Respiratory Motion Management in Stereotactic Ablative Radiotherapy:

Transcription

1 Respiratory Motion Management in Stereotactic Ablative Radiotherapy: A pilot study investigating the efficacy and reproducibility of the CIVCO Body Pro-Lok Respiratory Belt Lloyd Smyth, Yolanda Aarons, Jim Frantzis, Nola Bailey Epworth HealthCare Excellence. Everywhere. Everyday

2 Introduction Role of motion management in Stereotactic Ablative Radiotherapy (SABR) Aims & methods of this pilot study Results Discussion and clinical possibilities Future directions 2

3 Oligometastases and SABR Limited number of well localised metastases Can be controlled with SABR delay disease progression 1-4 Improves quality of life 4 Deliver BED > 100Gy Additional dose escalation may further improve outcomes 4 3

4 Respiratory Motion Management Pulmonary and hepatic lesions are subject to respiratory motion Motion Restrictive Abdominal Compression Rigid Plate Drape Pneumatic Belt Breath Hold Techniques Motion Compensating Real-Time Tumour Tracking Respiratory Gating 4

5 CIVCO Respiratory Belt Pneumatic Evenly disperses pressure across abdominal plane Low electron density Image courtesy of CIVCO Medical Solutions (Orange City, Iowa) 5

6 Clinical Context Can respiratory compression facilitate SABR dose escalation? Respiratory Motion Reduced Smaller Target Volumes Decreased health tissue irradiation Dose escalation permitted 6

7 Clinical Context Can we combine respiratory compression with respiratory gating to increase treatment efficiency? Motion Restrictive Motion Compensating Abdominal Compression Pneumatic Belt Real-Time Tumour Tracking Breath Hold Techniques Respiratory Gating 7

8 Aim To evaluate: The efficacy of the respiratory belt in limiting respiratory motion The reproducibility of using the respiratory belt The comfort of the respiratory belt The impact of belt pressure on the above outcomes 8

9 Methodology Prospective pilot study Ten healthy participants Low Risk HREC approval Varian Real-time Position Management (RPM) system Analysis of breathing traces Free breathing (FB), Low pressure (LP), High pressure (HP) 9

10 Methodology Set-up TOX/JOR level Rail System Belt Index RPM Marker Box 10

11 Methodology Healthy Participants (n=10) RPM Breathing Traces Free Breathing x3 (Base-line) Low Pressure x3 (~1kPa) High Pressure x3 (~5kPa) Random Order 11

12 Methodology - Endpoints Efficacy: Average maximum displacement of the RPM marker box from origin Amplitude of breathing motion Reproducibility: Variation in average maximum displacement of the RPM marker box Comfort: Scored by each participant on a visual analogue scale 12

13 Methodology Average max. displacement from origin was determined by measuring the magnitude of peaks and troughs Magnitude of peak Origin Magnitude of trough 13

14 Methodology Average max. displacement from origin was determined by measuring the magnitude of peaks and troughs Average maximum displacement from origin for each breathing trace (FB, LP, HP) 14

15 Results Average Max. Displacement vs Pressure Free Breathing Baseline Mean 15

16 Results Efficacy - Difference between group means Comparison Mean Max. Displacement p value FB vs LP 0.01mm LP vs HP 0.09mm FB vs HP 1mm Reproducibility Difference in STD of group means Belt Pressure Free Breathing Low Pressure p<0.05 for significance Standard Deviation 0.11mm 0.09mm High Pressure 0.05mm p=

17 Results Mean Comfort Score LP vs HP Mean = 1.8 Mean = 6.2 Mean difference = 4.37 P<

18 Discussion Need to use a higher pressure when using belt Average Max. Displacement vs Pressure Comfort/tolerability should be considered Require n=60 to confirm statistical significance 18

19 Expected Results Breathing traces for participant 7 Solid lines indicate mean magnitude of peaks/troughs 19

20 Paradoxical Effect Breathing traces for participant 5 Solid lines indicate mean magnitude of peaks/troughs 20

21 Limitations Study size of 10 participants Healthy volunteers vs real patients Use of RPM cube as a surrogate for respiratory motion Ant-Post motion vs Sup-Inf motion

22 Future Directions 4DCT study Analyse internal organ motion and tumour motion To what extent does compression reduce internal target motion and subsequent treatment margins? 22

23 Conclusion CIVCO Respiratory Belt shows promising results Reduces extent and variability of respiratory motion 4DCT and greater study size needed to confirm the significance of benefits Potential use of the belt in the future to facilitate SABR dose escalation and to increase the efficiency of respiratory gating 23

24 Acknowledgements CMS Alphatech, Sydney, Australia Sean McGuigan, Biostatastician, Clinical Trials Unit, Epworth Healthcare Yolanda Aarons, Jim Frantzis, Nola Bailey and the entire team at Epworth Radiation Oncology Department of Medical Imaging and Radiation Sciences, Monash University, Victoria 24

25 References 1. Weichselbaum RR, Hellman S. Oligometastases revisited. Nat Rev Clin Oncol 2011;8: Tree AC, Khoo VS, Eeles RA, et al. Stereotactic body radiotherapy for oligometastases. Lancet Oncol. 2013;14:1:e Corbin KS, Hellman S, Weichselbaum RR. Extracranial oligometastases: a subset of metastases curable with stereotactic radiotherapy. J Clin Oncol 2013;31: Oh D, Ahn YC, Seo JM, et al. Potentially curative stereotactic body radiation therapy (SBRT) for single or oligometastasis to the lung. Acta Oncol 2012;51: Heinzerling JH, Anderson JF, Papiez L, et al. Four-dimensional computed tomography scan analysis of tumour and organ motion at varying levels of abdominal compression during stereotactic treatment of lung and liver. Int J Radiat Oncol Biol Phys 2008;70: Bouilhol G, Ayadi M, Rit S, et al. Is abdominal compression useful in lung stereotactic body radiation therapy? A 4DCT and dosimetric lobe-dependent study. Phys Med 2013;29: Eccles CL, Patel R, Simeonov AK, et al. Comparison of liver tumour motion with and without abdominal compression using cine-magnetic resonance imaging. Int J Radiat Oncol Biol Phys 2011;79: