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Han C, Qiu J, Bai L, Liu T, Chen J, Wang H, Dang J. Pneumonitis Risk After Chemoradiotherapy With and Without Immunotherapy in Patients With Locally Advanced Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis. Int J Radiat Oncol Biol Phys 2024; 119:1179-1207. [PMID: 38360117 DOI: 10.1016/j.ijrobp.2024.01.217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 12/28/2023] [Accepted: 01/28/2024] [Indexed: 02/17/2024]
Abstract
PURPOSE Chemoradiotherapy (CRT) combined with immune checkpoint inhibitors (ICIs) is the standard of care for patients with unresectable and locally advanced non-small cell lung cancer. This study aimed to determine whether the addition of ICIs to CRT is associated with an increased risk of pneumonitis. METHODS AND MATERIALS The PubMed, Embase, Cochrane Library, and Web of Science databases were searched for eligible studies published between January 1, 2015, and July 31, 2023. The outcome of interest was the incidence rate of pneumonitis. A random-effects model was used for statistical analysis. RESULTS A total of 185 studies with 24,527 patients were included. The pooled rate of grade ≥2 pneumonitis for CRT plus ICIs was significantly higher than that for CRT alone (29.6%; 95% CI, 25.7%-33.6% vs 20.2%; 95% CI, 17.7%-22.8%; P < .0001) but not that of grade ≥3 (5.7%; 95% CI, 4.8%-6.6% vs 5.6%; 95% CI, 4.7%-6.5%; P = .64) or grade 5 (0.1%; 95% CI, 0.0%-0.2% vs 0.3%; 95% CI, 0.1%-0.4%; P = .68). The results from the subgroup analyses of prospective studies, retrospective studies, Asian and non-Asian studies, concurrent CRT (cCRT), and durvalumab consolidation were comparable to the overall results. However, CRT or cCRT plus PD-1 inhibitors not only significantly increased the incidence of grade ≥2 but also that of grade ≥3 pneumonitis compared to CRT alone or cCRT plus PD-L1 inhibitors. CONCLUSIONS Compared with CRT alone, durvalumab consolidation after CRT appears to be associated with a higher incidence of moderate pneumonitis and CRT plus PD-1 inhibitors with an increased risk of severe pneumonitis. Nevertheless, these findings are based on observational studies and need to be validated in future large head-to-head studies.
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Affiliation(s)
- Chong Han
- Department of Radiation Oncology, First Hospital of China Medical University, Shenyang, China
| | - Jingping Qiu
- Department of Radiation Oncology, First Hospital of China Medical University, Shenyang, China
| | - Lu Bai
- Department of Radiation Oncology, First Hospital of China Medical University, Shenyang, China
| | - Tingting Liu
- Department of Radiation Oncology, Anshan Cancer Hospital, Anshan, China
| | - Jun Chen
- Department of Radiation Oncology, Shenyang Tenth People's Hospital, Shenyang, China
| | - He Wang
- Department of Radiation Oncology, First Hospital of China Medical University, Shenyang, China
| | - Jun Dang
- Department of Radiation Oncology, First Hospital of China Medical University, Shenyang, China.
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Liu T, Li S, Ding S, Qiu J, Ren C, Chen J, Wang H, Wang X, Li G, He Z, Dang J. Comparison of post-chemoradiotherapy pneumonitis between Asian and non-Asian patients with locally advanced non-small cell lung cancer: a systematic review and meta-analysis. EClinicalMedicine 2023; 64:102246. [PMID: 37781162 PMCID: PMC10539643 DOI: 10.1016/j.eclinm.2023.102246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 08/28/2023] [Accepted: 09/13/2023] [Indexed: 10/03/2023] Open
Abstract
Background Pneumonitis is a common complication for patients with locally advanced non-small cell lung cancer undergoing definitive chemoradiotherapy (CRT). It remains unclear whether there is ethnic difference in the incidence of post-CRT pneumonitis. Methods PubMed, Embase, Cochrane Library, and Web of Science were searched for eligible studies from January 1, 2000 to April 30, 2023. The outcomes of interest were incidence rates of pneumonitis. The random-effect model was used for statistical analysis. This meta-analysis was registered with PROSPERO (CRD42023416490). Findings A total of 248 studies involving 28,267 patients were included. Among studies of CRT without immunotherapy, the pooled rates of pneumonitis for Asian patients were significantly higher than that for non-Asian patients (all grade: 66.8%, 95% CI: 59.2%-73.9% vs. 28.1%, 95% CI: 20.4%-36.4%; P < 0.0001; grade ≥2: 25.1%, 95% CI: 22.9%-27.3% vs. 14.9%, 95% CI: 12.0%-18.0%; P < 0.0001; grade ≥3: 6.5%, 95% CI: 5.6%-7.3% vs. 4.6%, 95% CI: 3.4%-5.9%; P = 0.015; grade 5: 0.6%, 95% CI: 0.3%-0.9% vs. 0.1%, 95% CI: 0.0%-0.2%; P < 0.0001). Regarding studies of CRT plus immunotherapy, Asian patients had higher rates of all-grade (74.8%, 95% CI: 63.7%-84.5% vs. 34.3%, 95% CI: 28.7%-40.2%; P < 0.0001) and grade ≥2 (34.0%, 95% CI: 30.7%-37.3% vs. 24.6%, 95% CI: 19.9%-29.3%; P = 0.001) pneumonitis than non-Asian patients, but with no significant differences in the rates of grade ≥3 and grade 5 pneumonitis. Results from subgroup analyses were generally similar to that from the all studies. In addition, the pooled median/mean of lung volume receiving ≥20 Gy and mean lung dose were relatively low in Asian studies compared to that in non-Asian studies. Interpretation Asian patients are likely to have a higher incidence of pneumonitis than non-Asian patients, which appears to be due to the poor tolerance of lung to radiation. Nevertheless, these findings are based on observational studies and with significant heterogeneity, and need to be validated in future large prospective studies focusing on the subject. Funding None.
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Affiliation(s)
- Tingting Liu
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
- Department of Radiation Oncology, Anshan Cancer Hospital, Anshan, China
| | - Sihan Li
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
| | - Silu Ding
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
| | - Jingping Qiu
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
| | - Chengbo Ren
- Department of Radiation Oncology, The First Affiliated Hospital of Hebei North University, Zhangjiakou, Hebei, China
| | - Jun Chen
- Department of Radiation Oncology, Shenyang Tenth People's Hospital, Shenyang, China
| | - He Wang
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
| | - Xiaoling Wang
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
| | - Guang Li
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
| | - Zheng He
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
| | - Jun Dang
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
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Wass R, Hochmair M, Kaiser B, Grambozov B, Feurstein P, Weiß G, Moosbrugger R, Sedlmayer F, Lamprecht B, Studnicka M, Zehentmayr F. Durvalumab after Sequential High Dose Chemoradiotherapy versus Standard of Care (SoC) for Stage III NSCLC: A Bi-Centric Trospective Comparison Focusing on Pulmonary Toxicity. Cancers (Basel) 2022; 14:3226. [PMID: 35804997 PMCID: PMC9265119 DOI: 10.3390/cancers14133226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/27/2022] [Accepted: 06/27/2022] [Indexed: 01/09/2023] Open
Abstract
Introduction: The standard of care (SoC) for unresectable stage III non-small-cell lung cancer (NSCLC) is durvalumab maintenance therapy after concurrent chemoradiation in patients with PD-L1 > 1%. However, the concurrent approach is only amenable for about one-third of patients due to co-morbidities. Although sequential regimens are usually not regarded as curative, these schedules applied in a dose-escalated manner may be similarly radical as SoC. As combining high-dose radiation and durvalumab remains a question of debate this retrospective bi-center study aims to evaluate pulmonary toxicity after high-dose chemoradiotherapy beyond 70 Gy compared to SoC. Patients and Methods: Patients with NSCLC stage III received durvalumab after either sequential high-dose chemoradiation or concomitant SoC. Chemotherapy consisted of platinum combined with either pemetrexed, taxotere, vinorelbine, or gemcitabine. The primary endpoint was short-term pulmonary toxicity occurring within six months after the end of radiotherapy (RT). Results: A total of 78 patients were eligible for this analysis. 18F-FDG-PET-CT, cranial MRT, and histological/cytological verification were mandatory in the diagnostic work-up. The high-dose and SoC group included 42/78 (53.8%) and 36/78 (46.2%) patients, respectively, which were matched according to baseline clinical variables. While the interval between the end of RT and the start of durvalumab was equal in both groups (p = 0.841), more courses were administered in the high-dose cohort (p = 0.031). Pulmonary toxicity was similar in both groups (p = 0.599), whereas intrathoracic disease control was better in the high-dose group (local control p = 0.081, regional control p = 0.184). Conclusion: The data of this hypothesis-generating study suggest that sequential high-dose chemoradiation followed by durvalumab might be similar to SoC in terms of pulmonary toxicity and potentially more effective with respect to intra-thoracic disease control. Larger trials with a prospective design are warranted to validate these results.
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Affiliation(s)
- Romana Wass
- Department of Pulmonology, Paracelsus Medical University, A-5020 Salzburg, Austria; (R.W.); (G.W.); (R.M.); (M.S.)
- Department of Pulmonology, Kepler University Hospital, A-4020 Linz, Austria; (B.K.); (B.L.)
| | - Maximilian Hochmair
- Department of Respiratory and Critical Care Medicine, Karl Landsteiner Institute of Lung Cancer Research and Pulmonary Oncology, Klinik Floridsdorf, A-1210 Vienna, Austria;
| | - Bernhard Kaiser
- Department of Pulmonology, Kepler University Hospital, A-4020 Linz, Austria; (B.K.); (B.L.)
| | - Brane Grambozov
- Department of Radiation Oncology, Paracelsus Medical University, A-5020 Salzburg, Austria; (B.G.); (F.S.)
| | - Petra Feurstein
- Department of Radiation Oncology, Klinik Ottakring, A-1160 Vienna, Austria;
| | - Gertraud Weiß
- Department of Pulmonology, Paracelsus Medical University, A-5020 Salzburg, Austria; (R.W.); (G.W.); (R.M.); (M.S.)
| | - Raphaela Moosbrugger
- Department of Pulmonology, Paracelsus Medical University, A-5020 Salzburg, Austria; (R.W.); (G.W.); (R.M.); (M.S.)
| | - Felix Sedlmayer
- Department of Radiation Oncology, Paracelsus Medical University, A-5020 Salzburg, Austria; (B.G.); (F.S.)
- radART—Institute for Research and Development on Advanced Radiation Technologies, Paracelsus Medical University, A-5020 Salzburg, Austria
| | - Bernd Lamprecht
- Department of Pulmonology, Kepler University Hospital, A-4020 Linz, Austria; (B.K.); (B.L.)
| | - Michael Studnicka
- Department of Pulmonology, Paracelsus Medical University, A-5020 Salzburg, Austria; (R.W.); (G.W.); (R.M.); (M.S.)
| | - Franz Zehentmayr
- Department of Radiation Oncology, Paracelsus Medical University, A-5020 Salzburg, Austria; (B.G.); (F.S.)
- radART—Institute for Research and Development on Advanced Radiation Technologies, Paracelsus Medical University, A-5020 Salzburg, Austria
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Niska JR, Hu J, Li J, Herman MG, Thorpe CS, Schild SE, Fatyga M. Using Novel Statistical Techniques to Accurately Determine the Predictive Dose Range in a Study of Overall Survival after Definitive Radiotherapy for Stage III Non-Small Cell Lung Cancer in Association with Heart Dose. JOURNAL OF CANCER THERAPY 2021; 12:505-529. [PMID: 34804634 PMCID: PMC8601657 DOI: 10.4236/jct.2021.129044] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE Recent studies of radiotherapy (RT) for stage III non-small-cell lung cancer (NSCLC) have associated high dose to the heart with cardiac toxicity and decreased overall survival (OS). We used advanced statistical techniques to account for correlations between dosimetric variables and more accurately determine the range of heart doses which are associated with reduced OS in patients receiving RT for stage III NSCLC. METHODS From 2006 to 2013, 119 patients with stage III NSCLC received definitive RT at our institution. OS data was obtained from institutional tumor registry. We used multivariate Cox model to determine patient specific covariates predictive for reduced overall survival. We examined age, prescription dose, mean lung dose, lung V20, RT technique, stage, chemotherapy, tumor laterality, tumor volume, and tumor site as candidate covariates. We subsequently used novel statistical techniques within multivariate Cox model to systematically search the whole heart dose-volume histogram (DVH) for dose parameters associated with OS. RESULTS Patients were followed until death or 2.5 to 81.2 months (median 30.4 months) in those alive at last follow up. On multivariate analysis of whole heart DVH, the dose of 51 Gy was identified as a threshold dose above which the dose volume relationship becomes predictive for OS. We identified V55Gy (percentage of the whole heart volume receiving at least 55 Gy) as the best single DVH index which can be used to set treatment optimization constraints (Hazard Ratio = 1.044 per 1% increase in heart volume exposed to at least 55 Gy, P = 0.03). Additional characteristics correlated with OS on multivariate analysis were age, stage (IIIA/IIIB), and administration of chemotherapy. CONCLUSION Doses above 51 Gy, applied to small volumes of the heart, are associated with worse OS in stage III NSCLC patients treated with definitive RT. Higher stage, older age and lack of chemotherapy were also associated with reduced OS.
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Affiliation(s)
- Joshua R. Niska
- Department of Radiation Oncology, Banner MD Anderson Cancer Center, Phoenix, Arizona, USA
| | - Jiuyun Hu
- School of Computing, Informatics, and Decision Systems Engineering, Tempe, Arizona, USA
| | - Jing Li
- School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Michael G. Herman
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
| | - Cameron S. Thorpe
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - Steven E. Schild
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - Mirek Fatyga
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
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Landman Y, Jacobi O, Kurman N, Yariv O, Peretz I, Rotem O, Dudnik E, Zer A, Allen AM. Durvalumab after concurrent chemotherapy and high-dose radiotherapy for locally advanced non-small cell lung cancer. Oncoimmunology 2021; 10:1959979. [PMID: 34408921 PMCID: PMC8366536 DOI: 10.1080/2162402x.2021.1959979] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The standard of care for stage III non-small cell lung cancer (NSCLC) is chemoradiotherapy (CRT) followed by durvalumab. Although doses higher than 66 Gy are standard in our center, they were used in only 6.9% of patients in the PACIFIC trial. We report our experience with durvalumab after high-dose radiotherapy. The database of a tertiary hospital for patients with stage III NSCLC who were treated with CRT and adjuvant durvalumab was evaluated. Progression-free survival (PFS), overall survival (OS), and local-regional failure (LRF) were measured from the administration of durvalumab. Thirty-nine patients were included. All were treated with intensity-modulated radiation (mean dose 69.9 Gy); Median follow-up time was 20.4 months (range 1–35.4). At 12 months, PFS was 49%, OS 79%, and LRF 14%. Intrathoracic failure at first progression was demonstrated in 8 (21%) patients. Adverse events requiring corticosteroids occurred in 10(25.6%) patients: pneumonitis – 6 (15.4%), hepatitis – 2 (5.1%), and arthralgia and pericarditis – 1 (2.6%). One patient (2.6%) died of pneumonitis. The occurrence of pneumonitis was significantly associated with lung V5 (55% vs. 42%, p = .04) and V20 (28% vs. 19%, p = .01) and mean lung dose (14.8 Gy vs.11.6 Gy, p = .05). The similar 12-month PFS and OS rates of our cohort and the PACIFIC trial support the use of high-dose radiotherapy in patients with stage III NSCLC. Treatment-related mortality was similar to the PACIFIC results. The intrathoracic failure rate in our cohort was lower than that reported from the PACIFIC trial, suggesting that radiation dose escalation may improve local control.
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Affiliation(s)
- Yosef Landman
- Thoracic Oncology Service, Davidoff Cancer Center, Rabin Medical Center - Beilinson Hospital, Petach Tikva, Israel
| | - Oded Jacobi
- Thoracic Oncology Service, Davidoff Cancer Center, Rabin Medical Center - Beilinson Hospital, Petach Tikva, Israel
| | - Noga Kurman
- Thoracic Oncology Service, Davidoff Cancer Center, Rabin Medical Center - Beilinson Hospital, Petach Tikva, Israel
| | - Orly Yariv
- Thoracic Oncology Service, Davidoff Cancer Center, Rabin Medical Center - Beilinson Hospital, Petach Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv; Israel
| | - Idit Peretz
- Thoracic Oncology Service, Davidoff Cancer Center, Rabin Medical Center - Beilinson Hospital, Petach Tikva, Israel
| | - Ofer Rotem
- Thoracic Oncology Service, Davidoff Cancer Center, Rabin Medical Center - Beilinson Hospital, Petach Tikva, Israel
| | - Elizabeth Dudnik
- Thoracic Oncology Service, Davidoff Cancer Center, Rabin Medical Center - Beilinson Hospital, Petach Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv; Israel
| | - Alona Zer
- Thoracic Oncology Service, Davidoff Cancer Center, Rabin Medical Center - Beilinson Hospital, Petach Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv; Israel
| | - Aaron M Allen
- Thoracic Oncology Service, Davidoff Cancer Center, Rabin Medical Center - Beilinson Hospital, Petach Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv; Israel
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Atkins KM, Chaunzwa TL, Lamba N, Bitterman DS, Rawal B, Bredfeldt J, Williams CL, Kozono DE, Baldini EH, Nohria A, Hoffmann U, Aerts HJWL, Mak RH. Association of Left Anterior Descending Coronary Artery Radiation Dose With Major Adverse Cardiac Events and Mortality in Patients With Non-Small Cell Lung Cancer. JAMA Oncol 2021; 7:206-219. [PMID: 33331883 PMCID: PMC7747040 DOI: 10.1001/jamaoncol.2020.6332] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 09/01/2020] [Indexed: 12/25/2022]
Abstract
IMPORTANCE Radiotherapy accelerates coronary heart disease (CHD), but the dose to critical cardiac substructures has not been systematically studied in lung cancer. OBJECTIVE To examine independent cardiac substructure radiotherapy factors for major adverse cardiac events (MACE) and all-cause mortality in patients with locally advanced non-small cell lung cancer (NSCLC). DESIGN, SETTING, AND PARTICIPANTS A retrospective cohort analysis of 701 patients with locally advanced NSCLC treated with thoracic radiotherapy at Harvard University-affiliated hospitals between December 1, 2003, and January 27, 2014, was performed. Data analysis was conducted between January 12, 2019, and July 22, 2020. Cardiac substructures were manually delineated. Radiotherapy dose parameters (mean, maximum, and the volume [V, percentage] receiving a specific Gray [Gy] dose in 5-Gy increments) were calculated. Receiver operating curve and cut-point analyses estimating MACE (unstable angina, heart failure hospitalization or urgent visit, myocardial infarction, coronary revascularization, and cardiac death) were performed. Fine and Gray and Cox regressions were adjusted for preexisting CHD and other prognostic factors. MAIN OUTCOMES AND MEASURES MACE and all-cause mortality. RESULTS Of the 701 patients included in the analysis, 356 were men (50.8%). The median age was 65 years (interquartile range, 57-73 years). The optimal cut points for substructure and radiotherapy doses (highest C-index value) were left anterior descending (LAD) coronary artery V15 Gy greater than or equal to 10% (0.64), left circumflex coronary artery V15 Gy greater than or equal to 14% (0.64), left ventricle V15 Gy greater than or equal to 1% (0.64), and mean total coronary artery dose greater than or equal to 7 Gy (0.62). Adjusting for baseline CHD status and other prognostic factors, an LAD coronary artery V15 Gy greater than or equal to 10% was associated with increased risk of MACE (adjusted hazard ratio, 13.90; 95% CI, 1.23-157.21; P = .03) and all-cause mortality (adjusted hazard ratio, 1.58; 95% CI, 1.09-2.29; P = .02). Among patients without CHD, associations with increased 1-year MACE were noted for LAD coronary artery V15 Gy greater than or equal to 10% (4.9% vs 0%), left circumflex coronary artery V15 Gy greater than or equal to 14% (5.2% vs 0.7%), left ventricle V15 Gy greater than or equal to 1% (5.0% vs 0.4%), and mean total coronary artery dose greater than or equal to 7 Gy (4.8% vs 0%) (all P ≤ .001), but only a left ventricle V15 Gy greater than or equal to 1% increased the risk among patients with CHD (8.4% vs 4.1%; P = .046). Among patients without CHD, 2-year all-cause mortality was increased with an LAD coronary artery V15 Gy greater than or equal to 10% (51.2% vs 42.2%; P = .009) and mean total coronary artery dose greater than or equal to 7 Gy (53.2% vs 40.0%; P = .01). CONCLUSIONS AND RELEVANCE The findings of this cohort study suggest that optimal cardiac dose constraints may differ based on preexisting CHD. Although the LAD coronary artery V15 Gy greater than or equal to 10% appeared to be an independent estimator of the probability of MACE and all-cause mortality, particularly in patients without CHD, left ventricle V15 Gy greater than or equal to 1% appeared to confer an increased risk of MACE among patients with CHD. These constraints are worthy of further study because there is a need for improved cardiac risk stratification and aggressive risk mitigation strategies.
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Affiliation(s)
- Katelyn M. Atkins
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
| | - Tafadzwa L. Chaunzwa
- Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
| | - Nayan Lamba
- Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
| | - Danielle S. Bitterman
- Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
| | - Bhupendra Rawal
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Jeremy Bredfeldt
- Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
| | - Christopher L. Williams
- Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
| | - David E. Kozono
- Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
| | - Elizabeth H. Baldini
- Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
| | - Anju Nohria
- Department of Cardiovascular Medicine, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
| | - Udo Hoffmann
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Hugo J. W. L. Aerts
- Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
- Department of Radiology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
| | - Raymond H. Mak
- Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts
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Teoh S, Fiorini F, George B, Vallis KA, Van den Heuvel F. Proton vs photon: A model-based approach to patient selection for reduction of cardiac toxicity in locally advanced lung cancer. Radiother Oncol 2020; 152:151-162. [PMID: 31431365 PMCID: PMC7707354 DOI: 10.1016/j.radonc.2019.06.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 06/25/2019] [Accepted: 06/25/2019] [Indexed: 12/25/2022]
Abstract
PURPOSE/OBJECTIVE To use a model-based approach to identify a sub-group of patients with locally advanced lung cancer who would benefit from proton therapy compared to photon therapy for reduction of cardiac toxicity. MATERIAL/METHODS Volumetric modulated arc photon therapy (VMAT) and robust-optimised intensity modulated proton therapy (IMPT) plans were generated for twenty patients with locally advanced lung cancer to give a dose of 70 Gy (relative biological effectiveness (RBE)) in 35 fractions. Cases were selected to represent a range of anatomical locations of disease. Contouring, treatment planning and organs-at-risk constraints followed RTOG-1308 protocol. Whole heart and ub-structure doses were compared. Risk estimates of grade⩾3 cardiac toxicity were calculated based on normal tissue complication probability (NTCP) models which incorporated dose metrics and patients baseline risk-factors (pre-existing heart disease (HD)). RESULTS There was no statistically significant difference in target coverage between VMAT and IMPT. IMPT delivered lower doses to the heart and cardiac substructures (mean, heart V5 and V30, P < .05). In VMAT plans, there were statistically significant positive correlations between heart dose and the thoracic vertebral level that corresponded to the most inferior limit of the disease. The median level at which the superior aspect of the heart contour began was the T7 vertebrae. There was a statistically significant difference in dose (mean, V5 and V30) to the heart and all substructures (except mean dose to left coronary artery and V30 to sino-atrial node) when disease overlapped with or was inferior to the T7 vertebrae. In the presence of pre-existing HD and disease overlapping with or inferior to the T7 vertebrae, the mean estimated relative risk reduction of grade⩾3 toxicities was 24-59%. CONCLUSION IMPT is expected to reduce cardiac toxicity compared to VMAT by reducing dose to the heart and substructures. Patients with both pre-existing heart disease and tumour and nodal spread overlapping with or inferior to the T7 vertebrae are likely to benefit most from proton over photon therapy.
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Affiliation(s)
- S Teoh
- CRUK/MRC Oxford Institute for Radiation Oncology, Old Road Campus Research Building, University of Oxford, Oxford, OX3 7DQ, UK; Department of Radiotherapy, Oxford Cancer Centre, Oxford University Hospitals NHS Foundation Trust, OX3 7LE, UK.
| | - F Fiorini
- CRUK/MRC Oxford Institute for Radiation Oncology, Old Road Campus Research Building, University of Oxford, Oxford, OX3 7DQ, UK; Department of Radiotherapy, Oxford Cancer Centre, Oxford University Hospitals NHS Foundation Trust, OX3 7LE, UK
| | - B George
- CRUK/MRC Oxford Institute for Radiation Oncology, Old Road Campus Research Building, University of Oxford, Oxford, OX3 7DQ, UK; Department of Radiotherapy, Oxford Cancer Centre, Oxford University Hospitals NHS Foundation Trust, OX3 7LE, UK
| | - K A Vallis
- CRUK/MRC Oxford Institute for Radiation Oncology, Old Road Campus Research Building, University of Oxford, Oxford, OX3 7DQ, UK; Department of Radiotherapy, Oxford Cancer Centre, Oxford University Hospitals NHS Foundation Trust, OX3 7LE, UK
| | - F Van den Heuvel
- CRUK/MRC Oxford Institute for Radiation Oncology, Old Road Campus Research Building, University of Oxford, Oxford, OX3 7DQ, UK; Department of Radiotherapy, Oxford Cancer Centre, Oxford University Hospitals NHS Foundation Trust, OX3 7LE, UK
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Pan L, Lei D, Wang W, Luo Y, Wang D. Heart dose linked with cardiac events and overall survival in lung cancer radiotherapy: A meta-analysis. Medicine (Baltimore) 2020; 99:e21964. [PMID: 32957314 PMCID: PMC7505339 DOI: 10.1097/md.0000000000021964] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The aim of this study was to investigate the link between heart dose and overall survival, the link between heart dose and cardiac events and whether radiation-induced heart diseases were associated with overall survival in lung cancer radiotherapy. METHODS We performed a literature search by using Pubmed, Embase, China National Knowledge Infrastructure (CNKI) databases. Pairs of reviewers independently screened literature according to the inclusion criteria, extracted data, assessed methodological quality, and publication bias. The primary end points included overall survival and cardiac events. I was calculated in a heterogeneity assessment. Publication bias was evaluated by using Begg funnel plot and Egger test. RESULTS Ten studies including 1 randomized controlled trial, 3 post hoc analysis of prospective trials, and 6 cohort studies were identified. The meta-analysis showed that heart volume receiving ≥5 Gy (HV5) (hazard ratio [HR] = 1.01; 95% confidence interval [CI]: 1.00-1.01), heart volume receiving ≥30 Gy (HV30) (HR = 1.01; 95% CI: 1.00-1.02), heart volume receiving ≥50 Gy (HV50) (HR = 1.05; 95%CI: 1.00-1.10), and mean heart dose (MHD) (HR = 1.01; 95%CI:1.00-1.02) all were associated with worse overall survival. In addition, the MHD (HR = 1.03; 95% CI: 1.02-1.05), HV5 (HR = 1.02; 95% CI: 1.01-1.03), and HV30 (HR = 1.02; 95% CI: 1.01-1.03) were significantly associated with all grade cardiac events. Meanwhile, compared with those who did not receive radiotherapy, the radiotherapy group experienced a significantly increased risk for cardiac-specific mortality (HR = 1.297; 95% CI: 1.213-1.387). However, the results did not show that cardiac events were associated with overall survival in lung cancer radiotherapy (HR = 1.472; 95% CI: 0.988-2.193). CONCLUSION Exposure of the heart to radiation increased the risk of cardiac events during radiotherapy for lung cancer. Meanwhile, heart dose including HV5 and HV30 were predictors of overall survival in lung cancer radiotherapy. It is necessary to constrain the heart dose when perform thoracic radiation therapy to decrease the incidence of cardiac events and improve the overall survival.
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Affiliation(s)
- Li Pan
- The people's Hospital of Rongchang District
| | - Dengshun Lei
- Chongqing Rongchang Maternal and Child Health Hospital, Chongqing, China
| | | | - Yanqiu Luo
- The people's Hospital of Rongchang District
| | - Dan Wang
- The people's Hospital of Rongchang District
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Liu X, Fatyga M, Schild SE, Li J. Detecting spatial susceptibility to cardiac toxicity of radiation therapy for lung cancer. ACTA ACUST UNITED AC 2020; 10:243-250. [PMID: 33506164 DOI: 10.1080/24725579.2020.1795012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Radiation therapy (RT) is a commonly used approach for treating lung cancer. Because the lungs are close to the heart, radiation dose may inevitably spill to the heart, causing heart damage and diminishing treatment outcomes. There is an urgent need to better understand how treatment outcomes are affected by radiation dose spilled to the heart in order to optimize RT planning. However, despite the fact that dose distribution on the heart is 3-D, most existing research collapses the 3-D dose map into a 1-D histogram to be linked with outcomes. This ignores the spatial information. We propose a novel method that automatically searches for subregions of the heart that are susceptible to radiation toxicity, called Toxicity-Susceptible Subregions (TSSs), based on the 3-D dose distribution. We apply the proposed method to a real-world dataset and find TSSs that harbor the sinoatrial node of the electronic conduction system of the heart. Damage of the sinoatrial node by radiation toxicity disrupts the crucial function of the heart, leading to shortening of the overall survival. Our finding suggests that protective strategies may be developed to spare the TSSs, and thus helping RT planning achieve optimal results in treating lung cancer patients.
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Affiliation(s)
- Xiaonan Liu
- Industrial Engineering, Arizona State University, Tempe, AZ, USA
| | - Mirek Fatyga
- Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, USA
| | | | - Jing Li
- Industrial Engineering, Arizona State University, Tempe, AZ, USA
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Zhao Q, Liu M, Wang Z, Huang W, Allen Li X, Zhou T, Zhang J, Zhang Z, Wang Q, Yu S, Han D, Sun H, Li H, Lin H, Li B. High dose radiation therapy based on normal tissue constraints with concurrent chemotherapy achieves promising survival of patients with unresectable stage III non-small cell lung cancer. Radiother Oncol 2019; 145:7-12. [PMID: 31869678 DOI: 10.1016/j.radonc.2019.11.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 11/19/2019] [Accepted: 11/25/2019] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND PURPOSE We aimed to investigate the potential of individual isotoxic dose escalation based on normal tissue constraints (NTC), hypothesizing that high dose radiation therapy would be superior to standard-dose in concurrent chemoradiotherapy for unresectable stage III non-small cell lung cancer (NSCLC). MATERIALS AND METHODS Individually prescribed radiation doses were calculated based on NTC. Patients with total tumour radiation doses ≥66 Gy were assigned to the high dose (HD, ≥66 Gy) group, and all other patients were assigned to the standard-dose (SD, <66 Gy) group. Each patient was retrospectively assigned an Eighth edition of American Joint Committee on Cancer disease stage based on the imaging data of initial diagnosis to avoid over- and under-staging. Intensity modulated radiation therapy plans were optimized to minimize the volumes of organs at risk exposed to radiation. The primary endpoint was overall survival. RESULTS From March 2006 to September 2012, 140 patients were enrolled and assigned to two groups: 71 patients into the HD group and 69 patients into the SD group. The median survival time (MST) was significantly higher in the HD group (33.5 months) than in the SD group (21 months), (p < 0.0001). Overall 5-year survival rates were significantly higher in the HD group than in the SD group (37.8% vs 16.7%). Median progression-free survival was 19 months in the HD group and 11 months in the SD group (p < 0.0001). No difference in severe (grade 3-5) toxic effects was noted between the two groups. CONCLUSIONS The significant positive association observed between prescribed dose and survival suggests that individualized isotoxic dose-escalated radiation based on NTC might improve survival in this cohort of stage III NSCLC Chinese patients.
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Affiliation(s)
- Qian Zhao
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Frist Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Ming Liu
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, China
| | - Zhongtang Wang
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Frist Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Wei Huang
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Frist Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - X Allen Li
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, USA
| | - Tao Zhou
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Frist Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Jian Zhang
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Frist Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Zicheng Zhang
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Frist Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Qiang Wang
- Department of Radiation Oncology, People's Hospital of Linzi District, Zibo, China
| | - Shuzeng Yu
- Department of Radiation Oncology, LiaoCheng People's Hospital, Liaocheng, China
| | - Dan Han
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Frist Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Hongfu Sun
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Frist Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Hongsheng Li
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Frist Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Haiqun Lin
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Frist Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Baosheng Li
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Frist Medical University and Shandong Academy of Medical Sciences, Jinan, China.
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Is the Importance of Heart Dose Overstated in the Treatment of Non-Small Cell Lung Cancer? A Systematic Review of the Literature. Int J Radiat Oncol Biol Phys 2019; 104:582-589. [PMID: 30630029 DOI: 10.1016/j.ijrobp.2018.12.044] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 12/12/2018] [Accepted: 12/15/2018] [Indexed: 12/25/2022]
Abstract
PURPOSE Some recent studies have suggested a relationship between cardiac dose and mortality in non-small cell lung cancer (NSCLC), but others have reported conflicting data. The goal of this study was to conduct a systematic review and meta-analysis to provide an evidence-based estimate of the relationship between cardiac dose and mortality in these patients. METHODS AND MATERIALS A systematic review of MEDLINE (PubMed) and Embase databases (inception to January 2018) was performed according to PRISMA guidelines. Studies that evaluated cardiac dosimetric factors in patients with NSCLC and included outcomes of cardiac events, cardiac mortality, and/or overall survival were identified. RESULTS From 5614 patients across 22 studies, a total of 214 cardiac dosimetric parameters (94 unique) were assessed as possible predictors of cardiac toxicity or death. Assessed predictors included general (eg, mean heart dose [MHD]), threshold-based (eg, heart V5), and anatomic-based (eg, atria, ventricles) dosimetric factors. The most commonly analyzed parameters were MHD, heart V5, and V30. Most studies did not make corrections for multiplicity of testing. For overall survival, V5 was found to be significant on multivariable analysis (MVA) in 1 of 11 studies and V30 in 2 of 12 studies; MHD was not significant in any of 8 studies. For cardiac events, V5 was found to be significant on multivariable analysis in 1 of 2 studies, V30 in 1 of 3 studies, and MHD in 2 of 4 studies. A meta-analysis of the data could not be performed because most negative studies did not report effect estimates. CONCLUSIONS Consistent heart dose-volume parameters associated with overall survival of patients with NSCLC were not identified. Multiplicity of testing is a major issue and likely inflates the overall risk of type I errors in the literature. Future studies should specify predictors a priori, correct for multiplicity of testing, and report effect estimates for nonsignificant variables.
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Niska JR, Thorpe CS, Allen SM, Daniels TB, Rule WG, Schild SE, Vargas CE, Mookadam F. Radiation and the heart: systematic review of dosimetry and cardiac endpoints. Expert Rev Cardiovasc Ther 2018; 16:931-950. [DOI: 10.1080/14779072.2018.1538785] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Joshua R. Niska
- Mayo Clinic - Department of Radiation Oncology, Phoenix, AZ, USA
| | | | - Sorcha M. Allen
- Mayo Clinic - Department of Cardio-Oncology, Scottsdale, AZ, USA
| | | | - William G. Rule
- Mayo Clinic - Department of Radiation Oncology, Phoenix, AZ, USA
| | - Steven E. Schild
- Mayo Clinic - Department of Radiation Oncology, Phoenix, AZ, USA
| | - Carlos E. Vargas
- Mayo Clinic - Department of Radiation Oncology, Phoenix, AZ, USA
| | - Farouk Mookadam
- Mayo Clinic - Department of Cardio-Oncology, Scottsdale, AZ, USA
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Lee E, Zeng J, Miyaoka RS, Saini J, Kinahan PE, Sandison GA, Wong T, Vesselle HJ, Rengan R, Bowen SR. Functional lung avoidance and response-adaptive escalation (FLARE) RT: Multimodality plan dosimetry of a precision radiation oncology strategy. Med Phys 2017; 44:3418-3429. [PMID: 28453861 DOI: 10.1002/mp.12308] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 03/22/2017] [Accepted: 04/21/2017] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Nonsmall cell lung cancer (NSCLC) patient radiation therapy (RT) is planned without consideration of spatial heterogeneity in lung function or tumor response. We assessed the dosimetric and clinical feasibility of functional lung avoidance and response-adaptive escalation (FLARE) RT to reduce dose to [99m Tc]MAA-SPECT/CT perfused lung while redistributing an escalated boost dose within [18 F]FDG-PET/CT-defined biological target volumes (BTV). METHODS Eight stage IIB-IIIB NSCLC patients underwent FDG-PET/CT and MAA-SPECT/CT treatment planning scans. Perfused lung objectives were derived from scatter/collimator/attenuation-corrected MAA-SPECT uptake relative to ITV-subtracted lung to maintain < 20 Gy mean lung dose (MLD). Prescriptions included 60 Gy to the planning target volume (PTV) and concomitant boost of 74 Gy mean to biological target volumes (BTV = GTV + PET gradient segmentation) scaled to each BTV voxel by relative FDG-PET SUV. Dose-painting-by-numbers prescriptions were integrated into commercial treatment planning systems via uptake threshold discretization. Dose constraints for lung, heart, cord, and esophagus were defined. FLARE RT plans were optimized with volumetric modulated arc therapy (VMAT), proton pencil beam scanning (PBS) with 3%-3 mm robust optimization, and combination of PBS (avoidance) plus VMAT (escalation). The high boost dose region was evaluated within a standardized SUVpeak structure. FLARE RT plans were compared to reference VMAT plans. Linear regression between radiation dose to BTV and normalized FDG PET SUV at every voxel was conducted, from which Pearson linear correlation coefficients and regression slopes were extracted. Spearman rank correlation coefficients were estimated between radiation dose to lung and normalized SPECT uptake. Dosimetric differences between treatment modalities were evaluated by Friedman nonparametric paired test with multiple sampling correction. RESULTS No unacceptable violations of PTV and normal tissue objectives were observed in 24 FLARE RT plans. Compared to reference VMAT plans, FLARE VMAT plans achieved a higher mean dose to BTV (73.7 Gy 98195. 61.3 Gy), higher mean dose to SUVpeak (89.7 Gy vs. 60.8 Gy), and lower mean dose to highly perfused lung (7.3 Gy vs. 14.9 Gy). These dosimetric gains came at the expense of higher mean heart dose (9.4 Gy vs. 5.8 Gy) and higher maximum cord dose (50.1 Gy vs. 44.6 Gy) relative to the reference VMAT plans. Between FLARE plans, FLARE VMAT achieved higher dose to the SUVpeak ROI than FLARE PBS (89.7 Gy vs. 79.2 Gy, P = 0.01), while FLARE PBS delivered lower dose to lung than FLARE VMAT (11.9 Gy vs. 15.6 Gy, P < 0.001). Voxelwise linear dose redistribution slope between BTV dose and FDG PET uptake was higher in magnitude for FLARE PBS + VMAT (0.36 Gy per %SUVmax ) compared to FLARE VMAT (0.27 Gy per %SUVmax ) or FLARE PBS alone (0.17 Gy per %SUVmax ). CONCLUSIONS FLARE RT is clinically feasible with VMAT and PBS. A combination of PBS for functional lung avoidance and VMAT for FDG PET dose escalation balanced target and normal tissue objective tradeoffs. These results provide a technical platform for testing of FLARE RT safety and efficacy within a precision radiation oncology trial.
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Affiliation(s)
- Eunsin Lee
- Department of Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA, 98195, USA
| | - Jing Zeng
- Department of Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA, 98195, USA
| | - Robert S Miyaoka
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA, 98195, USA
| | - Jatinder Saini
- Seattle Cancer Care Alliance Proton Therapy Center, 1570 N 115th Ave, Seattle, WA, 98133, USA
| | - Paul E Kinahan
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA, 98195, USA
| | - George A Sandison
- Department of Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA, 98195, USA
| | - Tony Wong
- Seattle Cancer Care Alliance Proton Therapy Center, 1570 N 115th Ave, Seattle, WA, 98133, USA
| | - Hubert J Vesselle
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA, 98195, USA
| | - Ramesh Rengan
- Department of Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA, 98195, USA
| | - Stephen R Bowen
- Departments of Radiation Oncology and Radiology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA, 98195, USA
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