1. Stereotactic Radiosurgery Jimmy Johannes Physics 335 – Spring 2004 Final Presentation http://www.sdgkc.com/

2. Outline Case Study Case Study What is Stereotactic Radiosurgery? What is Stereotactic Radiosurgery? Stereotactic Localization Stereotactic Localization Radiosurgery Radiosurgery Applications Applications Different technologies Different technologies Gamma Knife Gamma Knife LINAC-based systems LINAC-based systems CyberKnife CyberKnife

3. Case Study Imagine… Imagine… You’re an undergrad at NU… You’re an undergrad at NU… As you approach Finals Week you acquire the following symptoms: As you approach Finals Week you acquire the following symptoms: Headaches Headaches Nausea Nausea Searle?  Mono Searle?  Mono Evanston Northwestern Healthcare  MRI Evanston Northwestern Healthcare  MRI

4. MRI Result: http://splweb.bwh.harvard.edu:8000/pages/papers/kaus/radiology2001/5a.gif

5. Diagnosis and Treatment Diagnosis: Benign Brain Tumor Diagnosis: Benign Brain Tumor Treatment:? Treatment:? Chemo/Immuno therapy Chemo/Immuno therapy Invasive brain surgery Invasive brain surgery Non-invasive radiotherapy Non-invasive radiotherapy Non-invasive stereotactic radiosurgery Non-invasive stereotactic radiosurgery

6. Diagnosis and Treatment Diagnosis: Benign Brain Tumor Diagnosis: Benign Brain Tumor Treatment:? Treatment:? Chemo/Immuno therapy  Blood Brain Barrier Chemo/Immuno therapy  Blood Brain Barrier Invasive brain surgery Invasive brain surgery Non-invasive radiotherapy Non-invasive radiotherapy Non-invasive stereotactic radiosurgery Non-invasive stereotactic radiosurgery

7. Diagnosis and Treatment Diagnosis: Benign Brain Tumor Diagnosis: Benign Brain Tumor Treatment:? Treatment:? Chemo/Immuno therapy  Blood Brain Barrier Chemo/Immuno therapy  Blood Brain Barrier Invasive brain surgery  High Risk Invasive brain surgery  High Risk Non-invasive radiotherapy Non-invasive radiotherapy Non-invasive stereotactic radiosurgery Non-invasive stereotactic radiosurgery

8. Diagnosis and Treatment Diagnosis: Benign Brain Tumor Diagnosis: Benign Brain Tumor Treatment:? Treatment:? Chemo/Immuno therapy  Blood Brain Barrier Chemo/Immuno therapy  Blood Brain Barrier Invasive brain surgery  High Risk Invasive brain surgery  High Risk Non-invasive radiotherapy  Too Non-Specific Non-invasive radiotherapy  Too Non-Specific Non-invasive stereotactic radiosurgery Non-invasive stereotactic radiosurgery

9. Diagnosis and Treatment Diagnosis: Benign Brain Tumor Diagnosis: Benign Brain Tumor Treatment:? Treatment:? Chemo/Immuno therapy  Blood Brain Barrier Chemo/Immuno therapy  Blood Brain Barrier Invasive brain surgery  High Risk Invasive brain surgery  High Risk Non-invasive radiotherapy  Too Non-Specific Non-invasive radiotherapy  Too Non-Specific Non-invasive stereotactic radiosurgery Non-invasive stereotactic radiosurgery

10. What is Stereotactic Radiosurgery? Method to non-invasively & specifically treat benign/malignant tumors and tissue abnormalities Method to non-invasively & specifically treat benign/malignant tumors and tissue abnormalities Uses methods of stereotactic 3-D localization of surgical site Uses methods of stereotactic 3-D localization of surgical site Uses radiosurgical techniques to perform the “surgery” Uses radiosurgical techniques to perform the “surgery”

11. 3-D Stereotactic Localization Goal: To target the tissue of interest with as much accuracy as possible Goal: To target the tissue of interest with as much accuracy as possible Use imaging and 3-D mapping techniques to target tissue of interest Use imaging and 3-D mapping techniques to target tissue of interest 4 general medical imaging modalities used: 4 general medical imaging modalities used: X-Ray X-Ray PET PET MRI MRI Digital Subtracted Angiography Digital Subtracted Angiography Use the patient as a reference for the localization Use the patient as a reference for the localization 2 general methods: 2 general methods: Frame stereotactic localization (old school) Frame stereotactic localization (old school) Frameless stereotactic localization (new school) Frameless stereotactic localization (new school)

12. The Imaging Modalities Tomographic Techniques: Tomographic Techniques: PET (CT) and MRI PET (CT) and MRI Good for tumor pathologies Good for tumor pathologies Use multiple layers to get 3-D image Use multiple layers to get 3-D image X-ray-based Techniques: X-ray-based Techniques: X-ray and Digital Subtracted Angiography X-ray and Digital Subtracted Angiography Good for vascular imaging (for treatment of vascular malformations) Good for vascular imaging (for treatment of vascular malformations) Use pins and depth perception methods to get 3-D localization Use pins and depth perception methods to get 3-D localization

13. Frame Techniques With tomographic imaging modalities (CT and MRI), use the N-frame as a basis for 3- D visualization: CT N-Frame MRI Gibson D, et al. Stereotactic Localization in Medical Imaging: A Technical and Methodological Review. Journal of Radiosurgery, Vol 2, No. 3, 1999

14. Frame Techniques With X-ray imaging modalities: Schematic Angiography (X-ray) Schematic of basis for 3-D imaging

15. Frameless Stereotaxy Implanted Gold Markers Amorphous silicon detectors (CyberKnife)

16. Display of treatment planning: http://virtualtrials.com/jhrs.cfm

17. Radiosurgery Focused radiation beams delivered to a specific tissue volume Focused radiation beams delivered to a specific tissue volume Multiple beams or multiple passes (fractionated treatment) that intersect Multiple beams or multiple passes (fractionated treatment) that intersect Keeps radiation exposure to surrounding tissue at benign levels Keeps radiation exposure to surrounding tissue at benign levels Treats targeted tissue (the point of intersection) with a higher dose of radiation Treats targeted tissue (the point of intersection) with a higher dose of radiation http://neurosurgery.medsch.ucla.edu/programs/radios urgery/radiosurgery_intro.html

18. How does it work? How is it therapeutic? How is it therapeutic? Radiation does not remove the tumor or tissue abnormality Radiation does not remove the tumor or tissue abnormality For tumors, radiation distorts DNA (ionizing radiation induces mutations and other forms of DNA damage) For tumors, radiation distorts DNA (ionizing radiation induces mutations and other forms of DNA damage) High incidence of DNA damage and ionization induces cell- cycle arrest (cells stop growing and replicating) and causes the cell to lose its ability to retain water High incidence of DNA damage and ionization induces cell- cycle arrest (cells stop growing and replicating) and causes the cell to lose its ability to retain water Tumor reduction happens at the rate of the normal growth rate of that tumor Tumor reduction happens at the rate of the normal growth rate of that tumor For arteriovenous malformations (tangle of blood vessels), radiation induces the thickening and closing off of the blood vessel For arteriovenous malformations (tangle of blood vessels), radiation induces the thickening and closing off of the blood vessel

19. How does it work? Benign tumors take up to 2 years to disappear Benign tumors take up to 2 years to disappear Metastatic (Cancerous) tumors (with a much faster growth rate) take only months to disappear Metastatic (Cancerous) tumors (with a much faster growth rate) take only months to disappear

20. Side Effects Swelling: cells lose ability to retain fluid, edema may occur Swelling: cells lose ability to retain fluid, edema may occur Necrosis: dead tumor cells may cause complications (inflammation, fibrosis) Necrosis: dead tumor cells may cause complications (inflammation, fibrosis) Psychological side effects: loss of memory, decreased cognitive abilities, etc. (you are taking out a chunk of brain!) Psychological side effects: loss of memory, decreased cognitive abilities, etc. (you are taking out a chunk of brain!) Radiation-induced tumor/cancer: radiation-induced mutations may result in a new tumor or cancer Radiation-induced tumor/cancer: radiation-induced mutations may result in a new tumor or cancer

21. Applications Mostly used for brain surgery Mostly used for brain surgery It’s where other more invasive procedures are deemed too risky It’s where other more invasive procedures are deemed too risky Machines are designed mostly for brain surgeries Machines are designed mostly for brain surgeries Frame stereotaxy only allows for brain surgery Frame stereotaxy only allows for brain surgery But new machines and stereotaxy techniques are allowing for application in other parts of the body But new machines and stereotaxy techniques are allowing for application in other parts of the body Mostly used for tumors and vascular malformations Mostly used for tumors and vascular malformations But new therapeutic applications have been developed for other tissue diseases and functional disorders But new therapeutic applications have been developed for other tissue diseases and functional disorders

22. Types of Radiation Differs with different machines: Differs with different machines: High-energy X-ray High-energy X-ray From linear accelerator systems From linear accelerator systems Gamma radation Gamma radation From Cobalt-60 source From Cobalt-60 source Proton Proton From particle beam or cyclotron From particle beam or cyclotron Limited use in the US Limited use in the US Uses Bragg Peak principle: Uses Bragg Peak principle: As proton slows down, it gives off disproportionately more energy As proton slows down, it gives off disproportionately more energy Right before it stops, it gives off most of its energy, resulting in a peak at that depth of tissue Right before it stops, it gives off most of its energy, resulting in a peak at that depth of tissue

23. Different Machines in Use Gamma Knife Gamma Knife Gamma radiation from Cobalt-60 Source Gamma radiation from Cobalt-60 Source Use multiple beams to treat tissue volume Use multiple beams to treat tissue volume LINAC-based systems (X-Knife) LINAC-based systems (X-Knife) High-energy X-ray from Linear Accelerator device High-energy X-ray from Linear Accelerator device Use fractionation Use fractionation CyberKnife CyberKnife Also a LINAC system, but LINAC is on a robotic arm Also a LINAC system, but LINAC is on a robotic arm Use fractionation Use fractionation Can be used for parts of body other than the head Can be used for parts of body other than the head

24. Gamma Knife -Over 30 years of clinical use and a great deal of publications -Targeting Precision of within 2mm -Multiple targets can be easily treated in one session http://www.elekta.com/ContentUS. nsf

25. LINAC-Based Systems -Less accurate -In use in more hospitals -Less efficient (longer treatment times) http://www.radionics.com/resources/patient/xknife_description.s html

26. CyberKnife -Can treat most regions of body -w/ Stereotactic frame, can approach accuracy of LINAC or GammaKnife -Real-time frameless stereotaxy can be used

27. Questions?