Voluntary breath hold in radiotherapy Radiotherapy Beacon centre
Voluntary breath hold in radiotherapy Radiotherapy, Beacon centre, Musgrove Park Hospital, Taunton Simon Goldsworthy, Principal research Radiographer Dr Mohini Varughese, Consultant Oncologist
The background Improving outcome by reducing risk of ischaemic heart disease: HEARTPSPARE II study Dr Anna Kirby et al. , Royal Marsden Hospital
Heart-sparing breast RT techniques • Various techniques developed • Voluntary deep inspiration breath hold (v. DIBH) technique – Cheap – Comfortable for patient – Reproducible
Initial concerns • How will patients cope with breath holding for 20 seconds? – What if they cough/sneeze? – What about co morbidities – ………
Initial concerns • Capacity – Initial appointment times will have to be 40 minutes. – Can we manage this? • Training of radiographers – How many? – Can we do it? • Risk assessment – Potential for geometric error • Stability and reproducibility – Better or worse geometric accuracy?
The story at the beacon centre: HEARTSPARE II to routine practice • PI: Dr Mohini Varughese • Fastest recruiting centre – 10 pts recruited within 2 months (03/14 -05/14) • Although financial pressure(capacity) the MDT concluded that this technique is for the greater good • June 2014 team felt all pts should have access to v. DIBH
The procedure at the Beacon centre • v. DIBH equipment needed: Philips wide bore CT scanner, ELEKTA lin. Ac with 2 D portal imaging, CCTV & intercom • In clinic: Oncologist checks patient can breath hold • Planning CT: All patients have one CT scan in breath hold (standard 30 minutes) – Coaching takes place within this timeframe (no extra coaching session) • NB. Patients asked to practice holding their breath for 20 seconds at home • Planning: 1 plan is produced • Treatment: Patient attends for #1 to n RT and coaching is delivered within 15 -20 minutes time slot, image verification daily to start with
How did patients cope? • Patients could breath hold easily for 20 seconds • Some patients needed altered breath hold management – Co morbidities = reduced breath hold times – Not able to follow usual instruction = we adapt our instruction – Patient anxiety = give the patient time • 6/175 patients could not manage breath hold for the following reasons: – Alcoholism – Multiple sclerosis – Just can not do it • Patients have not coughed or sneezed during the breath hold procedure!
Capacity • March 2014; for the HEARTSPARE II study the initial appointment times were 40 minutes. – After 3 patients appointment times were reduced to 20 minutes • September 2014; v. DIBH implemented for all patients – whole breast/chest wall (no bolus) – A 20 minute appointment slot was assigned • November 2014; v. DIBH extended to include nodal irradiation and photon boosts – A 30 minute appointment slot was assigned • December 2015 – v. DIBH tangents assigned 15 minute apoitments – v. DIBH tangs + nodal assigned 20 minute appointment
Training of radiographers • March 2014; initially started with 2 radiographers trained! – Increased to 6 after 2 weeks of opening HEARTSPARE • September 2014; All radiographers are competent in the breast hold technqie became standard practice • The training program: – – – Takes 1 -2 weeks to gain competence Radiographers watch training video on www. jove. com 1. do an offline run through x 1 2. Observe x 3 patients 3. Are supervised x 3 patients doing all tasks
Risk assessment • Risk of incorrect reference set in planning system • Risk of geometric error due to radiographers not making the manual longitudinal shift of the couch while patient in breath hold = Risk mitigated through comprehensive training = Risk mitigated as radiographers have to really focus reducing automaticity
Reproducibility & stability
2 D Image match of the breast @ the Beacon centre Portal image from radiotherapy treatment (MV) Digitally reconstructed radiograph (KV) from CT
PATIENT 1 Evaluating geometric displacements FRACTION AP SI ROT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 2. 0 1. 0 0. 0 -0. 1 1. 3 -0. 9 -0. 3 -2. 0 -0. 8 2. 0 3. 0 1. 0 0. 0 2. 0 0. 3 1. 6 2. 8 3. 0 2. 0 3. 0 1. 0 8. 0 3. 0 -4. 1 -4. 7 -1. 3 -3. 3 ∑ind σind 0. 1 1. 5 0. 9 1. 1 3. 8
Evaluating populations σpop ∑pop Population random error Population systematic error Population Random Error (mm) Population Systematic Error (mm) Per patient ∑ind SD of all mean geometric displacements Patient 1 2 3 4 5 6 7 8 9 10 ∑pop AP 0. 1 -1. 5 1. 3 -0. 4 -0. 3 -0. 6 -0. 4 -0. 6 -0. 5 0. 73 SI 1. 5 -1. 6 -2. 2 -0. 1 -1. 6 -1. 0 1. 6 1. 5 -0. 1 1. 41 ROT 0. 9 1. 6 0. 7 2. 9 -0. 3 2. 0 0. 0 -0. 9 2. 3 -0. 4 1. 30 σind Add in quadrature AP 1. 1 1. 7 1. 4 2. 4 1. 2 2. 5 3. 5 2. 5 1. 8 3. 2 1 2 3 4 5 6 7 8 9 10 σpop = =AVERAGE(B 5: B 37) =SQRT(D 104) 1. 31 2. 86 2. 02 5. 56 1. 45 6. 23 12. 39 6. 32 3. 24 10. 46 5. 19 2. 28 SI 1. 1 0. 8 3. 1 1. 5 1. 4 1. 9 1. 3 2. 5 3. 0 1. 12 1. 11 0. 66 9. 39 2. 17 1. 83 3. 44 1. 75 6. 21 9. 10 3. 68 1. 92 ROT 3. 8 2. 3 0. 8 1. 4 1. 3 1. 8 3. 2 2. 7 1. 1 14. 81 5. 51 0. 66 2. 09 2. 01 1. 78 3. 27 10. 44 7. 27 1. 24 4. 91 2. 22
The beginning: • Pre breath hold free breathing; March 2014 –∑pop & σpop for 10 patients with left sided breast cancer (50 images matched) Free breathing technique = Population Systematic Error (mm) Population Random Error (mm) • (AP) Ventral Dorsal ∑pop 2. 68 (SI) Craniocaudal ∑pop 2. 29 Rot (Pitch) ∑pop 1. 28 (AP) Ventral Dorsal σpop 3. 45 (SI) Craniocaudal σpop 3. 42 Rot (Pitch) σpop 1. 33 Breath hold; June 2014 –∑pop & σpop for 9 patients with left sided breast cancer recruited to the HEARTSPARE II study (135 images matched) v. DIBH technique = Population Systematic Error (mm) (AP) Ventral Dorsal ∑pop 1. 21 (SI) Craniocaudal ∑pop 0. 29 Rot (Pitch) ∑pop 1. 20 Population Random Error (mm) (AP) Ventral Dorsal σpop 1. 47 (SI) Craniocaudal σpop 0. 98 Rot (Pitch) σpop 2. 35 This informed us that v. DIBH is safe and more accurate than our standard free breathing technique!
Monitoring technique saturation • Standard breath hold technique; Dec 2014 to May 2015 –∑pop & σpop for 20 patients with left sided breast cancer (tangents/nodal/boost) (300 images matched) v. DIBH = Population Systematic Error (mm) Population Random Error (mm) (AP) Ventral Dorsal ∑pop 1. 70 (SI) Craniocaudal ∑pop 2. 01 Rot (Pitch) ∑pop 0. 68 (AP) Ventral Dorsal σpop 2. 04 (SI) Craniocaudal σpop 1. 95 Rot (Pitch) σpop 0. 87 This shows that both population systematic and random errors are within 5 mm tolerance prior to any pre treatment correction
Moving to an offline correction Strategy Image #1 -3 the weekly • Standard breath hold technique; July 2015 to Sept 2015 –∑pop & σpop for 20 patients with left sided breast cancer (tangents/nodal/boost) (120 images matched) v. DIBH = Population Systematic Error (mm) Population Random Error (mm) (AP) Ventral Dorsal ∑pop 1. 41 (SI) Craniocaudal ∑pop 1. 43 Rot (Pitch) ∑pop 0. 67 (AP) Ventral Dorsal σpop 2. 33 (SI) Craniocaudal σpop 2. 46 Rot (Pitch) σpop 0. 86 Population systematic and random errors are within 5 mm image tolerance justifying the move towards an offline image protocol
Aiming to improve comfort by adding a combi fix knee/foot rest • Standard breath hold technique ; Oct 2015 to Jan 2015 –∑pop & σpop for 17 patients with left sided breast cancer (ongoing data collection for (tangents/nodal/boost) (120 images matched) v. DIBH = Population Systematic Error (mm) Population Random Error (mm) (AP) Ventral Dorsal ∑pop 1. 18 (SI) Craniocaudal ∑pop 2. 03 Rot (Pitch) ∑pop 0. 80 (AP) Ventral Dorsal σpop 1. 84 (SI) Craniocaudal σpop 2. 26 Rot (Pitch) σpop 0. 77 Population systematic and random errors are within 5 mm. Slightly less variability as shown by reduction in random error, however not strong enough to justify using the comb fix. Also not suitable for 35% of patients as they are too tall.
All very exciting! over 175 patients treated Tangible patient benefits A simple technique Needs MDT approach No-brainer!?
What's next Deliver electron boosts in v. DIBH ? ? Right sided treatment – grey evidence from colleagues that mean lung dose can be reduced while patient in breath hold! How do we fully implement v. DIBH in our region?
Thank you simon. goldsworthy@tst. nhs. uk
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