Improving Plan Quality & Safety Using Surface Guided Planning and Dose Visualization
- 2. Improving Plan Quality & Safety Using Surface Guided Planning and Dose Visualization Adi Robinson Ph.D., DABR AdventHealth Celebration
- 3. Disclosures • AdventHealth Celebration has a COE agreement with VisionRT • AdventHealth Parker has a PSA agreement with VisionRT
- 4. AdventHealth Hospitals • AdventHealth Celebration • SimRT • AlignRT • MapRT • DoseRT • PatientID • AdventHealth Parker • SimRT • AlignRT • MapRT • DoseRT • PatientID
- 6. Surface guided Planning with Clearance Mapping • From day 1, ensure safe plan delivery and reduce physical collision checks • Introduce plan optimization based on the clearance map • Coplanar planning • Non-coplanar planning •No dry runs or collision checks •Insure safe plan delivery Safe Delivery •Optimize treatment plan based on “allowed” fields •Improve target coverage and reduce OAR dose Coplanar Optimization •Optimize treatment plan to include both non- coplanar options •Improve target dose conformality Non-Coplanar Planning
- 8. The Clearance Map Imported Plan Collision Area Collision Area Safety Buffers Passing Field Collision Area Collision Area Colliding Field Potential transition collision Arc static Iso location and couch shift
- 9. Surface Guided Planning Workflow • In the CT sim room • Capture surface prior to CT sim • Check for collisions • Adjust patient position or immobilization device accordingly. • Treatment Planning • Use clearance map to optimize the plan • Treatment • Plan can be safely delivered
- 10. Case Study: Rt Breast • 69 year old female with malignant neoplasm of the upper-inner quadrant of the right female breast
- 11. Rt Breast Clearance Map
- 12. Case Study: Lt APBI • 75-year-old female with malignant neoplasm of the central portion of the left breast • VMAT DIBH plan, 267cGy x 15 fractions
- 13. Standard Approach to APBI • 2 Field VMAT DIBH • CCW G155-G330 • CW G330-G155 Structure Constraint Lt APBI CP Lumpectomy_Lt 95% ≥ 95% 99.981% Lumpectomy_Lt V100% ≤ 93% 95% Lumpectomy_Lt Max ≤ 107% 105.619% Heart V1600cGy ≤ 5% 0% Heart Mean ≤ 200cGy 112cGy Lung_L V1750cGy ≤ 15% 0% Lung_L V880cGy ≤ 10% 0% Lung_L V144cGy ≤ 50% 11.972% Breast_R V144cGy ≤ 10% 0% Lung_R V440cGy ≤ 10% 0%
- 14. Non-Coplanar Surface Guided Planning • 2 Field VMAT DIBH with Non- Coplanar Fields • CCW G155-G330, T345 • CW G330-G155, T15 Structure Constraint Lt APBI CP Lt APBI NCP Difference Lumpectomy_Lt 95% ≥ 95% 99.981% 99.952% 0.029 Lumpectomy_Lt V100% ≤ 93% 95% 95% 0 Lumpectomy_Lt Max ≤ 107% 105.619% 104.427% 1.192 Heart V1600cGy ≤ 5% 0% 0% 0 Heart Mean ≤ 200cGy 112cGy 110cGy 2 Lung_L V1750cGy ≤ 15% 0% 0% 0 Lung_L V880cGy ≤ 10% 0% 0% 0 Lung_L V144cGy ≤ 50% 11.972% 2.66% 9.312 Breast_R V144cGy ≤ 10% 0% 0% 0 Lung_R V440cGy ≤ 10% 0% 0% 0
- 15. Lt APBI Non-coplanar Clearance Map
- 16. Case Study: Lt Deltoid • 41-year-old female with secondary malignant neoplasm of the left deltoid muscle • Previous radiation to the left chest wall and lymph nodes
- 17. Surface Guided Planning for Lt Deltoid • Coplanar plan • LAO G35 • LPO G120 • Noncoplanar Plan • LAO G35, T30 • LPO G120, T325 Structure Constraint NCP CP Diff Lt Deltoid Max ≤ 110% 109.71% 111.56% -1.85% Lt Deltoid V95% ≥ 95% 99.56% 99.31% 0.25% Breast_L V300cGy ≤ 10% 0% 0.02% -0.02% Breast_L Max ≤ 300cGy 49.6cGy 655.2cGy -605.60 cGy Heart V2500cGy ≤ 10% 0% 0% 0.00% Heart Mean ≤ 300cGy 4cGy 10cGy -6.00 Lung_L V2000cGy ≤ 35% 0% 0% 0.00% Breast_R V300cGy ≤ 10% 0% 0% 0.00% Breast_R Max ≤ 300cGy 1.5cGy 1.8cGy -0.30 cGy Lung_R V500cGy ≤ 10% 0% 0% 0.00%
- 18. Lt Deltoid Clearance Map
- 19. TPS Integration - Raystation
- 20. TPR Integration • Raystation – full integration with clearance check and map • Eclipse – integration via API. Mike Tallhamer will do a show and tell.
- 21. Surface Guided Treatment with Dose Visualization
- 22. SGRT with Dose Visualization • Simultaneous real time visualization of dose delivery and patient positioning. • Can help prevent treatment errors in real time and improve clinical outcome
- 23. Cherenkov Radiation • Cherenkov radiation is emitted when a charged particle moves through a medium faster than the phase velocity of light in that medium. • First observed in 1934 by Pavel Cherenkov when he saw a bluish light around a radioactive source placed in water. Tamm and Frank developed the theory in 1937 and all 3 share the 1958 Nobel Prize.
- 24. Cherenkov Imaging • Cherenkov light can be seen on the patient’s skin surface during treatment with special light sensitive cameras. • The Cherenkov signal is a result of the interaction of the entrance and exit beam during treatment. • This allows us to visualize the radiation treatment directly on the patient’s skin
- 25. Case Study: Bolus Misplacement • 62-year-old female, whole right breast treatment. • 13 with bolus, 12 fractions without. • On fraction 8 her bolus was misplaced • Corrected right away and closely monitored after.
- 26. Case Study: Lt Breast with Contralateral Breast Dose • 51 -year-old female, whole left breast treatment. • Treated with DIBH • On the 5th fraction, dose to the right breast was visualized • AlignRT tolerances and positioning were adjusted • On fraction 6, no dose to the right breast was seen,
- 27. Case Study: Dose to the Chin • 61-year-old female with malignant neoplasm of the left breast. • During the treatment of her SCV lymph node, dose to the chin was visualized. • Positioning of the patient was corrected for the next fraction
- 28. Prostate – Hand in Beam • 75 year old male with malignant neoplasm of the prostate • 4 field VMAT plan • On fraction 8, his hands moved into the beam path during the first arc.
- 29. Case Study: Rt Knee • 21 year old female with Villonodular Synovitis of the right knee (benign) • 4 field 3D conformal plan
- 30. Case Study: SRS Treatment • 53 year old female with malignant neoplasm of brain. • 9 Gy x 3 to 3 lesions. • 4 VMAT arcs in a non coplanar treatment.
- 31. Thymoma • 50 year old make with malignant neoplasm of the thymus • 2 field VMAT plan
- 32. Cherenkov Signal Linearity 300 250 200 150 100 75 50 25 y = 2393.3x - 6655.7 R² = 0.998 y = 2342.3x - 7456 R² = 0.9989 0 100000 200000 300000 400000 500000 600000 700000 800000 0 100 200 300 400 Cherenkov Signal Dose (cGy) Linearity 0 100000 200000 300000 400000 500000 600000 700000 800000 900000 1000000 0 100 200 300 400 500 600 700 800 300 250 200 150 100 75 50 25
- 33. Cherenkov Signal Constancy 0 5000 10000 15000 20000 25000 30000 35000 40000 24/11/2024 04/12/2024 14/12/2024 24/12/2024 03/01/2025 13/01/2025 23/01/2025 02/02/2025 12/02/2025 22/02/2025 04/03/2025 14/03/2025 Cherenkov Mean Signal Date 10X Cam0 10X Cam1 10FFF Cam0 10FFF Cam1 10X Cam0 15X Cam1 6X Cam0 6X Cam1 -10% -8% -6% -4% -2% 0% 2% 4% 6% 8% 10% 24/11/2024 04/12/2024 14/12/2024 24/12/2024 03/01/2025 13/01/2025 23/01/2025 02/02/2025 12/02/2025 22/02/2025 04/03/2025 14/03/2025 Difference from Mean Date 10X Cam0 10X Cam1 10FFF Cam0 10FFF Cam1 15X Cam0 15X Cam1 6X Cam0 6X Cam1 • Singal constancy check daily for 3 months. • All photon energies (except 6FFF) • Variation from mean does not exceed +/-6%
- 34. Cherenkov Signal Geometric Constancy • Field size check for 3 months • 6MV • All measurements under 2% following TG-142. 0.00 0.50 1.00 1.50 2.00 2.50 24/11/2024 04/12/2024 14/12/2024 24/12/2024 03/01/2025 13/01/2025 23/01/2025 02/02/2025 12/02/2025 22/02/2025 04/03/2025 Absolute Percent Difference Date 6X Cam0 6X Cam1
- 35. Cherenkov Signal vs Linac Output • Linac output was measured using ion chamber • Cherenkov signal was measured at the same time • Similarity was observed between the two 17 17.2 17.4 17.6 17.8 18 18.2 18.4 18.6 18.8 19 29/11/2024 04/12/2024 09/12/2024 14/12/2024 19/12/2024 24/12/2024 29/12/2024 03/01/2025 Charge (nC) Date 6X Output 6X Output 200000 250000 300000 350000 400000 450000 500000 29/11/2024 04/12/2024 09/12/2024 14/12/2024 19/12/2024 24/12/2024 29/12/2024 03/01/2025 Mean Signal Intensity Date 6X Cherenkov Signal 6X Cam0 6X Cam1 200000 250000 300000 350000 400000 450000 500000 29/11/2024 04/12/2024 09/12/2024 14/12/2024 19/12/2024 24/12/2024 29/12/2024 03/01/2025 Mean Signal Intensity Date Combined 6X Cam0 6X Cam1 6X Output
- 36. Conclusion • MapRT provides a clearance map that eliminates the need for collision checks and dry runs while assisting in improving the quality of the treatment plan • DoseRT provides dose visualization in real time. assists in improving the quality and safety of treatment delivery.