Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Radiotherapy And Sarcomas

4,899 views

Published on

Published in: Health & Medicine
  • Sex in your area is here: ❶❶❶ http://bit.ly/2u6xbL5 ❶❶❶
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • Dating for everyone is here: ♥♥♥ http://bit.ly/2u6xbL5 ♥♥♥
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here

Radiotherapy And Sarcomas

  1. 1. Radiotherapy and Sarcomas Wendy Ella University College London Hospitals NHS Foundation Trust
  2. 2. Introduction <ul><li>Rare malignant tumours arising from mesenchymal tissue </li></ul><ul><li><1% malignant tumours </li></ul><ul><li>78% originate from soft tissue, remainder from bone </li></ul><ul><li>Diverse group </li></ul>
  3. 3. Heterogenous group of tumours <ul><li>Malignant Fibrous histiocytoma 28% </li></ul><ul><li>Liposarcoma 15% </li></ul><ul><li>Leiomyosarcoma 12% </li></ul><ul><li>Synovial sarcoma 10% </li></ul><ul><li>MPNST 5% </li></ul><ul><li>Rhabdomyosarcoma 5% </li></ul><ul><li>Fibrosarcoma <5 </li></ul><ul><li>Ewings sarcoma </li></ul><ul><li>Angiosarcoma </li></ul><ul><li>Osteosarcoma </li></ul><ul><li>Clear cell sarcoma </li></ul><ul><li>Alveolar soft part sarcoma </li></ul><ul><li>Hamangiopericytoma </li></ul><ul><li>Chondrosarcoma </li></ul>
  4. 4. Introduction <ul><li>Increasing frequency with age </li></ul><ul><li>Most commonly arising in the limbs </li></ul><ul><ul><li>Extremities 50% </li></ul></ul><ul><ul><li>Trunk and retroperitoneal space 40% </li></ul></ul><ul><ul><li>Head and neck region 10% </li></ul></ul>
  5. 5. Heterogenous group of tumours
  6. 6. Heterogenous group of tumours
  7. 7. Heterogenous group of tumours
  8. 8. Heterogenous group of tumours
  9. 9. Principles of management: soft tissue sarcomas Surgery +/- Radiotherapy +/- Chemotherapy
  10. 10. Radiotherapy for soft tissue sarcoma <ul><li>Radiotherapy – role optimise local control </li></ul><ul><li>Local control rates for combination of surgery + radiotherapy similar to amputation without affecting patient survival (Potter et al; 1986). </li></ul><ul><li>Yang et al , J Clin Oncol, 1998, looked at high grade extremity lesions: Surgery vs Surgery + EBRT (63Gy in 1.8Gy), - increased local control from 70% to 99%, No difference in OS. </li></ul><ul><li>Summary : Post operative radiotherapy is highly effective in preventing local recurrence. </li></ul>
  11. 11. Pre- or Post-Op Radiotherapy ? <ul><li>O’Sullivan et al; Five year results of randomised phase III trial of pre-op vs. post-op radiotherapy in extremity STS; JCO 2004 </li></ul><ul><li>190 patients (94 pre-op/96 post-op) 5 year local control 93% v 92%, metastatic relapse free 67% v 69%, recurrence free survival; 58% v 59%, overall survival 73% v 67% </li></ul><ul><li>Pre-op and post-op radiotherapy equally effective, normal tissue complication rate varies for both - therefore need to take in to account anatomical site </li></ul>
  12. 12. Indications for Post Operative Radiotherapy; <ul><li>Consider for all high grade sarcomas . </li></ul><ul><li>Consider for low-intermediate grade with marginal excision/positive margins if further surgery not possible </li></ul><ul><li>Following removal of recurrent tumour </li></ul>
  13. 13. Indications for pre-operative radiotherapy <ul><li>If tumour adjacent to or involving critical structures. </li></ul><ul><li>Likely difficult resection. </li></ul><ul><li>Tumour initially inoperable at diagnosis </li></ul>
  14. 14. Planning post-operative radiotherapy <ul><li>Immobilisation </li></ul><ul><li>Definition of target volume </li></ul><ul><li>Phase I & II </li></ul><ul><li>Field arrangements </li></ul><ul><li>Implementation of plan </li></ul>
  15. 15. Immobilisation <ul><li>Impression of limb with patient in the optimum treatment position -sheet of thermoplastic (Orfit) moulded around limb – clipped onto baseboard </li></ul><ul><li>Immobilise limb </li></ul><ul><li>Same position every day </li></ul><ul><li>Reduce marks being drawn on skin </li></ul>
  16. 16. Immobilisation: Lower limb
  17. 17. Immobilisation: Upper limb
  18. 18. Phase I Volume definition <ul><li>GTV reconstructed from pre-op imaging. </li></ul><ul><li>Consider compartment at risk of microscopic spread. Should include biopsy site and scar </li></ul><ul><li>CTV (length) = GTV + 4-9cm (usually ~5cm) </li></ul><ul><li>PTV = CTV + 5-10mm (depending on departmental set up) or 1 cm beyond scar </li></ul><ul><li>Trans-axial CTV - treat width of compartment or </li></ul><ul><li>GTV + 2-3cm </li></ul>
  19. 19. Phase II Volume definition <ul><li>Length </li></ul><ul><li>PTV = GTV +2-3cm </li></ul><ul><li>Width </li></ul><ul><li>PTV is usually the same as phase I in axial plane </li></ul>
  20. 20. Sparing a “corridor ” <ul><li>Leaving an area of normal tissue within the circumference of the limb can reduce risk of lymphoedema </li></ul>
  21. 21. Vortex <ul><li>CTV1 = axial 2cm or fascia </li></ul><ul><li>Longitudinal 2cm </li></ul><ul><li>CTV2 = axial 2cm or fascia </li></ul><ul><li>Longitudinally 2cm </li></ul><ul><li>CTV- PTV = 5mm </li></ul>
  22. 25. Margin calculation <ul><li>Van Herk, Seminars in Radiation Oncology, 14, 2004, 52-64 </li></ul><ul><li>Margin = (2.5 X SD of group systematic error) + (0.7 X SD of random error) </li></ul>
  23. 26. Systematic/Random errors Margin = (2.5 X SD of group systematic error) + (0.7 X SD of random error) - Van Herk, 2004 4.4 mm +/- 0.8mm 0.3 mm +/- 1.5 SD A–P on Lat 5.3 mm +/- 1.7mm -0.2 mm +/- 1.7 SD S-I on AP 4.3 mm +/- 1.1mm 0.2 mm +/- 1.4 SD L-R on AP Margins calculated Group SD of random error Group systematic error
  24. 27. Implementation of Plan <ul><li>6MV photons </li></ul><ul><li>Prescribed to 100% </li></ul><ul><li>Given isocentrically treating all fields daily </li></ul><ul><li>Limbs 2 phase technique; </li></ul><ul><li> phase I 50Gy in 25# over 5 weeks </li></ul><ul><li>phase II 10 -16Gy in 5# over 1 week </li></ul><ul><li>60Gy is standard post op dose, 66Gy if positive margin </li></ul>
  25. 28. MRI Scan
  26. 29. Planning
  27. 30. Planning
  28. 31. Radiotherapy for soft tissue sarcoma <ul><li>Complex radiotherapy </li></ul><ul><li>Highly individualised </li></ul><ul><li>Requires good anatomical knowledge </li></ul>
  29. 32. Questions? University College London Hospitals NHS Foundation Trust

×