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Evaluation of an Integrated Minimally Interactive Tool for the Segmentation of Relevant Oar in Lung Cancer
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Volume 90 Number 1S Supplement 2014 Results: The PAC-specific CAPP-Seq selector covered w135 kb and targeted 979 genomic regions from 925 recurrently mutated genes. Although comprising <0.005% of the human genome, the selector identified a median of 11 mutations per tumor and was able to identify multiple mutations in >96% of PACs. Using an optimized protocol, we extracted adequate tumor genomic DNA for CAPP-Seq genotyping from 95% of FFPE samples, including 13 of 13 FNA/core samples (mean Z 178 ng; range Z 4-1075 ng) and 9 of 10 surgical samples (mean Z 680 ng; range Z 3-2351 ng). Finally, we used CAPP-Seq to identify tumor-specific mutations and to quantitate ctDNA in pre- and post-treatment plasma samples. Conclusions: CAPP-Seq is a promising method for the ultrasensitive and specific quantification of ctDNA in patients with PAC. Isolation of tumor DNA from PAC FFPE FNA/core biopsy specimens using our optimized protocol provides sufficient tumor DNA for genotyping using CAPP-Seq. Ongoing analyses are exploring the prognostic and predictive utility of ctDNA analysis in PAC. Author Disclosure: E. Osmundson: None. A.M. Newman: None. S.V. Bratman: None. D.M. Klass: None. L. Zhou: None. J. Pai: None. T.A. Longacre: None. A.A. Alizadeh: None. A.C. Koong: None. M. Diehn: None.
3547 Blinded Evaluation of Sinogram Affirmed Iterative Reconstruction in Radiation Therapy Planning Images N. Nguyen,1 G. Charron,2 and D. Roberge2; 1Juravinski Cancer CentreMcMaster University, Hamilton, ON, Canada, 2Universite´ de Montre´alCentre Hospitalier de l’Universite´ de Montre´al, Montreal, QC, Canada Purpose/Objective(s): The current standard reconstruction algorithm for CT scans is filtered back projection (FBP). Recently, an alternative algorithm of iterative reconstruction (IR) has been increasingly implemented in the realm of diagnostic CT imaging, allowing decoupling of spatial resolution and image noise while reducing radiation doses. We studied a variant of IR, known as “Sinogram affirmed iterative reconstruction” (SAFIRE) and assessed its potential to improve the quality of radiation therapy (RT) planning images. Materials/Methods: Raw CT data sets of patients planned for brain, spine, head and neck, lung, breast, gastrointestinal, liver, gynecological, genitourinary and limb tumors were included. A total of 50 scans were acquired using our standard imaging protocols and reconstructed using FBP and SAFIRE levels 1, 3 and 5 (higher levels referring to more noise correction). For each disease site, two to seven scans were selected. For each site, 2 to 3 specialized radiation oncologists evaluated the 3D image sets in a blind fashion. Using a visual analogue scale, they assessed the image sharpness, noise, perceived ease in delineating gross tumor/clinical target volume (GTV/CTV) and organs at risk (OAR) and overall appreciation of the planning images. Inter-observer correlation was calculated with the Spearman correlation coefficient (r). Generalized estimating equations (GEA) assessed the differences in the mean score for each criteria, between reconstructions, adjusted for observer status. When there were significant differences, pairwise comparisons (PC) were done to compare the least-squares means. The preference for each scan was rank ordered for each observer. The mean rank across all observers and the ranks occurrences were computed. GEA was calculated again for the mean ranks; PC were done when differences existed. Results: The sharpness of borders had r Z -0.22-0.53, the ease of GTV/ CTV delineation r Z -0.28-0.53, the ease of OAR delineation r Z -0.470.42, the image noise r Z -0.34-0.38 and the overall appreciation r Z -0.17-0.38. Although there were discrepancies between physicians, SAFIRE levels 3 and 5 had consistently higher scores than FBP scans and were the highest rated scans for all criteria and for all disease sites (p Z 0.02 and p Z 0.015, respectively). Paradoxically, although SAFIRE level 5 scored well on average, it was ranked as worst the most often. SAFIRE level 3 was consistently well ranked for all criteria. Conclusions: This report is the first to report the potential benefit of IR in RT planning scans. Although highly processed images polarized observers, the use of IR is globally preferred over standard FBP for planning CT
scans. The preference for IR is seen for all disease sites, for all facets of images. This work will lead to clinical implementation of intermediate IR processing and further study investigating quantitatively IR’s impact on contouring. Author Disclosure: N. Nguyen: None. G. Charron: None. D. Roberge: None.
3548 Evaluation of an Integrated Minimally Interactive Tool for the Segmentation of Relevant Oar in Lung Cancer T. Fechter,1 J. Dolz,2 H. Kirisli,2 A. Chirindel,1 S. Adebahr,1 T. SchimekJasch,1 M. Vermandel,3 L. Massoptier,2 and U. Nestle1; 1 Universitaetsklinik Freiburg, Freiburg im Breisgau, Germany, 2 AQUILAB, Lille, France, 3Centre Hospitalier Universitaire, Lille, France Purpose/Objective(s): Radiation therapy aims at delivering the highest possible dose to the GTV while minimizing the irradiation of surrounding healthy tissue. Therefore an accurate delineation of organs at risk (OAR) is an absolute prerequirement for radiation treatment planning (RTP). However, it is maybe a very time consuming and tedious task. In this work we present and evaluate a software prototype which integrates fully automatic and minimally interactive algorithms to perform segmentation for relevant OAR in lung cancer. Materials/Methods: The software prototype was implemented within MITK and the body contour, lung, heart, spinal cord, trachea and central bronchi were delineated. Lung, heart and spinal cord were segmented interactively using seed points provided by the user. Between five to seven seed points were needed to obtain satisfactory results. The remainder of the OAR was segmented fully automatically. Quantitative evaluation was performed for lung, heart, spinal cord and body contour. The Dice’s coefficient (DC) were computed between the contours generated with our software and the reference standard contoured by a clinical expert for a real RTP. For trachea and central bronchi a qualitative visual evaluation was performed by a clinical expert as no reference standard was available for these OAR. The contour analysis was carried out on planning CT scans for 12 patients treated with SBRT for locally advanced lung tumors. Results: Mean DC obtained was higher than 90% for lungs, heart and body, with a maximum standard deviation (SD) of 2.2%. For spinal cord, the mean DC decreased to 79.7%, with a SD of 10.7%. The results demonstrate strong agreement between segmentation provided by the proposed software prototype and reference standard segmentations used for RTP. Qualitative visual analysis suggests that the proposed method for trachea and central bronchi segmentation could be a surrogate for the manual contours used in a treatment planning. Conclusions: The proposed minimally interactive software prototype offers a fast way to contour and demonstrates good agreement to standard expert delineated contours in the majority of analyzed OAR. For the spinal cord a relatively decreased concordance was noted, which was not surprising, as the clinical expert used different anatomic landmarks (vertebral canal) in order to overcome the limited visualization of the spinal cord on CT. Changing the prototype in a way to follow the bony limits of the spinal canal will increase concordance. An extended user testing will explore the possible use of this tool in clinical practice. Author Disclosure: T. Fechter: None. J. Dolz: None. H. Kirisli: None. A. Chirindel: None. S. Adebahr: None. T. Schimek-Jasch: None. M. Vermandel: None. L. Massoptier: None. U. Nestle: None.
3549 An Electronic Medical Record Search Engine for Clinical Outcome Research A. Gopal, J.J. Gordon, J. Kim, and I.J. Chetty; Henry Ford Health System, Detroit, MI Purpose/Objective(s): Among common first steps in a study of treatment response is a search of the radiation therapy EMR for patient records meeting study criteria, e.g. “Lung tumors treated with SBRT over the last 5
Volume 90 Number 1S Supplement 2014 Results: The PAC-specific CAPP-Seq selector covered w135 kb and targeted 979 genomic regions from 925 recurrently mutated genes. Although comprising <0.005% of the human genome, the selector identified a median of 11 mutations per tumor and was able to identify multiple mutations in >96% of PACs. Using an optimized protocol, we extracted adequate tumor genomic DNA for CAPP-Seq genotyping from 95% of FFPE samples, including 13 of 13 FNA/core samples (mean Z 178 ng; range Z 4-1075 ng) and 9 of 10 surgical samples (mean Z 680 ng; range Z 3-2351 ng). Finally, we used CAPP-Seq to identify tumor-specific mutations and to quantitate ctDNA in pre- and post-treatment plasma samples. Conclusions: CAPP-Seq is a promising method for the ultrasensitive and specific quantification of ctDNA in patients with PAC. Isolation of tumor DNA from PAC FFPE FNA/core biopsy specimens using our optimized protocol provides sufficient tumor DNA for genotyping using CAPP-Seq. Ongoing analyses are exploring the prognostic and predictive utility of ctDNA analysis in PAC. Author Disclosure: E. Osmundson: None. A.M. Newman: None. S.V. Bratman: None. D.M. Klass: None. L. Zhou: None. J. Pai: None. T.A. Longacre: None. A.A. Alizadeh: None. A.C. Koong: None. M. Diehn: None.
3547 Blinded Evaluation of Sinogram Affirmed Iterative Reconstruction in Radiation Therapy Planning Images N. Nguyen,1 G. Charron,2 and D. Roberge2; 1Juravinski Cancer CentreMcMaster University, Hamilton, ON, Canada, 2Universite´ de Montre´alCentre Hospitalier de l’Universite´ de Montre´al, Montreal, QC, Canada Purpose/Objective(s): The current standard reconstruction algorithm for CT scans is filtered back projection (FBP). Recently, an alternative algorithm of iterative reconstruction (IR) has been increasingly implemented in the realm of diagnostic CT imaging, allowing decoupling of spatial resolution and image noise while reducing radiation doses. We studied a variant of IR, known as “Sinogram affirmed iterative reconstruction” (SAFIRE) and assessed its potential to improve the quality of radiation therapy (RT) planning images. Materials/Methods: Raw CT data sets of patients planned for brain, spine, head and neck, lung, breast, gastrointestinal, liver, gynecological, genitourinary and limb tumors were included. A total of 50 scans were acquired using our standard imaging protocols and reconstructed using FBP and SAFIRE levels 1, 3 and 5 (higher levels referring to more noise correction). For each disease site, two to seven scans were selected. For each site, 2 to 3 specialized radiation oncologists evaluated the 3D image sets in a blind fashion. Using a visual analogue scale, they assessed the image sharpness, noise, perceived ease in delineating gross tumor/clinical target volume (GTV/CTV) and organs at risk (OAR) and overall appreciation of the planning images. Inter-observer correlation was calculated with the Spearman correlation coefficient (r). Generalized estimating equations (GEA) assessed the differences in the mean score for each criteria, between reconstructions, adjusted for observer status. When there were significant differences, pairwise comparisons (PC) were done to compare the least-squares means. The preference for each scan was rank ordered for each observer. The mean rank across all observers and the ranks occurrences were computed. GEA was calculated again for the mean ranks; PC were done when differences existed. Results: The sharpness of borders had r Z -0.22-0.53, the ease of GTV/ CTV delineation r Z -0.28-0.53, the ease of OAR delineation r Z -0.470.42, the image noise r Z -0.34-0.38 and the overall appreciation r Z -0.17-0.38. Although there were discrepancies between physicians, SAFIRE levels 3 and 5 had consistently higher scores than FBP scans and were the highest rated scans for all criteria and for all disease sites (p Z 0.02 and p Z 0.015, respectively). Paradoxically, although SAFIRE level 5 scored well on average, it was ranked as worst the most often. SAFIRE level 3 was consistently well ranked for all criteria. Conclusions: This report is the first to report the potential benefit of IR in RT planning scans. Although highly processed images polarized observers, the use of IR is globally preferred over standard FBP for planning CT
scans. The preference for IR is seen for all disease sites, for all facets of images. This work will lead to clinical implementation of intermediate IR processing and further study investigating quantitatively IR’s impact on contouring. Author Disclosure: N. Nguyen: None. G. Charron: None. D. Roberge: None.
3548 Evaluation of an Integrated Minimally Interactive Tool for the Segmentation of Relevant Oar in Lung Cancer T. Fechter,1 J. Dolz,2 H. Kirisli,2 A. Chirindel,1 S. Adebahr,1 T. SchimekJasch,1 M. Vermandel,3 L. Massoptier,2 and U. Nestle1; 1 Universitaetsklinik Freiburg, Freiburg im Breisgau, Germany, 2 AQUILAB, Lille, France, 3Centre Hospitalier Universitaire, Lille, France Purpose/Objective(s): Radiation therapy aims at delivering the highest possible dose to the GTV while minimizing the irradiation of surrounding healthy tissue. Therefore an accurate delineation of organs at risk (OAR) is an absolute prerequirement for radiation treatment planning (RTP). However, it is maybe a very time consuming and tedious task. In this work we present and evaluate a software prototype which integrates fully automatic and minimally interactive algorithms to perform segmentation for relevant OAR in lung cancer. Materials/Methods: The software prototype was implemented within MITK and the body contour, lung, heart, spinal cord, trachea and central bronchi were delineated. Lung, heart and spinal cord were segmented interactively using seed points provided by the user. Between five to seven seed points were needed to obtain satisfactory results. The remainder of the OAR was segmented fully automatically. Quantitative evaluation was performed for lung, heart, spinal cord and body contour. The Dice’s coefficient (DC) were computed between the contours generated with our software and the reference standard contoured by a clinical expert for a real RTP. For trachea and central bronchi a qualitative visual evaluation was performed by a clinical expert as no reference standard was available for these OAR. The contour analysis was carried out on planning CT scans for 12 patients treated with SBRT for locally advanced lung tumors. Results: Mean DC obtained was higher than 90% for lungs, heart and body, with a maximum standard deviation (SD) of 2.2%. For spinal cord, the mean DC decreased to 79.7%, with a SD of 10.7%. The results demonstrate strong agreement between segmentation provided by the proposed software prototype and reference standard segmentations used for RTP. Qualitative visual analysis suggests that the proposed method for trachea and central bronchi segmentation could be a surrogate for the manual contours used in a treatment planning. Conclusions: The proposed minimally interactive software prototype offers a fast way to contour and demonstrates good agreement to standard expert delineated contours in the majority of analyzed OAR. For the spinal cord a relatively decreased concordance was noted, which was not surprising, as the clinical expert used different anatomic landmarks (vertebral canal) in order to overcome the limited visualization of the spinal cord on CT. Changing the prototype in a way to follow the bony limits of the spinal canal will increase concordance. An extended user testing will explore the possible use of this tool in clinical practice. Author Disclosure: T. Fechter: None. J. Dolz: None. H. Kirisli: None. A. Chirindel: None. S. Adebahr: None. T. Schimek-Jasch: None. M. Vermandel: None. L. Massoptier: None. U. Nestle: None.
3549 An Electronic Medical Record Search Engine for Clinical Outcome Research A. Gopal, J.J. Gordon, J. Kim, and I.J. Chetty; Henry Ford Health System, Detroit, MI Purpose/Objective(s): Among common first steps in a study of treatment response is a search of the radiation therapy EMR for patient records meeting study criteria, e.g. “Lung tumors treated with SBRT over the last 5