Sarah A Mattonen1, David A Palma2, Carol Johnson3, Alexander V Louie4, Mark Landis5, George Rodrigues4, Ian Chan5, Roya Etemad-Rezai5, Timothy P C Yeung1, Suresh Senan6, Aaron D Ward7. 1. Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada; Baines Imaging Research Laboratory, London Regional Cancer Program, London, Ontario, Canada. 2. Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada; Baines Imaging Research Laboratory, London Regional Cancer Program, London, Ontario, Canada; Department of Oncology, The University of Western Ontario, London, Ontario, Canada. Electronic address: david.palma@lhsc.on.ca. 3. Baines Imaging Research Laboratory, London Regional Cancer Program, London, Ontario, Canada. 4. Department of Oncology, The University of Western Ontario, London, Ontario, Canada. 5. Department of Diagnostic Radiology, London Health Sciences Centre, London, Ontario, Canada. 6. Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands. 7. Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada; Baines Imaging Research Laboratory, London Regional Cancer Program, London, Ontario, Canada; Department of Oncology, The University of Western Ontario, London, Ontario, Canada.
Abstract
PURPOSE: Stereotactic ablative radiation therapy (SABR) is a guideline-specified treatment option for early-stage lung cancer. However, significant posttreatment fibrosis can occur and obfuscate the detection of local recurrence. The goal of this study was to assess physician ability to detect timely local recurrence and to compare physician performance with a radiomics tool. METHODS AND MATERIALS: Posttreatment computed tomography (CT) scans (n=182) from 45 patients treated with SABR (15 with local recurrence matched to 30 with no local recurrence) were used to measure physician and radiomic performance in assessing response. Scans were individually scored by 3 thoracic radiation oncologists and 3 thoracic radiologists, all of whom were blinded to clinical outcomes. Radiomic features were extracted from the same images. Performances of the physician assessors and the radiomics signature were compared. RESULTS: When taking into account all CT scans during the whole follow-up period, median sensitivity for physician assessment of local recurrence was 83% (range, 67%-100%), and specificity was 75% (range, 67%-87%), with only moderate interobserver agreement (κ = 0.54) and a median time to detection of recurrence of 15.5 months. When determining the early prediction of recurrence within <6 months after SABR, physicians assessed the majority of images as benign injury/no recurrence, with a mean error of 35%, false positive rate (FPR) of 1%, and false negative rate (FNR) of 99%. At the same time point, a radiomic signature consisting of 5 image-appearance features demonstrated excellent discrimination, with an area under the receiver operating characteristic curve of 0.85, classification error of 24%, FPR of 24%, and FNR of 23%. CONCLUSIONS: These results suggest that radiomics can detect early changes associated with local recurrence that are not typically considered by physicians. This decision support system could potentially allow for early salvage therapy of patients with local recurrence after SABR.
PURPOSE: Stereotactic ablative radiation therapy (SABR) is a guideline-specified treatment option for early-stage lung cancer. However, significant posttreatment fibrosis can occur and obfuscate the detection of local recurrence. The goal of this study was to assess physician ability to detect timely local recurrence and to compare physician performance with a radiomics tool. METHODS AND MATERIALS: Posttreatment computed tomography (CT) scans (n=182) from 45 patients treated with SABR (15 with local recurrence matched to 30 with no local recurrence) were used to measure physician and radiomic performance in assessing response. Scans were individually scored by 3 thoracic radiation oncologists and 3 thoracic radiologists, all of whom were blinded to clinical outcomes. Radiomic features were extracted from the same images. Performances of the physician assessors and the radiomics signature were compared. RESULTS: When taking into account all CT scans during the whole follow-up period, median sensitivity for physician assessment of local recurrence was 83% (range, 67%-100%), and specificity was 75% (range, 67%-87%), with only moderate interobserver agreement (κ = 0.54) and a median time to detection of recurrence of 15.5 months. When determining the early prediction of recurrence within <6 months after SABR, physicians assessed the majority of images as benign injury/no recurrence, with a mean error of 35%, false positive rate (FPR) of 1%, and false negative rate (FNR) of 99%. At the same time point, a radiomic signature consisting of 5 image-appearance features demonstrated excellent discrimination, with an area under the receiver operating characteristic curve of 0.85, classification error of 24%, FPR of 24%, and FNR of 23%. CONCLUSIONS: These results suggest that radiomics can detect early changes associated with local recurrence that are not typically considered by physicians. This decision support system could potentially allow for early salvage therapy of patients with local recurrence after SABR.
Authors: William Rogers; Sithin Thulasi Seetha; Turkey A G Refaee; Relinde I Y Lieverse; Renée W Y Granzier; Abdalla Ibrahim; Simon A Keek; Sebastian Sanduleanu; Sergey P Primakov; Manon P L Beuque; Damiënne Marcus; Alexander M A van der Wiel; Fadila Zerka; Cary J G Oberije; Janita E van Timmeren; Henry C Woodruff; Philippe Lambin Journal: Br J Radiol Date: 2020-02-26 Impact factor: 3.039