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137: Mentorship, development and implementation of SABR for NSCLC: the Bristol experience
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Poster abstracts, 13th Annual British Thoracic Oncology Group Conference, 2015: Radiotherapy
radiologists to review imaging with information of treatment technique is increasingly important. Disclosure: All authors have declared no conflicts of interest. 137 Mentorship, development and implementation of SABR for NSCLC: the Bristol experience J. Mason *, J. Kinsman, C.J. Comins. Oncology, Bristol Haematology and Oncology Centre, Bristol, United Kingdom Introduction: SABR is now the treatment of choice for early stage peripheral lung tumours in patients with contraindications to surgery. Development of the service within the UK has been driven by the “UK SABR consortium” and Bristol was one of three pilot centres mentored to initiate their SABR program. Under the mentorship of Leeds Cancer Centre the department has established a SABR MDT, rigorous QA and a fully trained team of radiographers, physicists and clinicians. Patients are identified using strict eligibility criteria according to the SABR Consortium guidelines, and the first patient was treated in February 2014. We present our experience of mentorship and audit of outcomes to date. Methods: All patients treated with SABR were identified from the database. Data was analysed to assess appropriate patient selection against consortium guidelines, acute toxicity data according to CTCAE and initial assessment of clinical outcomes. Results: The mentoring process began in June 2013. We treated our first patient in February 2014 and 19 patients have been treated to date. All patients fulfilled eligibility criteria. No grade 3/4 acute toxicities have been encountered. Commonest toxicities have included fatigue, skin erythema and chest wall discomfort. One patient has progressed with disseminated disease. Further follow up is required to determine response. Feedback about the mentoring scheme from the mentors and mentees will be presented. Conclusion: The mentoring process has proved a successful model for expediting implementation of a new technique to our centre in a safe manner with rigorous QA. Bristol continues to gain experience in SABR and will continue to audit outcomes against national standards and published international series. Disclosure: All authors have declared no conflicts of interest. 138 Cyberknife® for early stage non-small cell lung cancer (NSCLC) at a tertiary referral centre results of the first year of treatment at Birmingham R. Stevenson *, V. Harrop, G. Heyes, H. Howard, R. Simmons, A. Kapadia, T. Mitchell, Q. Ghafoor. Oncology, University Hospitals Birmingham NHS Trust, Birmingham, United Kingdom Introduction: Linac-based 4D Stereotactic Ablative Body Radiotherapy (SABR) was introduced at UHB in May 2013 and has treated 31 patients. The CyberKnife® is a frameless stereotactic radiotherapy system that involves a light-weight 6MV linear accelerator mounted on a mobile robotic arm and a real time image guidance system. UHB is funded for the treatment of medically inoperable early stage primary NSCLC on the CyberKnife® . We describe our experience and outcomes of the first 7 patients treated with this new technique. Methods: Patients eligible for stereotactic radiotherapy were selected via lung MDT. Of these patients; those with tumours 2 cm and deemed to be trackable with preferably ‘2 views’ were selected for treatment on the CyberKnife® . Prospective data was collected between June and September 2014 including demographics, tumour stage, histology, surgical contra-indications, pulmonary function and alternative treatment options. The dosefractionations delivered were those stipulated in the UK SABR Consortium guidance (54 Gy/3#; 55 Gy/5#). Results: Between 5th June and 12th August 2014, 7 patients with medically inoperable early stage primary NSCLC have been treated with the CyberKnife® . Six cases were evaluated for tumour response. Without treatment, 2 of the 6 patients would have
received best supportive care; the others radical radiotherapy with predicted 5 year survival rates of 10 30%. Responses were evaluated at 6 weeks post-treatment with CXR; all 6 patients achieving a partial response (PR). Five of these patients have 3 month CT followup data, 4 showing a maintained PR, the other stable disease. Two cases of grade 1 pneumonitis were documented. Conclusion: Our data illustrates the demographic profile of the initial 7 patients treated with CyberKnife® for early stage NSCLC. The majority of patients selected were medically unfit for surgery. At present our data is too immature to draw any conclusions regarding progression free and overall survival, but it appears to be a well tolerated treatment. Disclosure: All authors have declared no conflicts of interest. 139 Assessment of radiation induced gross target volume (GTV) changes using weekly cone-beam CT (CBCT) for NSCLC A. Duffton1 *, C. Lamb1 , M. McJury1 , S. Harrow2 . 1 Radiotherapy, Beatson West of Scotland Cancer Centre, Glasgow, United Kingdom, 2 Clinical Oncology, Beatson West of Scotland Cancer Centre, Glasgow, United Kingdom Introduction: To investigate the potential use of cone-beam CT (CBCT) in the adaptive radiotherapy (ART) planning process for nonsmall cell lung cancer (NSCLC) patients. Further investigation was to: Compare gross target volumes (GTV) on planning CT (pCT) and weekly CBCT, compare GTV change in volume and centre of mass (COM) throughout treatment and predict at which point patients would benefit from ART. Methods: 17 NSCLC patients completed a course of radiotherapy with weekly CBCT images acquired, matched and online correction applied. GTV delineation was carried out on weekly CBCT by a Clinical Oncologist (CO). GTV volume and COM displacement were calculated. The mean estimated change in GTV relative to volume was used to predict for the patient population if ART would be of benefit. Results: Comparison of CBCT GTV acquired prior to fraction 1 (cbctGTV1) to planning GTV (pGTV) showed a mean 20% volume increase (p = 0.04). A correlation was identified between volume reductions with increasing dose. Compared with baseline CBCT GTV, week 1, 2, 3 and 4 CBCT GTV mean ratios were 0.93, 0.84, and 0.75 respectively. A fitted model predicts a mean estimated change of 30% volume relative to baseline occurs at a dose of ~50 Gy. Conclusion: This study can conclude that CBCT may play an important role in determining the potential for lung ART. We recommend that all analysis should be done using the baseline GTV measurement acquired immediately before day 1 of treatment. We have shown that CBCT imaging can help us understand how the tumour changes as it responds to treatment. Although we cannot predict a strategy for the group as a whole, serial imaging can be used as a screening tool to filter patients who are demonstrating significant changes following radiation being delivered. Disclosure: All authors have declared no conflicts of interest.
Poster abstracts, 13th Annual British Thoracic Oncology Group Conference, 2015: Radiotherapy
radiologists to review imaging with information of treatment technique is increasingly important. Disclosure: All authors have declared no conflicts of interest. 137 Mentorship, development and implementation of SABR for NSCLC: the Bristol experience J. Mason *, J. Kinsman, C.J. Comins. Oncology, Bristol Haematology and Oncology Centre, Bristol, United Kingdom Introduction: SABR is now the treatment of choice for early stage peripheral lung tumours in patients with contraindications to surgery. Development of the service within the UK has been driven by the “UK SABR consortium” and Bristol was one of three pilot centres mentored to initiate their SABR program. Under the mentorship of Leeds Cancer Centre the department has established a SABR MDT, rigorous QA and a fully trained team of radiographers, physicists and clinicians. Patients are identified using strict eligibility criteria according to the SABR Consortium guidelines, and the first patient was treated in February 2014. We present our experience of mentorship and audit of outcomes to date. Methods: All patients treated with SABR were identified from the database. Data was analysed to assess appropriate patient selection against consortium guidelines, acute toxicity data according to CTCAE and initial assessment of clinical outcomes. Results: The mentoring process began in June 2013. We treated our first patient in February 2014 and 19 patients have been treated to date. All patients fulfilled eligibility criteria. No grade 3/4 acute toxicities have been encountered. Commonest toxicities have included fatigue, skin erythema and chest wall discomfort. One patient has progressed with disseminated disease. Further follow up is required to determine response. Feedback about the mentoring scheme from the mentors and mentees will be presented. Conclusion: The mentoring process has proved a successful model for expediting implementation of a new technique to our centre in a safe manner with rigorous QA. Bristol continues to gain experience in SABR and will continue to audit outcomes against national standards and published international series. Disclosure: All authors have declared no conflicts of interest. 138 Cyberknife® for early stage non-small cell lung cancer (NSCLC) at a tertiary referral centre results of the first year of treatment at Birmingham R. Stevenson *, V. Harrop, G. Heyes, H. Howard, R. Simmons, A. Kapadia, T. Mitchell, Q. Ghafoor. Oncology, University Hospitals Birmingham NHS Trust, Birmingham, United Kingdom Introduction: Linac-based 4D Stereotactic Ablative Body Radiotherapy (SABR) was introduced at UHB in May 2013 and has treated 31 patients. The CyberKnife® is a frameless stereotactic radiotherapy system that involves a light-weight 6MV linear accelerator mounted on a mobile robotic arm and a real time image guidance system. UHB is funded for the treatment of medically inoperable early stage primary NSCLC on the CyberKnife® . We describe our experience and outcomes of the first 7 patients treated with this new technique. Methods: Patients eligible for stereotactic radiotherapy were selected via lung MDT. Of these patients; those with tumours 2 cm and deemed to be trackable with preferably ‘2 views’ were selected for treatment on the CyberKnife® . Prospective data was collected between June and September 2014 including demographics, tumour stage, histology, surgical contra-indications, pulmonary function and alternative treatment options. The dosefractionations delivered were those stipulated in the UK SABR Consortium guidance (54 Gy/3#; 55 Gy/5#). Results: Between 5th June and 12th August 2014, 7 patients with medically inoperable early stage primary NSCLC have been treated with the CyberKnife® . Six cases were evaluated for tumour response. Without treatment, 2 of the 6 patients would have
received best supportive care; the others radical radiotherapy with predicted 5 year survival rates of 10 30%. Responses were evaluated at 6 weeks post-treatment with CXR; all 6 patients achieving a partial response (PR). Five of these patients have 3 month CT followup data, 4 showing a maintained PR, the other stable disease. Two cases of grade 1 pneumonitis were documented. Conclusion: Our data illustrates the demographic profile of the initial 7 patients treated with CyberKnife® for early stage NSCLC. The majority of patients selected were medically unfit for surgery. At present our data is too immature to draw any conclusions regarding progression free and overall survival, but it appears to be a well tolerated treatment. Disclosure: All authors have declared no conflicts of interest. 139 Assessment of radiation induced gross target volume (GTV) changes using weekly cone-beam CT (CBCT) for NSCLC A. Duffton1 *, C. Lamb1 , M. McJury1 , S. Harrow2 . 1 Radiotherapy, Beatson West of Scotland Cancer Centre, Glasgow, United Kingdom, 2 Clinical Oncology, Beatson West of Scotland Cancer Centre, Glasgow, United Kingdom Introduction: To investigate the potential use of cone-beam CT (CBCT) in the adaptive radiotherapy (ART) planning process for nonsmall cell lung cancer (NSCLC) patients. Further investigation was to: Compare gross target volumes (GTV) on planning CT (pCT) and weekly CBCT, compare GTV change in volume and centre of mass (COM) throughout treatment and predict at which point patients would benefit from ART. Methods: 17 NSCLC patients completed a course of radiotherapy with weekly CBCT images acquired, matched and online correction applied. GTV delineation was carried out on weekly CBCT by a Clinical Oncologist (CO). GTV volume and COM displacement were calculated. The mean estimated change in GTV relative to volume was used to predict for the patient population if ART would be of benefit. Results: Comparison of CBCT GTV acquired prior to fraction 1 (cbctGTV1) to planning GTV (pGTV) showed a mean 20% volume increase (p = 0.04). A correlation was identified between volume reductions with increasing dose. Compared with baseline CBCT GTV, week 1, 2, 3 and 4 CBCT GTV mean ratios were 0.93, 0.84, and 0.75 respectively. A fitted model predicts a mean estimated change of 30% volume relative to baseline occurs at a dose of ~50 Gy. Conclusion: This study can conclude that CBCT may play an important role in determining the potential for lung ART. We recommend that all analysis should be done using the baseline GTV measurement acquired immediately before day 1 of treatment. We have shown that CBCT imaging can help us understand how the tumour changes as it responds to treatment. Although we cannot predict a strategy for the group as a whole, serial imaging can be used as a screening tool to filter patients who are demonstrating significant changes following radiation being delivered. Disclosure: All authors have declared no conflicts of interest.