- Email: [email protected]
127: An audit of online cone beam CT (CBCT) verification data for stereotactic ablative radiotherapy (SABR)
S46
Poster abstracts, 13th Annual British Thoracic Oncology Group Conference, 2015: Radiotherapy
Cancer Network (N27), Anglia Cancer Network (N37) and South West London (N25). Results: The graph shows the Trust and Network have shorter survival times as compared to the best performing trusts. RWH has a median survival of 141 days compared to 188 days nationally. The longest survival of 221 days is the N27 Dorset Cancer Network.
5 patients had no evidence of local recurrence and 1 had distant metastases with no evidence of local recurrence. Patient
Age
Gender
Stage
WHO PS
Reason for not having surgery
1 2 3 4
82 78 76 83
F F F F
T1aN0M0 T1aN0M0 T1aN0M0 T2aN0M0
1 1 1 2
5
81
F
T1aN0M0
1
6
70
F
T1aN0M0
1
Unknown Refused surgery Inoperable (close to large bullae) Assessed by surgeon, inadequate lung function Assessed by surgeon, inadequate lung function Assessed by surgeon, inadequate lung function
Conclusion: This retrospective analysis found SABR results in low acute toxicity in this cohort. Longer follow-up is needed to assess local control and progression-free survival. For the future, the department plans to use RapidArc radiotherapy technology which will shorten the treatment time. Disclosure: All authors have declared no conflicts of interest.
Conclusion: East and North Hertfordshire NHS Trust and its Network have comparably shorter median times of survival than nationally. The reason remains unknown. Time to diagnosis may be an important influence on these figures due to lead time bias, because median survival is calculated from diagnosis. The whole patient pathway is being examined to determine if this can explain the results. Disclosure: All authors have declared no conflicts of interest.
Radiotherapy 126 Our experience in treating lung tumours using stereotactic ablative body radiotherapy (SABR) at Northampton General Hospital H. Yusof *, A. Gore, C.I. Mak, H. Eldeeb, D. Vaidya, H. Acquah, N. Whilde. Oncology, Northampton General Hospital, United Kingdom Introduction: A retrospective analysis of patients demographic, dosimetric parameters, toxicity and outcome of lung cancer patients treated with SABR at Northampton General Hospital. Methods: 6 patients were treated from April 2013 to February 2014. Patients’ demographic, toxicity and outcome data were obtained from the hospital oncology database. Dosimetric parameters data were obtained from the hospital medical physics database. We used SABR UK consortium protocol as guidelines. Only peripheral lesions outside a 2 cm radius of main airways and proximal bronchial tree were treated. All had gold seed fiducial markers implanted for tumour localisation at treatment. Fine needle aspiration (FNA) for histological diagnosis was carried out at the time of fiducial placement. All had 4DCT scan for assessing tumour motion for radiotherapy planning. ITV to PTV margin used was 5 mm. All treatment plans used fixed coplanar beam arrangements. Image guided radiotherapy (IGRT) was implemented via ExacTrac kV imaging of the marker. Results: Patient demographics are shown in the table. Five patients received 55 Gy in 5 fractions and 1 received 54 Gy in 3 fractions, both dose fractionation delivered a biologically effective dose in 2 Gy fractions (BED2) of >150 Gy. PTV volume ranged from 22.6 to 83.89 cc. Lung V20 ranged from 3.2% to 10.0%. Treatment time ranged from 1 hour 40 minutes to 30 minutes per fraction. Acute toxicities were Grade 1 skin reaction in 1 patient, Grade 2 lethargy in 1 and the other 4 denied any toxicities. At the most recent follow-up appointments up to September 2014,
127 An audit of online cone beam CT (CBCT) verification data for stereotactic ablative radiotherapy (SABR) R. Mendes *, L. Allington, D. Carnell, N. Haji, K. Osborn. Radiotherapy, University College London Hospitals, London, United Kingdom Introduction: Since May 2012, UCLH has treated 45 patients with a diagnosis of stage 1 non-small-cell lung cancer patients using SABR. All patients are treated using volumetric arc therapy (VMAT) on a TrueBeamTM STx. A significant challenge for SABR is to accurately and precisely deliver highly conformal, hypofractionated radiation doses to a small target while minimising dose to normal tissues and organs at risk. Therefore, for the implementation of this technique within a department, it is vital that a rigorous treatment verification protocol is adopted. Methods: At UCLH a daily CBCT imaging protocol is in place whereby translational shifts are applied following an online tumour match. In order to evaluate the impact of this protocol on the delivery of SABR and the validity of this imaging procedure, an audit of 25 patients was undertaken assessing both inter- and intra-fractional match variations. Systematic and random errors were calculated, and validation of planning target volume set-up margins undertaken. Results: Evaluation of data indicated no systematic set-up error within the patient cohort. Mean displacements of 0.3 to 0.4 cm were observed at initial setup in all three directions. Total intrafraction motion of up to 0.5 cm was recorded over an entire treatment session. Conclusion: This presentation will describe the verification protocol adopted at UCLH and discuss results from the audit and how ammendments were made post evaluation. Disclosure: All authors have declared no conflicts of interest. 128 Experience of lung stereotactic ablative body radiotherapy (SABR) in a non-academic cancer centre in the UK M. Shahid Iqbal1 *, A. Cyriac1 , E. Aynsley1 , D. Shakespeare1 , N. Richmond2 , C. Walker2 , K. Piling3 , C. Peedell1 . 1 Clinical Oncology, South Tees Hospitals NHS Trust, Middlesbrough, United Kingdom, 2 Physics, South Tees Hospitals NHS Trust, Middlesbrough, United Kingdom, 3 Radiographer, South Tees Hospitals NHS Trust, Middlesbrough, United Kingdom Introduction: SABR has recently gained wider popularity in the treatment of ‘medically inoperable’ early stage non-small cell lung cancer (NSCLC) but the availability of technique remains limited to big academic centres. We describe our experience of building
Poster abstracts, 13th Annual British Thoracic Oncology Group Conference, 2015: Radiotherapy
Cancer Network (N27), Anglia Cancer Network (N37) and South West London (N25). Results: The graph shows the Trust and Network have shorter survival times as compared to the best performing trusts. RWH has a median survival of 141 days compared to 188 days nationally. The longest survival of 221 days is the N27 Dorset Cancer Network.
5 patients had no evidence of local recurrence and 1 had distant metastases with no evidence of local recurrence. Patient
Age
Gender
Stage
WHO PS
Reason for not having surgery
1 2 3 4
82 78 76 83
F F F F
T1aN0M0 T1aN0M0 T1aN0M0 T2aN0M0
1 1 1 2
5
81
F
T1aN0M0
1
6
70
F
T1aN0M0
1
Unknown Refused surgery Inoperable (close to large bullae) Assessed by surgeon, inadequate lung function Assessed by surgeon, inadequate lung function Assessed by surgeon, inadequate lung function
Conclusion: This retrospective analysis found SABR results in low acute toxicity in this cohort. Longer follow-up is needed to assess local control and progression-free survival. For the future, the department plans to use RapidArc radiotherapy technology which will shorten the treatment time. Disclosure: All authors have declared no conflicts of interest.
Conclusion: East and North Hertfordshire NHS Trust and its Network have comparably shorter median times of survival than nationally. The reason remains unknown. Time to diagnosis may be an important influence on these figures due to lead time bias, because median survival is calculated from diagnosis. The whole patient pathway is being examined to determine if this can explain the results. Disclosure: All authors have declared no conflicts of interest.
Radiotherapy 126 Our experience in treating lung tumours using stereotactic ablative body radiotherapy (SABR) at Northampton General Hospital H. Yusof *, A. Gore, C.I. Mak, H. Eldeeb, D. Vaidya, H. Acquah, N. Whilde. Oncology, Northampton General Hospital, United Kingdom Introduction: A retrospective analysis of patients demographic, dosimetric parameters, toxicity and outcome of lung cancer patients treated with SABR at Northampton General Hospital. Methods: 6 patients were treated from April 2013 to February 2014. Patients’ demographic, toxicity and outcome data were obtained from the hospital oncology database. Dosimetric parameters data were obtained from the hospital medical physics database. We used SABR UK consortium protocol as guidelines. Only peripheral lesions outside a 2 cm radius of main airways and proximal bronchial tree were treated. All had gold seed fiducial markers implanted for tumour localisation at treatment. Fine needle aspiration (FNA) for histological diagnosis was carried out at the time of fiducial placement. All had 4DCT scan for assessing tumour motion for radiotherapy planning. ITV to PTV margin used was 5 mm. All treatment plans used fixed coplanar beam arrangements. Image guided radiotherapy (IGRT) was implemented via ExacTrac kV imaging of the marker. Results: Patient demographics are shown in the table. Five patients received 55 Gy in 5 fractions and 1 received 54 Gy in 3 fractions, both dose fractionation delivered a biologically effective dose in 2 Gy fractions (BED2) of >150 Gy. PTV volume ranged from 22.6 to 83.89 cc. Lung V20 ranged from 3.2% to 10.0%. Treatment time ranged from 1 hour 40 minutes to 30 minutes per fraction. Acute toxicities were Grade 1 skin reaction in 1 patient, Grade 2 lethargy in 1 and the other 4 denied any toxicities. At the most recent follow-up appointments up to September 2014,
127 An audit of online cone beam CT (CBCT) verification data for stereotactic ablative radiotherapy (SABR) R. Mendes *, L. Allington, D. Carnell, N. Haji, K. Osborn. Radiotherapy, University College London Hospitals, London, United Kingdom Introduction: Since May 2012, UCLH has treated 45 patients with a diagnosis of stage 1 non-small-cell lung cancer patients using SABR. All patients are treated using volumetric arc therapy (VMAT) on a TrueBeamTM STx. A significant challenge for SABR is to accurately and precisely deliver highly conformal, hypofractionated radiation doses to a small target while minimising dose to normal tissues and organs at risk. Therefore, for the implementation of this technique within a department, it is vital that a rigorous treatment verification protocol is adopted. Methods: At UCLH a daily CBCT imaging protocol is in place whereby translational shifts are applied following an online tumour match. In order to evaluate the impact of this protocol on the delivery of SABR and the validity of this imaging procedure, an audit of 25 patients was undertaken assessing both inter- and intra-fractional match variations. Systematic and random errors were calculated, and validation of planning target volume set-up margins undertaken. Results: Evaluation of data indicated no systematic set-up error within the patient cohort. Mean displacements of 0.3 to 0.4 cm were observed at initial setup in all three directions. Total intrafraction motion of up to 0.5 cm was recorded over an entire treatment session. Conclusion: This presentation will describe the verification protocol adopted at UCLH and discuss results from the audit and how ammendments were made post evaluation. Disclosure: All authors have declared no conflicts of interest. 128 Experience of lung stereotactic ablative body radiotherapy (SABR) in a non-academic cancer centre in the UK M. Shahid Iqbal1 *, A. Cyriac1 , E. Aynsley1 , D. Shakespeare1 , N. Richmond2 , C. Walker2 , K. Piling3 , C. Peedell1 . 1 Clinical Oncology, South Tees Hospitals NHS Trust, Middlesbrough, United Kingdom, 2 Physics, South Tees Hospitals NHS Trust, Middlesbrough, United Kingdom, 3 Radiographer, South Tees Hospitals NHS Trust, Middlesbrough, United Kingdom Introduction: SABR has recently gained wider popularity in the treatment of ‘medically inoperable’ early stage non-small cell lung cancer (NSCLC) but the availability of technique remains limited to big academic centres. We describe our experience of building