- Email: [email protected]
MA 09.09 Isotoxic Dose-Escalated Radiotherapy (RT) in Non-Small Cell Lung Cancer (NSCLC) with Deep Inspiration Breath Hold (DIBH)
S1838
MA 09.09 Isotoxic Dose-Escalated Radiotherapy (RT) in NonSmall Cell Lung Cancer (NSCLC) with Deep Inspiration Breath Hold (DIBH) H. Bainbridge, A. Dunlop, D. Mcquaid, R. Colgan, S. Popat, N. Yousaf, J. Bhosle, M. O’Brien, M. Ahmed, I. Locke, F. Mcdonald The Royal Marsden Hospital, NHS Foundation Trust, London/GB Background: With interest in the use of isotoxic dose-escalated RT in treatment of inoperable NSCLC, this study investigated the impact of DIBH using the Active Breathing CoordinatorTM (ABC- Elekta, Stockholm, Sweden) device on isotoxic dose escalation potential. Method: Following informed consent, a four-dimensional (4D) planning CT scan and a DIBH scan using the ABC device were acquired in patients sequentially in the same session. A motion-encompassing target volume on the 4D scan and a motion-managed target volume on the DIBH scan were created. The RayStation radiotherapy treatment planning system (research version 5.99.0.16) was used to generate two corresponding volumetric modulated arc therapy (VMAT) plans for each patient, following the guidelines of the isotoxic IMRT trial (NCT01836692). The target dose was escalated up to a maximum of 79.2 Gy in 44 twice daily fractions and plans optimized to minimize dose to normal tissues. Potential to escalate target dose and differences in dose-volume metrics between the plans were compared using the Wilcoxon signed-rank test. Result: 21 patients were included. The mean total lung volume was significantly higher with DIBH compared to 4D scans with an increase of 44.7 % ± 17.4 % (mean ± standard deviation), p <0.001). In 20/21 patients, the maximum target dose of 79.2 Gy was achievable in both plans, however in one patient 61.2 Gy was achieved with 4D compared to 75.6 Gy with DIBH planning. In the 20 patients achieving equivalent target dose-escalation, the mean lung dose was 17.0 Gy (± 0.3Gy ) with 4D versus 14.6 Gy (± 0.3 Gy) with DIBH (p <0.001). There was a significant mean reduction in heart dose between the DIBH compared to 4D plans of 0.3 Gy (± 0.2 Gy, p<0.001) and significant reductions in heart D100 %, D66 % and D33 %(p <0.01). Mediastinal envelope and oesophageal doses were similar using both techniques. Conclusion: The use of DIBH compared to 4D planning aids lung and cardiac sparing in isotoxic dose escalated RT and for a small number of patients may allow an increase in target dose. Particularly given the interaction between lung and cardiac toxicity in locally advanced NSCLC treated with radical RT, use of DIBH for treatment may lead to a reduction in toxicity compared to a 4D approach. In acknowledgement of the use of a mid-ventilation technique in some institutions, comparison with this method is planned. Keywords: Breath-hold, Isotoxic, Radiotherapy
MA 09.10 Toward a Radiological Scoring System of Radiotherapy-Induced Lung Damage C. Veiga,1 D. Landau,2 A. Devaraj,3 T. Doel,1 D. Hawkes,1 J. Mcclelland1 1University College London, London/GB, 2Oncology, Guy’s and St Thomas’ NHS Foundation Trust, London/GB, 3Royal Brompton Hospital, London/GB Background: There is no objective criteria to quantify radiotherapyinduced lung damage (RILD), leading to under-reporting of toxicity across centers and trials. Our objective is to build a radiological scoring system of RILD that correlates with decline in lung function. Method: Baseline and 12-month CT scans and formal respiratory function tests (FVC, FEV1 and DLCO) from 23 patients enrolled in an isotoxic chemoradiation clinical trial (IDEAL CRT) were available for central review. First, the presence of new CT findings of RILD was qualitatively scored into eleven sub-categories: consolidation, ground-glass opacities, traction bronchiectasis, reticulation, pleural thickening, pleural effusion, reduction in lung height, distortions of the diaphragm,
Journal of Thoracic Oncology
Vol. 12 No. 11S2
fissures, anterior junction line and major airways. From these, three main categories were derived: parenchymal change, pleural changes and volume reduction. The correlation between number of features scored and decline in breathing function was investigated. Later, twelve imaging markers were defined to quantify the severity of the radiological findings. The correlation between each imaging marker and decline in breathing scores was also investigated. Result: Each patient scored either two or three (out of three) categories of damage. Differences in variation of FVC, FEV1 and DLCO between these two groups were statistically significant (p0.02). The number of sub-categories scored was moderately correlated with decline in FVC (r¼-0.67, p<0.01), FEV1 (r¼-0.41, p¼0.05) and DLCO (r¼-0.50, p¼0.01). Six of the twelve imaging markers were moderately correlated with changes in FVC and FEV1 (rz-0.5, p<0.05); five were weakly correlated (rz0.2, p<0.05). The strongest correlations were found for imaging markers that quantify change in lung volume and shape, mediastinal shift and pleural reaction. Conclusion: We investigated the relationship between radiological findings of RILD and decline in lung function. Our findings suggest that a scoring system can be proposed when investigated in a larger cohort. Keywords: computed tomography, radiationinduced lung damage, breathing scores
Fig. Relationship between radiological findings of RILD and changes in FVC.
MA 09.11 Isotoxic Intensity Modulated Radiotherapy (IMRT) in Stage III Non-Small Cell Lung Cancer (NSCLC) e a Feasibility Study K. Haslett,1 N. Bayman,1 K. Franks,2 N. Groom,3 G. Hanna,4 S. Harden,5 C. Harris,1 S. Harrow,6 M. Hatton,7 P. Mccloskey,8 F. Mcdonald,9 L. Ashcroft,10 D. Ryder,10 C. Faivre-Finn11 1The Christie NHS Foundation Trust, Manchester/GB, 2Department of Clinical Oncology, Leeds Cancer Center/university of Leeds, Leeds/GB, 3 Radiotherapy Physics, Mount Vernon Hospital, London/GB, 4Belfast City Hospital, Belfast/GB, 5Addenbrookes Hospital, Cambridge/GB, 6Beatson West of Scotland Cancer Center, Glasgow/GB, 7Weston Park Hospital, Sheffield/GB, 8Northern Ireland Cancer Center, Belfast/GB, 915 Cotswold Road, Institute of Cancer Research & Royal Marsden Hospital, London/ GB, 10Manchester Academic Health Science Center - Trials Coordination Unit, The Christie NHS Foundation Trust, Manchester/GB, 11 Radiotherapy Research Related, The University of Manchester and the Christie NHS Foundation Trust, Manchester/GB Background: The majority of stage III patients with non-small cell lung cancer (NSCLC) are unsuitable for concurrent chemoradiotherapy. Alternative treatment options include sequential chemoradiotherapy and radiotherapy (RT) alone. As the rate of local failure is high there is a rationale for treatment intensification. Method: Isotoxic Intensity Modulated Radiotherapy (IMRT) is a multicenter feasibility study combining a number of intensification strategies; dose escalation, acceleration and hyperfractionation. Patients with inoperable stage III NSCLC, ECOG performance status (PS) 0-2, unsuitable for concurrent chemoradiotherapy were recruited. A minimum of 2 cycles of induction chemotherapy was mandated before RT. The dose of radiation was increased until one or more of the organs at risk (OAR) met predefined constraints or the maximum dose of 79.2Gy was reached. RT was delivered twice-daily in 1.8 Gy fractions. A RT quality assurance
MA 09.09 Isotoxic Dose-Escalated Radiotherapy (RT) in NonSmall Cell Lung Cancer (NSCLC) with Deep Inspiration Breath Hold (DIBH) H. Bainbridge, A. Dunlop, D. Mcquaid, R. Colgan, S. Popat, N. Yousaf, J. Bhosle, M. O’Brien, M. Ahmed, I. Locke, F. Mcdonald The Royal Marsden Hospital, NHS Foundation Trust, London/GB Background: With interest in the use of isotoxic dose-escalated RT in treatment of inoperable NSCLC, this study investigated the impact of DIBH using the Active Breathing CoordinatorTM (ABC- Elekta, Stockholm, Sweden) device on isotoxic dose escalation potential. Method: Following informed consent, a four-dimensional (4D) planning CT scan and a DIBH scan using the ABC device were acquired in patients sequentially in the same session. A motion-encompassing target volume on the 4D scan and a motion-managed target volume on the DIBH scan were created. The RayStation radiotherapy treatment planning system (research version 5.99.0.16) was used to generate two corresponding volumetric modulated arc therapy (VMAT) plans for each patient, following the guidelines of the isotoxic IMRT trial (NCT01836692). The target dose was escalated up to a maximum of 79.2 Gy in 44 twice daily fractions and plans optimized to minimize dose to normal tissues. Potential to escalate target dose and differences in dose-volume metrics between the plans were compared using the Wilcoxon signed-rank test. Result: 21 patients were included. The mean total lung volume was significantly higher with DIBH compared to 4D scans with an increase of 44.7 % ± 17.4 % (mean ± standard deviation), p <0.001). In 20/21 patients, the maximum target dose of 79.2 Gy was achievable in both plans, however in one patient 61.2 Gy was achieved with 4D compared to 75.6 Gy with DIBH planning. In the 20 patients achieving equivalent target dose-escalation, the mean lung dose was 17.0 Gy (± 0.3Gy ) with 4D versus 14.6 Gy (± 0.3 Gy) with DIBH (p <0.001). There was a significant mean reduction in heart dose between the DIBH compared to 4D plans of 0.3 Gy (± 0.2 Gy, p<0.001) and significant reductions in heart D100 %, D66 % and D33 %(p <0.01). Mediastinal envelope and oesophageal doses were similar using both techniques. Conclusion: The use of DIBH compared to 4D planning aids lung and cardiac sparing in isotoxic dose escalated RT and for a small number of patients may allow an increase in target dose. Particularly given the interaction between lung and cardiac toxicity in locally advanced NSCLC treated with radical RT, use of DIBH for treatment may lead to a reduction in toxicity compared to a 4D approach. In acknowledgement of the use of a mid-ventilation technique in some institutions, comparison with this method is planned. Keywords: Breath-hold, Isotoxic, Radiotherapy
MA 09.10 Toward a Radiological Scoring System of Radiotherapy-Induced Lung Damage C. Veiga,1 D. Landau,2 A. Devaraj,3 T. Doel,1 D. Hawkes,1 J. Mcclelland1 1University College London, London/GB, 2Oncology, Guy’s and St Thomas’ NHS Foundation Trust, London/GB, 3Royal Brompton Hospital, London/GB Background: There is no objective criteria to quantify radiotherapyinduced lung damage (RILD), leading to under-reporting of toxicity across centers and trials. Our objective is to build a radiological scoring system of RILD that correlates with decline in lung function. Method: Baseline and 12-month CT scans and formal respiratory function tests (FVC, FEV1 and DLCO) from 23 patients enrolled in an isotoxic chemoradiation clinical trial (IDEAL CRT) were available for central review. First, the presence of new CT findings of RILD was qualitatively scored into eleven sub-categories: consolidation, ground-glass opacities, traction bronchiectasis, reticulation, pleural thickening, pleural effusion, reduction in lung height, distortions of the diaphragm,
Journal of Thoracic Oncology
Vol. 12 No. 11S2
fissures, anterior junction line and major airways. From these, three main categories were derived: parenchymal change, pleural changes and volume reduction. The correlation between number of features scored and decline in breathing function was investigated. Later, twelve imaging markers were defined to quantify the severity of the radiological findings. The correlation between each imaging marker and decline in breathing scores was also investigated. Result: Each patient scored either two or three (out of three) categories of damage. Differences in variation of FVC, FEV1 and DLCO between these two groups were statistically significant (p0.02). The number of sub-categories scored was moderately correlated with decline in FVC (r¼-0.67, p<0.01), FEV1 (r¼-0.41, p¼0.05) and DLCO (r¼-0.50, p¼0.01). Six of the twelve imaging markers were moderately correlated with changes in FVC and FEV1 (rz-0.5, p<0.05); five were weakly correlated (rz0.2, p<0.05). The strongest correlations were found for imaging markers that quantify change in lung volume and shape, mediastinal shift and pleural reaction. Conclusion: We investigated the relationship between radiological findings of RILD and decline in lung function. Our findings suggest that a scoring system can be proposed when investigated in a larger cohort. Keywords: computed tomography, radiationinduced lung damage, breathing scores
Fig. Relationship between radiological findings of RILD and changes in FVC.
MA 09.11 Isotoxic Intensity Modulated Radiotherapy (IMRT) in Stage III Non-Small Cell Lung Cancer (NSCLC) e a Feasibility Study K. Haslett,1 N. Bayman,1 K. Franks,2 N. Groom,3 G. Hanna,4 S. Harden,5 C. Harris,1 S. Harrow,6 M. Hatton,7 P. Mccloskey,8 F. Mcdonald,9 L. Ashcroft,10 D. Ryder,10 C. Faivre-Finn11 1The Christie NHS Foundation Trust, Manchester/GB, 2Department of Clinical Oncology, Leeds Cancer Center/university of Leeds, Leeds/GB, 3 Radiotherapy Physics, Mount Vernon Hospital, London/GB, 4Belfast City Hospital, Belfast/GB, 5Addenbrookes Hospital, Cambridge/GB, 6Beatson West of Scotland Cancer Center, Glasgow/GB, 7Weston Park Hospital, Sheffield/GB, 8Northern Ireland Cancer Center, Belfast/GB, 915 Cotswold Road, Institute of Cancer Research & Royal Marsden Hospital, London/ GB, 10Manchester Academic Health Science Center - Trials Coordination Unit, The Christie NHS Foundation Trust, Manchester/GB, 11 Radiotherapy Research Related, The University of Manchester and the Christie NHS Foundation Trust, Manchester/GB Background: The majority of stage III patients with non-small cell lung cancer (NSCLC) are unsuitable for concurrent chemoradiotherapy. Alternative treatment options include sequential chemoradiotherapy and radiotherapy (RT) alone. As the rate of local failure is high there is a rationale for treatment intensification. Method: Isotoxic Intensity Modulated Radiotherapy (IMRT) is a multicenter feasibility study combining a number of intensification strategies; dose escalation, acceleration and hyperfractionation. Patients with inoperable stage III NSCLC, ECOG performance status (PS) 0-2, unsuitable for concurrent chemoradiotherapy were recruited. A minimum of 2 cycles of induction chemotherapy was mandated before RT. The dose of radiation was increased until one or more of the organs at risk (OAR) met predefined constraints or the maximum dose of 79.2Gy was reached. RT was delivered twice-daily in 1.8 Gy fractions. A RT quality assurance