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Vuong T, Garant A, Vendrely V, Martin AG, Devic S. Clinical applications of high dose rate endorectal brachytherapy for patients with rectal cancer. Cancer Radiother 2022; 26:879-883. [PMID: 36031497 DOI: 10.1016/j.canrad.2022.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 11/29/2022]
Abstract
With the establishment of total mesorectal excision for the treatment of rectal cancer, local recurrence rates have significantly decreased. The addition of preoperative external beam irradiation further reduces this risk to less than 6%. As the local treatment becomes successful and more widely used, the associated treatment-related toxicity is becoming clinically important. If 4 to 6% of the patients are to benefit from neo-adjuvant therapy before total mesorectal excision, the acute and the long-term toxicity burden must be reasonable. With the introduction of better-quality imaging for tumour visualization and treatment planning, a new-targeted radiation treatment was introduced with high dose rate endorectal brachytherapy. The treatment concept was tested in phase I and II studies first in the preoperative setting, then as a boost after external beam radiation therapy as a dose escalation study to achieve higher tumour local control in a radical treatment setting with no surgery. High dose rate endorectal brachytherapy is safe and effective in achieving high tumour regression rate and was well tolerated. It is presently explored in a phase III dose escalation study in the non-operative management of patients with operable rectal cancer.
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Affiliation(s)
- T Vuong
- Radiation Oncology Department, Jewish General Hospital, McGill University, Montreal, Québec, Canada H3T 1E2.
| | - A Garant
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, USA
| | - V Vendrely
- Department of Radiation Oncology, CHU de Bordeaux, 33000 Bordeaux, France; BoRdeaux Institute of onCology (BRIC), UMR1312, Inserm, université de Bordeaux, 33000 Bordeaux, France
| | - A-G Martin
- Service de radio-oncologie, CHU de Québec, Université Laval, Québec, Canada
| | - S Devic
- Radiation Oncology Department, Jewish General Hospital, McGill University, Montreal, Québec, Canada H3T 1E2
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Vuong T, Garant A, Khosrow-Khavar F, Devic S, Enger S, Boutros M, Cohen A, Miller CS, Friedman G, Galiatsatos P, Nguyen V, Benoit N, Lan Thai H, Diec H, Desgroseilliers C, Faria J, Vasilevsky C. A141 IS SURGERY STILL THE ONLY TREATMENT OPTION FOR CURABLE RECTAL CANCER? J Can Assoc Gastroenterol 2022. [PMCID: PMC8859336 DOI: 10.1093/jcag/gwab049.140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background Rectal cancer is curable by standard surgery with Total Mesorectal Excision (TME). However, there are well known associated long-term bowel and sexual dysfunctions. Non-operative management (NOM) is an emerging treatment for patients with operable rectal cancer. There is evidence supporting dose response for tumor control in rectal adenocarcinoma. Aims In the era of modern technologies, Image-guided adaptive endorectal brachytherapy is a means to deliver local radiotherapy boost treatments. We explored its role in a randomized phase II/III trial (NCT03051464) for patients aiming to achieve cure without surgery. Total Mesorectal Excision (TME) free survival at 2 years was the primary endpoint. We now present the interim analysis upon accrual of the first 40 patients. Methods In randomized trial, patients with operable cT2-3ab N0 M0 rectal cancer received 45 Gy in 25 fractions of pelvic external beam radiotherapy (EBRT) with concurrent 5-FU/ Capecitabine. They were randomized to receive either an EBRT boost of 9 Gy in 5 fractions (Arm A), or three weekly adaptive brachytherapy boosts for a total of 30 Gy in 3 fractions (Arm B). Results Forty patients were included (20 per arm). The median age was 66 years; baseline characteristics were well balanced in terms of age, tumor location, T stage and tumor size (Table 1). The acute treatment related toxicities are similar as shown in table 2 but in arm B, there were two deaths: one patient died during his chemotherapy and external beam treatment from congestive heart failure and one patient from a heart attack after treatment prior to salvage TME surgery. The proportion of complete clinical response was 50% (n=10/20) in Arm A and 90% in Arm B (n=18/20). With a median follow-up of 2.2 years, local regrowth at 2 years occurred in 4/10 patients (40%) in Arm A and 4/18 patients (22%) in Arm B. TME-free survival rate at 2 years was 45.9% in Arm A and 85.1% in Arm B (p=0.0036) (Figure 1). Conclusions The interim analysis of this trial suggests that these two strategies of radiation dose escalation are feasible and lead to high chances of organ preservation in patients with operable rectal cancer. The Independent Monitoring Comittee (IDMC) approved the continuation of patient recruitment in the phase III study as planned. ![]()
Funding Agencies Elekta
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Affiliation(s)
- T Vuong
- Radiation Oncology, Sir Mortimer B Davis Jewish General Hospital, Montreal, QC, Canada
| | - A Garant
- The University of Texas Southwestern Medical Center, Dallas, TX
| | - F Khosrow-Khavar
- Radiation Oncology, Sir Mortimer B Davis Jewish General Hospital, Montreal, QC, Canada
| | - S Devic
- Radiation Oncology, Sir Mortimer B Davis Jewish General Hospital, Montreal, QC, Canada
| | - S Enger
- Radiation Oncology, Sir Mortimer B Davis Jewish General Hospital, Montreal, QC, Canada
| | - M Boutros
- Radiation Oncology, Sir Mortimer B Davis Jewish General Hospital, Montreal, QC, Canada
| | - A Cohen
- Radiation Oncology, Sir Mortimer B Davis Jewish General Hospital, Montreal, QC, Canada
| | - C S Miller
- Radiation Oncology, Sir Mortimer B Davis Jewish General Hospital, Montreal, QC, Canada
| | - G Friedman
- Radiation Oncology, Sir Mortimer B Davis Jewish General Hospital, Montreal, QC, Canada
| | - P Galiatsatos
- Medicine, Division of Gastroenterology, SMBD Jewish General Hospital, Montrreal, QC, Canada
| | - V Nguyen
- Hopital Pierre-Boucher, Longueuil, QC, Canada
| | - N Benoit
- Hopital Pierre-Boucher, Longueuil, QC, Canada
| | - H Lan Thai
- Hopital Pierre-Boucher, Longueuil, QC, Canada
| | - H Diec
- Hopital Pierre-Boucher, Longueuil, QC, Canada
| | | | - J Faria
- Radiation Oncology, Sir Mortimer B Davis Jewish General Hospital, Montreal, QC, Canada
| | - C Vasilevsky
- Radiation Oncology, Sir Mortimer B Davis Jewish General Hospital, Montreal, QC, Canada
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Aldelaijan S, Khosravi M, Khouj Y, Harris T, O'Farrell D, Seuntjens J, Devic S, Buzurovic I. PO-0229 Towards informed and digitized HDR brachytherapy QA: Quantitative analysis of GYN applicators. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)06388-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Petitjean N, Dusfour G, Cañadas P, Maumus M, Valorge P, Devic S, Berthelot J, Belamie E, Royer P, Jorgensen C, Noël D, Le Floc'h S. Validation of a new fluidic device for mechanical stimulation and characterization of microspheres: A first step towards cartilage characterization. Mater Sci Eng C Mater Biol Appl 2021; 121:111800. [PMID: 33579447 DOI: 10.1016/j.msec.2020.111800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/23/2020] [Accepted: 12/05/2020] [Indexed: 11/30/2022]
Abstract
Articular cartilage is made of chondrocytes surrounded by their extracellular matrix that can both sense and respond to various mechanical stimuli. One of the most widely used in vitro model to study cartilage growth is the model of mesenchymal stromal cells-derived cartilage micropellet. However, mechanical stimulation of micropellets has never been reported probably because of their small size and imperfect round shape. The objective of the study was to develop an original custom-made device allowing both the mechanical stimulation and characterization of cartilage micropellets. The fluidic-based device was designed for the concomitant stimulation or characterization of six microspheres placed into the conical wells of a tank. In the present study, the device was validated using alginate-, collagen- and crosslinked collagen-based microspheres. Different types and ranges of pressure signals (square, sinusoidal and constant) were applied. The mechanical properties of microspheres were equivalent to those determined by a conventional compression test. Accuracy, repeatability and reproducibility of all types of pressure signals were demonstrated even though square signals were less accurate and sinusoidal signals were less reproducible than the others. The interest of this new device lies in the reliability to mechanically stimulate and characterize microspheres with diameters in the range of 900 to 1500 μm. Mechanical stimulation can be performed on six microspheres in parallel allowing the mechanical and molecular characterization of the same group of cartilage micropellets. The device will be useful to evaluate the growth of cartilage micropellets under mechanical stimuli.
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Affiliation(s)
- N Petitjean
- LMGC, Univ Montpellier, CNRS, Montpellier, France; IRMB, Univ Montpellier, INSERM, Montpellier, France
| | - G Dusfour
- LMGC, Univ Montpellier, CNRS, Montpellier, France
| | - P Cañadas
- LMGC, Univ Montpellier, CNRS, Montpellier, France
| | - M Maumus
- IRMB, Univ Montpellier, INSERM, Montpellier, France
| | - P Valorge
- LMGC, Univ Montpellier, CNRS, Montpellier, France
| | - S Devic
- LMGC, Univ Montpellier, CNRS, Montpellier, France
| | - J Berthelot
- ICGM, Univ Montpellier, CNRS, ENSCM, Montpellier, France; EPHE, PSL Research University, 75014 Paris, France
| | - E Belamie
- ICGM, Univ Montpellier, CNRS, ENSCM, Montpellier, France; EPHE, PSL Research University, 75014 Paris, France
| | - P Royer
- LMGC, Univ Montpellier, CNRS, Montpellier, France
| | - C Jorgensen
- IRMB, Univ Montpellier, INSERM, Montpellier, France; Clinical Immunology and Osteoarticular Disease Therapeutic Unit, Department of Rheumatology, CHU Montpellier, France
| | - D Noël
- IRMB, Univ Montpellier, INSERM, Montpellier, France; Clinical Immunology and Osteoarticular Disease Therapeutic Unit, Department of Rheumatology, CHU Montpellier, France
| | - S Le Floc'h
- LMGC, Univ Montpellier, CNRS, Montpellier, France.
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Aldelaijan S, O'Farrell D, Harris T, Cormack R, Seuntjens J, Devic S, Devlin P, Buzurovic I. OC-1032: In-vivo film dosimetry indicates a role for model-based algorithms in HDR surface brachytherapy. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01971-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Tomic N, Seuntjens J, Devic S. PO-1308: Relative Dose Measurements in Diagnostic Radiology Beams Using the XR-QA2 GafChromicTM Film Model. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01326-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Aldelaijan S, Devic S, Bekerat H, Papaconstadopoulos P, Schneider J, Seuntjens J, Cormack RA, Buzurovic IM. Positional and angular tracking of HDR 192 Ir source for brachytherapy quality assurance using radiochromic film dosimetry. Med Phys 2020; 47:6122-6139. [PMID: 33064876 DOI: 10.1002/mp.14540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/31/2020] [Accepted: 09/25/2020] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To quantify and verify the dosimetric impact of high-dose rate (HDR) source positional uncertainty in brachytherapy, and to introduce a model for three-dimensional (3D) position tracking of the HDR source based on a two-dimensional (2D) measurement. This model has been utilized for the development of a comprehensive source quality assurance (QA) method using radiochromic film (RCF) dosimetry including assessment of different digitization uncertainties. METHODS An algorithm was developed and verified to generate 2D dose maps of the mHDR-V2 192 Ir source (Elekta, Veenendaal, Netherlands) based on the AAPM TG-43 formalism. The limits of the dosimetric error associated with source (0.9 mm diameter) positional uncertainty were evaluated and experimentally verified with EBT3 film measurements for 6F (2.0 mm diameter) and 4F (1.3 mm diameter) size catheters at the surface (4F, 6F) and 10 mm further (4F only). To quantify this uncertainty, a source tracking model was developed to incorporate the unique geometric features of all isodose lines (IDLs) within any given 2D dose map away from the source. The tracking model normalized the dose map to its maximum, then quantified the IDLs using blob analysis based on features such as area, perimeter, weighted centroid, elliptic orientation, and circularity. The Pearson correlation coefficients (PCCs) between these features and source coordinates (x, y, z, θy , θz ) were calculated. To experimentally verify the accuracy of the tracking model, EBT3 film pieces were positioned within a Solid Water® (SW) phantom above and below the source and they were exposed simultaneously. RESULTS The maximum measured dosimetric variations on the 6F and 4F catheter surfaces were 39.8% and 36.1%, respectively. At 10 mm further, the variation reduced to 2.6% for the 4F catheter which is in agreement with the calculations. The source center (x, y) was strongly correlated with the low IDL-weighted centroid (PCC = 0.99), while the distance to source (z) was correlated with the IDL areas (PCC = 0.96) and perimeters (PCC = 0.99). The source orientation θy was correlated with the difference between high and low IDL-weighted centroids (PCC = 0.98), while θz was correlated with the elliptic orientation of the 60-90% IDLs (PCC = 0.97) for a maximum distance of z = 5 mm. Beyond 5 mm, IDL circularity was significant, therefore limiting the determination of θz (PCC ≤ 0.48). The measured positional errors from the film sets above and below the source indicated a source position at the bottom of the catheter (-0.24 ± 0.07 mm). CONCLUSIONS Isodose line features of a 2D dose map away from the HDR source can reveal its spatial coordinates. RCF was shown to be a suitable dosimeter for source tracking and dosimetry. This technique offers a novel source QA method and has the potential to be used for QA of commercial and customized applicators.
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Affiliation(s)
- Saad Aldelaijan
- Department of Radiation Oncology, Dana Farber/Brigham and Women's Cancer Center, Harvard Medical School, Boston, MA, 02115, USA.,Department of Biomedical Engineering, Montreal Neurological Institute, McGill University, Montréal, QC, H3A 2B4, Canada.,Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada.,Department of Radiation Oncology, SMBD Jewish General Hospital, Montréal, QC, H3T 1E2, Canada.,Biomedical Physics Department, King Faisal Specialist Hospital & Research Centre, Riyadh, 12713, Saudi Arabia
| | - Slobodan Devic
- Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada.,Department of Radiation Oncology, SMBD Jewish General Hospital, Montréal, QC, H3T 1E2, Canada
| | - Hamed Bekerat
- Department of Radiation Oncology, SMBD Jewish General Hospital, Montréal, QC, H3T 1E2, Canada
| | | | - James Schneider
- Department of Radiation Oncology, SMBD Jewish General Hospital, Montréal, QC, H3T 1E2, Canada
| | - Jan Seuntjens
- Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada
| | - Robert A Cormack
- Department of Radiation Oncology, Dana Farber/Brigham and Women's Cancer Center, Harvard Medical School, Boston, MA, 02115, USA
| | - Ivan M Buzurovic
- Department of Radiation Oncology, Dana Farber/Brigham and Women's Cancer Center, Harvard Medical School, Boston, MA, 02115, USA
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Moftah B, Aldelaijan S, Shehadeh M, Alzorkany F, Alrumayan F, Alsbeih G, Alshabanah M, Seuntjens J, Tomic N, Devic S. Calibration of MTT assay in proton beams using radiochromic films. Phys Med 2020; 77:146-153. [PMID: 32861190 DOI: 10.1016/j.ejmp.2020.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/31/2020] [Accepted: 08/04/2020] [Indexed: 10/23/2022] Open
Abstract
PURPOSE This study provides methodology of calibrating as well as controlling the output for an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) colorimetric assay irradiated in a low energy proton beam using EBT3-model GAFCHROMICTM film, without correcting for quenching effect. METHODS A calibrated Markus ionization chamber was used to measure the depth dose and beam output for 26.5 MeV protons produced by a CS30 cyclotron. A time-controlled aluminum cylinder was added in front of the horizontal beam-exit serving as a radiation shutter. Following the TRS-398 reference dosimetry protocol for proton beams, the output was calibrated in water at a reference depth of 3 mm. EBT3 film was calibrated for doses up to 8 Gy at the same depth. To verify the dose distribution for each 96-well MTT assay plate, EBT3 film was placed at the reference depth during irradiation and cell doses were scaled by measured percent depth dose (PDD) data. RESULTS The radiochromic film dosimetry system in this study provides dose measurements with an uncertainty better than 3.3% for doses higher than 1 Gy. From a single exposure and utilizing the Gaussian shape of the beam, multiple dose points can be obtained within different wells of the same plate ranging from 6.9 Gy (sigma ∼4%) in the central well, and 2 Gy (sigma ∼8%) for wells positioned closer to the periphery. CONCLUSIONS We described a methodology for radiochromic film-based dose monitoring system, using low-energy protons, which can be used for the MTT assay in any proton beam, except within Bragg peak region.
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Affiliation(s)
- B Moftah
- Radiation Physics Section, Biomedical Physics Department, King Faisal Specialist Hospital & Research Centre, Riyadh, Kingdom of Saudi Arabia; Medical Physics Unit, McGill University, Montréal, Québec, Canada
| | - S Aldelaijan
- Radiation Physics Section, Biomedical Physics Department, King Faisal Specialist Hospital & Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - M Shehadeh
- Radiation Physics Section, Biomedical Physics Department, King Faisal Specialist Hospital & Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - F Alzorkany
- Radiation Physics Section, Biomedical Physics Department, King Faisal Specialist Hospital & Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - F Alrumayan
- Cyclotron and Radiopharmaceuticals Department, King Faisal Specialist Hospital & Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - G Alsbeih
- Radiation Biology Section, Biomedical Physics Department, King Faisal Specialist Hospital & Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - M Alshabanah
- Oncology Centre, King Faisal Specialist Hospital & Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - J Seuntjens
- Medical Physics Unit, McGill University, Montréal, Québec, Canada; Department of Oncology, Faculty of Medicine, McGill University, Montréal, Québec, Canada
| | - N Tomic
- Medical Physics Unit, McGill University, Montréal, Québec, Canada; Department of Radiation Oncology, Jewish General Hospital, Montréal, Québec, Canada
| | - S Devic
- Medical Physics Unit, McGill University, Montréal, Québec, Canada; Department of Radiation Oncology, Jewish General Hospital, Montréal, Québec, Canada.
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Watson PGF, Popovic M, Liang L, Tomic N, Devic S, Seuntjens J. Clinical Implication of Dosimetry Formalisms for Electronic Low-Energy Photon Intraoperative Radiation Therapy. Pract Radiat Oncol 2020; 11:e114-e121. [PMID: 32795615 DOI: 10.1016/j.prro.2020.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 05/27/2020] [Accepted: 07/27/2020] [Indexed: 11/26/2022]
Abstract
PURPOSE Intraoperative radiation therapy (IORT) using the INTRABEAM, a miniature x-ray source, has shown to be effective in treating breast cancer. However, recent investigations have suggested a significant deviation between the reported and delivered doses. In this work, the dose delivered by INTRABEAM in the TARGIT breast protocol was investigated, along with the dose from the Xoft Axxent, another source used in breast IORT. METHODS AND MATERIALS The absorbed dose from the INTRABEAM was determined from ionization chamber measurements using: (a) the manufacturer-recommended formula (Zeiss V4.0 method), (b) a Monte Carlo calculated chamber conversion factor (CQ method), and (c) the formula consistent with the TARGIT breast protocol (TARGIT method). The dose from the Xoft Axxent was determined from ionization chamber measurements using the Zeiss V4.0 method and calculated using the American Association of Physicists in Medicine TG-43 formalism. RESULTS For a nominal TARGIT prescription of 20 Gy, the dose at the INTRABEAM applicator surface ranged from 25.2 to 31.7 Gy according to the CQ method for the largest (5 cm) and smallest (1.5 cm) diameter applicator, respectively. The Zeiss V4.0 method results were 7% to 10% lower (23.2 to 28.6 Gy). At 1 cm depth, the CQ and Zeiss V4.0 absorbed doses were also larger than those predicted by the TARGIT method. The dose at 1 cm depth from the Xoft Axxent for a surface dose of 20 Gy was slightly less than INTRABEAM (3%-7% compared with CQ method). An exception was for the 3 cm applicator, where the Xoft dose was appreciably lower (31%). CONCLUSIONS The doses delivered in the TARGIT breast protocol with INTRABEAM were significantly greater than the prescribed 20 Gy and depended on the size of spherical applicator used. Breast IORT treatments with the Xoft Axxent received less dose compared with TARGIT INTRABEAM, which could have implications for studies comparing clinical outcomes between the 2 devices.
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Affiliation(s)
| | - Marija Popovic
- Medical Physics Unit, McGill University, Montreal, QC, Canada
| | - Liheng Liang
- Medical Physics Unit, Department of Radiation Oncology, SMBD Jewish General Hospital, McGill University, Montreal, QC, Canada
| | - Nada Tomic
- Medical Physics Unit, Department of Radiation Oncology, SMBD Jewish General Hospital, McGill University, Montreal, QC, Canada
| | - Slobodan Devic
- Medical Physics Unit, Department of Radiation Oncology, SMBD Jewish General Hospital, McGill University, Montreal, QC, Canada
| | - Jan Seuntjens
- Medical Physics Unit, McGill University, Montreal, QC, Canada
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Devic S, Aldelaijan S, Bekerat H. Impact of inertia on possible fundamental drawbacks in radiochromic film dosimetry. Phys Med 2019; 66:133-134. [DOI: 10.1016/j.ejmp.2019.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 08/23/2019] [Accepted: 08/25/2019] [Indexed: 10/25/2022] Open
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Aldelaijan S, Devic S, Papaconstadopoulos P, Bekerat H, Cormack RA, Seuntjens J, Buzurovic IM. Dose-response linearization in radiochromic film dosimetry based on multichannel normalized pixel value with an integrated spectral correction for scanner response variations. Med Phys 2019; 46:5336-5349. [PMID: 31529516 DOI: 10.1002/mp.13818] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/02/2019] [Accepted: 09/05/2019] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To introduce a model that reproducibly linearizes the response from radiochromic film (RCF) dosimetry systems at extended dose range. To introduce a correction method, generated from the same scanned images, which corrects for scanner temporal response variation and scanner bed inhomogeneity. METHODS Six calibration curves were established for different lot numbers of EBT3 GAFCHROMIC™ film model based on four EPSON scanners [10000XL (2 units), 11000XL, 12000XL] at three different centers. These films were calibrated in terms of absorbed dose to water based on TG51 protocol or TRS398 with dose ranges up to 40 Gy. The film response was defined in terms of a proposed normalized pixel value ( n P V RGB ) as a summation of first-order equations based on information from red, green, and blue channels. The fitting parameters of these equations are chosen in a way that makes the film response equal to dose at the time of calibration. An integrated set of correction factors (one per color channel) was also introduced. These factors account for the spatial and temporal changes in scanning states during calibration and measurements. The combination of n P V RGB and this "fingerprint" correction formed the basis of this new protocol and it was tested against net optical density ( n e t O D X = R , G , B ) single-channel dosimetry in terms of accuracy, precision, scanner response variability, scanner bed inhomogeneity, noise, and long-term stability. RESULTS Incorporating multichannel features (RGB) into the normalized pixel value produced linear response to absorbed dose (slope of 1) in all six RCF dosimetry systems considered in this study. The "fingerprint" correction factors of each of these six systems displayed unique patterns at the time of calibration. The application of n P V RGB to all of these six systems could achieve a level of accuracy of ± 2.0% in the dose range of interest within modeled uncertainty level of 2.0%-3.0% depending on the dose level. Consistent positioning of control and measurement film pieces and integrating the multichannel correction into the response function formalism mitigated possible scanner response variations of as much as ± 10% at lower doses and scanner bed inhomogeneity of ± 8% to the established level of uncertainty at the time of calibration. The system was also able to maintain the same level of accuracy after 3 and 6 months post calibration. CONCLUSIONS Combining response linearity with the integrated correction for scanner response variation lead to a sustainable and practical RCF dosimetry system that mitigated systematic response shifts and it has the potential to reduce errors in reporting relative information from the film response.
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Affiliation(s)
- Saad Aldelaijan
- Department of Radiation Oncology, Dana Farber/Brigham and Women's Cancer Center, Harvard Medical School, Boston, MA, 02115, USA
- Department of Biomedical Engineering, Montreal Neurological Institute, McGill University, Montréal, QC, H3A 2B4, Canada
- Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada
- Department of Radiation Oncology, SMBD Jewish General Hospital, Montréal, QC, H3T 1E2, Canada
- Biomedical Physics Department, King Faisal Specialist Hospital & Research Centre, Riyadh, 12713, Saudi Arabia
| | - Slobodan Devic
- Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada
- Department of Radiation Oncology, SMBD Jewish General Hospital, Montréal, QC, H3T 1E2, Canada
| | | | - Hamed Bekerat
- Department of Radiation Oncology, SMBD Jewish General Hospital, Montréal, QC, H3T 1E2, Canada
| | - Robert A Cormack
- Department of Radiation Oncology, Dana Farber/Brigham and Women's Cancer Center, Harvard Medical School, Boston, MA, 02115, USA
| | - Jan Seuntjens
- Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada
| | - Ivan M Buzurovic
- Department of Radiation Oncology, Dana Farber/Brigham and Women's Cancer Center, Harvard Medical School, Boston, MA, 02115, USA
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Kostou T, Papadimitroulas P, Papaconstadopoulos P, Devic S, Seuntjens J, Kagadis GC. Size-specific dose estimations for pediatric chest, abdomen/pelvis and head CT scans with the use of GATE. Phys Med 2019; 65:181-190. [PMID: 31494372 DOI: 10.1016/j.ejmp.2019.08.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 07/24/2019] [Accepted: 08/29/2019] [Indexed: 01/17/2023] Open
Abstract
PURPOSE The purpose of this study is to create an organ dose database for pediatric individuals undergoing chest, abdomen/pelvis, and head computed tomography (CT) examinations, and to report the differences in absorbed organ doses, when anatomical differences exist for pediatric patients. METHODS The GATE Monte Carlo (MC) toolkit was used to model the GE BrightSpeed Elite CT model. The simulated scanner model was validated with the standard Computed Tomography Dose Index (CTDI) head phantom. Twelve computational models (2.1-14 years old) were used. First, contributions to effective dose and absorbed doses per CTDIvol and per 100 mAs were estimated for all organs. Then, doses per CTDIvol were correlated with patient model weight for the organs inside the scan range for chest and abdomen/pelvis protocols. Finally, effective doses per dose-length product (DLP) were estimated and compared with the conventional conversion k-factors. RESULTS The system was validated against experimental CTDIw measurements. The doses per CTDIvol and per 100 mAs for selected organs were estimated. The magnitude of the dependency between the dose and the anatomical characteristics was calculated with the coefficient of determination at 0.5-0.7 for the internal scan organs for chest and abdomen/pelvis protocols. Finally, effective doses per DLP were compared with already published data, showing discrepancies between 13 and 29% and were correlated strongly with the total weight (R2 > 0.8) for the chest and abdomen protocols. CONCLUSIONS Big differences in absorbed doses are reported even for patients of similar age or same gender, when anatomical differences exist on internal organs of the body.
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Affiliation(s)
- Theodora Kostou
- University of Patras, Department of Medical Physics, Patras, Greece
| | | | | | - Slobodan Devic
- McGill University, Department of Medical Physics, Montreal, Canada
| | - Jan Seuntjens
- McGill University, Department of Medical Physics, Montreal, Canada
| | - George C Kagadis
- University of Patras, Department of Medical Physics, Patras, Greece.
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Garant A, Magnan S, Devic S, Martin AG, Boutros M, Vasilevsky CA, Ferland S, Bujold A, DesGroseilliers S, Sebajang H, Richard C, Vuong T. Image Guided Adaptive Endorectal Brachytherapy in the Nonoperative Management of Patients With Rectal Cancer. Int J Radiat Oncol Biol Phys 2019; 105:1005-1011. [PMID: 31476417 DOI: 10.1016/j.ijrobp.2019.08.042] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 08/20/2019] [Accepted: 08/20/2019] [Indexed: 02/07/2023]
Abstract
PURPOSE Organ preservation or nonoperative management of rectal cancer is of growing interest. Image guided adaptive endorectal brachytherapy is a radiation dose escalation modality: we explored its role in elderly patients unfit for surgery and patients refusing surgery. METHODS AND MATERIALS In this registry study, patients with rectal cancer who were ineligible for surgery received 40 Gy in 16 fractions of pelvic external beam radiation therapy. They subsequently received 3 weekly image guided adaptive brachytherapy boosts of 10 Gy to the residual tumor, for a total of 30 Gy in 3 fractions. Complete clinical response (cCR) and local control were the primary endpoints. RESULTS 94 patients were included; the median age was 81.1 years. With a median follow-up of 1.9 years, the proportion of cCR was 86.2%, the tumor regrowth proportion was 13.6%, and the cumulative incidence of local relapse was 2.7% at 1 year and 16.8% at 2 years. When considering responders and nonresponders, the 2-year local control was 71.5%. The overall survival at 2 years was 63.6%. Acute rectal grade 1 to 2 toxicity included all patients: 12.8% of patients had late bleeding requiring iron replacement, blood transfusions, or argon plasma therapy. CONCLUSIONS Results of this registry study, evaluating radiation dose escalation for elderly medically unfit patients with unselected tumors, reveal that a high proportion of patients achieved cCR with a manageable toxicity profile. This technology will likely contribute to the challenging nonoperative management paradigm of rectal cancer.
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Affiliation(s)
- Aurelie Garant
- Department of Oncology, Division of Radiation Oncology, Sir Mortimer B. Davis Jewish General Hospital, Montreal, QC, Canada
| | - Sindy Magnan
- Division of Cancer Epidemiology, McGill University, Montreal, QC, Canada
| | - Slobodan Devic
- Department of Oncology, Division of Radiation Oncology, Sir Mortimer B. Davis Jewish General Hospital, Medical Physics Unit, McGill University, Montreal, QC H4A 3J1, Canada
| | - André-Guy Martin
- Centre hospitalier universitaire de Québec, Université Laval, Department of Radiation Oncology, Quebec City, QC, Canada
| | - Marylise Boutros
- Department of Surgery, Division of Colon and Rectal Surgery, Sir Mortimer B. Davis Jewish General Hospital, Montreal, QC, Canada
| | - Carol-Ann Vasilevsky
- Department of Surgery, Division of Colon and Rectal Surgery, Sir Mortimer B. Davis Jewish General Hospital, Montreal, QC, Canada
| | - Stéphanie Ferland
- CISSSO, Hôpital de Gatineau, Department of Radiation Oncology, Gatineau, QC, Canada
| | - Alexis Bujold
- Hôptial Maisonneuve-Rosemont, Université de Montréal, Department of Radiation Oncology, Montreal, QC, Canada
| | | | - Herawaty Sebajang
- Centre hospitalier de l'Université de Montréal, Department of Surgery, Division of Colon and Rectal Surgery, Montreal, QC, Canada
| | - Carole Richard
- Centre hospitalier de l'Université de Montréal, Department of Surgery, Division of Colon and Rectal Surgery, Montreal, QC, Canada
| | - Té Vuong
- Department of Oncology, Division of Radiation Oncology, Sir Mortimer B. Davis Jewish General Hospital, Montreal, QC, Canada.
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Devic S, Liang L, Tomic N, Bekerat H, Morcos M, Popovic M, Watson P, Aldelaijan S, Seuntjens J. Dose measurements nearby low energy electronic brachytherapy sources using radiochromic film. Phys Med 2019; 64:40-44. [DOI: 10.1016/j.ejmp.2019.05.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 05/24/2019] [Accepted: 05/25/2019] [Indexed: 11/25/2022] Open
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Papaconstadopoulos P, Levesque IR, Aldelaijan S, O’Grady K, Devic S, Seuntjens J. Modeling the primary source intensity distribution: reconstruction and inter-comparison of six Varian TrueBeam sources. ACTA ACUST UNITED AC 2019; 64:135005. [DOI: 10.1088/1361-6560/ab1ccc] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Devic S, Bekerat H, Garant A, Vuong T. Optimization of HDRBT boost dose delivery for patients with rectal cancer. Brachytherapy 2019; 18:559-563. [DOI: 10.1016/j.brachy.2019.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 01/31/2019] [Accepted: 02/11/2019] [Indexed: 10/27/2022]
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Asiev K, Devic S, Bahoric B. EP-2136 Brachytherapy study between patients treated with HDR Ir-192 and Xoft 50kVp source for uterus cancer. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)32556-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Aldelaijan SI, Papaconstadopoulos P, Schneider J, Bekerat H, Seuntjens J, Buzurovic I, Devic S. Dosimetric Impact of Source Position Variation Inside Different Catheter Sizes in HDR Brachytherapy. Brachytherapy 2018. [DOI: 10.1016/j.brachy.2018.04.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Aldelaijan SI, Papaconstadopoulos P, Schneider J, Bekerat H, Seuntjens J, Buzurovic I, Devic S. Decomposition of Source Dwell Positions and Dwell Times: A Novel Method for Accurate Source Tracking and Quality Assurance in HDR Brachytherapy Based on Film Dosimetry. Brachytherapy 2018. [DOI: 10.1016/j.brachy.2018.04.239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Papaconstadopoulos P, O'Grady K, Aldelaijan S, Devic S, Levesque I, Seuntjens J. EP-2153: The primary X-ray source: reconstruction and characterization of six Varian TrueBeam sources. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32462-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Tomic N, Papaconstadopoulos P, Seuntjrns J, Devic S. EP-2076: Impact of Beam Quality Changes on Radiochromic Film based CTDI measurements. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32385-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Tomic N, Papaconstadopoulos P, Aldelaijan S, Rajala J, Seuntjens J, Devic S. Image quality for radiotherapy CT simulators with different scanner bore size. Phys Med 2018; 45:65-71. [DOI: 10.1016/j.ejmp.2017.11.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 11/22/2017] [Accepted: 11/24/2017] [Indexed: 11/30/2022] Open
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Aldelaijan S, Tomic N, Papaconstadopoulos P, Schneider J, Seuntjens J, Shih S, Lewis D, Devic S. Technical Note: Response time evolution of XR-QA2 GafChromic™ film models. Med Phys 2017; 45:488-492. [DOI: 10.1002/mp.12689] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 09/25/2017] [Accepted: 11/10/2017] [Indexed: 11/07/2022] Open
Affiliation(s)
- Saad Aldelaijan
- Department of Biomedical Engineering; Montreal Neurological Institute; Montréal Québec H3A 2B4 Canada
- Radiation Oncology Department; Jewish General Hospital; Montreal Quebec H3T 1E2 Canada
- Medical Physics Unit; McGill University; Montreal Quebec H4A 3J1 Canada
- Biomedical Physics Department; King Faisal Specialist Hospital and Research Centre; Riyadh Saudi Arabia
| | - Nada Tomic
- Radiation Oncology Department; Jewish General Hospital; Montreal Quebec H3T 1E2 Canada
- Medical Physics Unit; McGill University; Montreal Quebec H4A 3J1 Canada
| | - Pavlos Papaconstadopoulos
- Radiation Oncology Department; Jewish General Hospital; Montreal Quebec H3T 1E2 Canada
- Medical Physics Unit; McGill University; Montreal Quebec H4A 3J1 Canada
| | - James Schneider
- Radiation Oncology Department; Jewish General Hospital; Montreal Quebec H3T 1E2 Canada
- Medical Physics Unit; McGill University; Montreal Quebec H4A 3J1 Canada
| | - Jan Seuntjens
- Medical Physics Unit; McGill University; Montreal Quebec H4A 3J1 Canada
- Department of Oncology; McGill University; Montreal Quebec H4A 3T2 Canada
| | - Shelley Shih
- Ashland Specialty Ingredients; 1361 Alps Road Wayne New Jersey 07470 USA
| | - David Lewis
- RCF Consulting, LLC; 54 Benedict Road Monroe Connecticut 06468 USA
| | - Slobodan Devic
- Radiation Oncology Department; Jewish General Hospital; Montreal Quebec H3T 1E2 Canada
- Medical Physics Unit; McGill University; Montreal Quebec H4A 3J1 Canada
- Segal Cancer Centre; Jewish General Hospital McGill University; Montréal Québec Canada
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Liang LH, Tomic N, Vuong T, Aldelaijan S, Bekerat H, DeBlois F, Seuntjens J, Devic S. Physics aspects of the Papillon technique-Five decades later. Brachytherapy 2017; 17:234-243. [PMID: 29102741 DOI: 10.1016/j.brachy.2017.09.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/26/2017] [Accepted: 09/26/2017] [Indexed: 12/15/2022]
Abstract
PURPOSE The Papillon technique using 50-kVp soft X-rays to treat rectal adenocarcinomas was developed and clinically implemented in the 1960s. We describe differences between accurate dosimetry and clinical implementation of this technique that is extending from its very inception to date. METHODS AND MATERIALS A renaissance of the Papillon technique occurred with two recently introduced 50-kVp systems: Papillon+ by Ariane and a custom-made rectal applicator (consisting of a surface applicator inserted into a proctoscope) by iCAD's Xoft Axxent Electronic Brachytherapy (eBT) System (iCad, Inc., Sunnyvale, CA). In contrast to the initial design, we investigated the impact of introducing a plastic lid, which would provide more reproducible and more accurate dose delivery across the rectal adenocarcinoma patient population. We use both parallel-plate chamber and radiochromic film dosimeters to determine differences in basic dosimetry characteristics (beam half-value layers, outputs, percent depth doses, and profiles) between the Xoft Electronic Brachytherapy rectal applicator system with and without the plastic lid in place. RESULTS Compared to the open-cone applicator, the proposed applicator with the plastic lid produces a slightly harder (more penetrating) beam quality (half-value layer of 1.4 vs. 1.3-mm Al), but with reduced output (by 33%), and a slightly broader beam with flatness not worse than 3% and symmetry not worse than 2%. CONCLUSIONS In addition to characterizing beam properties modified by the possible introduction of the plastic cap, we also pointed out and addressed misconceptions in the use of radiochromic films for dose measurements at low-energy photon beams.
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Affiliation(s)
- Li Heng Liang
- Radiation Oncology Department, Jewish General Hospital, Montreal, Quebec, Canada; Medical Physics Unit, McGill University, Montreal, Quebec, Canada
| | - Nada Tomic
- Radiation Oncology Department, Jewish General Hospital, Montreal, Quebec, Canada; Medical Physics Unit, McGill University, Montreal, Quebec, Canada
| | - Te Vuong
- Radiation Oncology Department, Jewish General Hospital, Montreal, Quebec, Canada; Oncology Department, McGill University, Montreal, Quebec, Canada
| | - Saad Aldelaijan
- Medical Physics Unit, McGill University, Montreal, Quebec, Canada; Biological & Biomedical Engineering Department, Montreal Neurological Institute, Montréal, Québec, Canada; Biomedical Physics Department, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Hamed Bekerat
- Radiation Oncology Department, Jewish General Hospital, Montreal, Quebec, Canada; Medical Physics Unit, McGill University, Montreal, Quebec, Canada
| | - Francois DeBlois
- Radiation Oncology Department, Jewish General Hospital, Montreal, Quebec, Canada; Medical Physics Unit, McGill University, Montreal, Quebec, Canada
| | - Jan Seuntjens
- Medical Physics Unit, McGill University, Montreal, Quebec, Canada; Oncology Department, McGill University, Montreal, Quebec, Canada
| | - Slobodan Devic
- Radiation Oncology Department, Jewish General Hospital, Montreal, Quebec, Canada; Medical Physics Unit, McGill University, Montreal, Quebec, Canada; Segal Cancer Centre, Jewish General Hospital, McGill University, Montréal, Québec, Canada.
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Schneider J, Tomic N, Vuong T, Lisbona R, Hickeson M, Chaussé G, DeBlois F, Seuntjens J, Devic S. EP-1701: FDG-PET Background Definition in Rectal Cancer Patients Using Differential Uptake Volume Histograms. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)32233-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Aldelaijan S, Bekerat H, Buzurovic I, Devlin P, Deblois F, Seuntjens J, Collins L, Devic S. Improving Dose Accuracy of HDR Brachytherapy Treatment of Skin Lesions Using Freiburg Flap Applicator Based on Reference Radiochromic Film Dose Measurements. Brachytherapy 2017. [DOI: 10.1016/j.brachy.2017.04.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Devic S, Mwidu U, Alkafi A, Moftah B, Shakir S, Hijazi H, Yeung C, Vuong T. EP-1798: Highly conformal external beam modalities vs. brachytherapy boost for rectal cancer patients. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)32160-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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28
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Vuong T, Garant A, Devic S, Kezouth A. PO-0703: Bowel dysfunction resulting from different treatment strategies in patients with rectal cancer. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31140-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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29
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Tomic N, Papaconstadopoulos P, Seuntjens J, DeBlois F, Devic S. EP-1717: Image Quality Comparison Between Two Radiotherapy Simulators. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)32249-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Devic S, Schneider J, Vuong T, Tomic N, Lisbona R, Hickeson M, Chaussé G, DeBlois F, Seuntjens J, Batist G. Differential Uptake Volume Histograms as a Predictor of Response in Rectal Adenocarcinoma Patients Treated with Preoperative Endorectal Brachytherapy. Brachytherapy 2017. [DOI: 10.1016/j.brachy.2017.04.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Rabaeh KA, Basfar AA, Almousa AA, Devic S, Moftah B. New normoxic N-(Hydroxymethyl)acrylamide based polymer gel for 3D dosimetry in radiation therapy. Phys Med 2017; 33:121-126. [PMID: 28094138 DOI: 10.1016/j.ejmp.2016.12.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 12/05/2016] [Accepted: 12/28/2016] [Indexed: 11/15/2022] Open
Abstract
A novel composition of normoxic polymer gel dosimeters based on radiation-induced polymerization of N-(Hydroxymethyl)acrylamide (NHMA) is introduced in this study for 3D dosimetry for Quality Assurance (QA) in radiation therapy. Dosimeters were irradiated by 6, 10 and 18MV photon beams of a medical linear accelerator at various dose rates to doses of up to 20Gy. The dose response of polymer gel dosimeters was studied using nuclear magnetic resonance (NMR) spin-spin relaxation rate (R2) of hydrogen protons within the water molecule. Also, we measured gel response using absorption spectroscopy and found that this novel gel can be successfully utilized for both MRI- and OCT- (Optical Computed Tomography) based 3D dosimetry. We investigated dosimetric properties of six different compositions of the new NHMA-based gel in terms of dose rate, radiation beam quality and stability of dose-dependent polymerization after irradiation. We found no significant effects of these parameters on the novel gel dosimeter performance in both relaxation rate and absorbance measurements.
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Affiliation(s)
- Khalid A Rabaeh
- Radiation Technology Center, Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia; Medical Imaging Department, Faculty of Allied Health Sciences, Hashemite University, Zarqa, Jordan.
| | - Ahmed A Basfar
- Radiation Technology Center, Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Akram A Almousa
- Biomedical Physics Department, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Slobodan Devic
- Medical Physics Unit, McGill University, Montréal, Québec, Canada
| | - Belal Moftah
- Biomedical Physics Department, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia; Medical Physics Unit, McGill University, Montréal, Québec, Canada
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Mwidu U, Devic S, Shehadeh M, AlKafi M, Mahmood R, Moftah B. SU-F-T-420: Dosimetry Comparison of Advanced External Beam Radiation Treatment Modalities to Brachytherapy Treatments in Patients with Cervical Cancer. Med Phys 2016. [DOI: 10.1118/1.4956605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Tomic N, Bekerat H, Seuntjens J, Forghani R, DeBlois F, Devic S. SU-F-T-398: Improving Radiotherapy Treatment Planning Using Dual Energy Computed Tomography Based Tissue Characterization. Med Phys 2016. [DOI: 10.1118/1.4956583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Schneider J, Vuong T, Tomic N, Hickeson M, Lisbona R, DeBlois F, Seuntjens J, Devic S. WE-FG-202-04: Decomposition of FDG-PET Based Differential Uptake Volume Histograms in Rectal Cancer Patients. Med Phys 2016. [DOI: 10.1118/1.4957916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Devic S, Tomic N, Lewis D, Aldelaijan S, DeBlois F, Seuntjens J. SU-G-BRB-14: Uncertainty of Radiochromic Film Based Relative Dose Measurements. Med Phys 2016. [DOI: 10.1118/1.4956921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Nout RA, Bekerat H, Devic S, Vuong T. Is Daily CT-Based Adaptive Endorectal Brachytherapy of Benefit Compared to Using a Single Treatment Plan for Preoperative Treatment of Locally Advanced Rectal Cancer? Brachytherapy 2016. [DOI: 10.1016/j.brachy.2016.04.133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
Ever since its discovery (1924) the Warburg effect (aerobic glycolysis) remains an unresolved puzzle: why the aggressive cancer cells "prefer" to use the energetically highly inefficient method of burning the glucose at the cellular level? While in the course of the last 90 years several hypotheses have been suggested, to this date there is no clear explanation of this rather unusual effect. Even though it is commonly assumed that Warburg effect is a consequence of carcinogenesis, yet another hypothesis could be brought up that the cellular switch to aerobic glycolysis may represent the very point in time when a normal cell becomes cancerous. Furthermore, this switch may happen at the point where the fate of pyruvic acid is determined, caused by the inadequate supply of enzymes that promote citric as opposed to lactic acid cycle. Currently, few clinical observations, like low cancer incidence in Type 1 diabetes mellitus and increased cancer incidence in people on high carbohydrate diets might be called upon to support such hypothesis.
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Affiliation(s)
- Slobodan Devic
- Department of Radiation Oncology, SMBD Jewish General Hospital, McGill University, Montréal, Québec, Canada
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Devic S, Tomic N, Lewis D. Reference radiochromic film dosimetry: Review of technical aspects. Phys Med 2016; 32:541-56. [DOI: 10.1016/j.ejmp.2016.02.008] [Citation(s) in RCA: 168] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 01/30/2016] [Accepted: 02/23/2016] [Indexed: 11/29/2022] Open
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Devic S, Aldelaijan S, Alzorkany F, Tomic N, Seuntjens J, DeBlois F, Moftah B. EP-1482: Improving accuracy of radiochromic film dosimetry system using control film piece. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32732-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Tomic N, Bekerat H, DeBlois F, Seuntjens J, Forghani R, Devic S. EP-1827: Dual energy Computed Tomography based tissue characterisation for Radiotherapy treatment planning. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)33078-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Devic S, Mohammed H, Tomic N, Aldelaijan S, De Blois F, Seuntjens J, Lehnert S, Faria S. FDG-PET-based differential uptake volume histograms: a possible approach towards definition of biological target volumes. Br J Radiol 2016; 89:20150388. [PMID: 27007269 DOI: 10.1259/bjr.20150388] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVE Integration of fluorine-18 fludeoxyglucose ((18)F-FDG)-positron emission tomography (PET) functional data into conventional anatomically based gross tumour volume delineation may lead to optimization of dose to biological target volumes (BTV) in radiotherapy. We describe a method for defining tumour subvolumes using (18)F-FDG-PET data, based on the decomposition of differential uptake volume histograms (dUVHs). METHODS For 27 patients with histopathologically proven non-small-cell lung carcinoma (NSCLC), background uptake values were sampled within the healthy lung contralateral to a tumour in those image slices containing tumour and then scaled by the ratio of mass densities between the healthy lung and tumour. Signal-to-background (S/B) uptake values within volumes of interest encompassing the tumour were used to reconstruct the dUVHs. These were subsequently decomposed into the minimum number of analytical functions (in the form of differential uptake values as a function of S/B) that yielded acceptable net fits, as assessed by χ(2) values. RESULTS Six subvolumes consistently emerged from the fitted dUVHs over the sampled volume of interest on PET images. Based on the assumption that each function used to decompose the dUVH may correspond to a single subvolume, the intersection between the two adjacent functions could be interpreted as a threshold value that differentiates them. Assuming that the first two subvolumes spread over the tumour boundary, we concentrated on four subvolumes with the highest uptake values, and their S/B thresholds [mean ± standard deviation (SD)] were 2.88 ± 0.98, 4.05 ± 1.55, 5.48 ± 2.06 and 7.34 ± 2.89 for adenocarcinoma, 3.01 ± 0.71, 4.40 ± 0.91, 5.99 ± 1.31 and 8.17 ± 2.42 for large-cell carcinoma and 4.54 ± 2.11, 6.46 ± 2.43, 8.87 ± 5.37 and 12.11 ± 7.28 for squamous cell carcinoma, respectively. CONCLUSION (18)F-FDG-based PET data may potentially be used to identify BTV within the tumour in patients with NSCLC. Using the one-way analysis of variance statistical tests, we found a significant difference among all threshold levels among adenocarcinomas, large-cell carcinoma and squamous cell carcinomas. On the other hand, the observed significant variability in threshold values throughout the patient cohort (expressed as large SDs) can be explained as a consequence of differences in the physiological status of the tumour volume for each patient at the time of the PET/CT scan. This further suggests that patient-specific threshold values for the definition of BTVs could be determined by creation and curve fitting of dUVHs on a patient-by-patient basis. ADVANCES IN KNOWLEDGE The method of (18)F-FDG-PET-based dUVH decomposition described in this work may lead to BTV segmentation in tumours.
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Affiliation(s)
- Slobodan Devic
- 1 Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, QC, Canada
| | - Huriyyah Mohammed
- 1 Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, QC, Canada
| | - Nada Tomic
- 1 Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, QC, Canada
| | - Saad Aldelaijan
- 1 Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, QC, Canada
| | - François De Blois
- 1 Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, QC, Canada
| | - Jan Seuntjens
- 2 Department of Radiation Oncology, Montreal General Hospital, McGill University, Montréal, QC, Canada
| | - Shirley Lehnert
- 2 Department of Radiation Oncology, Montreal General Hospital, McGill University, Montréal, QC, Canada
| | - Sergio Faria
- 2 Department of Radiation Oncology, Montreal General Hospital, McGill University, Montréal, QC, Canada
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Papaconstadopoulos P, Seuntjens J, Devic S. Response to “Comment on ‘A protocol for EBT3 radiochromic film dosimetry using reflection scanning’ ” [Med. Phys. 41(12), 122101 (6pp.) (2014)]. Med Phys 2016; 43:1580-2. [DOI: 10.1118/1.4941006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Pavlos Papaconstadopoulos
- Medical Physics Unit, Montreal General Hospital, McGill University, Montreal, Quebec H3G 1A4, Canada
| | - Jan Seuntjens
- Medical Physics Unit, Montreal General Hospital, McGill University, Montreal, Quebec H3G 1A4, Canada
| | - Slobodan Devic
- Medical Physics Unit, Department of Radiation Oncology, SMBD Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada
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Di Lillo F, Mettivier G, Sarno A, Tromba G, Tomic N, Devic S, Russo P. Energy dependent calibration of XR-QA2 radiochromic film with monochromatic and polychromatic x-ray beams. Med Phys 2016; 43:583. [DOI: 10.1118/1.4939063] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Aldelaijan S, Alzorkany F, Moftah B, Buzurovic I, Seuntjens J, Tomic N, Devic S. Use of a control film piece in radiochromic film dosimetry. Phys Med 2016; 32:202-7. [DOI: 10.1016/j.ejmp.2015.12.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Revised: 11/25/2015] [Accepted: 12/11/2015] [Indexed: 10/22/2022] Open
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Vuong T, Nout R, Niazi T, Garant A, Bujold A, Martin A, Ferland S, Stroian G, Thebaut J, Sym A, Devic S. Radiation Therapy as a Curative Modality for Patients With Rectal Cancer. Int J Radiat Oncol Biol Phys 2015. [DOI: 10.1016/j.ijrobp.2015.07.982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Lewis D, Devic S. Correcting scan-to-scan response variability for a radiochromic film-based reference dosimetry system. Med Phys 2015; 42:5692-701. [DOI: 10.1118/1.4929563] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Seuntjens J, Beaulieu L, Collins L, Despres P, Devic S, El Naqa I, Nadeau J, Pike B, Reader A. MO-DE-BRA-04: The CREATE Medical Physics Research Training Network: Training of New Generation Innovators. Med Phys 2015. [DOI: 10.1118/1.4925339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Liang L, Bekerat H, Tomic N, DeBlois F, Devic S, Morcos M, Popovic M, Watson P, Seuntjens J. SU-E-T-462: Impact of the Radiochromic Film Energy Response On Dose Measurements of Low Energy Electronic Brachytherapy Sources. Med Phys 2015. [DOI: 10.1118/1.4924824] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Aldelaijan S, Alzorkany F, Moftah B, Alrumayan F, Seuntjens J, Lewis D, Devic S. SU-E-T-665: Radiochromic Film Quenching Effect Reduction for Proton Beam Dosimetry. Med Phys 2015. [DOI: 10.1118/1.4925028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Asgharizadeh S, Bekerat H, Syme A, Aldelaijan S, DeBlois F, Vuong T, Evans M, Seuntjens J, Devic S. Radiochromic film-based quality assurance for CT-based high-dose-rate brachytherapy. Brachytherapy 2015; 14:578-85. [PMID: 25865477 DOI: 10.1016/j.brachy.2015.02.192] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 01/09/2015] [Accepted: 02/08/2015] [Indexed: 11/29/2022]
Abstract
PURPOSE In the past, film dosimetry was developed into a powerful tool for external beam radiotherapy treatment verification and quality assurance. The objective of this work was the development and clinical testing of the EBT3 model GafChromic film based brachytherapy quality assurance (QA) system. METHODS AND MATERIALS Retrospective dosimetry study was performed to test a patient-specific QA system for preoperative endorectal brachytherapy that uses a radiochromic film dosimetry system. A dedicated phantom for brachytherapy applicator used for rectal cancer treatment was fabricated enabling us to compare calculated-to-measured dose distributions. Starting from the same criteria used for external beam intensity-modulated radiation therapy QA (3%, 3 mm), passing criteria for high- and low-dose gradient regions were subsequently determined. Finally, we investigated the QA system's sensitivity to controlled source positional errors on selected patient plans. RESULTS In low-dose gradient regions, measured dose distributions with criteria of 3%, 3 mm barely passed the test, as they showed 95% passing pixels. However, in the high-dose gradient region, a more stringent condition could be established. Both criteria of 2%, 3 mm and 3%, 2 mm with gamma function calculated using normalization to the same absolute dose value in both measured and calculated dose distributions, and matrix sizes rescaled to match each other showed more than 95% of pixels passing, on average, for 15 patient plans analyzed. CONCLUSIONS Although the necessity of the patient-specific brachytherapy QA needs yet to be justified, we described a radiochromic film dosimetry-based QA system that can be a part of the brachytherapy commissioning process, as well as yearly QA program.
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Affiliation(s)
- Saeid Asgharizadeh
- Medical Physics Unit, McGill University, Montréal, Québec, Canada; Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, Québec, Canada
| | - Hamed Bekerat
- Medical Physics Unit, McGill University, Montréal, Québec, Canada; Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, Québec, Canada
| | - Alasdair Syme
- Medical Physics Unit, McGill University, Montréal, Québec, Canada; Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, Québec, Canada
| | - Saad Aldelaijan
- Medical Physics Unit, McGill University, Montréal, Québec, Canada; Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, Québec, Canada
| | - François DeBlois
- Medical Physics Unit, McGill University, Montréal, Québec, Canada; Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, Québec, Canada
| | - Té Vuong
- Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, Québec, Canada
| | - Michael Evans
- Medical Physics Unit, McGill University, Montréal, Québec, Canada; Department of Medical Physics, McGill University Health Centre, Montréal, Québec, Canada
| | - Jan Seuntjens
- Medical Physics Unit, McGill University, Montréal, Québec, Canada
| | - Slobodan Devic
- Medical Physics Unit, McGill University, Montréal, Québec, Canada; Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, Québec, Canada.
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