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Karius A, Schweizer C, Strnad V, Lotter M, Kreppner S, Lamrani A, Fietkau R, Bert C. Seed-displacements in the immediate post-implant phase in permanent prostate brachytherapy. Radiother Oncol 2023; 183:109590. [PMID: 36858202 DOI: 10.1016/j.radonc.2023.109590] [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: 12/08/2022] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 03/03/2023]
Abstract
PURPOSE To investigate differences in seed-displacements between the immediate post-implant phase (day 0-1) and the time to post-plan computed tomography (CT) (day 1-30) in seed prostate brachytherapy. MATERIALS AND METHODS Seed positions were identified on the intra-operatively created ultrasound-based treatment plan (day 0) and CT scans of day 1 and 30 for 33 patients. The day 1 (30) seed arrangement was registered onto the day 0 (1) arrangement using a seed-only approach. Based on a 1:1 assignment of seeds via the Kuhn-Munkres algorithm, seed-displacements were analyzed. Displacements were evaluated depending on strand-length and anatomical implant location. Resulting dosimetric effects were calculated. RESULTS Seed-displacements in the immediate post-implant phase (median displacements: 3.8 ± 3.6 mm) were stronger than in the time to post-plan CT (2.1 ± 2.6 mm) and enhanced along the superior-inferior direction. From day 0 to 1, strands containing one (7.3 ± 5.4 mm) or two (8.1 ± 5.8 mm) seeds showed larger displacements than strands of higher lengths (up to 4.2 ± 7.0 mm), whereas no length-dependency was found to day 30. Seeds implanted in base and apex tended to move towards the prostate midzone during both time periods. D90 (dose that 90% of prostate receives) was with variations of 2 ± 15 Gy more stable from day 1 to 30 than in the immediate post-implant phase (-18 ± 11 Gy). CONCLUSION Seed-displacements in the immediate post-implant phase was enhanced compared to day 1-30. This may result from uncertainties in the gold-standard ultrasound-based treatment planning and implantation. Adaptive implantation workflows appear useful for ensuring high implant stability from the beginning.
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Affiliation(s)
- Andre Karius
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany.
| | - Claudia Schweizer
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Vratislav Strnad
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Michael Lotter
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Stephan Kreppner
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Allison Lamrani
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
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Alasti H, Cho YB, Catton C, Berlin A, Chung P, Bayley A, Vandermeer A, Kong V, Jaffray D. Evaluation of high dose volumetric CT to reduce inter-observer delineation variability and PTV margins for prostate cancer radiotherapy. Radiother Oncol 2017; 125:118-123. [DOI: 10.1016/j.radonc.2017.08.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 07/20/2017] [Accepted: 08/07/2017] [Indexed: 01/28/2023]
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Yang TJ, Tao R, Elkhuizen PH, van Vliet-Vroegindeweij C, Li G, Powell SN. Tumor bed delineation for external beam accelerated partial breast irradiation: A systematic review. Radiother Oncol 2013; 108:181-9. [DOI: 10.1016/j.radonc.2013.05.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 05/12/2013] [Accepted: 05/12/2013] [Indexed: 11/15/2022]
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De Brabandere M, Hoskin P, Haustermans K, Van den Heuvel F, Siebert FA. Prostate post-implant dosimetry: interobserver variability in seed localisation, contouring and fusion. Radiother Oncol 2012; 104:192-8. [PMID: 22857857 DOI: 10.1016/j.radonc.2012.06.014] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 05/11/2012] [Accepted: 06/17/2012] [Indexed: 11/17/2022]
Abstract
AIM Reliable post-implant evaluation of prostate seed implants requires optimal seed identification and accurate delineation of anatomical structures. In this study the GEC-ESTRO groups BRAPHYQS and PROBATE investigated the interobserver variability in post-implant prostate contouring, seed reconstruction and image fusion and its impact on the dose-volume parameters. MATERIALS Post-implant T2-TSE, T1-GE and CT images were acquired for three patients, in order to evaluate four post-plan techniques: (a) CT, (b) T1+T2, (c) CT+T2, (d) CT+T1(int)+T2. Three interobserver studies were set up. (1) Contouring: the CTV-prostate was delineated on CT and T2 by eight physicians. Additionally one reference contour was defined on both image modalities for each patient. (2) Seed reconstruction: seven physicists localised the seeds on T1 and CT, manually and with CT seed finder tools. A reference seed geometry was defined on CT and T1. (3) Fusion: six physicists registered the image sets for technique (b)-(d), using seeds (if visible) and anatomical landmarks. A reference fusion was determined for each combined technique. RESULTS (1) The SD(ref) for contouring (1 SD with respect to the reference volume) was largest for CT (23%), but also surprisingly large for MRI (17%). This resulted in large SD(ref) values for D90 for all techniques (17-23%). The surprisingly large SD(ref) for MRI was partly due to variations in interpretation of what to include in the prostate contour. (2) The SD(ref) in D90 for seed reconstruction was small (2%) for all techniques, except for T1+T2 (7%). (3) The SD(ref) in D90 due to image fusion was quite large, especially for direct fusion of CT+T2 (16%) where clearly corresponding landmarks were missing (seeds hardly visible on T2). In general, we observed large differences in D90 depending on the technique used. CONCLUSIONS The dosimetric parameters for prostate post-implant evaluation showed large technique-dependent interobserver variabilities. Contouring and image fusion are the 'weak links' in the procedure. Guidelines and training in contouring together with incorporation of automated fusion software need to be implemented.
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Fotina I, Lütgendorf-Caucig C, Stock M, Pötter R, Georg D. Critical discussion of evaluation parameters for inter-observer variability in target definition for radiation therapy. Strahlenther Onkol 2012; 188:160-7. [PMID: 22281878 DOI: 10.1007/s00066-011-0027-6] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 10/20/2011] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE Inter-observer studies represent a valid method for the evaluation of target definition uncertainties and contouring guidelines. However, data from the literature do not yet give clear guidelines for reporting contouring variability. Thus, the purpose of this work was to compare and discuss various methods to determine variability on the basis of clinical cases and a literature review. PATIENTS AND METHODS In this study, 7 prostate and 8 lung cases were contoured on CT images by 8 experienced observers. Analysis of variability included descriptive statistics, calculation of overlap measures, and statistical measures of agreement. Cross tables with ratios and correlations were established for overlap parameters. RESULTS It was shown that the minimal set of parameters to be reported should include at least one of three volume overlap measures (i.e., generalized conformity index, Jaccard coefficient, or conformation number). High correlation between these parameters and scatter of the results was observed. CONCLUSION A combination of descriptive statistics, overlap measure, and statistical measure of agreement or reliability analysis is required to fully report the interrater variability in delineation.
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Affiliation(s)
- I Fotina
- Div. Medical Radiation Physics, Department of Radiotherapy, Medical University Vienna/AKH Vienna, Währinger Gürtel 18-20, Vienna, Austria.
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Assessment of in vivo calculation with ultrasonography compared to physical sections in vitro: a stereological study of prostate volumes. Anat Sci Int 2010; 86:78-85. [PMID: 20734181 DOI: 10.1007/s12565-010-0090-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Accepted: 06/30/2010] [Indexed: 10/19/2022]
Abstract
We compared three methods for the determination of prostate volume: prostate volume measured via transrectal ultrasonography (TRUS); the Cavalieri method for measuring physical sections; and volume by displacement. TRUS volumes were calculated by the prolate ellipsoid volume formula. Five patients underwent TRUS examination of the prostate prior to radical prostatectomy; specimens were measured when freshly excised. Mean prostate volume by fluid displacement, before formalin fixation was 52.8 ± 21.5 cm(3), and after formalin fixation 50.4 ± 20.9 cm(3). Volumes determined by the Cavalieri principle (point-counting and planimetry) were 47.8 ± 19.3 and 49.1 ± 20.5 cm(3); volume measured by TRUS was 42.9 ± 21.9 cm(3). Thus TRUS underestimated prostate volume by 21.4%, but excellent agreement was found between actual volume and point counting techniques. We believe that the classic ellipsoid formula is inadequate for determining prostate volume.
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Everitt S, Kron T, Leong T, Schneider-Kolsky M, Manus MM. Geographic miss in radiation oncology: Have we missed the boat? J Med Imaging Radiat Oncol 2009; 53:506-9. [DOI: 10.1111/j.1754-9485.2009.02102.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Rosewall T, Kong V, Vesprini D, Catton C, Chung P, Ménard C, Bayley A. Prostate delineation using CT and MRI for radiotherapy patients with bilateral hip prostheses. Radiother Oncol 2009; 90:325-30. [DOI: 10.1016/j.radonc.2008.11.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 11/14/2008] [Accepted: 11/16/2008] [Indexed: 11/26/2022]
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9
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Computed tomography imaging in patients with prostate cancer. Prostate Cancer 2008. [DOI: 10.1017/cbo9780511551994.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Petersen RP, Truong PT, Kader HA, Berthelet E, Lee JC, Hilts ML, Kader AS, Beckham WA, Olivotto IA. Target Volume Delineation for Partial Breast Radiotherapy Planning: Clinical Characteristics Associated with Low Interobserver Concordance. Int J Radiat Oncol Biol Phys 2007; 69:41-8. [PMID: 17707265 DOI: 10.1016/j.ijrobp.2007.01.070] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2006] [Revised: 01/27/2007] [Accepted: 01/31/2007] [Indexed: 11/24/2022]
Abstract
PURPOSE To examine variability in target volume delineation for partial breast radiotherapy planning and evaluate characteristics associated with low interobserver concordance. METHODS AND MATERIALS Thirty patients who underwent planning CT for adjuvant breast radiotherapy formed the study cohort. Using a standardized scale to score seroma clarity and consensus contouring guidelines, three radiation oncologists independently graded seroma clarity and delineated seroma volumes for each case. Seroma geometric center coordinates, maximum diameters in three axes, and volumes were recorded. Conformity index (CI), the ratio of overlapping volume and encompassing delineated volume, was calculated for each case. Cases with CI </=0.50 were analyzed to identify features associated with low concordance. RESULTS The median time from surgery to CT was 42.5 days. For geometric center coordinates, variations from the mean were 0.5-1.1 mm and standard deviations (SDs) were 0.5-1.8 mm. For maximum seroma dimensions, variations from the mean and SDs were predominantly <5 mm, with the largest SDs observed in the medial-lateral axis. The mean CI was 0.61 (range, 0.27-0.84). Five cases had CI </=0.50. Conformity index was significantly associated with seroma clarity (p < 0.001) and seroma volume (p < 0.002). Features associated with reduced concordance included tissue stranding from the surgical cavity, proximity to muscle, dense breast parenchyma, and benign calcifications that may be mistaken for surgical clips. CONCLUSION Variability in seroma contouring occurred in three dimensions, with the largest variations in the medial-lateral axis. Awareness of clinical features associated with reduced concordance may be applied toward training staff and refining contouring guidelines for partial breast radiotherapy trials.
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Affiliation(s)
- Ross P Petersen
- Radiation Therapy Program, British Columbia Cancer Agency, Vancouver Island Centre, Victoria, Canada
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11
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Smith WL, Lewis C, Bauman G, Rodrigues G, D'Souza D, Ash R, Ho D, Venkatesan V, Downey D, Fenster A. Prostate volume contouring: a 3D analysis of segmentation using 3DTRUS, CT, and MR. Int J Radiat Oncol Biol Phys 2007; 67:1238-47. [PMID: 17336224 DOI: 10.1016/j.ijrobp.2006.11.027] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2006] [Revised: 11/08/2006] [Accepted: 11/09/2006] [Indexed: 11/16/2022]
Abstract
PURPOSE This study evaluated the reproducibility and modality differences of prostate contouring after brachytherapy implant using three-dimensional (3D) transrectal ultrasound (3DTRUS), T2-weighted magnetic resonance (MR), and computed tomography (CT) imaging. METHODS AND MATERIALS Seven blinded observers contoured 10 patients' prostates, 30 day postimplant, on 3DTRUS, MR, and CT images to assess interobserver variability. Randomized images were contoured twice by each observer. We analyzed length and volume measurements and performed a 3D analysis of intra- and intermodality variation. RESULTS Average volume ratios were 1.16 for CT/MR, 0.90 for 3DTRUS/MR, and 1.30 for CT/3DTRUS. Overall contouring variability was largest for CT and similar for MR and 3DTRUS. The greatest variability of CT contours occurred at the posterior and anterior portions of the midgland. On MR, overall variability was smaller, with a maximum in the anterior region. On 3DTRUS, high variability occurred in anterior regions of the apex and base, whereas the prostate-rectum interface had the smallest variability. The shape of the prostate on MR was rounder, with the base and apex of similar size, whereas CT contours had broad, flat bases narrowing toward the apex. The average percent of surface area that was significantly different (95% confidence interval) for CT/MR was 4.1%; 3DTRUS/MR, 10.7%; and CT/3DTRUS, 6.3%. The larger variability of CT measurements made significant differences more difficult to detect. CONCLUSIONS The contouring of prostates on CT, MR, and 3DTRUS results in systematic differences in the locations of and variability in prostate boundary definition between modalities. MR and 3DTRUS display the smallest variability and the closest correspondence.
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Affiliation(s)
- Wendy L Smith
- Department of Medical Physics, Tom Baker Cancer Centre, and Departments of Oncology and Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada.
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Brindle JM, Trindade AA, Pichardo JC, Myers SL, Shah AP, Bolch WE. CT volumetry of the skeletal tissues. Med Phys 2006; 33:3796-803. [PMID: 17089844 DOI: 10.1118/1.2337272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Computed tomography (CT) is an important and widely used modality in the diagnosis and treatment of various cancers. In the field of molecular radiotherapy, the use of spongiosa volume (combined tissues of the bone marrow and bone trabeculae) has been suggested as a means to improve the patient-specificity of bone marrow dose estimates. The noninvasive estimation of an organ volume comes with some degree of error or variation from the true organ volume. The present study explores the ability to obtain estimates of spongiosa volume or its surrogate via manual image segmentation. The variation among different segmentation raters was explored and found not to be statistically significant (p value >0.05). Accuracy was assessed by having several raters manually segment a polyvinyl chloride (PVC) pipe with known volumes. Segmentation of the outer region of the PVC pipe resulted in mean percent errors as great as 15% while segmentation of the pipe's inner region resulted in mean percent errors within approximately 5%. Differences between volumes estimated with the high-resolution CT data set (typical of ex vivo skeletal scans) and the low-resolution CT data set (typical of in vivo skeletal scans) were also explored using both patient CT images and a PVC pipe phantom. While a statistically significant difference (p value <0.002) between the high-resolution and low-resolution data sets was observed with excised femoral heads obtained following total hip arthroplasty, the mean difference between high-resolution and low-resolution data sets was found to be only 1.24 and 2.18 cm3 for spongiosa and cortical bone, respectively. With respect to differences observed with the PVC pipe, the variation between the high-resolution and low-resolution mean percent errors was a high as approximately 20% for the outer region volume estimates and only as high as approximately 6% for the inner region volume estimates. The findings from this study suggest that manual segmentation is a reasonably accurate and reliable means for the in vivo estimation of spongiosa volume. This work also provides a foundation for future studies where spongiosa volumes are estimated by various raters in more comprehensive CT data
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Affiliation(s)
- James M Brindle
- Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, Florida 32611, USA
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Tanaka O, Hayashi S, Sakurai K, Matsuo M, Nakano M, Maeda S, Hoshi H, Deguchi T. Importance of the CT/MRI fusion method as a learning tool for CT-based postimplant dosimetry in prostate brachytherapy. Radiother Oncol 2006; 81:303-8. [PMID: 17125859 DOI: 10.1016/j.radonc.2006.10.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 09/22/2006] [Accepted: 10/04/2006] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND PURPOSE To compare the CT-based and CT/MRI fusion-based postimplant dosimetry after permanent prostate brachytherapy and to evaluate the improvement in CT-based dosimetry by physicians with or without experience in using the CT/MRI fusion method. PATIENTS AND METHODS Thirty-eight consecutive patients agreed to participate in a prospective study. The prostate contours from CT/MRI fusion are the gold standard for determining the prostate volume and dose volume histogram (DVH). CT-based postimplant dosimetries were performed by two physicians. Observer 1 was a radiologist who had never used CT/MRI fusion method for postimplant dosimetric analysis. Observer 2 was a radiation oncologist experienced in postimplant analysis using the CT/MRI fusion method. The prostate dosimetry was evaluated by prostate D90 and V100. RESULTS No significant difference was observed in the mean prostate volumes between the two observers and the CT/MRI fusion data. However, the correlation coefficient value for observer 2 (R(2)=0.932) was greater than that for observer 1 (R(2)=0.793). The D90 and V100 values as evaluated by the two observers were significantly underestimated in comparison to those evaluated using the CT/MRI fusion methods. The DVH related parameters were underestimated more frequently by observer 1 than by observer 2: (prostate D90: 99.56% for observer 1, 102.97% for observer 2, 109.37% for CT/MRI fusion. Prostate V100: 88.12% for observer 1, 90.14% for observer 2, 91.91% for CT/MRI fusion). CONCLUSIONS The difference in the mean value in D90 and V100 by observer 1 was significantly greater than that for observer 2. These findings suggest that the CT/MRI fusion method provides accurate feedback which thereby improves CT-based postimplant dosimetry for prostate brachytherapy.
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Affiliation(s)
- Osamu Tanaka
- Department of Radiology, Gifu University School of Medicine, Gifu City, Japan.
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14
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Wong EK, Truong PT, Kader HA, Nichol AM, Salter L, Petersen R, Wai ES, Weir L, Olivotto IA. Consistency in seroma contouring for partial breast radiotherapy: Impact of guidelines. Int J Radiat Oncol Biol Phys 2006; 66:372-6. [PMID: 16965989 DOI: 10.1016/j.ijrobp.2006.05.066] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Revised: 04/28/2006] [Accepted: 05/02/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE Inconsistencies in contouring target structures can undermine the precision of conformal radiation therapy (RT) planning and compromise the validity of clinical trial results. This study evaluated the impact of guidelines on consistency in target volume contouring for partial breast RT planning. METHODS AND MATERIALS Guidelines for target volume definition for partial breast radiation therapy (PBRT) planning were developed by members of the steering committee for a pilot trial of PBRT using conformal external beam planning. In phase 1, delineation of the breast seroma in 5 early-stage breast cancer patients was independently performed by a "trained" cohort of four radiation oncologists who were provided with these guidelines and an "untrained" cohort of four radiation oncologists who contoured without guidelines. Using automated planning software, the seroma target volume (STV) was expanded into a clinical target volume (CTV) and planning target volume (PTV) for each oncologist. Means and standard deviations were calculated, and two-tailed t tests were used to assess differences between the "trained" and "untrained" cohorts. In phase 2, all eight radiation oncologists were provided with the same contouring guidelines, and were asked to delineate the seroma in five new cases. Data were again analyzed to evaluate consistency between the two cohorts. RESULTS The "untrained" cohort contoured larger seroma volumes and had larger CTVs and PTVs compared with the "trained" cohort in three of five cases. When seroma contouring was performed after review of contouring guidelines, the differences in the STVs, CTVs, and PTVs were no longer statistically significant. CONCLUSION Guidelines can improve consistency among radiation oncologists performing target volume delineation for PBRT planning.
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Affiliation(s)
- Elaine K Wong
- Radiation Therapy Program, British Columbia (BC) Cancer Agency, Vancouver Island Centre, Victoria and Vancouver, BC, Canada
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Berthelet E, Truong PT, Zavgorodni S, Moravan V, Liu MC, Runkel J, Bendorffe B, Sayers D. Consistency in electronic portal imaging registration in prostate cancer radiation treatment verification. Radiat Oncol 2006; 1:37. [PMID: 16984655 PMCID: PMC1592498 DOI: 10.1186/1748-717x-1-37] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Accepted: 09/19/2006] [Indexed: 11/17/2022] Open
Abstract
Background A protocol of electronic portal imaging (EPI) registration for the verification of radiation treatment fields has been implemented at our institution. A template is generated using the reference images, which is then registered with the EPI for treatment verification. This study examines interobserver consistency among trained radiation therapists in the registration and verification of external beam radiotherapy (EBRT) for patients with prostate cancer. Materials and methods 20 consecutive patients with prostate cancer undergoing EBRT were analyzed. The EPIs from the initial 10 fractions were registered independently by 6 trained radiation therapist observers. For each fraction, an anterior-posterior (AP or PA) and left lateral (Lat) EPIs were generated and registered with the reference images. Two measures of displacement for the AP EPI in the superior-inferior (SI) and right left (RL) directions and two measures of displacement for the Lat EPI in the AP and SI directions were prospectively recorded. A total of 2400 images and 4800 measures were analyzed. Means and standard deviations, as well as systematic and random errors were calculated for each observer. Differences between observers were compared using the chi-square test. Variance components analysis was used to evaluate how much variance is attributed to the observers. Time trends were estimated using repeated measures analysis. Results Inter-observer variation expressed as the standard deviation of the six observers' measurements within each image were 0.7, 1.0, 1.7 and 1.4 mm for APLR, APSI, LatAP and LatSI respectively. Variance components analysis showed that the variation attributed to the observers was small compared to variation due to the images. On repeated measure analysis, time trends were apparent only for the APLR and LatSI measurements. Their magnitude however was small. Conclusion No clinically important systematic observer effect or time trends were identified in the registration of EPI by the radiation therapist observers in this study. These findings are useful in the documentation of consistency and reliability in the quality assurance of treatment verification of EBRT for prostate cancer.
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Affiliation(s)
- Eric Berthelet
- Radiation Therapy Program, Vancouver Island Centre, British Columbia Cancer Agency, Victoria, BC, Canada
- University of British Columbia, Victoria, BC, Canada
| | - Pauline T Truong
- Radiation Therapy Program, Vancouver Island Centre, British Columbia Cancer Agency, Victoria, BC, Canada
- University of British Columbia, Victoria, BC, Canada
| | - Sergei Zavgorodni
- Radiation Therapy Program, Vancouver Island Centre, British Columbia Cancer Agency, Victoria, BC, Canada
| | - Veronika Moravan
- Population and Preventive Oncology, British Columbia Cancer Agency, Vancouver, BC, Canada
| | - Mitchell C Liu
- Radiation Therapy Program, Fraser Valley Centre, British Columbia Cancer Agency, Surrey, BC, Canada
- University of British Columbia, Victoria, BC, Canada
| | - Jim Runkel
- Radiation Therapy Program, Vancouver Island Centre, British Columbia Cancer Agency, Victoria, BC, Canada
| | - Bill Bendorffe
- Radiation Therapy Program, Vancouver Island Centre, British Columbia Cancer Agency, Victoria, BC, Canada
| | - Dorothy Sayers
- Radiation Therapy Program, Vancouver Island Centre, British Columbia Cancer Agency, Victoria, BC, Canada
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Gual-Arnau X, Ibáñez-Gual MV, Lliso F, Roldán S. Organ contouring for prostate cancer: Interobserver and internal organ motion variability. Comput Med Imaging Graph 2005; 29:639-47. [PMID: 16275028 DOI: 10.1016/j.compmedimag.2005.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2005] [Revised: 06/17/2005] [Accepted: 06/17/2005] [Indexed: 10/25/2022]
Abstract
The purpose of this study is to assess the uncertainties that arise in locating the boundaries of anatomical structures, such as the prostate and the bladder, due to interobserver variability in the delineation of the structures and to internal organ motion. The variabilities are computed in all the radial directions and this information is used to obtain the margins, following the techniques and limitations imposed by medical practice. The margins obtained from the organ motions are significantly greater than those arising from interobserver variability. The developed tools, allow us to obtain the required margins in an efficient way.
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Affiliation(s)
- X Gual-Arnau
- Department of Mathematics. Universitat Jaume I, 12071-Castelló, Spain.
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Citrin D, Ning H, Guion P, Li G, Susil RC, Miller RW, Lessard E, Pouliot J, Huchen X, Capala J, Coleman CN, Camphausen K, Ménard C. Inverse treatment planning based on MRI for HDR prostate brachytherapy. Int J Radiat Oncol Biol Phys 2005; 61:1267-75. [PMID: 15752909 DOI: 10.1016/j.ijrobp.2004.11.024] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2004] [Revised: 11/10/2004] [Accepted: 11/17/2004] [Indexed: 11/15/2022]
Abstract
PURPOSE To develop and optimize a technique for inverse treatment planning based solely on magnetic resonance imaging (MRI) during high-dose-rate brachytherapy for prostate cancer. METHODS AND MATERIALS Phantom studies were performed to verify the spatial integrity of treatment planning based on MRI. Data were evaluated from 10 patients with clinically localized prostate cancer who had undergone two high-dose-rate prostate brachytherapy boosts under MRI guidance before and after pelvic radiotherapy. Treatment planning MRI scans were systematically evaluated to derive a class solution for inverse planning constraints that would reproducibly result in acceptable target and normal tissue dosimetry. RESULTS We verified the spatial integrity of MRI for treatment planning. MRI anatomic evaluation revealed no significant displacement of the prostate in the left lateral decubitus position, a mean distance of 14.47 mm from the prostatic apex to the penile bulb, and clear demarcation of the neurovascular bundles on postcontrast imaging. Derivation of a class solution for inverse planning constraints resulted in a mean target volume receiving 100% of the prescribed dose of 95.69%, while maintaining a rectal volume receiving 75% of the prescribed dose of <5% (mean 1.36%) and urethral volume receiving 125% of the prescribed dose of <2% (mean 0.54%). CONCLUSION Systematic evaluation of image spatial integrity, delineation uncertainty, and inverse planning constraints in our procedure reduced uncertainty in planning and treatment.
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Affiliation(s)
- Deborah Citrin
- Radiation Oncology Branch, CCR, NCI, National Institutes of Health, Department of Health and Human Services, Bldg. 10, Rm. B3B69, 9000 Rockville Pike, Bethesda, MD 20892, USA.
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Berthelet E, Liu M, Truong P, Czaykowski P, Kalach N, Yu C, Patterson K, Currie T, Kristensen S, Kwan W, Moravan V. CT slice index and thickness: impact on organ contouring in radiation treatment planning for prostate cancer. J Appl Clin Med Phys 2004; 4:365-73. [PMID: 14604426 PMCID: PMC5724462 DOI: 10.1120/jacmp.v4i4.2511] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Objective: To assess the impact of CT slice index and thickness (3 mm versus 5 mm) on (i) prostate volume, dimensions, and isocenter coordinates, (ii) bladder and rectal volumes, and (iii) DRR quality, in the treatment of prostate cancer. Methods: 16 patients with prostate cancer underwent two planning CT‐scans using 3 and 5 mm slice index/thickness. Prostate, bladder, and rectum were outlined on all scans. Prostate isocenter coordinates, maximum dimensions, and volumes were compared along with bladder and rectal volumes. Bladder volumes and maximum diameters were further investigated using a second observer. A comparative analysis of DRR quality was conducted as well as a dosimetric analysis using DVH. Results: The differences in measurements of prostate volume, isocenter coordinates and maximum dimensions between the 3 and 5 mm scans, were small and not statistically significant. Similar finding was seen for rectal volume. However, bladder volume was always larger on the 3 mm scan (mean difference=27.9 cc; SE=4.8 cc; 95% CI: 17.7−38.2 cc; p<0.001) and the findings were reproduced with the second observer (mean difference=31.9 cc; SE=4.7 cc; 95% CI: 21.9−41.9 cc; p<0.001). The differences in volume are caused by a slight increase in (1) the measurement of the longitudinal dimensions on the 3 mm scans, and (2) the slice by slice measured bladder area on the 3 mm scans. The latter is due to partial volume effect. The 3 mm DRR were slightly better than the 5 mm DRR. The bladder DVH differed significantly in some patients. Conclusion: Bladder volume is significantly larger on the 3 mm scans. Differences in contoured areas may be accounted for, in part, by the partial volume effect. PACS number(s): 87.57.–s, 87.53.–j
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Affiliation(s)
- E. Berthelet
- Department of Radiation OncologyBCCA‐Vancouver Island Centre2410 Lee AvenueVictoriaBCV8R 6V5Canada
| | - M. Liu
- Department of Radiation OncologyBCCA‐Fraser Valley Centre13750 96th AvenueSurreyBCV3V 1Z2Canada
| | - P. Truong
- Department of Radiation OncologyBCCA‐Vancouver Island Centre2410 Lee AvenueVictoriaBCV8R 6V5Canada
| | - P. Czaykowski
- Division of Hematology/Oncology, Department of Medical OncologyUniversity of Manitoba, CancerCare Manitoba675 McDermot AvenueWinnipegMBR3E 0V9Canada
| | - N. Kalach
- Department of Radiation OncologyBCCA‐Fraser Valley Centre13750 96th AvenueSurreyBCV3V 1Z2Canada
| | - C. Yu
- Department of Radiation OncologyBCCA‐Fraser Valley Centre13750 96th AvenueSurreyBCV3V 1Z2Canada
| | - K. Patterson
- Department of Radiation OncologyBCCA‐Fraser Valley Centre13750 96th AvenueSurreyBCV3V 1Z2Canada
| | - T. Currie
- Department of Radiation OncologyBCCA‐Fraser Valley Centre13750 96th AvenueSurreyBCV3V 1Z2Canada
| | - S. Kristensen
- Department of Radiation OncologyBCCA‐Fraser Valley Centre13750 96th AvenueSurreyBCV3V 1Z2Canada
| | - W. Kwan
- Department of Radiation OncologyBCCA‐Fraser Valley Centre13750 96th AvenueSurreyBCV3V 1Z2Canada
| | - V. Moravan
- Population and Preventative OncologyBCCA‐Vancouver Centre600 W 10th AvenueVancouverBOV5Z 4E6Canada
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Hoffelt SC, Marshall LM, Garzotto M, Hung A, Holland J, Beer TM. A comparison of CT scan to transrectal ultrasound-measured prostate volume in untreated prostate cancer. Int J Radiat Oncol Biol Phys 2003; 57:29-32. [PMID: 12909212 DOI: 10.1016/s0360-3016(03)00509-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To compare CT and transrectal ultrasound (TRUS)-measured prostate volumes in patients with untreated prostate cancer. METHODS AND MATERIALS Between 1995 and 1999, 48 consecutive patients at the Portland Veterans Affairs Medical Center were treated with external beam radiotherapy. In 36 of these patients, TRUS and CT measurements of the prostate volume were obtained before treatment and <6 months apart. The TRUS volume was calculated using the prolate ellipsoid formula. The CT volume was calculated from the contours of the prostate drawn by one physician, who was unaware of the TRUS volume calculation, on axial CT images. RESULTS The TRUS and CT prostate volume measurements correlated strongly (Pearson's correlation coefficient = 0.925, 95% confidence interval 0.856-0.961, p < 0.0001). The CT volume was consistently larger than the TRUS volume by a factor of approximately 1.5. In men with a TRUS prostate volume less than the median (<28 cm(3)), the CT/TRUS volume ratio was 1.7, and it was 1.4 for men whose volume was greater than the median. The CT volumes were correlated similarly with the TRUS volumes regardless of the CT slice interval. CONCLUSION A strong correlation was found between CT scan and TRUS measurement of the prostate volume; however, CT consistently overestimated the prostate volume by approximately 50% compared with TRUS.
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Affiliation(s)
- S Christopher Hoffelt
- Department of Radiation Oncology, Oregon Health Sciences University, Portland, OR 97239, USA
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Collier DC, Burnett SSC, Amin M, Bilton S, Brooks C, Ryan A, Roniger D, Tran D, Starkschall G. Assessment of consistency in contouring of normal-tissue anatomic structures. J Appl Clin Med Phys 2003; 4:17-24. [PMID: 12540815 PMCID: PMC5724429 DOI: 10.1120/jacmp.v4i1.2538] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2002] [Accepted: 09/25/2002] [Indexed: 11/23/2022] Open
Abstract
The purpose of this work is to estimate the uncertainty in the manual contouring of normal anatomical structures. The heart, esophagus, and spinal cord were contoured manually on six sets of computed tomography images by six dosimetrists whose experience ranged from 1 year to over 15 years. To determine the differences between inter- and intraobserver variations, each data set was contoured by one of the dosimetrists five times and once each by the five other dosimetrists. The magnitude of the discrepancies in delineating the contours was assessed. Intradosimetrist contouring discrepancies were as follows: esophagus, average 0.3 cm and maximum 2.9 cm; heart, average 0.5 cm and maximum 7.6 cm; and spinal cord, average 0.1 cm and maximum 0.7 cm. Interdosimetrist contouring discrepancies were as follows: esophagus, average 0.4 cm and maximum 3.1 cm; heart, average 0.7 cm and maximum 8.1 cm; and spinal cord, average 0.2 cm and maximum 0.9 cm. Significant discrepancies can occur when normal anatomic structures are contoured manually. Interdosimetrist discrepancies are typically slightly greater than intradosimetrist discrepancies. The magnitude of the discrepancies does not appear to be correlated to the experience of the dosimetrist.
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Affiliation(s)
- Dawn C. Collier
- Department of Radiation PhysicsThe University of Texas M. D. Anderson Cancer Center1515 Holcombe BoulevardHoustonTexas77030
| | - Stuart S. C. Burnett
- Department of Radiation PhysicsThe University of Texas M. D. Anderson Cancer Center1515 Holcombe BoulevardHoustonTexas77030
| | - Mayankkumar Amin
- Department of Radiation PhysicsThe University of Texas M. D. Anderson Cancer Center1515 Holcombe BoulevardHoustonTexas77030
| | - Stephen Bilton
- Department of Radiation PhysicsThe University of Texas M. D. Anderson Cancer Center1515 Holcombe BoulevardHoustonTexas77030
| | - Christopher Brooks
- Department of Radiation PhysicsThe University of Texas M. D. Anderson Cancer Center1515 Holcombe BoulevardHoustonTexas77030
| | - Amanda Ryan
- Department of Radiation PhysicsThe University of Texas M. D. Anderson Cancer Center1515 Holcombe BoulevardHoustonTexas77030
| | - Dominique Roniger
- Department of Radiation PhysicsThe University of Texas M. D. Anderson Cancer Center1515 Holcombe BoulevardHoustonTexas77030
| | - Danny Tran
- Department of Radiation PhysicsThe University of Texas M. D. Anderson Cancer Center1515 Holcombe BoulevardHoustonTexas77030
| | - George Starkschall
- Department of Radiation PhysicsThe University of Texas M. D. Anderson Cancer Center1515 Holcombe BoulevardHoustonTexas77030
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Beckendorf V, Bachaud JM, Bey P, Bourdin S, Carrie C, Chapet O, Cowen D, Guérif S, Hay HM, Lagrange JL, Maingon P, Le Prisé E, Pommier P, Simon JM. [Target-volume and critical-organ delineation for conformal radiotherapy of prostate cancer: experience of French dose-escalation trials]. Cancer Radiother 2002; 6 Suppl 1:78s-92s. [PMID: 12587386 DOI: 10.1016/s1278-3218(02)00217-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The delineation of target volume and organs at risk depends on the organs definition, and on the modalities for the CT-scan acquisition. Inter-observer variability in the delineation may be large, especially when patient's anatomy is unusual. During the two french multicentric studies of conformal radiotherapy for localized prostate cancer, it was made an effort to harmonize the delineation of the target volumes and organs at risk. Two cases were proposed for delineation during two workshops. In the first case, the mean prostate volume was 46.5 mL (extreme: 31.7-61.3), the mean prostate and seminal vesicles volume was 74.7 mL (extreme: 59.6-80.3), the rectal and bladder walls varied respectively in proportion from 1 to 1.45 and from 1 to 1.16; in the second case, the mean prostate volume was 53.1 mL (extreme: 40.8-73.1), the volume of prostate plus seminal vesicles was 65.1 mL (extreme: 53.2-89), the rectal wall varied proportionally from 1 to 1, 24 and the vesical wall varied from 1 to 1.67. For participating centers to the french studies of dose escalation, a quality control of contours was performed to decrease the inter-observer variability. The ways to reduce the discrepancies of volumes delineation, between different observers, are discussed. A better quality of the CT images, use of urethral opacification, and consensual definition of clinical target volumes and organs at risk may contribute to that improvement.
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Affiliation(s)
- V Beckendorf
- Radiothérapie, centre Alexis-Vautrin, 54511 Vandoeuvre-lès-Nancy, France.
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