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Inamdar A, Shinde RK. The Diagnostic Impact of Contrast-Enhanced Computed Tomography (CECT) in Evaluating Lymph Node Involvement in Colorectal Cancer: A Comprehensive Review. Cureus 2024; 16:e61832. [PMID: 38975400 PMCID: PMC11227440 DOI: 10.7759/cureus.61832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Accepted: 06/03/2024] [Indexed: 07/09/2024] Open
Abstract
Colorectal cancer (CRC) remains a significant global health burden, necessitating accurate staging and treatment planning for optimal patient outcomes. Lymph node involvement is a critical determinant of prognosis in CRC, emphasizing the importance of reliable imaging techniques for its evaluation. Contrast-enhanced computed tomography (CECT) has emerged as a cornerstone in CRC imaging, offering high-resolution anatomical detail and vascular assessment. This comprehensive review synthesizes the existing literature to evaluate the diagnostic impact of CECT in assessing lymph node involvement in CRC. Key findings highlight CECT's high sensitivity and specificity in detecting lymph node metastases, facilitating accurate staging and treatment selection. However, challenges such as limited resolution for small lymph nodes and potential false-positives call for a cautious interpretation. Recommendations for clinical practice suggest the integration of CECT into multidisciplinary treatment algorithms, optimizing imaging protocols and enhancing collaboration between radiologists and clinicians. Future research directions include refining imaging protocols, comparative effectiveness studies with emerging modalities, and prospective validation of CECT's prognostic value. Overall, this review stresses the pivotal role of CECT in CRC management and identifies avenues for further advancements in imaging-guided oncology care.
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Affiliation(s)
- Akash Inamdar
- General Surgery, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Raju K Shinde
- General Surgery, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
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2
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Afifah M, Bulthuis MC, Goudschaal KN, Verbeek-Spijkerman JM, Rosario TS, den Boer D, Hinnen KA, Bel A, van Kesteren Z. Virtual unenhanced dual-energy computed tomography for photon radiotherapy: The effect on dose distribution and cone-beam computed tomography based position verification. Phys Imaging Radiat Oncol 2024; 29:100545. [PMID: 38369991 PMCID: PMC10869258 DOI: 10.1016/j.phro.2024.100545] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/24/2024] [Accepted: 01/29/2024] [Indexed: 02/20/2024] Open
Abstract
Background and Purpose Virtual Unenhanced images (VUE) from contrast-enhanced dual-energy computed tomography (DECT) eliminate manual suppression of contrast-enhanced structures (CES) or pre-contrast scans. CT intensity decreases in high-density structures outside the CES following VUE algorithm application. This study assesses VUE's impact on the radiotherapy workflow of gynecological tumors, comparing dose distribution and cone-beam CT-based (CBCT) position verification to contrast-enhanced CT (CECT) images. Materials and Methods A total of 14 gynecological patients with contrast-enhanced CT simulation were included. Two CT images were reconstructed: CECT and VUE. Volumetric Modulated Arc Therapy (VMAT) plans generated on CECT were recalculated on VUE using both the CECT lookup table (LUT) and a dedicated VUE LUT. Gamma analysis assessed 3D dose distributions. CECT and VUE images were retrospectively registered to daily CBCT using Chamfer matching algorithm.. Results Planning target volume (PTV) dose agreement with CECT was within 0.35% for D2%, Dmean, and D98%. Organs at risk (OARs) D2% agreed within 0.36%. A dedicated VUE LUT lead to smaller dose differences, achieving a 100% gamma pass rate for all subjects. VUE imaging showed similar translations and rotations to CECT, with significant but minor translation differences (<0.02 cm). VUE-based registration outperformed CECT. In 24% of CBCT-CECT registrations, inadequate registration was observed due to contrast-related issues, while corresponding VUE images achieved clinically acceptable registrations. Conclusions VUE imaging in the radiotherapy workflow is feasible, showing comparable dose distributions and improved CBCT registration results compared to CECT. VUE enables automated bone registration, limiting inter-observer variation in the Image-Guided Radiation Therapy (IGRT) process.
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Affiliation(s)
- Maryam Afifah
- Amsterdam UMC, Location Vrije Universiteit, Department of Radiation Oncology, De Boelelaan 1118, Amsterdam, the Netherlands
| | - Marloes C. Bulthuis
- Amsterdam UMC, Location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands
| | - Karin N. Goudschaal
- Amsterdam UMC, Location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands
| | - Jolanda M. Verbeek-Spijkerman
- Amsterdam UMC, Location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands
| | - Tezontl S. Rosario
- Amsterdam UMC, Location Vrije Universiteit, Department of Radiation Oncology, De Boelelaan 1118, Amsterdam, the Netherlands
| | - Duncan den Boer
- Amsterdam UMC, Location Vrije Universiteit, Department of Radiation Oncology, De Boelelaan 1118, Amsterdam, the Netherlands
| | - Karel A. Hinnen
- Amsterdam UMC, Location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands
| | - Arjan Bel
- Amsterdam UMC, Location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands
| | - Zdenko van Kesteren
- Amsterdam UMC, Location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands
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Tian M, Mu X, Fan D, Liu Z, Liu Q, Yue K, Song Z, Luo J, Zhang S. A Transformable Mucoadhesive Microgel Network for Noninvasive Multimodal Imaging And Radioprotection of a Large Area of the Gastrointestinal Tract. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2303436. [PMID: 37364891 DOI: 10.1002/adma.202303436] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/04/2023] [Indexed: 06/28/2023]
Abstract
The lack of noninvasive imaging and modulation of a large area of the gastrointestinal (GI) tract constrain the diagnosis and treatment of many GI-related diseases. Recent advances use novel mucoadhesive materials to coat a part of the GI tract and then modulate its functions. High mucoadhesion is the key factor of the partial coating, but also the limitation for not spreading and covering the lower GI tract. Here, a bismuth-pectin organic-inorganic hybrid complex is screened and engineered into a transformable microgel network (Bi-GLUE) with high flowability and mucoadhesion, such that it can quickly transit through and coat a large area of the GI tract. In murine and porcine models, Bi-GLUE delivers contrast agents to achieve real-time, large-area GI-tract imaging under X-ray or magnetic resonance modalities and to facilitate the non-invasive diagnosis of familial adenomatous polyposis. Moreover, Bi-GLUE, like an intracorporal radiation shield, decreases the radiotoxicity in a whole-abdomen irradiation rat model. This transformable microgel network offers a new direction that can modulate a large area of the GI tract and may have broad applications for GI-related conditions.
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Affiliation(s)
- Meng Tian
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Xin Mu
- Advanced Therapies, Siemens Healthineers Ltd., Shanghai, 200126, China
- School of Biomedical Engineering, ShanghaiTech University, Shanghai, 201210, China
| | - Dongyue Fan
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200030, China
- Einthoven Laboratory for Vascular and Regenerative Medicine, Division of Thrombosis and Hemostasis, Department of Internal Medicine, Leiden University Medical Center, Leiden, 2333 ZA, Netherlands
| | - Zhen Liu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Qi Liu
- South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter, South China University of Technology, Guangzhou, 510640, China
| | - Kan Yue
- South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter, South China University of Technology, Guangzhou, 510640, China
| | - Zhiling Song
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Jie Luo
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Shiyi Zhang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200030, China
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4
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Boldrini L, Alongi F, Romano A, Charles Davies D, Bassetti M, Chiloiro G, Corradini S, Gambacorta MA, Placidi L, Tree AC, Westley R, Nicosia L. Current practices and perspectives on the integration of contrast agents in MRI-guided radiation therapy clinical practice: a worldwide survey. Clin Transl Radiat Oncol 2023; 40:100615. [PMID: 36968577 PMCID: PMC10034422 DOI: 10.1016/j.ctro.2023.100615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 03/05/2023] [Indexed: 03/12/2023] Open
Abstract
Aims The introduction of on-line magnetic resonance image-guided radiotherapy (MRIgRT) has led to an improvement in the therapeutic workflow of radiotherapy treatments thanks to the better visualization of therapy volumes assured by the higher soft tissue contrast. Magnetic Resonance contrast agents (MRCA) could improve the target delineation in on-line MRIgRT planning as well as reduce inter-observer variability and enable innovative treatment optimization protocols. The aim of this survey is to investigate the utilization of MRCA among centres that clinically implemented on-line MRIgRT technology. Methods In September 2021, we conducted an online survey consisting of a sixteen-question questionnaire that was distributed to the all the hospitals around the world equipped with MR Linacs. The questionnaire was developed by two Italian 0.35 T and 1.5 T MR-Linac centres and was validated by four other collaborating centres, using a Delphi consensus methodology. Results The survey was distributed to 52 centres and 43 centres completed it (82.7%). Among these centres, 23 institutions (53.5%) used the 0.35T MR-Linac system, while the remaining 20 (46.5%) used the 1.5T MR-Linac system.According to results obtained, 25 (58%) of the centres implemented the use of MRCA for on-line MRIgRT. Gadoxetate (Eovist®; Primovist®) was reported to be the most used MRCA (80%) and liver the most common site of application (58%). Over 70% of responders agreed/strongly agreed to the need for international guidelines. Conclusions The use of MRCA in clinical practice presents several pitfalls and future research will be necessary to understand the actual advantage derived from the use of MRCA in clinical practice, their toxicity profiles and better define the need of formulating guidelines for standardising the use of MRCA in MRIgRT workflow.
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Affiliation(s)
- Luca Boldrini
- Department of Bioimaging, Radiation Oncology and Hematology, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy
| | - Filippo Alongi
- Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Verona, Italy
- University of Brescia, Brescia, Italy
| | - Angela Romano
- Department of Bioimaging, Radiation Oncology and Hematology, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy
- Corresponding author.
| | - Diepriye Charles Davies
- Department of Bioimaging, Radiation Oncology and Hematology, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy
| | - Michael Bassetti
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI, USA
| | - Giuditta Chiloiro
- Department of Bioimaging, Radiation Oncology and Hematology, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy
| | - Stefanie Corradini
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - Maria Antonietta Gambacorta
- Department of Bioimaging, Radiation Oncology and Hematology, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy
| | - Lorenzo Placidi
- Department of Bioimaging, Radiation Oncology and Hematology, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy
| | - Alison C. Tree
- The Royal Marsden NHS Foundation Trust, Sutton, UK
- The Institute of Cancer Research, London, UK
| | - Rosalyne Westley
- The Royal Marsden NHS Foundation Trust, Sutton, UK
- The Institute of Cancer Research, London, UK
| | - Luca Nicosia
- Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Verona, Italy
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Dosimetric effects of oral contrast in the planning of conventional radiotherapy and IMRT, for rectal cancer treatment. JOURNAL OF RADIOTHERAPY IN PRACTICE 2022. [DOI: 10.1017/s1460396922000243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Abstract
Introduction:
Contrast media are frequently used during radiation therapy simulation. However, there are concerns about dosimetric variations when dose calculation is done on contrast-enhanced computed tomography (CT). This study evaluates the dosimetric effect of oral contrast during three-dimensional conformal radiotherapy (3D-CRT) and volumetric modulated arc radiotherapy (VMAT) planning.
Methods:
Rectal cancer patients were consecutively enrolled. For each patient, one unenhanced CT and one contrast-enhanced CT were taken using oral and intravenous contrast. Then, a 3D-CRT plan and an Intensity-modulated radiation therapy (IMRT)/VMAT plan were generated in the enhanced CT, and the dose distribution was recalculated in the respective unenhanced CT. The beam intensities were kept the same as for the enhanced CT plans. Finally, the unenhanced and enhanced plans were compared by calculating the gamma index.
Results:
For 3D-CRT plans, there were statistically significant differences in second phase planning target volume (PTV) D2% (Mean difference (MD) between unenhanced and enhanced CT 0·01 Gy, 95% CI [0·003 to 0·02 Gy]) and in maximum doses to the bladder (MD 0·26 Gy, 95% CI [0·05 to 0·47 Gy]). For IMRT/VMAT plans, there were statistically significant differences in small intestine V45 Gy (MD 3·1 cc, 95% CI [0·81 to 5·4 cc]), bladder V45 Gy (MD 2·9%, 95% CI [1·4 to 4·3%]) and maximum dose to the bladder (MD 0·65 Gy, 95% CI [0·46 Gy to 0·85 Gy]). In addition, for PTV D98% the MD between unenhanced and enhanced CT was 0·22 Gy 95% CI [0·05 to 0·39].
Conclusions:
For most of the dose metrics, the differences were not clinically meaningful. The greatest differences were found in VMAT plans, especially in V45 Gy of the small intestine. This difference could lead to an underestimation of dose–volume metrics when the plan is based on an enhanced CT. The use of small bowel oral contrast does not significantly influence dose calculations and may not affect the acceptability of plans when adhering to constraints.
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Zhang J, Wang L, Xu B, Huang M, Chen Y, Li X. Influence of Using a Contrast-Enhanced CT Image as the Primary Image on CyberKnife Brain Radiosurgery Treatment Plans. Front Oncol 2021; 11:705905. [PMID: 34604041 PMCID: PMC8483719 DOI: 10.3389/fonc.2021.705905] [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: 05/06/2021] [Accepted: 08/30/2021] [Indexed: 11/13/2022] Open
Abstract
Background and Purpose This study aimed to quantify the differences between pre- and post-contrast agent (CA) CT for CyberKnife brain SRS plans. Materials and Methods Twenty-five patients were retrospectively analyzed. They were divided into two categories, inhomogeneous cases (13 patients) and homogeneous cases (12 patients), according to whether the tumor was close to the cavity and inhomogeneous tissues or not. The pre-CA and post-CA plans were designed and calculated using the same monitor unit and paths as those in the ray-tracing algorithm, respectively. Results The CT number difference of tumor between pre- and post-CA was significant (on average, 24.78 ± 18.56 HU, P-value < 0.01). The deviation value of the target was the largest at approximately 37 HU (inhomo-) and 13 HU (homo-) (P < 0.01), and the values of the organs at risk (OARs) were not statistically significant (P-value > 0.05). However, it was not statistically significant for the dose difference between the two groups with the injection of CA (P-value > 0.05). The absolute effective depth difference generally remained at a level of 1 mm, but the dose difference was quitely fluctuated sometimes more than 20%. The absolute effective depth difference of the inhomo-case (0.62 mm) was larger than that of the homo-case (0.37 mm) on median, as well as the variation amplitude (P-value < 0.05). Moreover, the relative dose differences between the two cases were 0.38% (inhomo-) and 0.2% (homo-), respectively (P-value < 0.05). At the criterion of 1 mm/1%, the gamma pass rate of the homo-case (95.89%) was larger than that of the inhomo-case (93.79%). For the OARs, except for the cochlea, the two cases were almost the same (>98.85%). The tumor control probability of the target was over 99.99% before and after injection of a CA, as well as the results for the homo-case and inhomo-case. Conclusions Considering the difference of evaluation indexes between pre- and post-CA images, we recommended plain CT to be employed as the primary image for improving the CK treatment accuracy of brain SRS, especially when the target was close to CA-sensitive OARs and cavity.
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Affiliation(s)
- Jianping Zhang
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China.,Fujian Medical University Union Clinical Medicine College, Fujian Medical University, Fuzhou, China.,Department of Medical Imaging Technology, College of Medical Technology and Engineering, Fujian Medical University, Fuzhou, China
| | - Lin Wang
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China.,Fujian Medical University Union Clinical Medicine College, Fujian Medical University, Fuzhou, China
| | - Benhua Xu
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China.,Fujian Medical University Union Clinical Medicine College, Fujian Medical University, Fuzhou, China.,Department of Medical Imaging Technology, College of Medical Technology and Engineering, Fujian Medical University, Fuzhou, China
| | - Miaoyun Huang
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China.,Fujian Medical University Union Clinical Medicine College, Fujian Medical University, Fuzhou, China
| | - Yuangui Chen
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Xiaobo Li
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China.,Fujian Medical University Union Clinical Medicine College, Fujian Medical University, Fuzhou, China.,Department of Medical Imaging Technology, College of Medical Technology and Engineering, Fujian Medical University, Fuzhou, China
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Bhushan M, Tripathi D, Yadav G, Kumar L, Dewan A, Tandon S, Kumar G, Wahi IK, Gairola M. Effect of contrast medium on treatment modalities planned with different photon beam energies: a planning study. Rep Pract Oncol Radiother 2021; 26:688-711. [PMID: 34760305 PMCID: PMC8575357 DOI: 10.5603/rpor.a2021.0103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 09/16/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Routinely, patient's planning scans are acquired after administration of iodinized contrast media but they will be treated in the absence of that. Similarly, high energy photons have a better penetrating power, while low energy photons will result in tighter dose distribution and negligible neutron contamination. The aim of the study was to investigate a suitable photon beam energy in the presence of intravenous contrast medium. MATERIALS AND METHODS An indigenously made original-contrast (OC) phantom was mentioned as virtual-contrast (VC) and virtual-without-contrast (VWC) phantom were generated by assigning the Hounsfield Units (HU) to different structures. Intensity-modulated (IMRT) and volumetric-modulated-arc (VMAT) plans were generated as per criteria of the TG-119 protocol. RESULTS It was observed that the maximum dose to the spinal cord was better with 6 mega-voltage (MV) in IMRT. The coverage of Prostate PTV (PR PTV) was similar with all the photon energies and was comparable with TG-119, except for original-contrast (OC) phantom using the VMAT technique. Homogeneity-index (HI) was comparatively better for VMAT plans. CONCLUSION The contrast CT images lower the dose to targets. IMRT or VMAT plans, generated on such CT images will be delivered with higher doses than evaluated. However, the overdose remains non-significant.
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Affiliation(s)
- Manindra Bhushan
- Division of Medical Physics and Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
- Amity School of Applied Sciences, Amity University (AUUP), NOIDA, Mumbai, India
| | - Deepak Tripathi
- Amity School of Applied Sciences, Amity University (AUUP), NOIDA, Mumbai, India
| | - Girigesh Yadav
- Division of Medical Physics and Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
| | - Lalit Kumar
- Division of Medical Physics and Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
| | - Abhinav Dewan
- Division of Medical Physics and Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
| | - Sarthak Tandon
- Division of Medical Physics and Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
| | - Gourav Kumar
- Division of Medical Physics and Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
| | - Inderjit Kaur Wahi
- Division of Medical Physics and Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
| | - Munish Gairola
- Division of Medical Physics and Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
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Ahangari S, Hansen NL, Olin AB, Nøttrup TJ, Ryssel H, Berthelsen AK, Löfgren J, Loft A, Vogelius IR, Schnack T, Jakoby B, Kjaer A, Andersen FL, Fischer BM, Hansen AE. Toward PET/MRI as one-stop shop for radiotherapy planning in cervical cancer patients. Acta Oncol 2021; 60:1045-1053. [PMID: 34107847 DOI: 10.1080/0284186x.2021.1936164] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Radiotherapy (RT) planning for cervical cancer patients entails the acquisition of both Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). Further, molecular imaging by Positron Emission Tomography (PET) could contribute to target volume delineation as well as treatment response monitoring. The objective of this study was to investigate the feasibility of a PET/MRI-only RT planning workflow of patients with cervical cancer. This includes attenuation correction (AC) of MRI hardware and dedicated positioning equipment as well as evaluating MRI-derived synthetic CT (sCT) of the pelvic region for positioning verification and dose calculation to enable a PET/MRI-only setup. MATERIAL AND METHODS 16 patients underwent PET/MRI using a dedicated RT setup after the routine CT (or PET/CT), including eight pilot patients and eight cervical cancer patients who were subsequently referred for RT. Data from 18 patients with gynecological cancer were added for training a deep convolutional neural network to generate sCT from Dixon MRI. The mean absolute difference between the dose distributions calculated on sCT and a reference CT was measured in the RT target volume and organs at risk. PET AC by sCT and a reference CT were compared in the tumor volume. RESULTS All patients completed the examination. sCT was inferred for each patient in less than 5 s. The dosimetric analysis of the sCT-based dose planning showed a mean absolute error (MAE) of 0.17 ± 0.12 Gy inside the planning target volumes (PTV). PET images reconstructed with sCT and CT had no significant difference in quantification for all patients. CONCLUSIONS These results suggest that multiparametric PET/MRI can be successfully integrated as a one-stop-shop in the RT workflow of patients with cervical cancer.
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Affiliation(s)
- Sahar Ahangari
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Naja Liv Hansen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Anders Beck Olin
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Trine Jakobi Nøttrup
- Department of Oncology, Section of Radiotherapy, University of Copenhagen, Rigshospitalet, Denmark
| | - Heidi Ryssel
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Anne Kiil Berthelsen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Johan Löfgren
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Annika Loft
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Ivan Richter Vogelius
- Department of Oncology, Section of Radiotherapy, University of Copenhagen, Rigshospitalet, Denmark
| | - Tine Schnack
- Department of Gynecology, University of Copenhagen, Copenhagen, Denmark
- Department of Gynecology and Obstetrics, Odense University Hospital, Odense, Denmark
| | | | - Andreas Kjaer
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Cluster for Molecular Imaging, University of Copenhagen, Copenhagen, Denmark
| | - Flemming Littrup Andersen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Barbara Malene Fischer
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
- The PET Centre, School of Biomedical Engineering and Imaging Sciences, Kings College London, St Thomas’ Hospital, London, UK
| | - Adam Espe Hansen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
- Department of Diagnostic Radiology, Rigshospitalet, University of Copenhagen, Denmark Copenhagen
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9
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Kamal R, Thaper D, Kumar R, Singh G, Yadav HP, Oinam AS, Kumar V, Sharma H. Dosimetric impact of contrast-enhanced 4d computed tomography for stereotactic body radiation therapy of hepatocelluar carcinoma. Rep Pract Oncol Radiother 2021; 26:598-604. [PMID: 34434576 PMCID: PMC8382070 DOI: 10.5603/rpor.a2021.0075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 02/27/2021] [Indexed: 05/08/2023] Open
Abstract
BACKGROUND A purpose of the study was to investigate the dosimetric impact of contrast media on dose calculation using average 4D contrast-enhanced computed tomography (4D-CECT) and delayed 4D-CT (d4D-CT) images caused by CT simulation contrast agents for stereotactic body radiation therapy (SBRT) of liver cases. MATERIALS AND METHODS Fifteen patients of liver SBRT treated using the volumetric modulated arc therapy (VMAT) technique were selected retrospectively. 4D-CECT, and d4D-CT were acquired with the Anzai gating system and GE CT. For all patients, gross target volume (GTV) was contoured on the ten phases after rigid registration of both the contrast and delayed scans and merged to generate internal target volume (ITV) on average CT images. Region of interest (ROI) was drawn on contrast images and then copied to the delayed images after rigid registration of two average CT datasets. The treatment plans were generated for contrast enhanced average CT, delayed average CT and contrast enhanced average CT with electron density of the heart overridden. RESULTS No significant dosimetric difference was observed in plans parameters (mean HU value of the liver, total monitor units, total control points, degree of modulation and average segment area) except mean HU value of the aorta amongst the three arms. All the OARs were evaluated and resulted in statistically insignificant variation (p > 0.05) using one way ANOVA analysis. CONCLUSIONS Contrast enhanced 4D-CT is advantageous in accurate delineation of tumors and assessing accurate ITV. The treatment plans generated on average 4D-CECT and average d4D-CT have a clinically insignificant effect on dosimetric parameters.
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Affiliation(s)
- Rose Kamal
- Centre for Medical Physics, Panjab University, Chandigarh, India
- Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Deepak Thaper
- Centre for Medical Physics, Panjab University, Chandigarh, India
- Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Rishabh Kumar
- Centre for Medical Physics, Panjab University, Chandigarh, India
| | - Gaganpreet Singh
- Centre for Medical Physics, Panjab University, Chandigarh, India
- Department of Radiotherapy, Post Graduate Institute of Medical Education and Research, Regional Cancer Centre, Chandigarh, India
| | - Hanuman P. Yadav
- Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Arun S. Oinam
- Department of Radiotherapy, Post Graduate Institute of Medical Education and Research, Regional Cancer Centre, Chandigarh, India
| | - Vivek Kumar
- Centre for Medical Physics, Panjab University, Chandigarh, India
| | - Hitesh Sharma
- Govt. Cancer Hospital, NSCB Medical College, Jabalpur, Madhya Pradesh, India
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Oral contrast agents lead to underestimation of dose calculation in volumetric-modulated arc therapy planning for pelvic irradiation. Chin Med J (Engl) 2020; 133:2061-2070. [PMID: 32810050 PMCID: PMC7478501 DOI: 10.1097/cm9.0000000000001025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Supplemental Digital Content is available in the text Background The effects of oral contrast agents (OCAs) on dosimetry have not been studied in detail. Therefore, this study aimed to examine the influence of OCAs on dose calculation in volumetric-modulated arc therapy plans for rectal cancer. Methods From 2008 to 2016, computed tomography (CT) images were obtained from 33 rectal cancer patients administered OCA with or without intravenous contrast agent (ICA) and 14 patients who received no contrast agent. CT numbers of organs at risk were recorded and converted to electronic densities. Volumetric-modulated arc therapy plans were designed before and after the original densities were replaced with non-enhanced densities. Doses to the planned target volume (PTV) and organs at risk were compared between the plans. Results OCA significantly increased the mean and maximum densities of the bowels, while the effects of ICA on these parameters depended on the blood supply of the organs. With OCA, the actual doses for PTV were significantly higher than planned and doses to the bowel increased significantly although moderately. However, the increase in the volume receiving a high-range doses was substantial (the absolute change of intestine volume receiving ≥52 Gy: 1.46 [0.05−3.99, cubic centimeter range: −6.74 to 128.12], the absolute change of colon volume receiving ≥50 Gy: 0.34 [0.01−1.53 cc, range: −0.08 to 3.80 cc]. Dose changes due to ICA were insignificant. Pearson correlation showed that dose changes were significantly correlated with a high intestinal volume within or near the PTV (ρ > 0.5, P < 0.05) and with the density of enhanced intestine (ρ > 0.3, P < 0.05). Conclusions Contrast agents applied in simulation cause underestimation of doses in actual treatment. The overdose due to ICA was slight, while that due to OCA was moderate. The bowel volume receiving ≥50Gy was dramatically increased when OCA within the bowel was absent. Physicians should be aware of these issues if the original plan is barely within clinical tolerance or if a considerable volume of enhanced intestine is within or near the PTV.
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