Treating Brain Lesion Regrowth After Radiosurgery

A new study suggests that stereotactic laser induced thermotherapy (SLITT) is a feasible alternative for the treatment of symptomatic regrowing metastatic lesions following radiosurgery.

Researchers at Yale University School of Medicine (New Haven, CT, USA) conducted a study to investigate the use of magnetic resonance imaging (MRI)-guided SLITT as a treatment option for regrowing lesions in six patients who had previously undergone gamma knife stereotactic radiosurgery for brain metastases; all patients had an initial favorable response to radiosurgery, but subsequently developed regrowth of at least one lesion associated with recurrent edema and progressive neurological symptoms. All the lesions were evaluated for craniotomy, but were deemed unresectable due to deep location or patient's comorbidities. Stereotactic biopsies were performed prior to the SLITT procedure in all cases.

SLITT was performed using the Visualase system and follow-up MRI imaging was used to determine treatment response. The biopsy results in all six patients were negative for tumor, and consistent with radiation necrosis. The patients tolerated the procedure well and were discharged from the hospital within 48 hours. In four of the cases there was durable improvement of neurological symptoms until death, one died from systemic causes related to cancer, and another had regrowth of the lesion 3 months after the procedure and required and standard craniotomy for surgical resection. There were no complications directly related to the thermocoagulation procedure. The study was published ahead of print on May 24, 2013, in the Journal of Neuro-Oncology.

“SLITT is a feasible alternative for the treatment of symptomatic regrowing metastatic lesions after radiosurgery,” concluded lead author Juan Torres-Reveron, MD, and colleagues of the department of neurosurgery. “The procedure carries minimal morbidity and, in this small series, shows some effectiveness in the symptomatic relief of edema and neurological symptoms paralleled by radiographic lesional control.”

The Visualase system is a product of Visualase (Houston, TX, USA), and consists of three components: a laser generator that produces the light energy used for thermal ablation of soft tissue; a disposable laser applicator probe with cooling catheter to deliver the energy to the desired target; and a workstation that interfaces with an MRI to allow temperature visualization, control, and monitoring of the ablation in real time, as well as modeling of the of the tissue coagulation as it is being created.


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Yale University School of Medicine
Visualase