Amir Iravani1,2, Guy-Anne Turgeon3, Tim Akhurst4, Jason W Callahan4, Mathias Bressel5, Sarah J Everitt6,7,8, Shankar Siva6,3, Michael S Hofman4, Rodney J Hicks4,6, David L Ball6,3, Michael P Mac Manus6,3. 1. Cancer Imaging, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, VIC, 3000, Australia. amir.iravani@petermac.org. 2. Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia. amir.iravani@petermac.org. 3. Division of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia. 4. Cancer Imaging, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, VIC, 3000, Australia. 5. Department of Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia. 6. Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia. 7. Radiation Therapy, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia. 8. Department of Medical Imaging and Radiation Sciences, Faculty of Medicine and Dentistry, Monash University, Clayton, VIC, Australia.
Abstract
PURPOSE: Inflammatory FDG uptake in the lung (PET-pneumonitis) following curative-intent radiotherapy (RT)/chemo-RT (CRT) in non-small cell lung cancer (NSCLC) can pose a challenge in FDG-PET/CT response assessment. The aim of this study is to describe different patterns of PET-pneumonitis to guide the interpretation of FDG-PET/CT and investigate its association with tumor response and overall survival (OS). METHODS: Retrospective analysis was performed on 87 NSCLC patients in three prospective trials who were treated with radical RT (n = 7) or CRT (n = 80), with baseline and post-treatment FDG-PET/CT. Visual criteria were performed for post-treatment FDG-PET/CT response assessment. The grading of PET-pneumonitis was based on relative lung uptake intensity compared to organs of reference and classified as per Deauville score from grade 1-5. Distribution patterns of PET-pneumonitis were defined as follows: A) patchy/sub-pleural; B) diffuse (involving more than a segment); and C) peripheral (diffusely surrounding a photopenic region). RESULTS: Follow-up FDG-PET/CT scans were performed approximately 3 months (median, 89 days; interquartile range, 79-93) after RT. Overall, PET-pneumonitis was present in 62/87 (71%) of patients, with Deauville 2 or 3 in 12/62 (19%) and 4 or 5 in 50/62 (81%) of patients. The frequency of patterns A, B and C of PET-pneumonitis was 19/62 (31%), 20/62 (32%) and 23/62 (37%), respectively. No association was found between grade or pattern of PET-pneumonitis and overall response at follow-up PET/CT (p = 0.27 and p = 0.56, respectively). There was also no significant association between PET-pneumonitis and OS (hazard ratio [HR], 1.3; 95% confidence interval [CI], 0.6-2.5; p = 0.45). Early FDG-PET/CT response assessment, however, was prognostic for OS (HR, 1.7; 95% CI, 1.2-2.2; p < 0.001). CONCLUSION: PET-pneumonitis is common in early post-CRT/RT, but pattern recognition may assist in response assessment by FDG-PET/CT. While FDG-PET/CT is a powerful tool for response assessment and prognostication, PET-pneumonitis does not appear to confound early response assessment or to independently predict OS.
PURPOSE: Inflammatory FDG uptake in the lung (PET-pneumonitis) following curative-intent radiotherapy (RT)/chemo-RT (CRT) in non-small cell lung cancer (NSCLC) can pose a challenge in FDG-PET/CT response assessment. The aim of this study is to describe different patterns of PET-pneumonitis to guide the interpretation of FDG-PET/CT and investigate its association with tumor response and overall survival (OS). METHODS: Retrospective analysis was performed on 87 NSCLCpatients in three prospective trials who were treated with radical RT (n = 7) or CRT (n = 80), with baseline and post-treatment FDG-PET/CT. Visual criteria were performed for post-treatment FDG-PET/CT response assessment. The grading of PET-pneumonitis was based on relative lung uptake intensity compared to organs of reference and classified as per Deauville score from grade 1-5. Distribution patterns of PET-pneumonitis were defined as follows: A) patchy/sub-pleural; B) diffuse (involving more than a segment); and C) peripheral (diffusely surrounding a photopenic region). RESULTS: Follow-up FDG-PET/CT scans were performed approximately 3 months (median, 89 days; interquartile range, 79-93) after RT. Overall, PET-pneumonitis was present in 62/87 (71%) of patients, with Deauville 2 or 3 in 12/62 (19%) and 4 or 5 in 50/62 (81%) of patients. The frequency of patterns A, B and C of PET-pneumonitis was 19/62 (31%), 20/62 (32%) and 23/62 (37%), respectively. No association was found between grade or pattern of PET-pneumonitis and overall response at follow-up PET/CT (p = 0.27 and p = 0.56, respectively). There was also no significant association between PET-pneumonitis and OS (hazard ratio [HR], 1.3; 95% confidence interval [CI], 0.6-2.5; p = 0.45). Early FDG-PET/CT response assessment, however, was prognostic for OS (HR, 1.7; 95% CI, 1.2-2.2; p < 0.001). CONCLUSION: PET-pneumonitis is common in early post-CRT/RT, but pattern recognition may assist in response assessment by FDG-PET/CT. While FDG-PET/CT is a powerful tool for response assessment and prognostication, PET-pneumonitis does not appear to confound early response assessment or to independently predict OS.
Entities:
Keywords:
FDG-PET/CT; Non-small cell lung cancer (NSCLC); PET response assessment; PET-pneumonitis; Radiation pneumonitis
Authors: Timothy J Jaykel; Michael S Clark; Daniel A Adamo; Brain T Welch; Scott M Thompson; Jason R Young; Eric C Ehman Journal: J Thorac Dis Date: 2020-11 Impact factor: 2.895
Authors: Sofia C Vaz; Judit A Adam; Roberto C Delgado Bolton; Pierre Vera; Wouter van Elmpt; Ken Herrmann; Rodney J Hicks; Yolande Lievens; Andrea Santos; Heiko Schöder; Bernard Dubray; Dimitris Visvikis; Esther G C Troost; Lioe-Fee de Geus-Oei Journal: Eur J Nucl Med Mol Imaging Date: 2022-01-13 Impact factor: 10.057