Comparison of Interfacility Implementation of Essential SBRT Components. Keith Neiderer B.S. CMD RT(T) VCU Health System

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1 Comparison of Interfacility Implementation of Essential SBRT Components Keith Neiderer B.S. CMD RT(T) VCU Health System

2 Disclosures None

3 Objectives Review essential components that characterize SBRT Compare and Contrast different institutional philosophies in regards to the SBRT planning and treatment process Provide information for attendee to form their own opinion on an optimal model for a SBRT program

4 SBRT Components Secure Immobilization Proper Accounting of Internal tumor and organ motion Accurate repositioning Creation of highly conformal dose distributions Registration of patient s anatomy, created dosimetry, and treatment delivery to a 3D coordinate system referenced to fiducials Biologically potent dose prescriptions

5 Secure Immobilization Body Conformal Bags - Vacuum-Lock Bags (+/- Wingboard) - Alpha Cradles

6 Secure Immobilization SBRT Body Frames

7 Accounting for Internal Tumor and Organ Motion Free Breathing ITV based Planning (encompassing entire range of tumor motion) Gating (Targeting a phase of the breathing cycle) Breath Hold Targeting either inhalation or exhalation Tumor Tracking

8 Accounting for Internal Tumor and Organ Motion ITV Based Planning - contour on MIP (maximum intensity projection) Maximum Intensity Projection Maximum Expiration Maximum Inspiration

9 Accounting for Internal Tumor and Organ Motion ITV Based Planning -create ITV based on contours from all 10 Phases

10 Accounting for Internal Tumor and Organ Motion Respiratory Gating

11 Accounting for Internal Tumor and Organ Motion Breath Hold Voluntary AV Biofeedback ABC (active breathing control)

$position Intrafraction To correct for any patient$

12 Accurate Repositioning Indexing of Immobilization devices to patients and couch Imaging CBCT kv OBI Pretreatment Isocenter localization and correct patient position Intrafraction To correct for any patient movement if necessary

13 Creation of Conformal Dose Distributions

14 Creation of Conformal Dose Distributions 3D Conformal Coplanar / Noncoplanar No parallel opposing beams Block margins 0 margin Negative margin Inhomogeneous distribution 3 7 mm margin Forward Planning Conformality and Normal Tissue Sparring Beam angles chosen Manual optimization of beam weights Adjustment of MLC positions

15 Creation of Conformal Dose Distributions IMRT / VMAT IMRT Parameters Interplay effects between MLC and target motion 1 3 Segments per beam (minimal modulation) Minimum segment size 2cm x 2cm Optimization Parameters Inhomogeneous Distribution No max dose constraint for target Conformality Use rings to keep distribution tight and create steep dose gradients

16 Potent Dose Prescriptions SBRT in early stage NSCLC achieving a BED of > 100 Gy leads to improved survival 20 Gy x 3 18 Gy x 3 12 Gy x 5 12 Gy x 4 10 Gy x Gy x Gy Gy 132 Gy Gy 100 Gy 105 Gy Onishi et al, Cancer, 2004

17 Site A Academic Institution Simulation Physicist is present at time of simulation Immobilization Vac-loc Bag Abdominal Compression Plate Plate is compressed to position of uncomfort, then dialed back slightly

18 Site A Accounting for Motion 4DCT Scan ITV planning AVG Scan for dose calculation and normal tissue contouring MIP (0 90%) for ITV delineation

19 Site A Accurate Repositioning Patient is indexed to table using compression frame with paddle just inferior to sternal notch Pretreatment CBCT to verify patient positioning and isocenter localization No intrafraction imaging Potent Dose Prescriptions 18 Gy x 3 Fxs 10 Gy x 5 Fxs 5 Gy x 10 Fxs (for retreats) Treat patient every day

20 Site A Conformal Dose Distributions beam noncoplanar arrangement Approximately 5 of the 13 beams would be noncoplanar Block Margin 0 margin in Ant, Post, Lt and Rt directions 2mm 5mm margin Sup and Inf Optimization No modulation of dose within field Isodose Optimization Number of beams, beam location, beam weight Manual manipulation of MLC to help with conformality and normal tissue sparring

21 Site A Patient 1: RUL Lung

22 Site A Patient 1: RUL Lung

23 Site A Patient 2: RLL Lung

24 Site A Patient 2: RLL Lung

25 Site A Patient 3: LUL Lung

26 Site A Patient 3: LUL Lung

27 Site B Dedicated Stereotactic Center Simulation Physicist is present at time of simulation Immobilization and 4DCBCT are done on treatment machine Vac-loc Bag Patient is given an anti-anxiety medication to help stay relaxed for both simulation and treatment Simulation on the treatment machine allows for testing of gantry and couch angles if necessary Patient is then taken to Radiology where a diagnostic CT is done in the treatment position for planning purposes

28 Site B Accounting for motion 4DCBCT ITV planning Diagnostic CT used for dose calculation and normal tissue contouring ITV delineation from 4DCBCT MIP Potent Dose Prescription 10 Gy x 5 15 Gy x 4 Patients treat once a week

29 Site B Accurate Repositioning Vacloc bag is indexed to table Patient is scheduled for a verification day Setup in Treatment position KV imaging orthogonals CBCT Test parameters for treatment fields On treatment day Pretreatment kv and CBCT Repeat CBCT half way through treatment

30 Site B Conformal Dose Distributions 20 or more noncoplanar arrangement Approximately half of the beams would be noncoplanar No heterogeneity corrections Block Margin Patient specific based on location and dose objectives Optimization No modulation of dose within field Isodose optimization Number of beams, beam location, beam weight Manual manipulation of MLC to help with conformality and normal tissue sparring

31 Site B Patient 1: RUL Lung

32 Site B Patient 1: RUL Lung Only 4 couch angles ~ 45 min treatment slot

33 Site B Patient 1: RUL Lung

34 Site B Patient 2: RLL Lung

35 Site B Patient 2: RLL Lung

36 Site B Patient 3: LUL Lung

37 Site B Patient 3: LUL Lung

38 Site B Heterogeneity Corrections On / Off

39 Site B Heterogeneity Corrections On / Off

40 Site C Academic Institution Simulation Physicist is not present at time of simulation Immobilization Vac-loc Bag with wing board

41 Site C Accounting for Motion 4DCT and Free Breathing Motion evaluation 0 0.5cm motion use free breathing scan cm motion ITV Planning (AVG and MIP) > 1.5cm motion rescan using breath hold (ABC) or

42 Site C Accurate Repositioning Wing board and vac-loc bag are indexed to the couch Pretreatment imaging kv OBI orthogonal images bony alignment CBCT soft tissue alignment Intrafraction imaging CBCT soft tissue alignment (midway through tx) Potent Dose Prescriptions 12 Gy x 4 Fx 18 Gy x 3 Fxs Patients treated every other day or twice a week depending on physician

43 Site C Conformal Dose Distributions 8 10 coplanar IMRT beams No parallel opposing beams IMRT Parameters 1 3 segments per beam Minimum segment size of 2cm x 2cm Optimization Parameters Inhomogeneous Distribution Max dose constraint = prescription dose / 0.8 Conformality Use rings to keep distribution tight and create steep dose gradients

44 Site C Patient 1: RUL Lung

45 Site C Patient 1: RUL Lung

46 Site C Patient 2: RLL Lung

47 Site C Patient 2: RLL Lung

48 Site C Patient 3: LUL Lung

49 Site C Patient 3: LUL Lung

50 Site D Academic Institution Simulation Physicist is present at time of simulation Immobilization Vac-loc Bag Alphacradle Potent Dose Prescriptions 18 Gy x 3 Fxs 12.5 x 4 Fxs 7.5 Gy x 8 Fxs

51 Site D Accounting for Motion Free Breathing, 4DCT, Breath Hold (if feasible) Motion Evaluation ITV Planning Avg dose calculation and normal tissue contouring MIP ITV delineation Consider Gating if motion is greater than 1cm Breath Hold

52 Site D Accurate Repositioning Vac-loc bag indexed to couch Pretreatment imaging kv OBI orthogonal images apply shifts CBCT apply shifts Retake CBCT if shift is greater than 1mm in any direction Verify motion with kv fluoro imaging Intrafraction imaging Cine images are taken for each field to monitor motion Not all fields will reveal tumor motion CBCT

53 Site D Conformal Dose Distributions 7 to 9 coplanar beams Block Margin 5mm margin in Ant, Post, Lt, and Rt directions 7mm margin Sup and Inf Optimization Wedges Manual manipulation of MLC and Jaws to help with conformality and normal tissue sparring

54 Site D Patient 2: RLL Lung

55 Site D Patient 2: RLL Lung

56 VMAT Patient 1: RUL Lung

57 VMAT Patient 1: RUL Lung

58 VMAT Patient 2: RLL Lung

59 VMAT Patient 2: RLL Lung

60 VMAT Patient 3: LUL Lung

61 VMAT Patient 3: LUL Lung

62 Patient 1: RUL Lung Conformity Index (CI) <1.2 R50 for 39cc PTV 4.3 minor 5.3 RTOG 0813

63 Patient 1: RUL Lung Lung DVH

64 Patient 1: RUL Lung Chestwall DVH

65 Patient 2: RLL Lung Conformity Index (CI) <1.2 R50 for 35cc PTV 4.3 minor 5.3 RTOG 0813

66 Patient 2: RLL Lung Lung DVH

67 Patient 2: RLL Lung Chestwall DVH

68 Patient 3: LUL Lung Conformity Index (CI) <1.2 R50 for 22cc PTV 4.5 minor 5.5 RTOG 0813

69 Patient 3: LUL Lung Lung DVH

70 Patient 3: LUL Lung Chestwall DVH

71 Summary You Tell me, how would you do it?

72 Acknowledgements VCU Health System Geoff Hugo, PhD Josh Evans, PhD Duke University Health System Rodney Hood, CMD Lei Ren, PhD Chesapeake Regional, Riverside and University of Virginia Radiosurgery Center K. Martin Richardson, MS Kelly Spencer, MS Wake Forest Baptist Health Jim Ververs, PhD Alton Fleming, BS, CMD William Andy Dezarn, PhD William H. Hinson, PhD University of Virginia Health System David Schlesinger, PhD

73 References 1. Brock J, Bedford J, Partridge M, McDonald F, Ashley S, McNair H, Brada M (2012) Optimizing Stereotactic Body Radiotherapy for Non-small Cell Lung Cancer with Volumetric Intensitymodulated Arc Therapy A Planning Study. Clinical Oncology 24: Hendrickson, K (2014, June) Treatment Planning AAPM Summer School. Lecture conducted from University of Vermont, Burlington, VT. 3. Kavanagh B, McGarry R, Timmerman R (2006) Extracranial Radiosurgery (Stereotactic Body Radiation Therapy) for Oligometastases. Semin Radiat Oncol 16: Lim DH, Yi BY, Mirmiran A, Dhople A, Suntharalingam M, D Souza W (2010) Optimal Beam Arrangement for Stereotactic Body Radiation Therapy Delivery in Lung Tumors. Acta Oncologica 49: Liu R, Buatti J, Howes T, Dill J, Modrick J, Meeks S (2006) Optimal Number of Beams for Stereotactic Body Radiotherapy of Lung and Liver Lesions. Int. J. Radiatin Oncology Biol Phys 3: Mcgrath S, Matuszak M, Yan D, Kestin L, Martinez A, Grills I (2010) Volumetric Modulated Arc Therapy for Delivery of Hypofractionated Stereotactic Lung Radiotherapy: A Dosimetric and Treatment Efficiency Analysis. Radiotherapy and Oncology 95: Ong CL, Verbakel W, Cuijpers J, Slotman B, Lagerwaard F, Senan S (2010) Stereotactic Radiotherapy for Peripheral Lung Tumors: A Comparison of Volumetric Modulated Arc Therapy with 3 other Delivery Techniques. Radiotherapy and Oncology 97: RTOG 0813 Seamless Phase I/II Study of Stereotactic Lung Radiotherapy for Early Stage, Centrally Located, Non Small Cell Lung Cancer in Medically Inoperable Patients. 9. RTOG 0915 A Randomized Pase II Study Comparing Two Stereotactic Body Radiation Therapy Schedules for Medically Inoperable Patients with Stage I Periperal Non-Small Cell Lung Cancer 10. Takayama K, Nagata Y, Negoro Y, Mizowaki T, Sakamoto T, Sakamoto M, Aoki T, Yano S, Koga S, Hiraoka M (2005) Treatment Planning of Stereotactic Radiotherapy for Solitary Lung Tumor. Int. J. Radiation Oncology Biol Phys 61: Timmerman R, Forster K, Cho LC (2005) Extracranial Stereotactic Radiation Delivery. Semin Radiat Oncol 15:

74 Happy 2 nd Birthday Gavin October 3, 2014

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