Understand broad treatment strategies in the treatment of tumors.

Radiosurgery Usually a one-time treatment involving a large amount of sharply focused radiation aimed at the brain tumor Stereotactic radiosurgery: Uses computer imaging to direct precisely focused radiation into the tumor from multiple angles – Used to treat surgically inaccessible tumors – May also be used at the end of conventional radiation treatment

Surgery Primary form of treatment for brain tumors that can be removed without damaging critical neurological functions Craniotomy: Most common type of surgery – Removal and subsequent replacement of a piece of the skull to access tumor Biopsy for definitive diagnosis often performed during actual surgical procedure May be followed by radiation and/or chemotherapy

Radiation Therapy Use of repeated doses of high-energy ionizing radiation to kill or arrest division of cancer cells May be delivered by external or internal means – External beam radiation therapy: Using focused beams of energy or charged particles that are directed at the tumor – Internal or interstitial radiation therapy (brachytherapy): Surgically implanting radioactive material directly in the tumor site

Chemotherapy Use of chemotherapeutics to kill or arrest division of cancer cells Given in cycles to more effectively harm cancer cells and give normal cells time to recover from any damage Mechanisms: – DNA damage – Inhibit DNA replication and transcription – Apoptosis

Chemotherapy Timing of chemotherapy: – Neo-adjuvant therapy: Receiving chemotherapy to shrink the tumor before surgery – In combination with radiation therapy, or – Adjuvant therapy: After radiation treatment to destroy any remaining cancer cells. Metronomic therapy: Continuous low-dose chemotherapy to block mechanisms that stimulate the growth of new blood vessels needed to feed the tumor. Used to treat CNS lymphoma and inaccessible tumors or tumors that do not respond to radiation therapy.