Implementing New Technologies with quality and safety

Transcription

1 Implementing New Technologies with quality and safety 3 rd Annual Stereotactic Radiosurgery and Stereotactic Body Radiotherapy Symposium October 2014 David J. Gladstone, Sc.D., DABMP

2 Disclosures Dartmouth-Hitchcock Medical Center and Varian Medical Systems are parties to an evaluation agreement of the Varian 6DoF couch. No specific products are endorsed by Dartmouth-Hitchcock Medical Center. All human studies were approved by the Dartmouth IRB. No off label use. No animal studies.

3 Dartmouth-Hitchcock Medical Center

4 Are the outcomes of new technologies 1940 s 1970 s Nasopharyngeal Radium Irradiation 1980 s Hyperthermia 1990 s Monoclonal antibodies (magic bullets) 1990 s BMT for breast cancer 2000 s Mamosite always positive? 2010 Radiation therapy accidents reported (IMRT, SRS, NYT)

5 Implementing new technologies with quality and safety Or improve quality and safety of existing technologies.

6 Treatment sites Intracranial SRS as boost Intracranial SRS post surgical setting SBRT Spine SBRT Lung

7 Techniques Surgical frame SRS GTC frame SRS / SRT Open face mask Circular collimators Conformal Arc / VMAT Image guidance (IGRT) 4D delivery (gating) Intra-cranial SBRT

8 Systems at Dartmouth Planning Varian Eclipse VMAT Philips Pinnacle Cones Localizataion BRW intracranial Vision RT surface CBCT internal anatomy Delivery Trilogy - Vision TrueBeam 2.0; 6DOF couch; Vision Aria R&V

9 Targets GTV- gross tumor volume CTV- clinical target volume ITV- internal target volume PTV- planning target volume ITV CTV GTV PTV

10 GTV defined by various image modalities

11 Image fusion for GTV definition CT Automated Fusion Software MRI

12 Radiosurgery for brain metastases Surgery Radiosurgery

13 Timing of cavity SRS Allow time for healing after surgery Allow time for cavity to collapse in order to treat the minimum volume Note- toxicity is related to treatment volume Balanced against the risk of tumor growth in the interval- radiation most effective when minimal tumor burden

14 Cavities collapse Post-op d1 6.6cm 3 Post-op d5 T2 T1 pre-gd 2.5cm 3 T1 post-gd

15 Cavities Expand Post-op d1 11.5cm 3 Post-op d14 T2 T1 pre-gd T1 post-gd 26.5cm 3

16 Patients 41 Resected brain metastases 43 Average age (y) 63 (range = 24-78) Histology NSCLC Melanoma breast cancer rectal cancer renal cell cancer unknown primary prostate cancer small cell lung cancer head and neck cancer bladder sarcoma Average time between (d) MRI-2 and MRI-3 MRI-3 and SRS treatment Surgery to SRS treatment Surgical resections GTR STR days (range days). 5.5 days (range 1-18 days) 29.8 days (range days). 35 8

17 Summary of cavity dynamics 20 cavities (46.5%) were stable in size as defined as a change of <2 cm 3 10 cavities (23.3%) collapsed by >2 cm 3 13 cavities (30.2%) increased by >2 cm 3

18 Cavity volume change depends on initial size Preop tumor size (largest diameter, cm) Pre-op volume (cm3) Post-op (cm3) GTV(cm3) PTV = GTV + 2mm (cm3) (n=8) > (n=13) 2.7 ( ) 4.27( ) 5.0( ) 8.1( ) 7.7 ( ( ) 5.9( ) 9.5( ) > 3.0 (n=22) 22.3( ) 11.8( ) 11.8( ) 17.3( )

19 Practice goals When medically appropriate, we will offer cavity SRS to patients immediately after surgical resection, during the same hospital stay Eliminates the need for an additional MRI Reduces outpatient clinic visits Reduce the lost to follow up patients Reduces the risk of tumor re-growth Lead to the need for a second surgery They may no longer be a candidate for SRS

20 SRS at Dartmouth (cones)

21 SRS Immobilization Surgical Frame GTC frame (less frame) Frameless

22 BRW coordinate system

23 Pre-treatment QA

24 Isocenter check 0.8 mm

25 Patient specific localization QA

26 Confirmation by imaging Frame based: planar imaging GTC or Mask: CBCT, 6DOF

27 GTC pre-treatment checks

28 Localization QA

29 Localization QA 2 Need annual QA screen shots and results

30 Localization QA 3

31 Isocentricity - Trilogy

32 TrueBeam MPC

33 TrueBeam MPC 2 Trend-lines for all measured parameters

34 Induced failures MPC 3

35 Uncorrelated errors add in quadrature BRW 2 + CT volume 2 + Gantry 2 + Couch 2 + OBI = 0.8 mm(trilogy) = 0.6 mm (TrueBeam) Image matching uncertainty at treatment

36 Frameless motivation Patient comfort Ability to plan ahead IMRT/VMAT possible Multiple lesions single isocenter Image based setup VS mechanical / laser

37 6 DOF for frameless delivery systems Trilogy with Vision 6DOF TrueBeam with Varian 6DOF and Vision monitoring

38 Vision QA

39 Multiple lesions, single isocenter with RapidArc

40 RapidArc DVH

41 Shielding for fetus

42 Fetal dose measurements Whole Brain 3 Gy X 10 RapidArc 12Gy 18 Gy Without lead With Lead 6.5 mgy 4.4 mgy 6 mgy 2.2 mgy

43 Towards WYSIWYG in Rad Onc Can we devise a method to directly verify the correct dose is given to the correct place? Radiation is invisible Cherenkov emission is VISABLE

44 The Cherenkov effect Physical origin Charged particle at rest Relativistic charged particle

45 The Cherenkov effect light emission The Cherenkov angle The Frank-Tamm formula cos θ = AC AB = c vn = 1 βn dn dx = 2παz2 1 1 β 2 n 2 1 λ 2 dλ

46 The Cerenkov effect *Strongest in the UV and blue Dose Production Cerenkov Production D = 1 ρ Φ dt dx de N = 1 ρ Φ dn dx de Cherenkov radiation and its applications, Jelley Glaser, et. al., Med. Phys. (2013)

47 Radiation induced Cherenkov Emission Galvin JCO 2007 e - e - e - e - Photograph of emission ring below water tank

48 Fluorescence randomizes emission direction e - e - Galvin JCO 2007 e - e - Galvin JCO 2007 Quinine sulphate (fluorophore) e - e - e - e -

49 Wavelength shifting Quinine sulphate (fluorophore)

50 LINAC Beam Profiling Hardware LINAC Water Tank ICCD Water tank ICCD Patient Bed Rotating arm

51 position Multiple Angle Beam Imaging Images at different angles ROTATE Sinogram 0 O 15 O 30 O 45 O Reconstructed 3D volume with FBP 0 O 90 Angle O 180 O

52 3D Cherenkography of LINAC Beams Square beam Complex shaped beam

53 Parallel beam tomography Field A Field A Medical Linear Accelerator z Primary Collimator 91 projections acquired θevery 2 o x y Exposure time: 18 sec. Field B Total scan time of < 30 min. Field B Resolution: 1 mm Multileaf Collimator Field of View Radiation Beam Reconstructed volume: 10x10x10 cm 3 Camera System Telecentric Lens Water Tank

54 IMRT and VMAT

55 Predicted versus measured

56 First imaging of Cherenkov emission from a human breast Entrance Cherenkov Exit Cherenkov 6MV Entrance 6MV Exit Whole breast radiotherapy with dynamic field. Real time monitoring and imaging (fps ~= 2.5).

57 First imaging of Cherenkov emission from a human breast 6MV 6MV Exit 6MV Entrance 6MV Exit Entrance 10MV Entrance 10MV Exit Cherenkov emission shows correct beam field shape on body. Signal from entrance beam shows high superficial dose in axilla, where skin reactions are common. Signal from entrance and exit beams show high surface dose in inframammary fold and near the arm, where skin reactions are also common.

58 TSE Total Cherenkov mean - bkg

59 Stereotactic team Alan Hartford, MD PhD Lesley Jarvis, MD PhD Phil Schaner, MD PhD Benjamin Williams, PhD Colleen Fox, PhD

60 Cherenkography Team Adam Glaser Rongxiao Zhang Chad Kanick, PhD Scott Davis, PhD Whitney Hitchcock Sergei Vinogradov, PhD Brian Pogue, PhD Colleen Fox, PhD Lesley Jarvis, MD PhD Audrey Prouty Development Fund R01CA P30 CA23108

61 Questions Sometimes you can get shown the light in the strangest of places if you look at it right. J. Garcia, R. Hunter

62 Spine Metastases Of cancer patients, 40 85% with spinal mets at autopsy 5% with MESCC (>20,000/year in U.S.) 1 95% extradural (mostly vertebral) Survival depends on histology, systemic disease, functional status Pain due to spine metastases is an important clinical problem

63 Traditional External Beam RT 2/3 patients have pain relief at 3 months Common fractionation schemes 3Gy X 102Gy X 20 4Gy X 5 8Gy X 1 No difference in ambulatory rates, but local recurrences increased in short schedules Consider protracted schedules to avoid local recurrences given the consequences of a failure and difficulty with re-irradiation Common techniques C spine: opposed laterals T spine: PA or AP/PA L/S spine: AP/PA

64 Traditional Tx field

65 Spine SRS plan

66 Spine SRS results From experience in brain- 85% local control Single day or few days of treatment Non-invasive Dose escalation while respecting spinal cord tolerance Decreased volume of treated bone marrow Improved pain control Reported results of 80% pain control and 95% LC, compared to ~60% pain control with fractionated RT

67 Definition of target on CT -77 yo man, diagnosed with prostate cancer in Initially treated with systemic therapy -Disease became androgen resistant in Received EBRT to prostate and pelvic LNs in At initial consult: PSA 109, back pain, bone scan +T10 only, MRI showed involvement of anterior and posterior elements, and involvement of left foramina

68 RapidArc treatment plan

69 On board imaging prior to and during treatment

70 Spine treatment verification Trilogy RapidArc delivered in three segments CBCT before each segment Out of plane rotations adjusted by patient setup Abort if motion detected 6 SRS Tx time ~45 min TrueBeam Single RapidArc CBCT before treatment 6DOF couch used for setup adjustment Real-time marker detection during treatment. FFF Tx time ~20 min

71 Rotations of cervical vertebrae C1 C2 C3 C4 C5 C6 C7-5 C1 C2 C3 C4 C5 C6 C7-5 C1 C2 C3 C4 C5 C6 C C1 C2 C3 C4 C5 C6 C7-5 C1 C2 C3 C4 C5 C6 C7-5 C1 C2 C3 C4 C5 C6 C C1 C2 C3 C4 C5 C6 C7-5 C1 C2 C3 C4 C5 C6 C7-5 C1 C2 C3 C4 C5 C6 C C1 C2 C3 C4 C5 C6 C7-5 C1 C2 C3 C4 C5 C6 C7-5 C1 C2 C3 C4 C5 C6 C C1 C2 C3 C4 C5 C6 C7-5 C1 C2 C3 C4 C5 C6 C7-5 C1 C2 C3 C4 C5 C6 C7 Frequency Frequency Frequency 40 Mean = 0.5 SD = xrot [deg] 40 Mean = -0.2 SD = yrot [deg] 40 Mean = -0.2 SD = zrot [deg] % vertebrae < -3 degrees % vertebrae > +3 degrees % vertebrae outside ± 3 degrees Rx rotation Ry rotation Rz rotation

72 RPM used for lung SBRT Plan is prepared on gated scan Copied to non-gated scan to match CBCT Dose grid removed from non-gated scan to preserve intent

73 Gated treatment details Trilogy RPM not integrated CBCT normal mode SRS mode (1000) MU/min TrueBeam RPM integrated CBCT (extra long) Gated fluoro Automated marker detection FFF ( MU/min)