Journal of Applied Clinical Medical Physics最新文献

{"title":"Expert panel on monitoring radiation doses from recurrent medical diagnostic procedures: Sixth Gilbert W. Beebe Webinar","authors":"Donald P. Frush,&nbsp;Armin Ansari,&nbsp;James A. Brink,&nbsp;Ourania Kosti,&nbsp;David B. Larson,&nbsp;Martha S. Linet,&nbsp;Mahadevappa Mahesh,&nbsp;Ioannis Sechopoulos,&nbsp;Jenia Vassileva","doi":"10.1002/acm2.70022","DOIUrl":"10.1002/acm2.70022","url":null,"abstract":"<p>Recurrent imaging is an essential tool for patient care but with an attendant dose from radiation exposure. Recurrent imaging has been the subject of increasing scrutiny and debate based largely on the risk from increasing cumulative doses. However, the accountability for and actions with recurrent imaging as a special component in the general construct of radiation protection in medicine is unclear. This is demonstrated by the perspectives provided by the various imaging community experts. Some perspectives may be different, but many share a common ground. Understanding these various perspectives illustrates the wide-ranging optics in considering benefits and costs in the recurrent imaging paradigm and, moreover, the value in pursuing multi-stakeholder-derived harmonization for recurrent imaging and radiation dose. This move towards consensus would be to the benefit of the imaging community, referrers, and other related healthcare professionals, as well as patients, their caregivers, and the public.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143515838","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}

{"title":"Impact of bulk density assignment of bone on MRI-based abdominal region radiotherapy planning for MR-linac workflow","authors":"Kota Abe,&nbsp;Masato Tsuneda,&nbsp;Yukio Fujita,&nbsp;Yukinao Abe,&nbsp;Takashi Uno","doi":"10.1002/acm2.70059","DOIUrl":"10.1002/acm2.70059","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>The purpose of the present study was to evaluate the impact of bone relative electron density (rED) assignment on radiotherapy planning for the abdominal region.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Twenty patients who received abdominal radiotherapy using MR-Linac and underwent magnetic resonance imaging (MRI) and computed tomography (CT) simulation were analyzed. The reference plan (RP) was established using both CT and MR image sets (RP_CT and RP_MRI). The RP_MRI utilized the bulk density method. The recalculated RPs derived from various rED assignment methods were evaluated for comparison on both datasets. The RPs were recalculated by excluding rED assignment for bones (scenario A). Based on the International Commission on Radiation Units and Measurements report, lung contours were assigned rED of 0.258, and body contours were assigned 1.000 (scenario B) and 1.019 (scenario C). Dose volume histogram (DVH) differences between the three recalculated scenarios and RPs were evaluated. D95, D99, and D1cc were evaluated for target volumes, including gross tumor volume, internal target volume, and planning target volume. DVH parameters, including D1cc for each abdominal organ at risk (OAR) and the mean dose to the liver and kidneys, were evaluated. Three-dimensional local gamma analysis was conducted to assess dose distribution differences between the three recalculated scenarios and RPs.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>In all scenarios of the CT- and MRI-based validation, the average gamma pass rates (2%/2 mm) were higher than 95%. In the CT-based validation, all target DVHs across the 20 patients showed that none exceeded 2% error in scenario A, whereas 2% and 14% exceeded the threshold in scenarios B and C, respectively. For OARs in CT and MRI-based validation, absolute maximum dose differences when compared with those of the RP were 0.19 Gy and 0.22 Gy, respectively, in scenario A.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Excluding bone rED considerations in abdominal treatment planning may not yield notable clinical differences.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70059","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501460","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}

{"title":"Effects of cardiac motion on dose distribution during stereotactic arrhythmia radioablation treatment: A simulation and phantom study","authors":"Takayuki Miyachi,&nbsp;Takeshi Kamomae,&nbsp;Fumitaka Kawabata,&nbsp;Kuniyasu Okudaira,&nbsp;Mariko Kawamura,&nbsp;Shunichi Ishihara,&nbsp;Shinji Naganawa","doi":"10.1002/acm2.70021","DOIUrl":"10.1002/acm2.70021","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Cardiac motion may degrade dose distribution during stereotactic arrhythmia radioablation using the CyberKnife system, a robotic radiosurgery system. This study evaluated the dose distribution changes using a self-made cardiac dynamic platform that mimics cardiac motion.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The cardiac dynamic platform was operated with amplitudes of 5 and 3.5 mm along the superior–inferior (SI) and left–right (LR) directions, respectively. The respiratory motion tracking of the CyberKnife system was applied when respiratory motion, simulated using a commercial platform, was introduced. The accuracy of respiratory motion tracking was evaluated by the correlation error between infrared markers and a fiducial marker. The dose distribution was compared with and without cardiac motion. The evaluations included error in the centroid analysis of the irradiated dose distribution, dose profile analysis in the SI and LR directions, and dose distribution analysis comparing the irradiated and planned dose distributions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Cardiac motion increased the correlation error in the direction of motion. Cardiac motion displaced the centroid by up to 0.23 and 0.19 mm in the SI and LR directions, respectively. Cardiac motion blurring caused the distance of the isodose lines to become smaller (bigger) at higher (lower) doses in the SI direction. The gamma pass rate was reduced by cardiac motion but exceeded 94.1% with 1 mm/3% for all conditions. Respiratory motion tracking was also effective under cardiac motion. The cardiac motion slightly varied the dose at the edges of the irradiation volume.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>While cardiac motion increased respiratory tracking correlation errors, its effects on dose distribution were limited in this study. Further studies using motion phantoms that are close to a human or individual patient are necessary for a more detailed understanding of the effects of cardiac motion.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 5","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143492118","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}

{"title":"Measurement of stopping power ratio of chemo-ports using energy spectrum extracted from integral depth dose","authors":"Rosette Gonzalez,&nbsp;Stephen Olis,&nbsp;Sina Mossahebi,&nbsp;Weiguang Yao","doi":"10.1002/acm2.70052","DOIUrl":"10.1002/acm2.70052","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>In proton radiotherapy, the stopping power ratio (SPR) of non-biological materials must be independently measured with proton beams for accurate dose calculation. Small-size chemo-ports challenge the measurement. The purpose of this work is to measure the SPR of chemo-ports by using the energy spectra of the proton pencil beams.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods and materials</h3>\u0000 \u0000 <p>Chemo-ports used in this study were irradiated in both lateral and vertical directions by 100-, 160-, and 200-MeV monoenergetic proton pencil beamlets. The integrated depth doses (IDDs) were acquired using a multi-layer ion chamber (MLIC), with and without the chemo port in front of the MLIC. The energy spectrum (ES) of the IDD was extracted. The water equivalent thickness (WET) of the chemo-port was determined from the shift in corresponding peaks in the spectra. To reduce the effect of spot size and its Gaussian distribution on the measurement, the measurements were repeated with a lead collimator (5 mm circular opening) in front of the chemo-ports. Additionally, the WET values were also obtained by a conventional approach that calculated the shift of the peaks in the IDDs rather than in the energy spectra.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The complex internal structure of the chemo-port was reflected in multiple peaks in the ES. The measured WET values from different energy beamlets agreed within 0.5 mm (4.6%) of each other using the ES method, while agreement up to 1 mm was observed from the traditional approach. When the collimator was used, the agreement was decreased to within 1.1 and 8 mm from the ES method and conventional approach, respectively.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Proton SPRs of chemo ports can be successfully measured using the ES method. Better agreement of the measured WET values from different energy pencil beams was obtained from the ES method than from a conventional approach. The use of a collimator can decrease accuracy.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70052","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143500811","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}

{"title":"Evaluating artifact-free four-dimensional computer tomography with 16 cm detector array","authors":"Inhwan Yeo,&nbsp;Wei Nie,&nbsp;Jiajin Fan,&nbsp;Mindy Joo,&nbsp;Michael Correa,&nbsp;Qianyi Xu","doi":"10.1002/acm2.70056","DOIUrl":"10.1002/acm2.70056","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To evaluate a 16 cm-array axial four-dimensional computer tomography (4DCT) in comparison with a 4 cm-array 4DCT in the presence of respiration irregularity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Method</h3>\u0000 \u0000 <p>Ten traces of lung tumor motion from CyberKnife treatments were imported to move the lung cylinder, containing a spherical target, of a phantom. Images were acquired for the lung that moved to each of the 10-positions/phases (1) step-wisely by nominal helical scan at each movement (ground truth), (2) continuously by 4D scan with the 16 cm array, and (3) the same with the 4 cm array, involving table shift. Irregularities, consisting of baseline shift and/or amplitude change of the traces in their second periods, affected #3 scan only in its second table position. The full-widths at half maximum of the target in the direction of the motion were determined on the average (Ave) CT, maximum-intensity (Mip) CT, and a phase (MP) CT that is associated with the maximum error, comparing #2 and 3 with #1. Three tumor-shaped targets were also imaged, and overlap ratios of them from #2 and 3 with the targets from #1 were inter-compared. Hounsfield unit (HU)s of the targets were also compared.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The average difference in the spherical-target length between #2 and #1 was found to be 0.28 ± 0.15 cm on AveCT, 0.00 ± 0.18 cm on MipCT, and 0.07 ± 0.06 cm on MPCT, showing agreement. The average difference between #3 and #1 was 0.34 ± 0.23 cm on AveCT, 0.48 ± 0.31 cm on MipCT, and 0.56 ± 0.50 cm on MPCT, showing disagreement. The overlap ratios were better with #2 than with #3 for all tumor-shaped targets in each phase CT and MipCT, but they were not perfect for #2 due to motion averaging and phase sorting limitations. The differences in HUs were smaller with #2 than with #3, but not fully satisfactory with #2.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>4DCT with the 16 cm array needs to be used to minimize the impact of the irregularity.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70056","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143483260","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}

{"title":"Exploring surface-guided systems for intelligent breathing-adapted four-dimensional computed tomography: A comparison to infrared-based reflective marker systems","authors":"Niklas Lackner,&nbsp;Andre Karius,&nbsp;Rainer Fietkau,&nbsp;Christoph Bert,&nbsp;Juliane Szkitsak","doi":"10.1002/acm2.70054","DOIUrl":"10.1002/acm2.70054","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>This study evaluates the technical feasibility of adapting a surface monitoring system, designed for conventional four-dimensional computed tomography (4DCT), to an intelligent, breathing-adapted 4DCT and examines its potential to expand the currently limited range of supported surrogate systems.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In an experimental phantom setting, we compared breathing curve quality and its impact on breathing-adapted 4DCT generation between a surface monitoring camera and our clinical infrared (IR) system, using a research-grade IR camera coupled with a radiation detector as an independent reference. Breathing curves from the surface monitoring system and the research-grade camera were corrected for table motion. We assessed the influence of differences in breathing curves on the automatic selection of parameters before scanning, intelligent X-ray triggering during acquisition, and the differences of binning point selection for reconstruction as well as image quality. Additionally, we simulated the impact of latency on image quality and measured the observed latencies between the surrogate systems relative to an X-ray measurement.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>During table movement, discrepancies were found in breathing signals from the surface monitoring system compared to the clinical and reference systems. After correcting for table motion, the surface monitoring system's curves aligned consistently with those of the other systems with amplitude (AMP) variations of less than 10% and breathing rate (BR) variations of less than 1%. Corrected curves showed improved performance in their ability to generate breathing-adapted 4DCTs. The clinical IR system showed a 45 ms latency advantage over the surface monitoring system, impacting image quality as simulated.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>After correcting surface monitoring breathing curves, satisfactory agreement with the clinical and independent reference systems was achieved. With modifications, the surface monitor solution could serve as a suitable surrogate for breathing-adapted 4DCT. In our experimental setting, the surface monitoring system had a 45 ms delay relative to the clinical system, potentially affecting image quality.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 5","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70054","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143483261","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}

{"title":"Characterization, commissioning, and clinical evaluation of a commercial BeO optically stimulated luminescence (OSL) system","authors":"Joseph P. Kowalski,&nbsp;Brett G. Erickson,&nbsp;Qiuwen Wu,&nbsp;Xinyi Li,&nbsp;Sua Yoo","doi":"10.1002/acm2.70057","DOIUrl":"10.1002/acm2.70057","url":null,"abstract":"<p>This article investigates the performance of a commercial BeO optically stimulated luminescent (OSL) dosimetry system (myOSLchip, RadPro GmbH International, Remscheid, Germany) through the application of the commissioning framework for luminescent dosimeters as described in the American Association of Physicists in Medicine Task Group 191 (AAPM TG191) report. Initial clinical experiences and dosimetric results are also presented. The following properties of the system were characterized: linearity correction factors ranged from -0.5% to +3% for dose levels spanning 0.1 to 20 Gy. Beam quality correction factors (relative to 6 MV) ranged from -4.5% (2.5FFF) to +4.5% (15MV) for photon beams and +1.9% (6 MeV) to +4.3% (20 MeV) for electron beams. An average (µ) signal loss per reading of -2.13% ± 0.20% was measured, however greater signal loss was observed in the first reading (µ = -2.6% ± 0.46%). An initial decline in individual element sensitivity relative to baseline was observed from 0–15 Gy cumulative dose (µ = -1.98% ± 0.55%), with negligible further deterioration from 15–32 Gy (µ = -2.38% ± 0.85%). Post-irradiation, there was a transient OSL signal which faded with a half-life of 1.8 min; this signal enhancement was +5% at 5 min post-irradiation and +1% at 15 min relative to 24 h. Dosimeter response was not dependent on average dose rate in the range of 100–2500 MU/min. With respect to clinical testing, equal or superior performance compared with aluminum oxide OSLs (nanoDots) is shown for a range of clinical techniques and modalities including TSET, TBI, en-face electrons, and pacemaker/out-of-field measurements. The feasibility of myOSLchip to serve as a primary clinical in vivo dosimetry system and direct replacement for Landauer's microStar system is demonstrated.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70057","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476612","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}

{"title":"Quantitative beam optimization for radiotherapy of peripheral lung lesions: A pilot study in stereotactic body radiotherapy","authors":"Hamed Hooshangnejad,&nbsp;Jina Lee,&nbsp;Leslie Bell,&nbsp;Russell K. Hales,&nbsp;Khinh Ranh Voong,&nbsp;Sarah Han-Oh,&nbsp;Kai Ding,&nbsp;Reza Farjam","doi":"10.1002/acm2.70029","DOIUrl":"10.1002/acm2.70029","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>To quantify beam optimization for stereotactic body radiotherapy (SBRT) of peripheral lung lesions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Method</h3>\u0000 \u0000 <p>The new beam optimization approach was based on maximizing the therapeutic gain (TG) of the beam set by minimizing the average physical depth of the lesion with respect to the beam's eye view (BEV). The new approach was evaluated by replanning the 25 SBRT lesions retrospectively to assess if a better plan is achievable in all aspects. Difference in 25 Gy isodose line volume (IDLV₂₅ _Gy), IDLV₂₀ _Gy, IDLV₁₅ _Gy, IDLV₁₀ _Gy, and IDLV₅ _Gy between the two plan cohorts were calculated as a measure of plan size and fitted in a linear regression model against the changes in the lesion depth with respect to the BEV to assess the relationship between the changes in the treatment depth and that of the plan size.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Beam optimization achieved a better plan in all cases by lowering the depth of treatment with an average of % 20.03 ± 12.30 (3.66%–45.78%). As the depth of treatment decreases, the size of the plan also decreases. We observed a reduction of % 4.64 ± 4.55 (0.02%–21.58%, <i>p</i> &lt; 3.8 × 10⁻⁵), %5.16 ± 5.54 (0.03%-24.68%, <i>p</i> &lt; 0.005), %6.46 ± 6.95 (−1.35%-29.05%, <i>p</i> &lt; 0.009), %12.83 ± 9.06 (0.89%–37.65%, <i>p</i> &lt; 0.0001), and %14.01 ± 9.87 (1.43%–41.84%, <i>p</i> &lt; 4.5 × 10⁻⁶) in IDLV₂₅ _Gy, IDLV₂₀ _Gy, IDLV₁₅ _Gy, IDLV₁₀ _Gy, and IDLV₅ _Gy, respectively.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Physical depth of the lesion with respect to the BEV is inversely proportional to the TG of a beam-set and can be used as a robust and standard metric to select an appropriate beam-set for SBRT of the peripheral lung lesions. Further evaluation warrants the utility of such concept in routine clinical use.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476630","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}

{"title":"The effect of kV imaging dose on PTV and OAR planning constraints in lung SBRT using stereoscopic/monoscopic real-time tumor-monitoring system","authors":"Ruwan Abeywardhana,&nbsp;Mike Sattarivand","doi":"10.1002/acm2.70019","DOIUrl":"10.1002/acm2.70019","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Quantify the impact of additional imaging doses on clinical dose constraints during lung stereotactic body radiotherapy (SBRT) treatment utilizing stereoscopic/monoscopic real-time tumor monitoring.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>Thirty lung SBRT patients treated with the volumetric arc therapy technique were randomly selected from the institutional clinical database. Contours of patients' and computed tomography data were extracted from the Eclipse treatment planning system, along with information regarding the treatment dose. Subsequently, patient-specific three-dimensional real-time imaging dose distributions were computed using a validated Monte Carlo simulation of the ExacTrac imaging. The 3D imaging dose was added to the treatment dose, and the influence of the imaging dose on clinical dose constraints was analyzed for planning target volume (PTV) and various organs at risk (OARs).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Among the 30 patients, 14 patients exhibited one or more failed OAR constraints based solely on the treatment dose, resulting in a total of 24 constraint failures. The addition of the real-time imaging dose altered the pass/fail criteria for one OAR constraint and two PTV constraints. The change in constraint due to additional imaging dose relative to the prescription dose was less than 1% for all patients, except for one case, where it reached 1.9%, which had remained below the threshold of 5% recommended by AAPM TG-180 guidelines. Furthermore, the additional imaging dose relative to the treatment dose resulted in an increase in OAR constraints ranging from 0 to 27% (mean of 0.8%), with nine cases exceeding 5%.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The current study represents the first attempt to investigate the impact of additional imaging doses on clinical planning constraints in real-time tumor monitoring during lung SBRT utilizing ExacTrac imaging system. The addition of an imaging dose will likely have minimal clinical impact.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 5","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476647","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}

{"title":"A knowledge-based planning model to identify fraction-reduction opportunities in brain stereotactic radiotherapy","authors":"Shane McCarthy,&nbsp;William St. Clair,&nbsp;Damodar Pokhrel","doi":"10.1002/acm2.70055","DOIUrl":"10.1002/acm2.70055","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>To develop and validate a HyperArc-based RapidPlan (HARP) model for three-fraction brain stereotactic radiotherapy (SRT) plans to then use to replan previously treated five-fraction SRT plans. Demonstrating the possibility of reducing the number of fractions while achieving acceptable organs-at-risk (OAR) doses with improved target biological effective dose (BED) to brain lesions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Thirty-nine high-quality clinical three-fraction HyperArc brain SRT plans (24–27 Gy) were used to train the HARP model, with a separate 10 plans used to validate its effectiveness. Fifty-eight five-fraction HyperArc brain SRT plans (30–40 Gy) attempted to be retrospectively replanned for three fractions scheme using the HARP model. All planning was done within the Eclipse treatment planning system for a TrueBeam LINAC with a 6 MV-FFF beam and Millenium 120 MLCs and dosimetric parameters were analyzed per brain SRT protocol.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The HyperArc RapidPlan model was successfully trained and tested, with the validation set demonstrating a statistically significant (<i>p</i> = 0.01) increase in GTV D_100% from 28.5 ± 0.7 Gy to 29.4 ± 0.6 Gy from the original to RapidPlan plans. No statistically significant differences were found for the OAR metrics (<i>p</i> &gt; 0.05). The five-fraction replans were successful for 20 of the 58 five-fraction brain SRT plans. For those 20 successful brain SRT plans, the maximum doses to OAR were clinically acceptable with a three-fraction scheme including an average V_18Gy to Brain-PTV of 9.9 ± 5.9 cc. Additionally, the replanned five-fraction brain SRT plans achieved a higher BED to the tumors, increasing from a GTV D_100% of 52.9 ± 4.5 Gy for the original five-fraction plans to 57.3 ± 3.1 Gy for the three-fraction RapidPlan plans. All RapidPlan plans were generated automatically, without manual input, in under 20 min.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The HARP model developed in this research was used to successfully identify select five-fraction plans that were able to be reduced to three-fraction SRT treatments while achieving clinically acceptable OAR doses and improved target BED. This tool encourages a fast and standardized way to provide physicians with more options when choosing the necessary fractionation scheme(s) for HyperArc SRT to single- and multiple brain lesions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70055","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476609","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}