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Challenges in Optimal Delivery of Radiation in Head and Neck Cancers Dr. J P Agarwal Associate Professor

Challenges in Optimal Delivery of Radiation in Head and Neck Cancers Dr. J P Agarwal Associate Professor Department of Radiation Oncology Tata Memorial Hospital, India. TMH ESTRO EBM 2005. Head and Neck Squamous Cell Carcinoma.

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Challenges in Optimal Delivery of Radiation in Head and Neck Cancers Dr. J P Agarwal Associate Professor

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  1. Challenges in Optimal Delivery of Radiation in Head and Neck Cancers Dr. J P Agarwal Associate Professor Department of Radiation Oncology Tata Memorial Hospital, India TMH ESTRO EBM 2005

  2. Head and Neck Squamous Cell Carcinoma Accounts for about 4,50,000 cases worldwide* 20% of cancer burden - 1,50,000 new cases in 2000 in India* TMH - 25% of all new cases annually > 75 % present with advanced disease *Globocan,2002 IARC

  3. General Management Guidelines for H & N Cancers • Aim • Highest loco- regional control • Anatomical with functional preservation • Stage I / II Single modality ( Surgery or RT ) • Stage III / IV Combined modality Surgery + RT (in most patients) Chemotherapy + RT in selected patients • When different modalities available, one with maximum chance of cure should be used • When different modalities have same results, one offering better quality of life, with organ, function preservation and good cosmetic results should be used

  4. Head And Neck Radiotherapy A Challenge for The Radiation Oncologist • Tumor • Very Close proximity Of Tumor and Critical structures • Total Dose Delivery Limited by Tolerance of Normal structures • Dosimetric Challenges Due to Varying Contour/Tissue Heterogeneity • Patient • Compromised Tolerance To Treatment • Poor Nutritional Status and Weight Loss • Inadequate oral Intake • Treatment Induced Mucositis

  5. The Goal Optimal Dose Delivery …With Minimum Acute And Long Term Toxicity

  6. Evolution Of Head And Neck Radiotherapy 1970-2005 Escalation Of Doses Through Precise Immobilization Tissue Compensation/Customized Blocks Better Skin Sparing (Megavoltage) Integration of brachytherapy 3DCRT /SRT/ IMRT

  7. Key Issues In Head And Neck Radiotherapy • Set up Uncertainties • Target Volume Delineation • Precise Treatment Planning & Delivery • Locoregional control & Overall Survival • Overall Treatment Time • Nutritional support & Quality of Life

  8. The changing paradigm Wide field radiation Conformal radiation Clinical motivation for high-precision techniques More conformality = Better sparing

  9. Key Issues In Head And Neck Radiotherapy • Set up Uncertainties • Target Volume Delineation • Precise Treatment Planning & Delivery • Overall Treatment time • Locoregional control • Overall Survival. • Nutritional status & Quality of life

  10. Conformal Radiotherapy ……The Need For Higher Accuracy • Immobilization Devices used • Head Rest alone • POP with Head Rest • Mouth Bite, Nasion & Chin support • Thermoplastic Moulds • Varying levels of level of Uncertainty • Set up errors 5 mm-1 cm.

  11. Head and Neck Immobilization devices 3 Clamp 4 Clamp 5 Clamp Random Errors with different Fixation devices Radiotherapy Oncology,2001

  12. Verification Of Patient Positioning • Incorporation of EPID. • Cone beam CT • Correction Software • IGRT

  13. Systemic & Random Errors Radiotherapy And Oncology 2001.

  14. Immobilization and Set Up Uncertainties Needs with the changing Paradigm Permissible Errors with State of Art equipment: Recommendations for Good Clinical Practice

  15. Guidelines for patient positioning in head and neck cancer Setup the patient with neutral neck position. minimizes intra-fraction patient motion Use a customized head and neck support and face mask for each patient. improves accuracy of field matching (Neck and LAN fields) Index immobilization apparatus to the treatment table. Improves treatment setup efficiency and accuracy Use active patient position monitoring system (LED camera System) Improves setup accuracy and reproducibility, and minimizes intra-fraction patient motion These strategies can reduce the setup random errors to less than 2 mm for upper neck.

  16. Tackling The Time…The Fourth Dimension Range:7mm Asselen et al IJROBP:56:2004

  17. Key Issues In Head And Neck Radiotherapy • Set up Uncertainties • Target Volume Delineation • Precise Treatment Planning & Delivery • Locoregional control & Overall Survival • Overall Treatment Time • Nutritional support & Quality of Life

  18. Challenges In Planning Radiation Treatment Shoot The Tumor….Save The Man

  19. Guidelines For Target Volume Delineation 7 Different Groups……Variations in the Target Volume Delineation Novak et al, Vijjers et al, Som et al, Gregoire et al, Palazzi et al, Van Triest et al, Gregoire et al Implications on Target Volume Delineation

  20. Heterogeneity In Target Volume Delineation Sanguinetti et al IJROBP,2004

  21. Imaging for target volume delineation Does Fusion Help ?

  22. Variations In Target Coverage with CT/ MRI Where Do we Stand?.....Where Do we Go? Emami et al IJROBP,2003

  23. Variations In Target Coverage with CT/ MRI fusion In Nasopharyngeal Primary MRI & CT are complementary Emami et al IJROBP,2003

  24. Is PET-CT the way ahead ?

  25. Heron et al IJROBP,2004

  26. PET CT Fusion And Effect On PTV Reduction In size of PTV at Primary Primary GTV CT/GTV PET = 3 Node Node PET/Node CT= 0.7 Heron et al IJROBP,2004

  27. Integration Of Biological Imaging In Target Volume Delineation Ling et al IJROBP:47:2001

  28. Key Issues In Head And Neck Radiotherapy • Set up Uncertainties • Target Volume Delineation • Precise Treatment Planning & Delivery • Locoregional control & Overall Survival • Overall Treatment Time • Nutritional support & Quality of Life

  29. Variation of Neck Contour at Different Levels causes Under and Overdosage….

  30. Close Proximity of Target Volume & Critical structures

  31. Heterogeneities within the H & N pose difficulty in treatment planning delivery Soft Tissue Varying Contour & Tissue Heterogeneities Bone Air Sinuses

  32. Is Planning At the Initiation of Treatment Enough?

  33. Evaluation on 13 patients • Mean time to rescanning 37 days • Results of Replanning • Reduction of dose to CTV &PTV (upto 8 Gy underdosage. • Over dosage to the Spinal Cord (Spinal Cord D Max exceeded 45 Gy in 92% patients). • Recommendations • Should be undertaken in patients having significant weight loss during chemoradiotherapy. ASTRO ,2004

  34. Key Issues In Head And Neck Radiotherapy • Set up Uncertainties • Target Volume Delineation • Precise Treatment Planning & Delivery • Locoregional control & Overall Survival • Overall Treatment Time • Nutritional support & Quality of Life

  35. Improving Efficacy of Irradiation • Dose escalation • Altered Fractionation Schemes • Chemoradiotherapy • Biological Therapy And Molecular Targetting

  36. Higher doses up to 70 Gy are related with better locoregional control ,however with enhanced acute and long term complications Tata Memorial Hospital Dinshaw et al (in press)

  37. Aids In Escalating Dose • Altering The Physical Dose • Tissue Compensators • Wedges • Integration of Brachytherapy/3DCRT/SRS Boost. • Altering The Biological Dose • Altered Fractionation Schedules. • Chemoradiotherapy Schedules

  38. Attempts in precise dose delivery with minimal toxicity Conformal RT/ 3DCRT/ IMRT/IMPT Conventional 3-D CRT IMRT IMPT

  39. Averaged End Point doses for T1/T2 tumors Averaged End Point doses for T3/T4 tumors IJROBP,2004

  40. 15 Randomized Trials of Varied Fractionation (1970-1998) 7073 patients 3% Increase In absolute Survival 7% Increase in locoregional control Maximum Benefit in Hyper fractionated RT with Increased Total Dose

  41. ChemoRadiotherapy • Absolute benefit of CT – 5% at 5yrs • Higher For Platinum Based Regimens. • No Benefit of NACT (MACH- NC update) • However NACT may still have a role in organ and function preservation as in Laryngeal tumors

  42. Can this depiction of enhanced tumor control translated into the clinics?

  43. Fractionation IMPACT (Intergroup Merger of Patient Data from Altered Or Conventional Treatment Schedule) EORTC 22791,22811,22851, PMH Trial, CHART

  44. Comparison of toxicity profile Conventional Vs Altered Fractionation Trotti et al IJROBP,2000

  45. Toxicity Profile with Chemoradiotherapy Trotti et al IJROBP,2000

  46. Key Issues In Head And Neck Radiotherapy • Set up Uncertainties • Target Volume Delineation • Precise Treatment Planning & Delivery • Locoregional control & Overall Survival • Overall Treatment Time • Nutritional support & Quality of Life

  47. Effect of Interruptions on Local control • 0.9 Gy loss Per day of Interruption. • 0.7-1.4% decrease in probability of local control for every missed day • 14-20% decrease in locoregional control for a gap of 7 days

  48. Importance of the Time interval between surgery and postoperative radiation therapy in the combined management of head and neck cancers N= 22 PORT within 7 weeks / later LRC 70% (PORT within 7 weeks) 27%(PORT more than 7 weeks) Bhadrasain V,IJROBP,1979

  49. Effect of delay in PORT on survival Bastit et al, IJROBP,2001

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