Case Study: First Reported Combination of Minimally Invasive Techniques for a Large Intracranial Tumor

By Alireza Mohammadi, MD

Presentation

The patient is a 49-year-old white woman who was diagnosed in 2004 with invasive ductal carcinoma of the right breast. Initial treatment included a right lumpectomy, radiation therapy and chemotherapy, followed by five years of tamoxifen therapy.

She fared well until April 2013, when she started noticing memory problems. After an MRI revealed multiple brain lesions, she underwent stereotactic biopsy of a left parietal brain lesion. Final pathology was consistent with metastatic carcinoma.

Treatment with whole brain radiation at an outside hospital resulted in improvement of her symptoms. She was then started on targeted therapy for her systemic progression and was subsequently treated with Gamma Knife® radiosurgery to four lesions (left parietal, right thalamic, right cerebellar and right periventricular) at Cleveland Clinic’s Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center.

The patient did well until December 2013, when she had an attack of dizziness that progressed into confusion. She was taken to the emergency room, where a CT scan showed edema. She was started on intravenous steroids, and her confusion resolved over four hours. She was treated with repeat Gamma Knife radiosurgery in March 2014 to the same left parietal lesion.

She was weaned off dexamethasone without difficulty and fared well until early May 2014, when she developed difficulty walking. An MRI showed progression of the left parietal lesion (1 × 2 inches, volume of 41 mL), so dexamethasone was restarted. She also started having problems with balance, stumbling and falling, as well as difficulty with words and numbers.

Evaluation

Despite treatment with whole brain radiation therapy and two separate courses of Gamma Knife surgery, the left parietal lesion continued to enlarge. This was consistent with radiation necrosis.

Radiation necrosis occurs in 7 percent of brain metastases treated with radiosurgery and is self-limited in about half the cases. However, 3 to 4 percent of cases require treatment due to enlarging mass effects and neurological symptoms.

The first treatment is often a steroid. However, the side effects of long-term steroid therapy in refractory cases led to consideration of other treatment options, including anti-angiogenic therapy, laser ablation and surgical resection.

Treatment: A novel combination of minimally invasive interventions

The patient was selected for a combination of two modern minimally invasive techniques: laser ablation of the tumor followed by endoscopically assisted internal debulking of the tumor.

Surgery was performed in the intraoperative MRI suite. After complete MRI-guided laser ablation of the tumor using the NeuroBlate® System, endoscopically assisted debulking of the tumor was performed using the BrainPath device through a 3-cm incision and a 2-cm craniotomy.

Outcome

After undergoing almost eight hours of surgery, the patient woke up without neurological complications. She was discharged two days after the operation, which was performed in summer 2014. She is currently doing well and is being followed routinely for her brain metastases.

Discussion: First report of this combo for a large intracranial tumor

This is the first report of the combined use of two modern, minimally invasive techniques to treat a large intracranial tumor. We have been using laser ablation for the past few years at Cleveland Clinic to treat difficult-to-access tumors and radiation necrosis, with promising results.

However, laser ablation does not resolve mass effects in very large lesions. Combining this treatment modality with endoscopically assisted debulking to decompress the mass effects of tumor resulted in the same outcome we would have achieved with a more extensive surgery involving regular craniotomy and resection of tumor.

These minimally invasive approaches are associated with less postoperative morbidity — especially in recurrent tumors and in postradiation settings, when we normally see more wound healing issues — and are tolerated better by our patients. We look forward to further exploration of their combined use in appropriately selected patients.

Dr. Mohammadi is a neurosurgeon in the Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center in Cleveland Clinic’s Neurological Institute.