HSC 340 9 9-16-10 <ul><li>Conventional Simulation procedures </li></ul><ul><li>Computed Tomography Simulation procedures <...
Radiation Therapy process <ul><li>Not all patients will need all steps, nor will they always occur in sequence </li></ul>
Diagnosis <ul><li>Screening </li></ul><ul><li>Cancer Imaging </li></ul><ul><li>Pathology </li></ul><ul><li>Staging </li></ul>
Therapeutic Decisions <ul><li>Cure </li></ul><ul><li>Palliation </li></ul><ul><li>Benign </li></ul><ul><li>Surgery-radiati...
Simulation <ul><li>Fluoroscopy based </li></ul><ul><li>CT simulation </li></ul><ul><li>Patient positioning </li></ul><ul><...
Treatment Planning <ul><li>Identifying PTV </li></ul><ul><li>Identifying critical structures </li></ul><ul><li>Selection o...
Treatment <ul><li>Treatment verification & imaging </li></ul><ul><li>Dosimetry checks </li></ul><ul><li>Treatment delivery...
Patient follow-up <ul><li>Patient assessment </li></ul><ul><li>Normal tissue response </li></ul><ul><li>Tumor control </li...
Conventional Simulation Procedures <ul><li>Synonymous with fluoroscopy-based simulation </li></ul><ul><li>Nomenclature </l...
ICRU Reports
<ul><li>GTV- gross tumor volume </li></ul><ul><li>CTV- clinical tumor volume </li></ul><ul><li>ITV- Internal target volume...
Acronyms pg. 446 image <ul><li>CAX </li></ul><ul><li>IFD </li></ul><ul><li>ISO </li></ul><ul><li>SAD </li></ul><ul><li>SFD...
Body Planes Sagittal- L and R Coronal- Ant and Post Transverse- Inf and Sup
 
Localization Methods <ul><li>SAD and SSD </li></ul><ul><li>SSD method </li></ul><ul><ul><li>Requires repositioning the pat...
Contrast Media <ul><li>Used to visually enhance structures </li></ul><ul><li>Positive- Barium, iodinated contrast </li></u...
Procedure <ul><li>*****Must be well documented***** </li></ul><ul><li>Presim planning </li></ul><ul><li>Room preparation <...
Presim planning <ul><li>Assessment of patient </li></ul><ul><li>Extent of disease </li></ul><ul><li>Concerns  </li></ul><u...
Room preparation <ul><li>Usually busy, make the most of it </li></ul><ul><li>H & N </li></ul><ul><ul><li>Water bath temp c...
<ul><li>Thorax </li></ul><ul><ul><li>Headrest </li></ul></ul><ul><ul><li>Vac-lok </li></ul></ul><ul><ul><li>Wingboard </li...
Explanation <ul><li>Assessment </li></ul><ul><li>Communication </li></ul><ul><li>Education </li></ul>
Patient Positioning <ul><li>If they are not comfortable, then not effective </li></ul><ul><li>If it is not reproducible th...
Patient Immobilization <ul><li>Effective immobilization devices restrict a patient from moving </li></ul><ul><li>Can range...
Setting Parameters <ul><li>Field parameters: </li></ul><ul><ul><li>Width, length, gantry angle, collimator angle, position...
Radiographic Exposure <ul><li>Radiographic images taken in sim are referred to as “masters” </li></ul><ul><li>kVp, mA, tim...
Documentation <ul><li>This is a medical record </li></ul><ul><li>Accuracy is key </li></ul><ul><li>Involves both patient a...
Contouring <ul><li>Contour is a reproduction of external body shape </li></ul><ul><li>Solder wire, thermoplastic tube, pla...
Shifts YouTube - RT Quick Clip - Patient Shifts
CT Simulation Procedures Hounsfield Units- attenuation rates displayed as pixels of different shades of gray. Correspond t...
<ul><li>Conventional CT- slice by slice, one image, table moves </li></ul><ul><li>Helical/spiral CT- volume, table moves w...
Major steps in CT Simulation <ul><li>Presim planning </li></ul><ul><li>Room preparation </li></ul><ul><li>Explanation of p...
Benefits of CT Simulation <ul><li>Outline and view critical structures </li></ul><ul><li>Optimal beam placement </li></ul>...
Contrast <ul><li>Intravascular </li></ul><ul><li>Oral </li></ul><ul><li>Intrathecal </li></ul><ul><li>Intraarticular </li>...
IV Contrast agents & site specificities <ul><li>H & N- injected seconds before scan </li></ul><ul><ul><li>Highlights vesse...
Other contrast agents and the specificities <ul><li>GI tumors- barium paste 30 min prior for small bowel </li></ul><ul><li...
Reactions to contrast <ul><li>Mild </li></ul><ul><li>Moderate </li></ul><ul><li>Severe </li></ul>
Room preparation <ul><li>Same as conventional, be aware of bore size and patient positioning </li></ul><ul><li>Flat table ...
CT Artifacts <ul><li>Unwanted image abnormalities that can be caused by patient motion, anatomy, design of scanner, or sys...
Fusion/Registration <ul><li>Starts with 2 sets of images </li></ul><ul><li>Locate similar image features (landmarks) </li>...
Respiratory Gating <ul><li>Used to have patients hold breath </li></ul><ul><li>Now we track the patients range of motion w...
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Hsc 340 9 16

  1. 1. HSC 340 9 9-16-10 <ul><li>Conventional Simulation procedures </li></ul><ul><li>Computed Tomography Simulation procedures </li></ul>
  2. 2. Radiation Therapy process <ul><li>Not all patients will need all steps, nor will they always occur in sequence </li></ul>
  3. 3. Diagnosis <ul><li>Screening </li></ul><ul><li>Cancer Imaging </li></ul><ul><li>Pathology </li></ul><ul><li>Staging </li></ul>
  4. 4. Therapeutic Decisions <ul><li>Cure </li></ul><ul><li>Palliation </li></ul><ul><li>Benign </li></ul><ul><li>Surgery-radiation-chemotherapy </li></ul><ul><li>Patient Interview </li></ul>
  5. 5. Simulation <ul><li>Fluoroscopy based </li></ul><ul><li>CT simulation </li></ul><ul><li>Patient positioning </li></ul><ul><li>Immobilization devices </li></ul><ul><li>DRRs </li></ul>
  6. 6. Treatment Planning <ul><li>Identifying PTV </li></ul><ul><li>Identifying critical structures </li></ul><ul><li>Selection of treatment technique </li></ul><ul><li>Isodose distribution </li></ul><ul><li>Calculation of treatment beams </li></ul><ul><li>Optimization </li></ul>
  7. 7. Treatment <ul><li>Treatment verification & imaging </li></ul><ul><li>Dosimetry checks </li></ul><ul><li>Treatment delivery and monitoring </li></ul><ul><li>Patient assessment </li></ul><ul><li>Record keeping </li></ul>
  8. 8. Patient follow-up <ul><li>Patient assessment </li></ul><ul><li>Normal tissue response </li></ul><ul><li>Tumor control </li></ul>
  9. 9. Conventional Simulation Procedures <ul><li>Synonymous with fluoroscopy-based simulation </li></ul><ul><li>Nomenclature </li></ul><ul><ul><li>Localization </li></ul></ul><ul><ul><li>Verification </li></ul></ul><ul><ul><li>Radiopaque marker </li></ul></ul><ul><ul><li>Contrast media </li></ul></ul><ul><ul><li>Seperation </li></ul></ul><ul><ul><li>Field Size </li></ul></ul>
  10. 10. ICRU Reports
  11. 11. <ul><li>GTV- gross tumor volume </li></ul><ul><li>CTV- clinical tumor volume </li></ul><ul><li>ITV- Internal target volume </li></ul><ul><li>PTV- planning target volume </li></ul><ul><li>TV- treated volume </li></ul><ul><li>IV- Irradiated volume </li></ul><ul><li>OAR- Organs at risk </li></ul>
  12. 12. Acronyms pg. 446 image <ul><li>CAX </li></ul><ul><li>IFD </li></ul><ul><li>ISO </li></ul><ul><li>SAD </li></ul><ul><li>SFD </li></ul><ul><li>SSD </li></ul><ul><li>TT </li></ul>
  13. 13. Body Planes Sagittal- L and R Coronal- Ant and Post Transverse- Inf and Sup
  14. 15. Localization Methods <ul><li>SAD and SSD </li></ul><ul><li>SSD method </li></ul><ul><ul><li>Requires repositioning the patient for each field before treatment </li></ul></ul><ul><ul><li>ODI reading on skin will always be 100cm </li></ul></ul><ul><li>SAD method </li></ul><ul><ul><li>aka: isocentric technique </li></ul></ul><ul><ul><li>ODI reading on skin will vary according to thickness or seperation of the patient, also depending on the depth of the tumor from the skin </li></ul></ul><ul><li>Both define the field size at 100cm, only difference is where that distance is located (on skin or within patient) </li></ul>
  15. 16. Contrast Media <ul><li>Used to visually enhance structures </li></ul><ul><li>Positive- Barium, iodinated contrast </li></ul><ul><li>Negative- air </li></ul><ul><li>Careful workup </li></ul>
  16. 17. Procedure <ul><li>*****Must be well documented***** </li></ul><ul><li>Presim planning </li></ul><ul><li>Room preparation </li></ul><ul><li>Explanation (Consent?) </li></ul><ul><li>Patient positioning </li></ul><ul><li>Immobilization </li></ul><ul><li>Setting parameters </li></ul><ul><li>Radiographic exposure </li></ul><ul><li>Documentation </li></ul>
  17. 18. Presim planning <ul><li>Assessment of patient </li></ul><ul><li>Extent of disease </li></ul><ul><li>Concerns </li></ul><ul><li>Therapist-Physician consult </li></ul><ul><li>Chart thoroughly read </li></ul>
  18. 19. Room preparation <ul><li>Usually busy, make the most of it </li></ul><ul><li>H & N </li></ul><ul><ul><li>Water bath temp checked </li></ul></ul><ul><ul><li>Mask ready </li></ul></ul><ul><ul><li>Headrest chosen (A to F) </li></ul></ul><ul><ul><li>Stent, bite block, mouthpiece </li></ul></ul><ul><ul><li>Wires for surgical scar delineation </li></ul></ul><ul><ul><li>Straps to pull shoulders down </li></ul></ul>
  19. 20. <ul><li>Thorax </li></ul><ul><ul><li>Headrest </li></ul></ul><ul><ul><li>Vac-lok </li></ul></ul><ul><ul><li>Wingboard </li></ul></ul><ul><ul><li>BBs, wire </li></ul></ul><ul><li>Pelvis </li></ul><ul><ul><li>Alpha cradle </li></ul></ul><ul><ul><li>T-bar with strap </li></ul></ul><ul><ul><li>Headrest </li></ul></ul><ul><ul><li>Ring for hands to hold </li></ul></ul><ul><ul><li>Contrast agents </li></ul></ul><ul><ul><li>Catheter </li></ul></ul>
  20. 21. Explanation <ul><li>Assessment </li></ul><ul><li>Communication </li></ul><ul><li>Education </li></ul>
  21. 22. Patient Positioning <ul><li>If they are not comfortable, then not effective </li></ul><ul><li>If it is not reproducible then it may cause a geographic miss or irradiation of critical structures </li></ul><ul><li>Supine or Prone </li></ul><ul><li>Emergencies may lead to semi-sitting position </li></ul>
  22. 23. Patient Immobilization <ul><li>Effective immobilization devices restrict a patient from moving </li></ul><ul><li>Can range from simple to complex </li></ul><ul><ul><li>Tape </li></ul></ul><ul><ul><li>Rubberbands </li></ul></ul><ul><ul><li>Alpha cradle YouTube - Alpha Cradle Mold Maker Instruction </li></ul></ul><ul><ul><li>Vac-lok YouTube - SecureVac Vacuum Cushions from Bionix </li></ul></ul><ul><ul><li>Head mask </li></ul></ul>
  23. 24. Setting Parameters <ul><li>Field parameters: </li></ul><ul><ul><li>Width, length, gantry angle, collimator angle, position of isocenter </li></ul></ul>
  24. 25. Radiographic Exposure <ul><li>Radiographic images taken in sim are referred to as “masters” </li></ul><ul><li>kVp, mA, time and distance </li></ul><ul><li>Note patients body type and condition </li></ul><ul><li>Source to film distance recorded to show mag factor </li></ul>
  25. 26. Documentation <ul><li>This is a medical record </li></ul><ul><li>Accuracy is key </li></ul><ul><li>Involves both patient and chart </li></ul><ul><li>Tattoos </li></ul><ul><li>Landmarks </li></ul>
  26. 27. Contouring <ul><li>Contour is a reproduction of external body shape </li></ul><ul><li>Solder wire, thermoplastic tube, plaster strip </li></ul><ul><li>Must be accurate!! </li></ul>
  27. 28. Shifts YouTube - RT Quick Clip - Patient Shifts
  28. 29. CT Simulation Procedures Hounsfield Units- attenuation rates displayed as pixels of different shades of gray. Correspond to different e- densities -1000 Air 0 water 1000 dense bone Figure 23-8 X-ray tube---collimation---360 rotation---transmission measurements recorded by detectors
  29. 30. <ul><li>Conventional CT- slice by slice, one image, table moves </li></ul><ul><li>Helical/spiral CT- volume, table moves while scanning </li></ul>
  30. 31. Major steps in CT Simulation <ul><li>Presim planning </li></ul><ul><li>Room preparation </li></ul><ul><li>Explanation of procedure </li></ul><ul><li>Patient positioning and immobilization </li></ul><ul><li>CT data acquisition </li></ul><ul><li>Target and normal tissue localization </li></ul><ul><li>Virtual sim of treatment fields </li></ul><ul><li>Generation of dose distribution </li></ul><ul><li>Documentation </li></ul>
  31. 32. Benefits of CT Simulation <ul><li>Outline and view critical structures </li></ul><ul><li>Optimal beam placement </li></ul><ul><li>Cone down or boost can be done w/o patient </li></ul><ul><li>BEV capability </li></ul><ul><li>Electronic field shaping </li></ul>
  32. 33. Contrast <ul><li>Intravascular </li></ul><ul><li>Oral </li></ul><ul><li>Intrathecal </li></ul><ul><li>Intraarticular </li></ul><ul><li>Must get medical history first </li></ul>
  33. 34. IV Contrast agents & site specificities <ul><li>H & N- injected seconds before scan </li></ul><ul><ul><li>Highlights vessels and distinguish from LN </li></ul></ul><ul><li>Liver- scan needs to be started 20 to 90 sec after injection </li></ul><ul><ul><li>Visualize blood supply from portal vein and hepatic artery </li></ul></ul><ul><li>Pelvis- IV contrast 15 minutes after injection </li></ul><ul><ul><li>Bladder </li></ul></ul><ul><li>Brain- 10 to 30 minutes prior to scan </li></ul><ul><ul><li>Highlight tumor due to vasculature </li></ul></ul>
  34. 35. Other contrast agents and the specificities <ul><li>GI tumors- barium paste 30 min prior for small bowel </li></ul><ul><li>Rectal marker, vaginal marker, radiopaque catheters…. </li></ul><ul><li>***High contrast materials may alter dose calcs*** </li></ul>
  35. 36. Reactions to contrast <ul><li>Mild </li></ul><ul><li>Moderate </li></ul><ul><li>Severe </li></ul>
  36. 37. Room preparation <ul><li>Same as conventional, be aware of bore size and patient positioning </li></ul><ul><li>Flat table top if regular couch is curved </li></ul>
  37. 38. CT Artifacts <ul><li>Unwanted image abnormalities that can be caused by patient motion, anatomy, design of scanner, or system failure </li></ul><ul><li>Beam hardening </li></ul><ul><li>Partial volume effect </li></ul><ul><li>Star artifact </li></ul><ul><li>Ring artifact </li></ul><ul><li>Motion and helical artifact </li></ul>
  38. 39. Fusion/Registration <ul><li>Starts with 2 sets of images </li></ul><ul><li>Locate similar image features (landmarks) </li></ul><ul><li>Manually move one image on top of another </li></ul>
  39. 40. Respiratory Gating <ul><li>Used to have patients hold breath </li></ul><ul><li>Now we track the patients range of motion while breathing </li></ul>

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