-growing after radiosurgery resulting in reduction of volume of both the enhancing lesion as well as the surrounding edema with low complication rates. Half of patients reported symptomatic improvement with 30-73% of patients achieving steroid cessation and the remaining achieving stabilization of functional status with preservation of neurocognition and quality of life. Divided by lesion histology, LTA resulted in significantly better local lesion control (87% versus 49% at 12 months, p < 0.001) and overall survival (93% versus 58% at 12 months, p = 0.01) in patients with radiation necrosis (as compared to patients with tumor recurrence) and in smaller lesions, allowing for more complete ablation.

No difference in clinical outcomes were observed between use of craniotomy and LTA for treatment of these patients. Given the shorter hospital length of stay, LTA can be considered an effective alternative to craniotomy for these patients. Eligible patients should be treated early and have biopsies for diagnosis. Given the lower rates of local control, tumor recurrence patients may require additional radiation or systemic therapy to supplement LTA.


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