Treatment of brain malignancies and other brain lesions: Emergence of stereotactic radiosurgery

Al Taira, M.D.Dorothy E. Schneider Cancer CenterWestern Radiation Oncology

Starting point: Surgical resection

Therapeutic and diagnostic

Surgical considerations

Urgency Ambiguity of diagnosis

Invasive Recovery time / perioperative morbidity Caution near eloquent and other critical

brain structures Extent of surgery Patient performance status

The innovator

A neurosurgeon from Sweden, Dr. Lars Leskel, worked for years to develop a non-invasive means for “surgically” treating brain tumors.

Established fundamental premise of radiosurgery

High dose to target with low dose to surrounding normal tissue.

Gamma Knife limitations

• Limited to single fraction treatments• Brain tumors only• Long treatment times and some discomfort

Next step: CyberKnife

Dr. John Adler, another neurosurgeon, pioneered the next breakthrough in stereotactic radiosurgery.

CyberKnife

Advantages (vs Gamma Knife)No head frame requiredCan treat lesions in brain AND rest of body

LimitationsLong treatment timesLimited to only radiosurgery treatments

The newest generation

Mills has just installed a state-of-the- art TrueBeam Varian linear accelerator developed to optimize stereotactic radiosurgery

-frameless -brain and body SRS -dramatically reduced treatment times -optimized to deliver highest quality radiosurgery and IMRT plans

Brain metastases

Approximately 150,000 - 200,000 new cases per year.

~10% of cancer patients will develop symptomatic brain metastases

Primary lung cancers are most common source of brain metastases. Increasing incidence of women with breast cancer developing brain metastases due to improvement in systemic therapy.

With improved identification and treatment of brain metastases, most patients improve after treatment and do not die from these metastatic lesions.

Historic standard: Whole brain radiotherapy

Treat entire brain parenchyma.

Target known lesions and potential micrometastases.

Improved survival versus observation/steroids-alone

Whole brain radiotherapy drawbacks

Fatigue

Hair loss

Risk of decreased cognitive functioning

Risk of decreased overall HRQoL

2-3 weeks of daily treatments

Can we treat initially with SRS instead?

Aoyama (JAMA 2006) SRS +/- WBRTNo difference in overall survival or initial MMSE.

Chang (Lancet Oncology 2009) SRS +/- WBRTInferior neurocognitive outcome and lower OS with WBRT.

Soffietti (JCO 2013) SRS (or surgery) +/- WBRTInferior HRQoL with WBRT. No difference in OS.

WBRT versus SRS dose distribution

Whole brain radiotherapy Stereotactic radiosurgery

2-3 weeks / daily treatments single short treatment

Shifting paradigm

53 year old woman with history breast cancer who completed breast conservation and adjuvant treatment 2.5 years ago. Now with 3 small brain metastases.

Original diagnosis disease-free

interval

Brainmetastases

WBRT

Traditional paradigm

Original diagnosis disease-free

interval

Brainmetastases

SRS

Emerging paradigm

disease-freeinterval

If new brainmetastasis

SRSdisease-freeinterval

If more brainmetastases

SRS or WBRT

Criteria for WBRT versus SRS

• Disease free interval

• Number of new metastases

• Extra-cranial disease control

• Patient performance status

Multidisciplinary decision-making:Brain metastases management

Medical oncologist

Neurosurgeon

Radiation oncologist

Customizedpatient plan

Patient

SRS

WBRT

Surgery

Supportivecare

Mills intracranial radiosugery program

• Program started upon delivery of TrueBeam

• Builds on many years of WRO radiosurgery experience at other cancer centers with wide range of available technologies

• Close collaboration among medical oncologists, neurosurgeons, radiation oncologists and radiologists

• Strong physics capabilities and support

Radiosurgery capabilities

Brain metastases

Schwannomas

Menigniomas

Pituitary adenomas

Vascular disorders

Functional disorders

Other