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Thomas Lars Andresen - One of the best experts on this subject based on the ideXlab platform.
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long term safety and visibility of a novel liquid Fiducial Marker for use in image guided radiotherapy of non small cell lung cancer
Clinical and Translational Radiation Oncology, 2018Co-Authors: Steen Riisgaard De Blanck, Rasmus Irming Jølck, Lena Specht, Jonas Scherman Rydhög, Per Munck Af Rosenschöld, Klaus Richter Larsen, Paul Frost Clementsen, Mirjana Josipovic, Marianne C Aznar, Thomas Lars AndresenAbstract:Abstract Safety and clinical feasibility of injecting a novel liquid Fiducial Marker for use in image guided radiotherapy in 15 patients with non-small cell lung cancer are reported. No major safety or toxicity issues were encountered. Markers present at start of radiotherapy remained visible in cone beam computed tomography and fluoroscopy images throughout the treatment course and on computed tomography images during follow-up (0–38 months). Marker volume reduction was seen until 9 months after treatment, after which no further Marker breakdown was found. No post-treatment migration or Marker related complications were found.
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Feasibility of a novel liquid Fiducial Marker for use in image guided radiotherapy of oesophageal cancer.
British Journal of Radiology, 2018Co-Authors: Steen Riisgaard De Blanck, Jonas Scherman-rydhög, Mette Siemsen, Merete Sanvig Christensen, Lene Baeksgaard, Rasmus Irming Jølck, Thomas Lars Andresen, Lena Specht, Gitte Fredberg PerssonAbstract:Objective:To evaluate the feasibility of a new liquid Fiducial Marker for use in image-guided radiotherapy for oesophageal cancer.Methods:Liquid Fiducial Markers were implanted in patients with met...
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liquid Fiducial Marker performance during radiotherapy of locally advanced non small cell lung cancer
Radiotherapy and Oncology, 2016Co-Authors: Jonas Scherman Rydhög, Rasmus Irming Jølck, Thomas Lars Andresen, Lena Specht, Klaus Richter Larsen, Paul Frost Clementsen, Mirjana Josipovic, Marianne C Aznar, Steen Riisgaard Mortensen, Per Munck Af RosenschöldAbstract:Abstract Background and purpose We analysed the positional and structural stability of a long-term biodegradable liquid Fiducial Marker (BioXmark) for radiotherapy in patients with locally advanced lung cancer. Material and methods Markers were injected via endoscopic- or endobronchial ultrasound in lymph nodes and reachable primary tumours. Marker volume and Hounsfield Units (HU) changing rates were estimated using breath-hold CBCT. Inter-fraction variation in Marker position relative to gross tumour volume (GTV) position was established, as well as the inter-fraction variation in mediastinal Marker registration relative to a carina registration through the treatment. Results Fifteen patients were included and 29 Markers analysed. All Markers that were in situ at planning were visible through the treatment. Mean HU was 902 ± 165 HU for lymph node and 991 ± 219 HU for tumour Markers. Volume degradation rates were −5% in lymph nodes and −23% in primary tumours. Three-dimensional inter-fraction variation for Marker position relative to the GTV position was −0.1 ± 0.7 mm in lymph nodes and −1.5 ± 2.3 mm in primary tumours. Inter-fraction variations in Marker registration relative to carina registration were −0.4 ± 1.2 mm in left–right, 0.2 ± 2.0 mm in anterior–posterior and −0.5 ± 2.0 mm in cranio-caudal directions. Conclusions The liquid Fiducial Markers were visible and stable in size and position throughout the treatment course.
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Quantification and comparison of visibility and image artifacts of a new liquid Fiducial Marker in a lung phantom for image‐guided radiation therapy
Medical Physics, 2015Co-Authors: Jonas Scherman Rydhög, Rasmus Irming Jølck, Thomas Lars Andresen, Per Munck Af RosenschöldAbstract:Purpose: A new biodegradable liquid Fiducial Marker was devised to allow for easy insertion in lung tumors using thin needles. The purpose of this study was to evaluate the visibility of the liquid Fiducial Markers for image-guided radiation therapy and compare to existing solid Fiducial Markers and to one existing liquid Fiducial Marker currently commercially available. Methods: Fiducial Marker visibility was quantified in terms of contrast to noise ratio (CNR) on planar kilovoltage x-ray images in a thorax phantom for different concentrations of the radio-opaque component of the new liquid Fiducial Marker, four solid Fiducial Markers, and one existing liquid Fiducial Marker. Additionally, the image artifacts produced on computer tomography (CT) and cone-beam CT (CBCT) of all Fiducial Markers were quantified. Results: The authors found that the new liquid Fiducial Marker with the highest concentration of the radio-opaque component had a CNR > 2.05 for 62/63 exposures, which compared favorably to the existing solid Fiducial Markers and to the existing liquid Fiducial Marker evaluated. On CT and CBCT, the new liquid Fiducial Marker with the highest concentration produced lower streaking index artifact (30 and 14, respectively) than the solid gold Markers (113 and 20, respectively) and the existing liquid Fiducialmore » Marker (39 and 20, respectively). The size of the image artifact was larger for all of the liquid Fiducial Markers compared to the solid Fiducial Markers because of their larger physical size. Conclusions: The visibility and the image artifacts produced by the new liquid Fiducial Markers were comparable to existing solid Fiducial Markers and the existing liquid Fiducial Marker. The authors conclude that the new liquid Fiducial Marker represents an alternative to the Fiducial Markers tested.« less
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quantification and comparison of visibility and image artifacts of a new liquid Fiducial Marker in a lung phantom for image guided radiation therapy
Medical Physics, 2015Co-Authors: Jonas Scherman Rydhög, Rasmus Irming Jølck, Thomas Lars Andresen, Per Munck Af RosenschöldAbstract:Purpose: A new biodegradable liquid Fiducial Marker was devised to allow for easy insertion in lung tumors using thin needles. The purpose of this study was to evaluate the visibility of the liquid Fiducial Markers for image-guided radiation therapy and compare to existing solid Fiducial Markers and to one existing liquid Fiducial Marker currently commercially available. Methods: Fiducial Marker visibility was quantified in terms of contrast to noise ratio (CNR) on planar kilovoltage x-ray images in a thorax phantom for different concentrations of the radio-opaque component of the new liquid Fiducial Marker, four solid Fiducial Markers, and one existing liquid Fiducial Marker. Additionally, the image artifacts produced on computer tomography (CT) and cone-beam CT (CBCT) of all Fiducial Markers were quantified. Results: The authors found that the new liquid Fiducial Marker with the highest concentration of the radio-opaque component had a CNR > 2.05 for 62/63 exposures, which compared favorably to the existing solid Fiducial Markers and to the existing liquid Fiducial Marker evaluated. On CT and CBCT, the new liquid Fiducial Marker with the highest concentration produced lower streaking index artifact (30 and 14, respectively) than the solid gold Markers (113 and 20, respectively) and the existing liquid Fiducialmore » Marker (39 and 20, respectively). The size of the image artifact was larger for all of the liquid Fiducial Markers compared to the solid Fiducial Markers because of their larger physical size. Conclusions: The visibility and the image artifacts produced by the new liquid Fiducial Markers were comparable to existing solid Fiducial Markers and the existing liquid Fiducial Marker. The authors conclude that the new liquid Fiducial Marker represents an alternative to the Fiducial Markers tested.« less
Jonas Scherman Rydhög - One of the best experts on this subject based on the ideXlab platform.
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long term safety and visibility of a novel liquid Fiducial Marker for use in image guided radiotherapy of non small cell lung cancer
Clinical and Translational Radiation Oncology, 2018Co-Authors: Steen Riisgaard De Blanck, Rasmus Irming Jølck, Lena Specht, Jonas Scherman Rydhög, Per Munck Af Rosenschöld, Klaus Richter Larsen, Paul Frost Clementsen, Mirjana Josipovic, Marianne C Aznar, Thomas Lars AndresenAbstract:Abstract Safety and clinical feasibility of injecting a novel liquid Fiducial Marker for use in image guided radiotherapy in 15 patients with non-small cell lung cancer are reported. No major safety or toxicity issues were encountered. Markers present at start of radiotherapy remained visible in cone beam computed tomography and fluoroscopy images throughout the treatment course and on computed tomography images during follow-up (0–38 months). Marker volume reduction was seen until 9 months after treatment, after which no further Marker breakdown was found. No post-treatment migration or Marker related complications were found.
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liquid Fiducial Marker applicability in proton therapy of locally advanced lung cancer
Radiotherapy and Oncology, 2017Co-Authors: Jonas Scherman Rydhög, Steen Riisgaard De Blanck, Rasmus Irming Jølck, Rosalind Perrin, F Gagnonmoisan, Klaus Richter Larsen, Paul Frost Clementsen, G Persson, Damien C Weber, Tony LomaxAbstract:Abstract Background and purpose We investigated the clinical applicability of a novel liquid Fiducial Marker (LFM) for image-guided pencil beam scanned (PBS) proton therapy (PBSPT) of locally advanced lung cancer (LALC). Materials and methods The relative proton stopping power (RSP) of the LFM was calculated and measured. Dose perturbations of the LFM and three solid Markers, in a phantom, were measured. PBSPT treatment planning on computer tomography scans of five patients with LALC with the LFM implanted was performed with 1–3 fields. Results The RSP was experimentally determined to be 1.164 for the LFM. Phantom measurements revealed a maximum relative deviation in dose of 4.8% for the LFM in the spread-out Bragg Peak, compared to 12–67% for the solid Markers. Using the experimentally determined RSP, the maximum proton range error introduced by the LFM is about 1mm. If the Marker was displaced at PBSPT, the maximum dosimetric error was limited to 2 percentage points for 3-field plans. Conclusion The dose perturbations introduced by the LFM were considerably smaller than the solid Markers investigated. The RSP of the Fiducial Marker should be corrected in the treatment planning system to avoid errors. The investigated LFM introduced clinically acceptable dose perturbations for image-guided PBSPT of LALC.
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liquid Fiducial Marker performance during radiotherapy of locally advanced non small cell lung cancer
Radiotherapy and Oncology, 2016Co-Authors: Jonas Scherman Rydhög, Rasmus Irming Jølck, Thomas Lars Andresen, Lena Specht, Klaus Richter Larsen, Paul Frost Clementsen, Mirjana Josipovic, Marianne C Aznar, Steen Riisgaard Mortensen, Per Munck Af RosenschöldAbstract:Abstract Background and purpose We analysed the positional and structural stability of a long-term biodegradable liquid Fiducial Marker (BioXmark) for radiotherapy in patients with locally advanced lung cancer. Material and methods Markers were injected via endoscopic- or endobronchial ultrasound in lymph nodes and reachable primary tumours. Marker volume and Hounsfield Units (HU) changing rates were estimated using breath-hold CBCT. Inter-fraction variation in Marker position relative to gross tumour volume (GTV) position was established, as well as the inter-fraction variation in mediastinal Marker registration relative to a carina registration through the treatment. Results Fifteen patients were included and 29 Markers analysed. All Markers that were in situ at planning were visible through the treatment. Mean HU was 902 ± 165 HU for lymph node and 991 ± 219 HU for tumour Markers. Volume degradation rates were −5% in lymph nodes and −23% in primary tumours. Three-dimensional inter-fraction variation for Marker position relative to the GTV position was −0.1 ± 0.7 mm in lymph nodes and −1.5 ± 2.3 mm in primary tumours. Inter-fraction variations in Marker registration relative to carina registration were −0.4 ± 1.2 mm in left–right, 0.2 ± 2.0 mm in anterior–posterior and −0.5 ± 2.0 mm in cranio-caudal directions. Conclusions The liquid Fiducial Markers were visible and stable in size and position throughout the treatment course.
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Quantification and comparison of visibility and image artifacts of a new liquid Fiducial Marker in a lung phantom for image‐guided radiation therapy
Medical Physics, 2015Co-Authors: Jonas Scherman Rydhög, Rasmus Irming Jølck, Thomas Lars Andresen, Per Munck Af RosenschöldAbstract:Purpose: A new biodegradable liquid Fiducial Marker was devised to allow for easy insertion in lung tumors using thin needles. The purpose of this study was to evaluate the visibility of the liquid Fiducial Markers for image-guided radiation therapy and compare to existing solid Fiducial Markers and to one existing liquid Fiducial Marker currently commercially available. Methods: Fiducial Marker visibility was quantified in terms of contrast to noise ratio (CNR) on planar kilovoltage x-ray images in a thorax phantom for different concentrations of the radio-opaque component of the new liquid Fiducial Marker, four solid Fiducial Markers, and one existing liquid Fiducial Marker. Additionally, the image artifacts produced on computer tomography (CT) and cone-beam CT (CBCT) of all Fiducial Markers were quantified. Results: The authors found that the new liquid Fiducial Marker with the highest concentration of the radio-opaque component had a CNR > 2.05 for 62/63 exposures, which compared favorably to the existing solid Fiducial Markers and to the existing liquid Fiducial Marker evaluated. On CT and CBCT, the new liquid Fiducial Marker with the highest concentration produced lower streaking index artifact (30 and 14, respectively) than the solid gold Markers (113 and 20, respectively) and the existing liquid Fiducialmore » Marker (39 and 20, respectively). The size of the image artifact was larger for all of the liquid Fiducial Markers compared to the solid Fiducial Markers because of their larger physical size. Conclusions: The visibility and the image artifacts produced by the new liquid Fiducial Markers were comparable to existing solid Fiducial Markers and the existing liquid Fiducial Marker. The authors conclude that the new liquid Fiducial Marker represents an alternative to the Fiducial Markers tested.« less
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quantification and comparison of visibility and image artifacts of a new liquid Fiducial Marker in a lung phantom for image guided radiation therapy
Medical Physics, 2015Co-Authors: Jonas Scherman Rydhög, Rasmus Irming Jølck, Thomas Lars Andresen, Per Munck Af RosenschöldAbstract:Purpose: A new biodegradable liquid Fiducial Marker was devised to allow for easy insertion in lung tumors using thin needles. The purpose of this study was to evaluate the visibility of the liquid Fiducial Markers for image-guided radiation therapy and compare to existing solid Fiducial Markers and to one existing liquid Fiducial Marker currently commercially available. Methods: Fiducial Marker visibility was quantified in terms of contrast to noise ratio (CNR) on planar kilovoltage x-ray images in a thorax phantom for different concentrations of the radio-opaque component of the new liquid Fiducial Marker, four solid Fiducial Markers, and one existing liquid Fiducial Marker. Additionally, the image artifacts produced on computer tomography (CT) and cone-beam CT (CBCT) of all Fiducial Markers were quantified. Results: The authors found that the new liquid Fiducial Marker with the highest concentration of the radio-opaque component had a CNR > 2.05 for 62/63 exposures, which compared favorably to the existing solid Fiducial Markers and to the existing liquid Fiducial Marker evaluated. On CT and CBCT, the new liquid Fiducial Marker with the highest concentration produced lower streaking index artifact (30 and 14, respectively) than the solid gold Markers (113 and 20, respectively) and the existing liquid Fiducialmore » Marker (39 and 20, respectively). The size of the image artifact was larger for all of the liquid Fiducial Markers compared to the solid Fiducial Markers because of their larger physical size. Conclusions: The visibility and the image artifacts produced by the new liquid Fiducial Markers were comparable to existing solid Fiducial Markers and the existing liquid Fiducial Marker. The authors conclude that the new liquid Fiducial Marker represents an alternative to the Fiducial Markers tested.« less
Per Munck Af Rosenschöld - One of the best experts on this subject based on the ideXlab platform.
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long term safety and visibility of a novel liquid Fiducial Marker for use in image guided radiotherapy of non small cell lung cancer
Clinical and Translational Radiation Oncology, 2018Co-Authors: Steen Riisgaard De Blanck, Rasmus Irming Jølck, Lena Specht, Jonas Scherman Rydhög, Per Munck Af Rosenschöld, Klaus Richter Larsen, Paul Frost Clementsen, Mirjana Josipovic, Marianne C Aznar, Thomas Lars AndresenAbstract:Abstract Safety and clinical feasibility of injecting a novel liquid Fiducial Marker for use in image guided radiotherapy in 15 patients with non-small cell lung cancer are reported. No major safety or toxicity issues were encountered. Markers present at start of radiotherapy remained visible in cone beam computed tomography and fluoroscopy images throughout the treatment course and on computed tomography images during follow-up (0–38 months). Marker volume reduction was seen until 9 months after treatment, after which no further Marker breakdown was found. No post-treatment migration or Marker related complications were found.
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liquid Fiducial Marker performance during radiotherapy of locally advanced non small cell lung cancer
Radiotherapy and Oncology, 2016Co-Authors: Jonas Scherman Rydhög, Rasmus Irming Jølck, Thomas Lars Andresen, Lena Specht, Klaus Richter Larsen, Paul Frost Clementsen, Mirjana Josipovic, Marianne C Aznar, Steen Riisgaard Mortensen, Per Munck Af RosenschöldAbstract:Abstract Background and purpose We analysed the positional and structural stability of a long-term biodegradable liquid Fiducial Marker (BioXmark) for radiotherapy in patients with locally advanced lung cancer. Material and methods Markers were injected via endoscopic- or endobronchial ultrasound in lymph nodes and reachable primary tumours. Marker volume and Hounsfield Units (HU) changing rates were estimated using breath-hold CBCT. Inter-fraction variation in Marker position relative to gross tumour volume (GTV) position was established, as well as the inter-fraction variation in mediastinal Marker registration relative to a carina registration through the treatment. Results Fifteen patients were included and 29 Markers analysed. All Markers that were in situ at planning were visible through the treatment. Mean HU was 902 ± 165 HU for lymph node and 991 ± 219 HU for tumour Markers. Volume degradation rates were −5% in lymph nodes and −23% in primary tumours. Three-dimensional inter-fraction variation for Marker position relative to the GTV position was −0.1 ± 0.7 mm in lymph nodes and −1.5 ± 2.3 mm in primary tumours. Inter-fraction variations in Marker registration relative to carina registration were −0.4 ± 1.2 mm in left–right, 0.2 ± 2.0 mm in anterior–posterior and −0.5 ± 2.0 mm in cranio-caudal directions. Conclusions The liquid Fiducial Markers were visible and stable in size and position throughout the treatment course.
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Quantification and comparison of visibility and image artifacts of a new liquid Fiducial Marker in a lung phantom for image‐guided radiation therapy
Medical Physics, 2015Co-Authors: Jonas Scherman Rydhög, Rasmus Irming Jølck, Thomas Lars Andresen, Per Munck Af RosenschöldAbstract:Purpose: A new biodegradable liquid Fiducial Marker was devised to allow for easy insertion in lung tumors using thin needles. The purpose of this study was to evaluate the visibility of the liquid Fiducial Markers for image-guided radiation therapy and compare to existing solid Fiducial Markers and to one existing liquid Fiducial Marker currently commercially available. Methods: Fiducial Marker visibility was quantified in terms of contrast to noise ratio (CNR) on planar kilovoltage x-ray images in a thorax phantom for different concentrations of the radio-opaque component of the new liquid Fiducial Marker, four solid Fiducial Markers, and one existing liquid Fiducial Marker. Additionally, the image artifacts produced on computer tomography (CT) and cone-beam CT (CBCT) of all Fiducial Markers were quantified. Results: The authors found that the new liquid Fiducial Marker with the highest concentration of the radio-opaque component had a CNR > 2.05 for 62/63 exposures, which compared favorably to the existing solid Fiducial Markers and to the existing liquid Fiducial Marker evaluated. On CT and CBCT, the new liquid Fiducial Marker with the highest concentration produced lower streaking index artifact (30 and 14, respectively) than the solid gold Markers (113 and 20, respectively) and the existing liquid Fiducialmore » Marker (39 and 20, respectively). The size of the image artifact was larger for all of the liquid Fiducial Markers compared to the solid Fiducial Markers because of their larger physical size. Conclusions: The visibility and the image artifacts produced by the new liquid Fiducial Markers were comparable to existing solid Fiducial Markers and the existing liquid Fiducial Marker. The authors conclude that the new liquid Fiducial Marker represents an alternative to the Fiducial Markers tested.« less
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quantification and comparison of visibility and image artifacts of a new liquid Fiducial Marker in a lung phantom for image guided radiation therapy
Medical Physics, 2015Co-Authors: Jonas Scherman Rydhög, Rasmus Irming Jølck, Thomas Lars Andresen, Per Munck Af RosenschöldAbstract:Purpose: A new biodegradable liquid Fiducial Marker was devised to allow for easy insertion in lung tumors using thin needles. The purpose of this study was to evaluate the visibility of the liquid Fiducial Markers for image-guided radiation therapy and compare to existing solid Fiducial Markers and to one existing liquid Fiducial Marker currently commercially available. Methods: Fiducial Marker visibility was quantified in terms of contrast to noise ratio (CNR) on planar kilovoltage x-ray images in a thorax phantom for different concentrations of the radio-opaque component of the new liquid Fiducial Marker, four solid Fiducial Markers, and one existing liquid Fiducial Marker. Additionally, the image artifacts produced on computer tomography (CT) and cone-beam CT (CBCT) of all Fiducial Markers were quantified. Results: The authors found that the new liquid Fiducial Marker with the highest concentration of the radio-opaque component had a CNR > 2.05 for 62/63 exposures, which compared favorably to the existing solid Fiducial Markers and to the existing liquid Fiducial Marker evaluated. On CT and CBCT, the new liquid Fiducial Marker with the highest concentration produced lower streaking index artifact (30 and 14, respectively) than the solid gold Markers (113 and 20, respectively) and the existing liquid Fiducialmore » Marker (39 and 20, respectively). The size of the image artifact was larger for all of the liquid Fiducial Markers compared to the solid Fiducial Markers because of their larger physical size. Conclusions: The visibility and the image artifacts produced by the new liquid Fiducial Markers were comparable to existing solid Fiducial Markers and the existing liquid Fiducial Marker. The authors conclude that the new liquid Fiducial Marker represents an alternative to the Fiducial Markers tested.« less
Rasmus Irming Jølck - One of the best experts on this subject based on the ideXlab platform.
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long term safety and visibility of a novel liquid Fiducial Marker for use in image guided radiotherapy of non small cell lung cancer
Clinical and Translational Radiation Oncology, 2018Co-Authors: Steen Riisgaard De Blanck, Rasmus Irming Jølck, Lena Specht, Jonas Scherman Rydhög, Per Munck Af Rosenschöld, Klaus Richter Larsen, Paul Frost Clementsen, Mirjana Josipovic, Marianne C Aznar, Thomas Lars AndresenAbstract:Abstract Safety and clinical feasibility of injecting a novel liquid Fiducial Marker for use in image guided radiotherapy in 15 patients with non-small cell lung cancer are reported. No major safety or toxicity issues were encountered. Markers present at start of radiotherapy remained visible in cone beam computed tomography and fluoroscopy images throughout the treatment course and on computed tomography images during follow-up (0–38 months). Marker volume reduction was seen until 9 months after treatment, after which no further Marker breakdown was found. No post-treatment migration or Marker related complications were found.
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Feasibility of a novel liquid Fiducial Marker for use in image guided radiotherapy of oesophageal cancer.
British Journal of Radiology, 2018Co-Authors: Steen Riisgaard De Blanck, Jonas Scherman-rydhög, Mette Siemsen, Merete Sanvig Christensen, Lene Baeksgaard, Rasmus Irming Jølck, Thomas Lars Andresen, Lena Specht, Gitte Fredberg PerssonAbstract:Objective:To evaluate the feasibility of a new liquid Fiducial Marker for use in image-guided radiotherapy for oesophageal cancer.Methods:Liquid Fiducial Markers were implanted in patients with met...
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Quantification of MRI visibility and artifacts at 3T of liquid Fiducial Marker in a pancreas tissue-mimicking phantom.
Medical Physics, 2017Co-Authors: Sergej Schneider, Rasmus Irming Jølck, Esther G.c. Troost, Aswin L. HoffmannAbstract:Purpose X-ray based position verification of the target volume in image-guided radiation therapy (IGRT) of patients with pancreatic ductal adenocarcinoma (PDAC) is currently performed on solid Fiducial Markers that are implanted under endoscopic ultrasonography. A new biodegradable liquid Fiducial Marker has recently been introduced. To assess its potential use for magnetic resonance imaging (MRI) guided photon or proton radiotherapy of PDAC, the MRI visibility and artefacts of this Marker were quantified and compared against solid gold Markers. Material and Methods Different spherical volumes (10 μL, 25 μL, 50 μL and 100 μL) of a biodegradable liquid Fiducial Marker as well as seven differently sized and oriented solid gold (0.35 mm diameter; 5 mm and 10 mm length) and iron-gold alloy Fiducial Markers (0.28 mm diameter; 1 cm and 2 cm length) were implanted in a spherical gel phantom, mimicking the proton spin relaxation properties of healthy pancreatic tissue at 3 Tesla. MR relaxometry was performed to quantify the size and magnitude of the decrease in the effective transversal relaxation time T2* and relative proton density ρ(H) as a measure of potential visibility, and to quantify the size and magnitude of the increase in magnetic field inhomogeneity ΔB0as a measure of potential signal artefacts. The phantom was scanned in a 3.0 T PET/MR scanner with an 8-channel head coil. Results The solid Fiducial Markers showed a direct linear relationship between the potentially visible size and artefact size. The liquid Fiducial Marker showed a tendency towards a potentially visible size at smaller artefacts. Liquid Markers from 25-100 μL generated visible volumes comparable to the size of the solid Markers. The magnitude of visibility was the highest for the liquid Fiducial Marker with volumes of 25μL – 100μL showing no correlation with the magnitude of artefact. The solid Markers showed a strong non-linear correlation between magnitude of visibility and artefact, whereas the solid Marker consisting of a gold-iron alloy induced the strongest artefacts. Conclusion The liquid Fiducial Marker causes signal voids on MRI due to its absence of water hydrogen atoms without strongly affecting the magnetic field in the surrounding tissue. The alteration of the static magnetic field was found to be the main effect leading to the visibility of the solid Fiducial Markers. Hence, especially when a low level of image distortion is required, MRI characteristics of the liquid Marker surpass those of solid gold Markers currently being used for IGRT of PDAC. This article is protected by copyright. All rights reserved.
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liquid Fiducial Marker applicability in proton therapy of locally advanced lung cancer
Radiotherapy and Oncology, 2017Co-Authors: Jonas Scherman Rydhög, Steen Riisgaard De Blanck, Rasmus Irming Jølck, Rosalind Perrin, F Gagnonmoisan, Klaus Richter Larsen, Paul Frost Clementsen, G Persson, Damien C Weber, Tony LomaxAbstract:Abstract Background and purpose We investigated the clinical applicability of a novel liquid Fiducial Marker (LFM) for image-guided pencil beam scanned (PBS) proton therapy (PBSPT) of locally advanced lung cancer (LALC). Materials and methods The relative proton stopping power (RSP) of the LFM was calculated and measured. Dose perturbations of the LFM and three solid Markers, in a phantom, were measured. PBSPT treatment planning on computer tomography scans of five patients with LALC with the LFM implanted was performed with 1–3 fields. Results The RSP was experimentally determined to be 1.164 for the LFM. Phantom measurements revealed a maximum relative deviation in dose of 4.8% for the LFM in the spread-out Bragg Peak, compared to 12–67% for the solid Markers. Using the experimentally determined RSP, the maximum proton range error introduced by the LFM is about 1mm. If the Marker was displaced at PBSPT, the maximum dosimetric error was limited to 2 percentage points for 3-field plans. Conclusion The dose perturbations introduced by the LFM were considerably smaller than the solid Markers investigated. The RSP of the Fiducial Marker should be corrected in the treatment planning system to avoid errors. The investigated LFM introduced clinically acceptable dose perturbations for image-guided PBSPT of LALC.
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liquid Fiducial Marker performance during radiotherapy of locally advanced non small cell lung cancer
Radiotherapy and Oncology, 2016Co-Authors: Jonas Scherman Rydhög, Rasmus Irming Jølck, Thomas Lars Andresen, Lena Specht, Klaus Richter Larsen, Paul Frost Clementsen, Mirjana Josipovic, Marianne C Aznar, Steen Riisgaard Mortensen, Per Munck Af RosenschöldAbstract:Abstract Background and purpose We analysed the positional and structural stability of a long-term biodegradable liquid Fiducial Marker (BioXmark) for radiotherapy in patients with locally advanced lung cancer. Material and methods Markers were injected via endoscopic- or endobronchial ultrasound in lymph nodes and reachable primary tumours. Marker volume and Hounsfield Units (HU) changing rates were estimated using breath-hold CBCT. Inter-fraction variation in Marker position relative to gross tumour volume (GTV) position was established, as well as the inter-fraction variation in mediastinal Marker registration relative to a carina registration through the treatment. Results Fifteen patients were included and 29 Markers analysed. All Markers that were in situ at planning were visible through the treatment. Mean HU was 902 ± 165 HU for lymph node and 991 ± 219 HU for tumour Markers. Volume degradation rates were −5% in lymph nodes and −23% in primary tumours. Three-dimensional inter-fraction variation for Marker position relative to the GTV position was −0.1 ± 0.7 mm in lymph nodes and −1.5 ± 2.3 mm in primary tumours. Inter-fraction variations in Marker registration relative to carina registration were −0.4 ± 1.2 mm in left–right, 0.2 ± 2.0 mm in anterior–posterior and −0.5 ± 2.0 mm in cranio-caudal directions. Conclusions The liquid Fiducial Markers were visible and stable in size and position throughout the treatment course.
Klaus Richter Larsen - One of the best experts on this subject based on the ideXlab platform.
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long term safety and visibility of a novel liquid Fiducial Marker for use in image guided radiotherapy of non small cell lung cancer
Clinical and Translational Radiation Oncology, 2018Co-Authors: Steen Riisgaard De Blanck, Rasmus Irming Jølck, Lena Specht, Jonas Scherman Rydhög, Per Munck Af Rosenschöld, Klaus Richter Larsen, Paul Frost Clementsen, Mirjana Josipovic, Marianne C Aznar, Thomas Lars AndresenAbstract:Abstract Safety and clinical feasibility of injecting a novel liquid Fiducial Marker for use in image guided radiotherapy in 15 patients with non-small cell lung cancer are reported. No major safety or toxicity issues were encountered. Markers present at start of radiotherapy remained visible in cone beam computed tomography and fluoroscopy images throughout the treatment course and on computed tomography images during follow-up (0–38 months). Marker volume reduction was seen until 9 months after treatment, after which no further Marker breakdown was found. No post-treatment migration or Marker related complications were found.
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liquid Fiducial Marker applicability in proton therapy of locally advanced lung cancer
Radiotherapy and Oncology, 2017Co-Authors: Jonas Scherman Rydhög, Steen Riisgaard De Blanck, Rasmus Irming Jølck, Rosalind Perrin, F Gagnonmoisan, Klaus Richter Larsen, Paul Frost Clementsen, G Persson, Damien C Weber, Tony LomaxAbstract:Abstract Background and purpose We investigated the clinical applicability of a novel liquid Fiducial Marker (LFM) for image-guided pencil beam scanned (PBS) proton therapy (PBSPT) of locally advanced lung cancer (LALC). Materials and methods The relative proton stopping power (RSP) of the LFM was calculated and measured. Dose perturbations of the LFM and three solid Markers, in a phantom, were measured. PBSPT treatment planning on computer tomography scans of five patients with LALC with the LFM implanted was performed with 1–3 fields. Results The RSP was experimentally determined to be 1.164 for the LFM. Phantom measurements revealed a maximum relative deviation in dose of 4.8% for the LFM in the spread-out Bragg Peak, compared to 12–67% for the solid Markers. Using the experimentally determined RSP, the maximum proton range error introduced by the LFM is about 1mm. If the Marker was displaced at PBSPT, the maximum dosimetric error was limited to 2 percentage points for 3-field plans. Conclusion The dose perturbations introduced by the LFM were considerably smaller than the solid Markers investigated. The RSP of the Fiducial Marker should be corrected in the treatment planning system to avoid errors. The investigated LFM introduced clinically acceptable dose perturbations for image-guided PBSPT of LALC.
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liquid Fiducial Marker performance during radiotherapy of locally advanced non small cell lung cancer
Radiotherapy and Oncology, 2016Co-Authors: Jonas Scherman Rydhög, Rasmus Irming Jølck, Thomas Lars Andresen, Lena Specht, Klaus Richter Larsen, Paul Frost Clementsen, Mirjana Josipovic, Marianne C Aznar, Steen Riisgaard Mortensen, Per Munck Af RosenschöldAbstract:Abstract Background and purpose We analysed the positional and structural stability of a long-term biodegradable liquid Fiducial Marker (BioXmark) for radiotherapy in patients with locally advanced lung cancer. Material and methods Markers were injected via endoscopic- or endobronchial ultrasound in lymph nodes and reachable primary tumours. Marker volume and Hounsfield Units (HU) changing rates were estimated using breath-hold CBCT. Inter-fraction variation in Marker position relative to gross tumour volume (GTV) position was established, as well as the inter-fraction variation in mediastinal Marker registration relative to a carina registration through the treatment. Results Fifteen patients were included and 29 Markers analysed. All Markers that were in situ at planning were visible through the treatment. Mean HU was 902 ± 165 HU for lymph node and 991 ± 219 HU for tumour Markers. Volume degradation rates were −5% in lymph nodes and −23% in primary tumours. Three-dimensional inter-fraction variation for Marker position relative to the GTV position was −0.1 ± 0.7 mm in lymph nodes and −1.5 ± 2.3 mm in primary tumours. Inter-fraction variations in Marker registration relative to carina registration were −0.4 ± 1.2 mm in left–right, 0.2 ± 2.0 mm in anterior–posterior and −0.5 ± 2.0 mm in cranio-caudal directions. Conclusions The liquid Fiducial Markers were visible and stable in size and position throughout the treatment course.