Treatment of brain malignancies and other brain lesions: Emergence of stereotactic radiosurgery
Al Taira, M.D.Dorothy E. Schneider Cancer CenterWestern Radiation OncologyTreatment of brain malignancies and otherbrain lesions: Emergence of stereotacticradiosurgery
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 ofradiosurgery 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, pio neered the next breakthrough in stereotactic radiosurgery.
CyberKnife Advantages (vs Gamma Knife) No head frame required Can treat lesions in brain AND rest of body Limitations Long treatment times Limited 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 brainradiotherapy 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 SRSinstead? Aoyama (JAMA 2006) SRS +/- WBRT No difference in overall survival or initial MMSE. Chang (Lancet Oncology 2009) SRS +/- WBRT Inferior neurocognitive outcome and lower OS with WBRT. Soffietti (JCO 2013) SRS (or surgery) +/- WBRT Inferior 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 paradigm53 year old woman with history breast cancer who completed breastconservation and adjuvant treatment 2.5 years ago. Now with 3 smallbrain metastases.Traditional paradigmOriginal Braindiagnosis disease-free metastases interval WBRTEmerging paradigmOriginal Brain If new brain If more brain metastasis metastasesdiagnosis disease-free metastases disease-free disease-free interval interval interval SRS SRS 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 managementMedical oncologist SRS Neurosurgeon Customized patient plan WBRTRadiation oncologist Surgery Patient Supportive care
Mills intracranial radiosugeryprogram• 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