Stereotactic Radiation Therapy for Brain Metastases

Case 1 -Single Brain Metastases

A 55 Years old lady was diagnosed with left breast cancer in August 2015. She was treated with breast surgery, chemotherapy, radiation therapy and hormonal therapy.

She remained disease free for 3 years. In October 2018, she had an episode of seizure. Contrast MRI Brain showed 1.5×1.4 x1.6 cm enhancing lesion in left posterior frontal region of brain with mild surrounding edema suggestive of solitary brain metastases. (Figure 1) MR Spectroscopy showed intense choline peak with reduced NAA suggestive of mitotic etiology. Patient also underwent FDG whole body PET CT scan which showed that brain was the only site of metastases.

Management

Neurosurgical resection of brain lesion was ruled out in view of location in close vicinity of motor and speech area.

She was then treated with stereotactic brain radiation therapy. He head was fixed in a non- invasive frame/mould. Radiation therapy (RT) was delivered in 3 fractions/sittings over 3 days using stereotactic radiosurgery (SRS) technique under image guidance. (Figure 2 and 3)

After brain radiosurgery, her hormonal treatment was changed in form of another pill. She was not given chemotherapy as her previous breast cancer was hormone receptor positive.

Follow up

Post brain SRS, patient has a follow up of close to 2 years and she is disease free. She has no neurological deficit and she continues to be on hormonal treatment.

Case 2 –Multiple  Brain Metastases

Mr NK, 54 years old gentleman from Kashmir, diagnosed case of metastatic renal cell carcinoma presented to us at the beginning of Corona pandemic with complaints of weakness of right and upper limb.

Clinically he was well preserved except for grade 3 power in right and upper limbs suggestive of right hemiparesis.

His MRI Brain showed total 10 SOLs in brain suggestive of metastases and largest was 1.2 cm in diameter and was causing hemiparesis. (Figure 4)

Figure 4 – Multiple brain metastases as seen on MRI Brain

We treated all his brain lesions with SRS delivered over 3 days and avoided whole brain radiation therapy. (Figure 5 &6)

Immediate after radiation therapy his power on right side improved to 4/5. Since it was a short treatment done over only 3 days, he could go back to Kashmir safely.

Discussion

Till few years back standard treatment of brain metastases was whole brain radiation therapy (WBRT). A new standard of care for brain metastases is to give focal stereotactic radiation therapy. There are several advantages of SRS over WBRT including short treatment, better local control of metastases, no neurocognition decline and no hair loss.