Ioannis A. Tsalafoutas, Shady AlKhazzam, Mohammed Hassan Kharita
PURPOSE
The exposure index (EI), the target exposure index (EIT), and the deviation index (DI) have been defined in the IEC Standard 62494-1 Ed.1 2008-08. This study investigates the impact of certain acquisition parameters, the imaged anatomy, and the manufacturer's specificities on the EI of radiological images and how these may affect EIT setting procedure.
METHODS
Images were acquired using two digital radiography (DR) systems of two different manufacturers, using aluminum attenuators and an anthropomorphic phantom. Acquisition parameters like the tube potential (kVp), the tube loading (mAs), the exposure time, the automatic exposure control (AEC) system settings (sensor and dose level selection), the grid (with or without), the additional filtration, the field size, and the imaged anatomy were varied and their effect on the EI was quantified separately for each system.
RESULTS
EI is linearly related to the incident air kerma (IAK) on the detector as expected (by definition). For constant IAK, EI increases with increasing kVp. While EI in general is reduced in the presence of scatter, this may not always be the case. Under AEC operation, even the exposure time can make a difference. EI is strongly affected by the imaged anatomy in combination with the AEC sensor and field size selections, the examination protocol, and the manufacturer.
CONCLUSIONS
Many parameters affect the EI calculation apart from IAK. Among them, the most important are the imaged anatomy and the manufacturer. Since the EI calculation is a complex procedure, setting of the EIT values should be done with caution on a per-examination and manufacturer basis, since the values that apply for one digital system are not always applicable to another. Furthermore, when EI is used as an image quality tool, a DI variation of at least ±2 should be allowed before a possibly meaningful red flag is activated.
{"title":"Exposure index in digital radiography and its dependence on acquisition parameters, anatomy, and manufacturer","authors":"Ioannis A. Tsalafoutas, Shady AlKhazzam, Mohammed Hassan Kharita","doi":"10.1002/acm2.70331","DOIUrl":"10.1002/acm2.70331","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> PURPOSE</h3>\u0000 \u0000 <p>The exposure index (EI), the target exposure index (EI<sub>T</sub>), and the deviation index (DI) have been defined in the IEC Standard 62494-1 Ed.1 2008-08. This study investigates the impact of certain acquisition parameters, the imaged anatomy, and the manufacturer's specificities on the EI of radiological images and how these may affect EI<sub>T</sub> setting procedure.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> METHODS</h3>\u0000 \u0000 <p>Images were acquired using two digital radiography (DR) systems of two different manufacturers, using aluminum attenuators and an anthropomorphic phantom. Acquisition parameters like the tube potential (kVp), the tube loading (mAs), the exposure time, the automatic exposure control (AEC) system settings (sensor and dose level selection), the grid (with or without), the additional filtration, the field size, and the imaged anatomy were varied and their effect on the EI was quantified separately for each system.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> RESULTS</h3>\u0000 \u0000 <p>EI is linearly related to the incident air kerma (IAK) on the detector as expected (by definition). For constant IAK, EI increases with increasing kVp. While EI in general is reduced in the presence of scatter, this may not always be the case. Under AEC operation, even the exposure time can make a difference. EI is strongly affected by the imaged anatomy in combination with the AEC sensor and field size selections, the examination protocol, and the manufacturer.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> CONCLUSIONS</h3>\u0000 \u0000 <p>Many parameters affect the EI calculation apart from IAK. Among them, the most important are the imaged anatomy and the manufacturer. Since the EI calculation is a complex procedure, setting of the EI<sub>T</sub> values should be done with caution on a per-examination and manufacturer basis, since the values that apply for one digital system are not always applicable to another. Furthermore, when EI is used as an image quality tool, a DI variation of at least ±2 should be allowed before a possibly meaningful red flag is activated.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12802571/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145965985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
RapidArc (RA) has advanced VMAT delivery; however, challenges remain in achieving optimal organ-at-risk (OAR) sparing in complex cases. RapidArc Dynamic (RAD), a next-generation Volumetric Modulation Arc Therapy (VMAT) technique, incorporates dynamic collimator rotation, embedded static fields, and a faster optimizer to enhance dose modulation. This study compares dosimetric outcomes between conventional RA and RAD across four anatomical sites.
Methods
A retrospective analysis was conducted on 40 patients (10 each for breast, lung SBRT, prostate, and head and neck cancers). Each case was initially treated with RA and subsequently replanned using RAD in Eclipse v18.1. Plans were evaluated using dose–volume histograms (DVH), and paired t-tests assessed differences in target coverage and OAR sparing (p < 0.05).
Results
RAD maintained equivalent target coverage compared to RA across all sites. Significant OAR sparing was observed with RAD, including reduced mean heart and contralateral lung doses in breast cases, lower rectal and bladder doses in prostate cases, improved conformity and reduced spinal cord and lung doses in lung SBRT, and superior sparing of parotids, cochleae, and mucosal structures in head and neck cases.
Conclusion
RAD offers superior OAR sparing and improved dose conformity without compromising target coverage compared to conventional RA. These results support RAD's clinical adoption, particularly for anatomically complex or high-precision treatments. Further prospective studies are needed to assess the long-term clinical benefits.
{"title":"RapidArc dynamic versus RapidArc: A multi anatomical-site dosimetric evaluation","authors":"Aram Rostami, Carole Naim, Renilmon Pottanplackal Sukumaran, Mohammad Usman, Abbass Yousef Mkanna, Alla Fuad Al-Sabahi, Ahamed Basith, Shelton Chuck, Mojtaba Barzegar, Bevan Orville Peltier, Bassim Aklan, Samaneh Baradaran, Satheesh Prasad Paloor, Rabih Wafiq Hammoud","doi":"10.1002/acm2.70404","DOIUrl":"10.1002/acm2.70404","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>RapidArc (RA) has advanced VMAT delivery; however, challenges remain in achieving optimal organ-at-risk (OAR) sparing in complex cases. RapidArc Dynamic (RAD), a next-generation Volumetric Modulation Arc Therapy (VMAT) technique, incorporates dynamic collimator rotation, embedded static fields, and a faster optimizer to enhance dose modulation. This study compares dosimetric outcomes between conventional RA and RAD across four anatomical sites.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A retrospective analysis was conducted on 40 patients (10 each for breast, lung SBRT, prostate, and head and neck cancers). Each case was initially treated with RA and subsequently replanned using RAD in Eclipse v18.1. Plans were evaluated using dose–volume histograms (DVH), and paired t-tests assessed differences in target coverage and OAR sparing (<i>p</i> < 0.05).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>RAD maintained equivalent target coverage compared to RA across all sites. Significant OAR sparing was observed with RAD, including reduced mean heart and contralateral lung doses in breast cases, lower rectal and bladder doses in prostate cases, improved conformity and reduced spinal cord and lung doses in lung SBRT, and superior sparing of parotids, cochleae, and mucosal structures in head and neck cases.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>RAD offers superior OAR sparing and improved dose conformity without compromising target coverage compared to conventional RA. These results support RAD's clinical adoption, particularly for anatomically complex or high-precision treatments. Further prospective studies are needed to assess the long-term clinical benefits.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12800903/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145965967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Neha Yadav, Xiaomeng Lei, Steven Y. Cen, Joshua Levy, Kristin Jensen, Bino A. Varghese
<div> <section> <h3> Background</h3> <p>Radiomic features derived from computed tomography (CT) are highly susceptible to variations in acquisition parameters, which can introduce confounding effects in multicenter research and reduce diagnostic accuracy. While the effects of parameters such as scanning mode and dose have been studied, the impact of gantry tilt—despite its routine clinical use—remains underexplored in radiomics literature.</p> </section> <section> <h3> Purpose</h3> <p>To systematically evaluate how scan mode (axial vs. helical), gantry tilt (0° vs. 5°), and radiation dose affect CT-based radiomic metrics using an anthropomorphic liver phantom containing six 3D-printed texture inserts, with special emphasis on the novel inclusion of tilt.</p> </section> <section> <h3> Methods</h3> <p>Twelve unique image acquisition configurations were scanned on a GE Revolution Apex CT scanner, with each configuration repeated once. Manual segmentation of volumes of interest (VOIs) was performed, and 93 radiomic features spanning six texture families were extracted using PyRadiomics. First-order dispersion metrics (standard deviation, interquartile range, and coefficient of variation) were analyzed alongside higher-order features via regression with heatmap visualization, and repeatable, robust, and calibratable features were identified.</p> </section> <section> <h3> Results</h3> <p>Helical scans without tilt generally exhibited lower first-order dispersion than axial scans. Introducing a 5° tilt reduced dispersion in axial scans but had inconsistent effects in helical scans, with no coherent trend observed. Radiation dose demonstrated an expected inverse relationship with dispersion metrics. Intraclass correlation coefficient (ICC) analysis revealed that 34% of radiomic metrics exhibited good or excellent repeatability across all trials (ICC ≥ 0.6), but only 13% demonstrated good or excellent robustness, highlighting the sensitivity of radiomic metrics to scanning conditions. Regression analysis yielded 31 metrics (33%) that can be calibrated using their significant linear relationships with the parameters varied in this study, thereby allowing researchers to correct for variations in acquisition settings.</p> </section> <section> <h3> Conclusions</h3> <p>These findings underscore the importance of accounting for acquisition variability—including less frequently examined parameters such as tilt—when designing radiomic studies, selecting robust feat
{"title":"Influence of scan mode, tilt, and radiation dose on CT radiomic metrics","authors":"Neha Yadav, Xiaomeng Lei, Steven Y. Cen, Joshua Levy, Kristin Jensen, Bino A. Varghese","doi":"10.1002/acm2.70462","DOIUrl":"10.1002/acm2.70462","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Radiomic features derived from computed tomography (CT) are highly susceptible to variations in acquisition parameters, which can introduce confounding effects in multicenter research and reduce diagnostic accuracy. While the effects of parameters such as scanning mode and dose have been studied, the impact of gantry tilt—despite its routine clinical use—remains underexplored in radiomics literature.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To systematically evaluate how scan mode (axial vs. helical), gantry tilt (0° vs. 5°), and radiation dose affect CT-based radiomic metrics using an anthropomorphic liver phantom containing six 3D-printed texture inserts, with special emphasis on the novel inclusion of tilt.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Twelve unique image acquisition configurations were scanned on a GE Revolution Apex CT scanner, with each configuration repeated once. Manual segmentation of volumes of interest (VOIs) was performed, and 93 radiomic features spanning six texture families were extracted using PyRadiomics. First-order dispersion metrics (standard deviation, interquartile range, and coefficient of variation) were analyzed alongside higher-order features via regression with heatmap visualization, and repeatable, robust, and calibratable features were identified.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Helical scans without tilt generally exhibited lower first-order dispersion than axial scans. Introducing a 5° tilt reduced dispersion in axial scans but had inconsistent effects in helical scans, with no coherent trend observed. Radiation dose demonstrated an expected inverse relationship with dispersion metrics. Intraclass correlation coefficient (ICC) analysis revealed that 34% of radiomic metrics exhibited good or excellent repeatability across all trials (ICC ≥ 0.6), but only 13% demonstrated good or excellent robustness, highlighting the sensitivity of radiomic metrics to scanning conditions. Regression analysis yielded 31 metrics (33%) that can be calibrated using their significant linear relationships with the parameters varied in this study, thereby allowing researchers to correct for variations in acquisition settings.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These findings underscore the importance of accounting for acquisition variability—including less frequently examined parameters such as tilt—when designing radiomic studies, selecting robust feat","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12800920/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145965969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Victor Malkov, Iymad R. Mansour, Vickie Kong, Winnie Li, Jennifer Dang, Parisa Sadeghi, Inmaculada Navarro, Jerusha Padayachee, Peter Chung, Jeff D. Winter, Tony Tadic
<div> <section> <h3> Background</h3> <p>MR-guided adaptive radiotherapy (ART) allows for daily plan optimization based on patient-specific anatomy. Accumulated doses, driven by deformable image registration (DIR), of daily fractions can provide cumulative dose metrics and insights into toxicity and tumor control. In prostate ART, inter- and intra-factional deformations, particularly due to bladder and rectum, pose a challenge to accurate DIR generation.</p> </section> <section> <h3> Purpose</h3> <p>To quantify geometric and dosimetric accuracy of a proposed prostate MR-to-MR DIR approach to support MR-guided ART dose accumulation.</p> </section> <section> <h3> Methods</h3> <p>We evaluated DIR accuracy in 25 patients treated with 30 Gy in five fractions on a 1.5 T MR-linac using an adaptive workflow. For all patients, a reference MR was used for planning, with three images collected at each fraction: adapt MR for adaptive planning, verify MR for pretreatment position verification and beam-on for capturing anatomy during radiation delivery. We assessed three DIR approaches: intensity-based, intensity-based with controlling structures (CS), and intensity-based with controlling structures and points of interest (CS + P). DIRs were performed between the reference and fraction images and within fractions (adapt-to-verify and adapt-to-beam-on). For the evaluation, we propagated CTV, bladder, and rectum contours using the DIRs and compared each to manually delineated contours using Dice similarity coefficient, mean distance to agreement, and dose–volume metrics.</p> </section> <section> <h3> Results</h3> <p>CS and CS + P improved geometric agreement between manual and propagated contours over intensity-only DIR. For example, mean distance to agreement (DTA<sub>mean</sub>) for reference-to-beam-on intensity-only DIR was 0.131 ± 0.009 cm (CTV), 0.46 ± 0.08 cm (bladder), and 0.154 ± 0.013 cm (rectum). For the CS, the DTA<sub>mean</sub> values were 0.018 ± 0.002, 0.388 ± 0.14, and 0.036 ± 0.013 cm. Finally, for CS + P, these values were 0.015 ± 0.001, 0.025 ± 0.004, and 0.021 ± 0.002 cm. Dosimetrically, comparing CS and CS + P for reference to beam-on DIRs resulted in a change of CTV D98% from [−29 cGy, 19 cGy] to [−18 cGy, 26 cGy], bladder D5cc from [−51 cGy, 544 cGy] to [−79 cGy, 36 cGy], and rectum D1cc from [−106 cGy, 72 cGy] to [−52 cGy, 74 cGy].</p> </section> <section> <h3> Conclusion</h3> <p>CS improved geometric and dosimetric accuracy over intensity-
{"title":"Evaluation of hybrid DIR performance using controlling structures and points of interest in MR-guided adaptive radiotherapy for prostate cancer patients","authors":"Victor Malkov, Iymad R. Mansour, Vickie Kong, Winnie Li, Jennifer Dang, Parisa Sadeghi, Inmaculada Navarro, Jerusha Padayachee, Peter Chung, Jeff D. Winter, Tony Tadic","doi":"10.1002/acm2.70437","DOIUrl":"10.1002/acm2.70437","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>MR-guided adaptive radiotherapy (ART) allows for daily plan optimization based on patient-specific anatomy. Accumulated doses, driven by deformable image registration (DIR), of daily fractions can provide cumulative dose metrics and insights into toxicity and tumor control. In prostate ART, inter- and intra-factional deformations, particularly due to bladder and rectum, pose a challenge to accurate DIR generation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To quantify geometric and dosimetric accuracy of a proposed prostate MR-to-MR DIR approach to support MR-guided ART dose accumulation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We evaluated DIR accuracy in 25 patients treated with 30 Gy in five fractions on a 1.5 T MR-linac using an adaptive workflow. For all patients, a reference MR was used for planning, with three images collected at each fraction: adapt MR for adaptive planning, verify MR for pretreatment position verification and beam-on for capturing anatomy during radiation delivery. We assessed three DIR approaches: intensity-based, intensity-based with controlling structures (CS), and intensity-based with controlling structures and points of interest (CS + P). DIRs were performed between the reference and fraction images and within fractions (adapt-to-verify and adapt-to-beam-on). For the evaluation, we propagated CTV, bladder, and rectum contours using the DIRs and compared each to manually delineated contours using Dice similarity coefficient, mean distance to agreement, and dose–volume metrics.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>CS and CS + P improved geometric agreement between manual and propagated contours over intensity-only DIR. For example, mean distance to agreement (DTA<sub>mean</sub>) for reference-to-beam-on intensity-only DIR was 0.131 ± 0.009 cm (CTV), 0.46 ± 0.08 cm (bladder), and 0.154 ± 0.013 cm (rectum). For the CS, the DTA<sub>mean</sub> values were 0.018 ± 0.002, 0.388 ± 0.14, and 0.036 ± 0.013 cm. Finally, for CS + P, these values were 0.015 ± 0.001, 0.025 ± 0.004, and 0.021 ± 0.002 cm. Dosimetrically, comparing CS and CS + P for reference to beam-on DIRs resulted in a change of CTV D98% from [−29 cGy, 19 cGy] to [−18 cGy, 26 cGy], bladder D5cc from [−51 cGy, 544 cGy] to [−79 cGy, 36 cGy], and rectum D1cc from [−106 cGy, 72 cGy] to [−52 cGy, 74 cGy].</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>CS improved geometric and dosimetric accuracy over intensity-","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12802555/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145965947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<div> <section> <h3> Background</h3> <p>Radiation protection in the operating room (OR) environment is a subject of much discussion in both the surgery and medical physics communities. Radiation exposure is often infrequent during image-guided procedures, especially when only 3D imaging for navigation is used. This is accompanied by unique personnel considerations, including staff that rotate in and out of the OR and staff that are scrubbed in and do not have the opportunity to easily don and doff radioprotective garments. These communities seek clear guidance about the magnitude of stray radiation dose in the OR environment. However, prior studies have reported conflicting data on the topic and have used different methods and instruments.</p> </section> <section> <h3> Purpose</h3> <p>To systematically measure the magnitude of stray radiation doses in a simulated OR environment in locations relevant to the placement of personnel during image-guided spine surgery and to make recommendations for radiation protection based on these data when using a mobile cone beam computed tomography (CBCT) system and a realistic anthropomorphic phantom on an actual spine surgery table.</p> </section> <section> <h3> Methods</h3> <p>Measurements of stray radiation dose were performed in a grid pattern in a simulated OR environment using pressurized ionization chamber survey meters and two configurations of a tissue-mimicking anthropomorphic phantom, large (L) and extra-large (XL). The phantom was imaged using “navigation” mode (i.e., CBCT) with standard and high definition (HD) protocols. Stray radiation dose was measured at heights corresponding to chest level (125 cm) and eye level (175 cm) of a typical operator and additional heights of 100 and 150 cm.</p> </section> <section> <h3> Results</h3> <p>The absolute per scan whole body dose in the shadow of the gantry console 2 m from isocenter at a height of 125 cm (chest level) was 1.26 µSv for an equal mix of L and XL patients, and at a height of 175 cm (eye lens level) the air kerma was 9.22 µGy. The dose at 2 m from isocenter on the head side of the patient at a height of 125 cm was 7.93 µSv and air kerma at a height of 175 cm was 14.7 µGy. Doses at the same distance from isocenter and same heights on the side of the gantry opposite the console were 13.5 µSv and 15.0 µGy.</p> </section> <section> <h3> Conclusions</h3> <p>Stray radiation doses were lowest in the shadow of the gantry console and were higher at a heig
{"title":"Evaluation of the stray radiation distribution around a mobile cone beam computed tomography system in a simulated operating room environment","authors":"A. Kyle Jones","doi":"10.1002/acm2.70434","DOIUrl":"10.1002/acm2.70434","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Radiation protection in the operating room (OR) environment is a subject of much discussion in both the surgery and medical physics communities. Radiation exposure is often infrequent during image-guided procedures, especially when only 3D imaging for navigation is used. This is accompanied by unique personnel considerations, including staff that rotate in and out of the OR and staff that are scrubbed in and do not have the opportunity to easily don and doff radioprotective garments. These communities seek clear guidance about the magnitude of stray radiation dose in the OR environment. However, prior studies have reported conflicting data on the topic and have used different methods and instruments.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To systematically measure the magnitude of stray radiation doses in a simulated OR environment in locations relevant to the placement of personnel during image-guided spine surgery and to make recommendations for radiation protection based on these data when using a mobile cone beam computed tomography (CBCT) system and a realistic anthropomorphic phantom on an actual spine surgery table.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Measurements of stray radiation dose were performed in a grid pattern in a simulated OR environment using pressurized ionization chamber survey meters and two configurations of a tissue-mimicking anthropomorphic phantom, large (L) and extra-large (XL). The phantom was imaged using “navigation” mode (i.e., CBCT) with standard and high definition (HD) protocols. Stray radiation dose was measured at heights corresponding to chest level (125 cm) and eye level (175 cm) of a typical operator and additional heights of 100 and 150 cm.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The absolute per scan whole body dose in the shadow of the gantry console 2 m from isocenter at a height of 125 cm (chest level) was 1.26 µSv for an equal mix of L and XL patients, and at a height of 175 cm (eye lens level) the air kerma was 9.22 µGy. The dose at 2 m from isocenter on the head side of the patient at a height of 125 cm was 7.93 µSv and air kerma at a height of 175 cm was 14.7 µGy. Doses at the same distance from isocenter and same heights on the side of the gantry opposite the console were 13.5 µSv and 15.0 µGy.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Stray radiation doses were lowest in the shadow of the gantry console and were higher at a heig","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12796718/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145959490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Colin J. Schaeffer, Katie W. Hulme, Ashley E. Rubinstein
Background
Digital breast tomosynthesis (DBT) has become standard practice; however, the acquisition method of DBT between vendors is far from standardized. Currently, there are three commercially available DBT tube motion techniques: (1) continuous motion, (2) step-and-shoot, and (3) continuous motion with flying focal spot. Each of these methods represents a trade-off between total acquisition time and focal spot blur.
Purpose
The aim of the study was to characterize the increase in effective focal spot size in DBT relative to standard 2D projections and assess the influence of this increase on spatial resolution using the modulation transfer function (MTF).
Methods
Focal spot size was measured for both a 2D acquisition and the 0° DBT projection using a 10 µm slit phantom. Imaging techniques were set to those used for a 2, 4, and 8 cm thick breast of 50/50 adipose/fat composition. MTF curves were measured using a copper edge phantom both at the breast support plane and 4 cm above the breast support.
Results
The effective focal spot size increase from 2D to DBT increased with breast thickness for all systems. The continuous motion systems showed the greatest increase in effective focal spot size with percent increases of 101% to 462% depending on unit and breast thickness. The flying focal spot system showed the smallest increase in effective focal spot size in DBT acquisitions, being 3%, 21%, and 25% for a 2, 4, and 8 cm thick breast, respectively. The step-and-shoot and flying focal spot systems showed no degradation in MTF curves due to increasing effective focal spot size in DBT acquisitions, while the continuous motion systems showed a reduction in the frequency at which the MTF curve reached 50% of 26%–45%.
Conclusion
Both step-and-shoot and flying focal spot systems minimized effective focal spot size increase in DBT acquisitions compared to continuous tube motion systems.
{"title":"Focal spot motion in digital breast tomosynthesis and its effect on spatial resolution","authors":"Colin J. Schaeffer, Katie W. Hulme, Ashley E. Rubinstein","doi":"10.1002/acm2.70443","DOIUrl":"10.1002/acm2.70443","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Digital breast tomosynthesis (DBT) has become standard practice; however, the acquisition method of DBT between vendors is far from standardized. Currently, there are three commercially available DBT tube motion techniques: (1) continuous motion, (2) step-and-shoot, and (3) continuous motion with flying focal spot. Each of these methods represents a trade-off between total acquisition time and focal spot blur.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>The aim of the study was to characterize the increase in effective focal spot size in DBT relative to standard 2D projections and assess the influence of this increase on spatial resolution using the modulation transfer function (MTF).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Focal spot size was measured for both a 2D acquisition and the 0° DBT projection using a 10 µm slit phantom. Imaging techniques were set to those used for a 2, 4, and 8 cm thick breast of 50/50 adipose/fat composition. MTF curves were measured using a copper edge phantom both at the breast support plane and 4 cm above the breast support.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The effective focal spot size increase from 2D to DBT increased with breast thickness for all systems. The continuous motion systems showed the greatest increase in effective focal spot size with percent increases of 101% to 462% depending on unit and breast thickness. The flying focal spot system showed the smallest increase in effective focal spot size in DBT acquisitions, being 3%, 21%, and 25% for a 2, 4, and 8 cm thick breast, respectively. The step-and-shoot and flying focal spot systems showed no degradation in MTF curves due to increasing effective focal spot size in DBT acquisitions, while the continuous motion systems showed a reduction in the frequency at which the MTF curve reached 50% of 26%–45%.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Both step-and-shoot and flying focal spot systems minimized effective focal spot size increase in DBT acquisitions compared to continuous tube motion systems.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12788966/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145944034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carlos Ferrer, Concepción Huertas, Marcos Feijoo, Alessandro Cardin, Moisés Sáez
Background
Plastic scintillation detectors (PSD) are widely used for detecting and measuring ionizing radiation. These detectors are versatile, with high efficiency, fast response and the ability to provide real-time measurements.
Purpose
Evaluate the suitability of Blue Physics PSD (BP-PSD) for performing ultra-fast dosimetric commissioning measurements with high accuracy and precision in a very short time.
Methods
Ultra-fast measurements were performed in water using a BP-PSD on an Elekta Unity MR-linac. Percentage depth doses (PDD) and profiles at different depths were measured at two movement velocities, 10 mm/s and 20 mm/s, for field sizes ranging from 10 × 10 cm2 to 1 × 1 cm2. Gamma analysis was conducted to compare these measurements with those obtained during machine commissioning using a PTW Semiflex 3D ionization chamber (for PDD) and a PTW micro-Diamond detector (for PDD and profiles). Gamma criteria of 2%/2 mm and 1%/1 mm dose difference/distance to agreement were studied, alongside field size, penumbra, and measurement time.
Results
All PDD and profile gamma passing rates were 100% at 2%/2 mm. At the stricter 1%/1 mm criteria, all PDD showed a passing rate above 96.97% for both velocities, with most of the profiles exceeding 95% at 10 mm/s and 90% at 20 mm/s. Gamma analysis results were superior for smaller fields (1 × 1 cm2 and 2 × 2 cm2) and generally better at 10 mm/s. On average, the penumbra measurements obtained with the PSD were greater than those achieved with the micro-Diamond detector. Measurement times were found to be between 7 and 14 times shorter for PDD, and between 5 and 9 times shorter for profiles at speeds of 10 mm/s and 20 mm/s, respectively.
Conclusions
Ultra-fast measurements using the Blue Physics PSD are suitable for acquiring dosimetric commissioning data with high accuracy and precision, and can be performed in a much shorter timeframe than with commonly used detectors.
{"title":"Ultra-fast dosimetric data collection with a commercial plastic scintillation detector in an MR-linac","authors":"Carlos Ferrer, Concepción Huertas, Marcos Feijoo, Alessandro Cardin, Moisés Sáez","doi":"10.1002/acm2.70460","DOIUrl":"10.1002/acm2.70460","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Plastic scintillation detectors (PSD) are widely used for detecting and measuring ionizing radiation. These detectors are versatile, with high efficiency, fast response and the ability to provide real-time measurements.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Evaluate the suitability of Blue Physics PSD (BP-PSD) for performing ultra-fast dosimetric commissioning measurements with high accuracy and precision in a very short time.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Ultra-fast measurements were performed in water using a BP-PSD on an Elekta Unity MR-linac. Percentage depth doses (PDD) and profiles at different depths were measured at two movement velocities, 10 mm/s and 20 mm/s, for field sizes ranging from 10 × 10 cm<sup>2</sup> to 1 × 1 cm<sup>2</sup>. Gamma analysis was conducted to compare these measurements with those obtained during machine commissioning using a PTW Semiflex 3D ionization chamber (for PDD) and a PTW micro-Diamond detector (for PDD and profiles). Gamma criteria of 2%/2 mm and 1%/1 mm dose difference/distance to agreement were studied, alongside field size, penumbra, and measurement time.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>All PDD and profile gamma passing rates were 100% at 2%/2 mm. At the stricter 1%/1 mm criteria, all PDD showed a passing rate above 96.97% for both velocities, with most of the profiles exceeding 95% at 10 mm/s and 90% at 20 mm/s. Gamma analysis results were superior for smaller fields (1 × 1 cm<sup>2</sup> and 2 × 2 cm<sup>2</sup>) and generally better at 10 mm/s. On average, the penumbra measurements obtained with the PSD were greater than those achieved with the micro-Diamond detector. Measurement times were found to be between 7 and 14 times shorter for PDD, and between 5 and 9 times shorter for profiles at speeds of 10 mm/s and 20 mm/s, respectively.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Ultra-fast measurements using the Blue Physics PSD are suitable for acquiring dosimetric commissioning data with high accuracy and precision, and can be performed in a much shorter timeframe than with commonly used detectors.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12779937/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145917694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christopher M. Walker, Maria G. Maldonado, Megan C. Jacobsen, Suprateek Kundu, Michelle L. Underwood, Joshua P. Yung, Brandy J. Reed, David Jaffray, R. Jason Stafford, Marshall E. Hicks, Caroline Chung, Aradhana M. Venkatesan
Background
As medical imaging demand grows, there is increasing stress on the currently available workforce to deliver consistent, high-quality imaging studies while ensuring rapid study turnaround times and round-the-clock radiology coverage. Advances in remote access technology facilitating remote scan assistance and control are now commercially available to address these pressing clinical needs.
Methods
This work evaluated an early clinical application of a virtual scanner operations system (syngo Virtual Cockpit (VA13A, Siemens Healthineers, Erlangen, Germany) for remote magnetic resonance imaging (MRI) monitoring and scan control at three geographically distant outpatient sites associated with our primary institution.
Results
The system facilitated execution of technically complex oncologic MRI exams at these geographically distant clinics with no measurable impact on acquisition time compared to MR imaging performed at our primary hospital location. Additional operational improvements were realized with the use of the system, including remote staff training, technical assistance, and scanning during staff shortages. This early iteration of remote scanning had some limitations including limited utility for additional assistance in the scanning of those protocols that require complex physical setup. Moreover, connectivity issues were noted to be a limiting factor that contributed to operational delays. It was still necessary to have an onsite MRI technologist at the scanner console to interface with the patient and ensure safe operation.
Conclusion
Despite these limitations, our initial experience demonstrates that the use of remote MRI scanning support facilitates staffing flexibility while providing expanded patient access to oncology MRI services.
{"title":"Initial experience with remote MRI scanning support in an oncology focused practice: Opportunities for expanded access to radiology care","authors":"Christopher M. Walker, Maria G. Maldonado, Megan C. Jacobsen, Suprateek Kundu, Michelle L. Underwood, Joshua P. Yung, Brandy J. Reed, David Jaffray, R. Jason Stafford, Marshall E. Hicks, Caroline Chung, Aradhana M. Venkatesan","doi":"10.1002/acm2.70461","DOIUrl":"10.1002/acm2.70461","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>As medical imaging demand grows, there is increasing stress on the currently available workforce to deliver consistent, high-quality imaging studies while ensuring rapid study turnaround times and round-the-clock radiology coverage. Advances in remote access technology facilitating remote scan assistance and control are now commercially available to address these pressing clinical needs.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This work evaluated an early clinical application of a virtual scanner operations system (syngo Virtual Cockpit (VA13A, Siemens Healthineers, Erlangen, Germany) for remote magnetic resonance imaging (MRI) monitoring and scan control at three geographically distant outpatient sites associated with our primary institution.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The system facilitated execution of technically complex oncologic MRI exams at these geographically distant clinics with no measurable impact on acquisition time compared to MR imaging performed at our primary hospital location. Additional operational improvements were realized with the use of the system, including remote staff training, technical assistance, and scanning during staff shortages. This early iteration of remote scanning had some limitations including limited utility for additional assistance in the scanning of those protocols that require complex physical setup. Moreover, connectivity issues were noted to be a limiting factor that contributed to operational delays. It was still necessary to have an onsite MRI technologist at the scanner console to interface with the patient and ensure safe operation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Despite these limitations, our initial experience demonstrates that the use of remote MRI scanning support facilitates staffing flexibility while providing expanded patient access to oncology MRI services.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12779931/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145917682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aimed to establish a framework for optimizing planning target volume (PTV) margins in liver SBRT using virtual 4DCT (v4DCT), by introducing the concept of the Dosimetric Coverage Amplitude (DCA) to quantify motion tolerance and deriving an Optimal Margin (OM) that balances tumor coverage with normal-tissue sparing.
Methods
VMAT plans were developed using a whole-body phantom with a virtual tumor, ensuring that the prescription dose corresponded to D95% of the PTV. The 60%–80% isodose levels were defined relative to the maximum dose to represent alternative prescription surfaces. v4DCT simulated free-breathing conditions across 10 respiratory phases to generate virtual four-dimensional radiotherapy (v4DRT) dose distributions. The DCA was defined as the maximum respiratory amplitude at which GTV dose coverage (D100% or D99%) was maintained. Based on DCA analysis, the OM was determined as the clinically applicable margin derived from the isodose plan that satisfied the DCA condition and minimized normal tissue dose.
Results
DCA analysis revealed that GTV dose coverage was maintained for respiratory motion amplitudes up to 1.9–2.2 times larger than the conventional PTV margin of 10 mm. Taking into account GTV dose coverage, average GTV dose relative to the 80%-static reference, and normal-tissue dose, the 60% isodose plan was identified as the optimal prescription level. From this plan, the OM was calculated as 5.6 mm, representing a 44% reduction compared with the conventional 10-mm PTV, while maintaining GTV coverage and minimizing liver dose. This margin reduction was attributed to the steeper dose gradient associated with prescribing to a lower isodose level. The v4DCT approach enabled the generation of multiple respiratory phase images, allowing quantitative evaluation of motion-induced dose distribution and optimization of margins based on respiratory variability.
Conclusion
The proposed v4DCT-based framework demonstrated that the 60% isodose plan provided the optimal balance between tumor coverage and normal-tissue sparing, yielding an OM of 5.6 mm (44% reduction compared with the conventional 10-mm PTV). This approach offers a clinically applicable strategy for margin reduction in liver SBRT while maintaining robust dosimetric coverage.
目的：本研究旨在通过引入剂量覆盖幅度（DCA）的概念来量化运动耐受性，并得出平衡肿瘤覆盖与正常组织保留的最佳边界（OM），建立一个使用虚拟4DCT （v4DCT）优化肝脏SBRT规划靶体积（PTV）边界的框架。方法：采用带虚拟肿瘤的全身假体制定VMAT计划，确保处方剂量符合PTV的D95%。60%-80%等剂量水平被定义为相对于最大剂量来代表可选择的处方表面。v4DCT模拟10个呼吸期的自由呼吸条件，生成虚拟四维放疗（v4DRT）剂量分布。DCA定义为维持GTV剂量覆盖（D100%或D99%）时的最大呼吸振幅。根据DCA分析，确定OM为满足DCA条件和最小正常组织剂量的等剂量方案得出的临床适用边界。结果：DCA分析显示，GTV对呼吸运动幅度的剂量覆盖范围比常规PTV的10 mm大1.9-2.2倍。综合考虑GTV剂量覆盖率、相对于80%静态参考的平均GTV剂量和正常组织剂量，确定60%等剂量计划为最佳处方水平。根据该方案，OM计算为5.6 mm，与传统的10 mm PTV相比减少了44%，同时保持GTV覆盖范围并使肝脏剂量最小化。这种边际减少归因于与较低等剂量水平处方相关的更陡峭的剂量梯度。v4DCT方法能够生成多个呼吸期图像，允许定量评估运动引起的剂量分布和基于呼吸变异性的边缘优化。结论：提出的基于v4dct的框架表明，60%等剂量计划提供了肿瘤覆盖和正常组织保留之间的最佳平衡，产生5.6 mm的OM（与传统的10 mm PTV相比减少44%）。该方法提供了一种临床适用的策略，可以在保持稳健剂量覆盖的同时减少肝脏SBRT的边缘。
{"title":"Margin reduction and optimal prescription isodose model for liver stereotactic radiotherapy with respiratory motion","authors":"Daisuke Kawahara, Hirokazu Masuda, Takuya Wada, Misato Kishi, Tsuyoshi Katsuta, Yuji Murakami","doi":"10.1002/acm2.70455","DOIUrl":"10.1002/acm2.70455","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>This study aimed to establish a framework for optimizing planning target volume (PTV) margins in liver SBRT using virtual 4DCT (v4DCT), by introducing the concept of the Dosimetric Coverage Amplitude (DCA) to quantify motion tolerance and deriving an Optimal Margin (OM) that balances tumor coverage with normal-tissue sparing.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>VMAT plans were developed using a whole-body phantom with a virtual tumor, ensuring that the prescription dose corresponded to D<sub>95%</sub> of the PTV. The 60%–80% isodose levels were defined relative to the maximum dose to represent alternative prescription surfaces. v4DCT simulated free-breathing conditions across 10 respiratory phases to generate virtual four-dimensional radiotherapy (v4DRT) dose distributions. The DCA was defined as the maximum respiratory amplitude at which GTV dose coverage (D100% or D99%) was maintained. Based on DCA analysis, the OM was determined as the clinically applicable margin derived from the isodose plan that satisfied the DCA condition and minimized normal tissue dose.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>DCA analysis revealed that GTV dose coverage was maintained for respiratory motion amplitudes up to 1.9–2.2 times larger than the conventional PTV margin of 10 mm. Taking into account GTV dose coverage, average GTV dose relative to the 80%-static reference, and normal-tissue dose, the 60% isodose plan was identified as the optimal prescription level. From this plan, the OM was calculated as 5.6 mm, representing a 44% reduction compared with the conventional 10-mm PTV, while maintaining GTV coverage and minimizing liver dose. This margin reduction was attributed to the steeper dose gradient associated with prescribing to a lower isodose level. The v4DCT approach enabled the generation of multiple respiratory phase images, allowing quantitative evaluation of motion-induced dose distribution and optimization of margins based on respiratory variability.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The proposed v4DCT-based framework demonstrated that the 60% isodose plan provided the optimal balance between tumor coverage and normal-tissue sparing, yielding an OM of 5.6 mm (44% reduction compared with the conventional 10-mm PTV). This approach offers a clinically applicable strategy for margin reduction in liver SBRT while maintaining robust dosimetric coverage.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12779934/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145917653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenchao Gao, Min Zhang, Shuchao Zhang, Jie Qi, Xin Wang, Liang Zhao, Ping Liu, Zhijun Yang, HongXiang Cheng
<div> <section> <h3> Background</h3> <p>Accurate dose calculations in radiotherapy depend on high-quality beam models in the Monaco treatment planning system (TPS). The accelerated go live (AGL) workflow, using a golden beam data (GBD) model, has improved beam modeling accuracy for various linear accelerators (linacs). However, similar studies specifically for the Harmony Pro, recently introduced for online adaptive radiotherapy, have not yet been reported internationally. Moreover, studies on dosimetric differences between TPS beam models with GBD and those with measured beam data (MBD) are limited, and no such studies have been published specifically for Elekta linacs.</p> </section> <section> <h3> Purpose</h3> <p>This study aimed to assess the clinical performance of GBD in the Monaco TPS for the harmony pro and infinity linacs.</p> </section> <section> <h3> Methods</h3> <p>Beam tuning and data collection were performed on the harmony pro and infinity linacs based on GBD. Subsequently, percentage depth doses (PDDs), off-axis dose profiles, output factors (OFs), absolute doses, and test fields were measured to evaluate the GBD model. Additionally, 31 clinical plans from multiple anatomical sites, including 17 conventional fractionated radiotherapy (CFRT) plans and 14 stereotactic body radiotherapy (SBRT) plans, were designed using the Monaco TPS (GBD model) and practically tested. An Infinity linac with MBD was introduced as a control.</p> </section> <section> <h3> Results</h3> <p>PDDs and profiles on both GBD linacs showed 100% passing rate (2%/2 mm). OFs and absolute doses on both GBD linacs agreed within ±1% and ±1.5%, respectively. Additionally, verification of the test fields yielded passing rates above 98% (2%/2 mm) for both GBD linacs. Furthermore, for CFRT plans, measurements on three linacs achieved a passing rate above 95% (3%/2 mm). The absolute dose deviations were within 3%, whereas one MBD linac case exceeded 3% (-3.73%). For SBRT plans, the gamma passing rates were 98.18 ± 1.58%, 98.76 ± 1.54%, and 94.72 ± 0.04% (3%/2 mm) and 96.69 ± 1.96, 96.29 ± 2.26, and 89.51 ± 0.06% (2%/2 mm), for the two GDB linacs and the MDB linac, respectively. The absolute dose deviations were within 3%, whereas two MBD linac cases exceeded 3% (−3.51%, −4.50%).</p> </section> <section> <h3> Conclusions</h3> <p>The harmony pro-GBD and infinity-GBD linac results demonstrated strong agreement with GBD. Clinical plans designed with Monaco TPS (GBD model) were
{"title":"Clinical evaluation of the golden beam data in the monaco treatment planning system for the harmony pro and infinity linear accelerators","authors":"Wenchao Gao, Min Zhang, Shuchao Zhang, Jie Qi, Xin Wang, Liang Zhao, Ping Liu, Zhijun Yang, HongXiang Cheng","doi":"10.1002/acm2.70457","DOIUrl":"10.1002/acm2.70457","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Accurate dose calculations in radiotherapy depend on high-quality beam models in the Monaco treatment planning system (TPS). The accelerated go live (AGL) workflow, using a golden beam data (GBD) model, has improved beam modeling accuracy for various linear accelerators (linacs). However, similar studies specifically for the Harmony Pro, recently introduced for online adaptive radiotherapy, have not yet been reported internationally. Moreover, studies on dosimetric differences between TPS beam models with GBD and those with measured beam data (MBD) are limited, and no such studies have been published specifically for Elekta linacs.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>This study aimed to assess the clinical performance of GBD in the Monaco TPS for the harmony pro and infinity linacs.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Beam tuning and data collection were performed on the harmony pro and infinity linacs based on GBD. Subsequently, percentage depth doses (PDDs), off-axis dose profiles, output factors (OFs), absolute doses, and test fields were measured to evaluate the GBD model. Additionally, 31 clinical plans from multiple anatomical sites, including 17 conventional fractionated radiotherapy (CFRT) plans and 14 stereotactic body radiotherapy (SBRT) plans, were designed using the Monaco TPS (GBD model) and practically tested. An Infinity linac with MBD was introduced as a control.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>PDDs and profiles on both GBD linacs showed 100% passing rate (2%/2 mm). OFs and absolute doses on both GBD linacs agreed within ±1% and ±1.5%, respectively. Additionally, verification of the test fields yielded passing rates above 98% (2%/2 mm) for both GBD linacs. Furthermore, for CFRT plans, measurements on three linacs achieved a passing rate above 95% (3%/2 mm). The absolute dose deviations were within 3%, whereas one MBD linac case exceeded 3% (-3.73%). For SBRT plans, the gamma passing rates were 98.18 ± 1.58%, 98.76 ± 1.54%, and 94.72 ± 0.04% (3%/2 mm) and 96.69 ± 1.96, 96.29 ± 2.26, and 89.51 ± 0.06% (2%/2 mm), for the two GDB linacs and the MDB linac, respectively. The absolute dose deviations were within 3%, whereas two MBD linac cases exceeded 3% (−3.51%, −4.50%).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The harmony pro-GBD and infinity-GBD linac results demonstrated strong agreement with GBD. Clinical plans designed with Monaco TPS (GBD model) were","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12766699/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145900539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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