Physics and Imaging in Radiation Oncology最新文献

英文中文

Potential of automated online adaptive proton therapy to reduce margins for oesophageal cancer

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-01-01 DOI: 10.1016/j.phro.2025.100712

Pascal Herbst , Camille Draguet , Ana M. Barragán-Montero , Elena Borderías Villarroel , Macarena Chocan Vera , Pieter Populaire , Karin Haustermans , Edmond Sterpin

Background and purpose:

Proton therapy for oesophageal cancer is administered over multiple fractions, based on a single pre-treatment image. However, anatomical changes can lead to the deterioration of the treatment plan, necessitating manual replanning. To keep this within limits, increased residual margins are employed. This study aimed to evaluate the proposed automated Online Adaptive Proton Therapy (OAPT) strategies on their capability to reduce the need for manual replanning, while also exploring the possibility of margin reduction.

Materials and methods:

Two automated OAPT methods were examined: Automated Dose Restoration (ADR) and Automated Full Adaptation (AFA). ADR makes use of dose restoration, restoring the original dose map based on the patient’s altered anatomy. AFA adapts the contours used for plan optimization by applying a deformation field, not only correcting for density changes, but also for the relative location of organs. A comparative analysis of OAPT strategies, evaluating

D_{98%}

tumour coverage on 17 patients, was conducted.

Results:

The nominal results of non-adapted plans with 7 mm residual margins required manual replanning for 18% of the patients. ADR reduced this to 6%, while AFA eliminated the need for manual replanning. With 2 mm margins, 47% of cases required manual replanning. ADR reduced this to 18%, and AFA further reduced it to 11%.

Conclusions:

The proposed OAPT strategies offered a marked improvement compared to a non-adaptive approach. ADR and AFA significantly reduced the necessity for manual replanning and facilitated the reduction of residual margins, enhancing dose conformity and reducing treatment toxicity.

{"title":"Potential of automated online adaptive proton therapy to reduce margins for oesophageal cancer","authors":"Pascal Herbst , Camille Draguet , Ana M. Barragán-Montero , Elena Borderías Villarroel , Macarena Chocan Vera , Pieter Populaire , Karin Haustermans , Edmond Sterpin","doi":"10.1016/j.phro.2025.100712","DOIUrl":"10.1016/j.phro.2025.100712","url":null,"abstract":"<div><h3>Background and purpose:</h3><div>Proton therapy for oesophageal cancer is administered over multiple fractions, based on a single pre-treatment image. However, anatomical changes can lead to the deterioration of the treatment plan, necessitating manual replanning. To keep this within limits, increased residual margins are employed. This study aimed to evaluate the proposed automated Online Adaptive Proton Therapy (OAPT) strategies on their capability to reduce the need for manual replanning, while also exploring the possibility of margin reduction.</div></div><div><h3>Materials and methods:</h3><div>Two automated OAPT methods were examined: Automated Dose Restoration (ADR) and Automated Full Adaptation (AFA). ADR makes use of dose restoration, restoring the original dose map based on the patient’s altered anatomy. AFA adapts the contours used for plan optimization by applying a deformation field, not only correcting for density changes, but also for the relative location of organs. A comparative analysis of OAPT strategies, evaluating <span><math><msub><mrow><mi>D</mi></mrow><mrow><mtext>98%</mtext></mrow></msub></math></span> tumour coverage on 17 patients, was conducted.</div></div><div><h3>Results:</h3><div>The nominal results of non-adapted plans with 7 mm residual margins required manual replanning for 18% of the patients. ADR reduced this to 6%, while AFA eliminated the need for manual replanning. With 2 mm margins, 47% of cases required manual replanning. ADR reduced this to 18%, and AFA further reduced it to 11%.</div></div><div><h3>Conclusions:</h3><div>The proposed OAPT strategies offered a marked improvement compared to a non-adaptive approach. ADR and AFA significantly reduced the necessity for manual replanning and facilitated the reduction of residual margins, enhancing dose conformity and reducing treatment toxicity.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"33 ","pages":"Article 100712"},"PeriodicalIF":3.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of 2D anti-scatter grid implementation in a gantry-mounted cone beam computed tomography system for proton therapy

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-01-01 DOI: 10.1016/j.phro.2025.100730

Uttam Pyakurel , Yawei Zhang , Ryan Sabounchi , Farhang Bayat , Sébastien Brousmiche , Curtis Bryant , Nancy Mendenhall , Perry Johnson , Cem Altunbas

Background and purpose

Robust scatter mitigation by 2D anti-scatter grids (2D-ASG) in proton therapy cone beam computed tomography (CBCT) may improve target visualization and computed tomography (CT) number fidelity, allowing online dose verifications and plan adaptations. However, grid artifact-free implementation of 2D-ASG depends on the CBCT system characteristics. Thus, we investigated the feasibility of 2D-ASG implementation in a proton therapy gantry-mounted CBCT system and evaluated its impact on image quality.

Materials and methods

A prototype 2D-ASG and a grid support platform were developed for a proton therapy CBCT system with a 340 cm source to imager distance. The effect of gantry flex on 2D-ASG’s wall shadows and scan-to-scan reproducibility of 2D-ASG’s wall shadows were evaluated. Experiments were conducted to assess 2D-ASG’s wall shadow suppression and the effect of 2D-ASG on image quality.

Results

While maximum displacement in 2D-ASG wall shadows was 103 µm during gantry rotation, the drift from baseline over 3 months was 8 µm and 1 µm in the transverse and axial directions. 2D-ASG shadows were successfully suppressed in CBCT images. With 2D-ASG, maximum Hounsfield Unit (HU) nonuniformity decreased from 134 to 45 HU, contrast-to-noise ratio (CNR) increased by a factor of 2.5, and HU errors were reduced from 34 % to 5 %.

Conclusions

Proton therapy gantry flex was highly reproducible and did not noticeably affect 2D-ASG wall shadow suppression in CBCT images, supporting its feasibility in proton therapy CBCT system. Improved CT accuracy and artifact reduction with 2D-ASG could enhance CBCT-based proton therapy dose calculations.

{"title":"Investigation of 2D anti-scatter grid implementation in a gantry-mounted cone beam computed tomography system for proton therapy","authors":"Uttam Pyakurel , Yawei Zhang , Ryan Sabounchi , Farhang Bayat , Sébastien Brousmiche , Curtis Bryant , Nancy Mendenhall , Perry Johnson , Cem Altunbas","doi":"10.1016/j.phro.2025.100730","DOIUrl":"10.1016/j.phro.2025.100730","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Robust scatter mitigation by 2D anti-scatter grids (2D-ASG) in proton therapy cone beam computed tomography (CBCT) may improve target visualization and computed tomography (CT) number fidelity, allowing online dose verifications and plan adaptations. However, grid artifact-free implementation of 2D-ASG depends on the CBCT system characteristics. Thus, we investigated the feasibility of 2D-ASG implementation in a proton therapy gantry-mounted CBCT system and evaluated its impact on image quality.</div></div><div><h3>Materials and methods</h3><div>A prototype 2D-ASG and a grid support platform were developed for a proton therapy CBCT system with a 340 cm source to imager distance. The effect of gantry flex on 2D-ASG’s wall shadows and scan-to-scan reproducibility of 2D-ASG’s wall shadows were evaluated. Experiments were conducted to assess 2D-ASG’s wall shadow suppression and the effect of 2D-ASG on image quality.</div></div><div><h3>Results</h3><div>While maximum displacement in 2D-ASG wall shadows was 103 µm during gantry rotation, the drift from baseline over 3 months was 8 µm and 1 µm in the transverse and axial directions. 2D-ASG shadows were successfully suppressed in CBCT images. With 2D-ASG, maximum Hounsfield Unit (HU) nonuniformity decreased from 134 to 45 HU, contrast-to-noise ratio (CNR) increased by a factor of 2.5, and HU errors were reduced from 34 % to 5 %.</div></div><div><h3>Conclusions</h3><div>Proton therapy gantry flex was highly reproducible and did not noticeably affect 2D-ASG wall shadow suppression in CBCT images, supporting its feasibility in proton therapy CBCT system. Improved CT accuracy and artifact reduction with 2D-ASG could enhance CBCT-based proton therapy dose calculations.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"33 ","pages":"Article 100730"},"PeriodicalIF":3.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigating the potential of diffusion tensor atlases to generate anisotropic clinical tumor volumes in glioblastoma patients

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-01-01 DOI: 10.1016/j.phro.2024.100688

Kim Hochreuter , Gregory Buti , Ali Ajdari , Christopher P. Bridge , Gregory C. Sharp , Sune Jespersen , Slávka Lukacova , Thomas Bortfeld , Jesper F. Kallehauge

Background and purpose:

Diffusion tensor imaging (DTI) has been proposed to guide the anisotropic expansion from gross tumor volume to clinical target volume (CTV), aiming to integrate known tumor spread patterns into the CTV. This study investigate the potential of using a DTI atlas as an alternative to patient-specific DTI for generating anisotropic CTVs.

Materials and Methods:

The dataset consisted of twenty-eight newly diagnosed glioblastoma patients from a Danish national DTI protocol with post-operative T1-contrast and DTI imaging. Three different DTI atlases, spatially aligned to the patient images using deformable image registration, were considered as alternatives. Anisotropic CTVs were constructed to match the volume of a 15 mm isotropic expansion by generating 3D distance maps using either patient- or atlas-DTI as input to the shortest path solver. The degree of CTV anisotropy was controlled by the migration ratio, modeling tumor cell migration along the dominant white matter fiber direction extracted from DTI. The similarity between patient- and atlas-DTI CTVs was analyzed using the Dice Similarity Coefficient (DSC), with significance testing according to a Wilcoxon test.

Results:

The median (range) DSC between anisotropic CTVs generated using patient-specific and atlas-based DTI was 0.96 (0.93–0.97), 0.96 (0.93–0.97), and 0.95 (0.93–0.97) for the three atlases, respectively (p

>

0.01), for a migration ratio of 10. The results remained consistent over the range of studied migration ratios (2 to 100).

Conclusion:

The high degree of similarity between all anisotropic CTVs indicates that atlas-DTI is a viable replacement for patient-specific DTI for incorporating fiber direction into the CTV.

{"title":"Investigating the potential of diffusion tensor atlases to generate anisotropic clinical tumor volumes in glioblastoma patients","authors":"Kim Hochreuter , Gregory Buti , Ali Ajdari , Christopher P. Bridge , Gregory C. Sharp , Sune Jespersen , Slávka Lukacova , Thomas Bortfeld , Jesper F. Kallehauge","doi":"10.1016/j.phro.2024.100688","DOIUrl":"10.1016/j.phro.2024.100688","url":null,"abstract":"<div><h3>Background and purpose:</h3><div>Diffusion tensor imaging (DTI) has been proposed to guide the anisotropic expansion from gross tumor volume to clinical target volume (CTV), aiming to integrate known tumor spread patterns into the CTV. This study investigate the potential of using a DTI atlas as an alternative to patient-specific DTI for generating anisotropic CTVs.</div></div><div><h3>Materials and Methods:</h3><div>The dataset consisted of twenty-eight newly diagnosed glioblastoma patients from a Danish national DTI protocol with post-operative T1-contrast and DTI imaging. Three different DTI atlases, spatially aligned to the patient images using deformable image registration, were considered as alternatives. Anisotropic CTVs were constructed to match the volume of a 15 mm isotropic expansion by generating 3D distance maps using either patient- or atlas-DTI as input to the shortest path solver. The degree of CTV anisotropy was controlled by the migration ratio, modeling tumor cell migration along the dominant white matter fiber direction extracted from DTI. The similarity between patient- and atlas-DTI CTVs was analyzed using the Dice Similarity Coefficient (DSC), with significance testing according to a Wilcoxon test.</div></div><div><h3>Results:</h3><div>The median (range) DSC between anisotropic CTVs generated using patient-specific and atlas-based DTI was 0.96 (0.93–0.97), 0.96 (0.93–0.97), and 0.95 (0.93–0.97) for the three atlases, respectively (p <span><math><mo>></mo></math></span> 0.01), for a migration ratio of 10. The results remained consistent over the range of studied migration ratios (2 to 100).</div></div><div><h3>Conclusion:</h3><div>The high degree of similarity between all anisotropic CTVs indicates that atlas-DTI is a viable replacement for patient-specific DTI for incorporating fiber direction into the CTV.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"33 ","pages":"Article 100688"},"PeriodicalIF":3.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11758580/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143047930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A deep learning algorithm to generate synthetic computed tomography images for brain treatments from 0.35 T magnetic resonance imaging

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-01-01 DOI: 10.1016/j.phro.2025.100708

Luca Vellini , Flaviovincenzo Quaranta , Sebastiano Menna , Elisa Pilloni , Francesco Catucci , Jacopo Lenkowicz , Claudio Votta , Michele Aquilano , Andrea D’Aviero , Martina Iezzi , Francesco Preziosi , Alessia Re , Althea Boschetti , Danila Piccari , Antonio Piras , Carmela Di Dio , Alessandro Bombini , Gian Carlo Mattiucci , Davide Cusumano

Background and Purpose

The development of Magnetic Resonance Imaging (MRI)-only Radiotherapy (RT) represents a significant advancement in the field. This study introduces a Deep Learning (DL) algorithm designed to quickly generate synthetic CT (sCT) images from low-field MR images in the brain, an area not yet explored.

Methods

Fifty-six patients were divided into training (32), validation (8), and test (16) groups. A conditional Generative Adversarial Network (cGAN) was trained on pre-processed axial paired images. sCTs were validated using mean absolute error (MAE) and mean error (ME) calculated within the patient body. Intensity Modulated Radiation Therapy (IMRT) plans were optimised on simulation MRI and calculated considering sCT and original CT as electron density (ED) map. Dose distributions using sCT and CT were compared using global gamma analysis at different tolerance criteria (2 %/2mm and 3 %/3mm) and evaluating the difference in estimating different Dose Volume Histogram (DVH) parameters for target and organs at risk (OARs).

Results

The network generated sCTs of each single patient in less than two minutes (mean time = 103 ± 41 s). For test patients, the MAE was 62.1 ± 17.7 HU, and the ME was −7.3 ± 13.4 HU. Dose parameters on sCTs were within 0.5 Gy of those on original CTs. Gamma passing rates 2 %/2mm, and 3 %/3mm criteria were 99.5 %±0.5 %, and 99.7 %±0.3 %, respectively.

Conclusion

The proposed DL algorithm generates in less than 2 min accurate sCT images in the brain for online adaptive radiotherapy, potentially eliminating the need for CT simulation in MR-only workflows for brain treatments.

{"title":"A deep learning algorithm to generate synthetic computed tomography images for brain treatments from 0.35 T magnetic resonance imaging","authors":"Luca Vellini , Flaviovincenzo Quaranta , Sebastiano Menna , Elisa Pilloni , Francesco Catucci , Jacopo Lenkowicz , Claudio Votta , Michele Aquilano , Andrea D’Aviero , Martina Iezzi , Francesco Preziosi , Alessia Re , Althea Boschetti , Danila Piccari , Antonio Piras , Carmela Di Dio , Alessandro Bombini , Gian Carlo Mattiucci , Davide Cusumano","doi":"10.1016/j.phro.2025.100708","DOIUrl":"10.1016/j.phro.2025.100708","url":null,"abstract":"<div><h3>Background and Purpose</h3><div>The development of Magnetic Resonance Imaging (MRI)-only Radiotherapy (RT) represents a significant advancement in the field. This study introduces a Deep Learning (DL) algorithm designed to quickly generate synthetic CT (sCT) images from low-field MR images in the brain, an area not yet explored.</div></div><div><h3>Methods</h3><div>Fifty-six patients were divided into training (32), validation (8), and test (16) groups. A conditional Generative Adversarial Network (cGAN) was trained on pre-processed axial paired images. sCTs were validated using mean absolute error (MAE) and mean error (ME) calculated within the patient body. Intensity Modulated Radiation Therapy (IMRT) plans were optimised on simulation MRI and calculated considering sCT and original CT as electron density (ED) map. Dose distributions using sCT and CT were compared using global gamma analysis at different tolerance criteria (2 %/2mm and 3 %/3mm) and evaluating the difference in estimating different Dose Volume Histogram (DVH) parameters for target and organs at risk (OARs).</div></div><div><h3>Results</h3><div>The network generated sCTs of each single patient in less than two minutes (mean time = 103 ± 41 s). For test patients, the MAE was 62.1 ± 17.7 HU, and the ME was −7.3 ± 13.4 HU. Dose parameters on sCTs were within 0.5 Gy of those on original CTs. Gamma passing rates 2 %/2mm, and 3 %/3mm criteria were 99.5 %±0.5 %, and 99.7 %±0.3 %, respectively.</div></div><div><h3>Conclusion</h3><div>The proposed DL algorithm generates in less than 2 min accurate sCT images in the brain for online adaptive radiotherapy, potentially eliminating the need for CT simulation in MR-only workflows for brain treatments.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"33 ","pages":"Article 100708"},"PeriodicalIF":3.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ultra-fast, one-click radiotherapy treatment planning outside a treatment planning system

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-01-01 DOI: 10.1016/j.phro.2025.100724

Gerd Heilemann , Lukas Zimmermann , Tufve Nyholm , Attila Simkó , Joachim Widder , Gregor Goldner , Dietmar Georg , Peter Kuess

We present an automated radiation oncology treatment planning pipeline that operates between segmentation and plan review, minimizing manual interaction and reliance on traditional planning systems. Two AI models work in sequence: the first generates a dose distribution, and the second creates a deliverable DICOM-RT plan. Trained and validated on 276 plans, and tested on 151 datasets, the system produced clinically deliverable plans—complete with all VMAT parameters—in about 38 s. These plans met target coverage and most organ-at-risk constraints. This proof-of-concept demonstrates the feasibility of generating high-quality, deliverable DICOM plans within seconds.

引用次数: 0

Effect of end expiration breath hold on target volumes and organ at risk doses for oesophageal cancer radiotherapy

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-01-01 DOI: 10.1016/j.phro.2025.100726

Christopher Mayhew , Jeyaanth Venkatasai , Marina Khan , Victoria Butterworth , Kasia Owczarczyk , Georgios Ntentas

Background and Purpose

The end expiration breath hold (EEBH) technique has the potential to reduce tumour motion during radiotherapy treatment of lower oesophageal cancer, and therefore, motion artefacts, target volumes and dose to surrounding organs at risk (OAR). EEBH is an emerging technique and clinical data on its use in oesophageal cancer is scarce.

Methods and Materials

A comparison of 20 lower oesophageal cancer patients was performed for radiotherapy treatment plans in both EEBH and free breathing (FB). EEBH and FB plans were evaluated and compared in terms of motion artefacts, target volumes and dose-volume metrics.

Results

EEBH was effective in reducing the observed motion artefacts seen in planning CTs compared to FB. EEBH also significantly reduced the average PTV size between EEBH and FB (ΔV = -48 ± 55 cm³; p < 0.001). OAR-PTV overlap volumes were also effectively reduced in EEBH compared to FB, including for lung-PTV overlaps (ΔV = -13 ± 13 cm³; p < 0.001) and for heart-PTV overlaps (ΔV = -8 ± 14 cm³; p = 0.02). Mean heart doses were lower on average by −1.2 ± 2.0 Gy with EEBH (p = 0.02), and mean lung doses by −1.0 ± 1.0 Gy (p < 0.001). Mean liver doses were on average reduced with EEBH by −0.6 ± 1.5 Gy, whereas spinal D_2cm3 increased in EEBH compared to FB by 1.8 ± 6.3 Gy, but neither were statistically significant.

Conclusion

Use of EEBH for oesophageal cancer radiotherapy reduced motion artefacts and increased confidence in contouring volumes. Additionally, planning target volumes and doses to key OARs were reduced with EEBH compared to FB plans.

{"title":"Effect of end expiration breath hold on target volumes and organ at risk doses for oesophageal cancer radiotherapy","authors":"Christopher Mayhew , Jeyaanth Venkatasai , Marina Khan , Victoria Butterworth , Kasia Owczarczyk , Georgios Ntentas","doi":"10.1016/j.phro.2025.100726","DOIUrl":"10.1016/j.phro.2025.100726","url":null,"abstract":"<div><h3>Background and Purpose</h3><div>The end expiration breath hold (EEBH) technique has the potential to reduce tumour motion during radiotherapy treatment of lower oesophageal cancer, and therefore, motion artefacts, target volumes and dose to surrounding organs at risk (OAR). EEBH is an emerging technique and clinical data on its use in oesophageal cancer is scarce.</div></div><div><h3>Methods and Materials</h3><div>A comparison of 20 lower oesophageal cancer patients was performed for radiotherapy treatment plans in both EEBH and free breathing (FB). EEBH and FB plans were evaluated and compared in terms of motion artefacts, target volumes and dose-volume metrics.</div></div><div><h3>Results</h3><div>EEBH was effective in reducing the observed motion artefacts seen in planning CTs compared to FB. EEBH also significantly reduced the average PTV size between EEBH and FB (ΔV = -48 ± 55 cm<sup>3</sup>; p < 0.001). OAR-PTV overlap volumes were also effectively reduced in EEBH compared to FB, including for lung-PTV overlaps (ΔV = -13 ± 13 cm<sup>3</sup>; p < 0.001) and for heart-PTV overlaps (ΔV = -8 ± 14 cm<sup>3</sup>; p = 0.02). Mean heart doses were lower on average by −1.2 ± 2.0 Gy with EEBH (p = 0.02), and mean lung doses by −1.0 ± 1.0 Gy (p < 0.001). Mean liver doses were on average reduced with EEBH by −0.6 ± 1.5 Gy, whereas spinal D<sub>2cm</sub>3 increased in EEBH compared to FB by 1.8 ± 6.3 Gy, but neither were statistically significant.</div></div><div><h3>Conclusion</h3><div>Use of EEBH for oesophageal cancer radiotherapy reduced motion artefacts and increased confidence in contouring volumes. Additionally, planning target volumes and doses to key OARs were reduced with EEBH compared to FB plans.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"33 ","pages":"Article 100726"},"PeriodicalIF":3.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143446139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Updating historical normal tissue dose/volume constraints to current levels of treatment precision and accuracy

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-01-01 DOI: 10.1016/j.phro.2025.100725

Tomas Kron, Marnix Witte, Ludvig P. Muren

引用次数: 0

Optimizing the dose-averaged linear energy transfer for the dominant intraprostatic lesions in high-risk localized prostate cancer patients

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-01-01 DOI: 10.1016/j.phro.2025.100727

Bo Zhao , Nobuyuki Kanematsu , Shuri Aoki , Shinichiro Mori , Hideyuki Mizuno , Takamitsu Masuda , Hideyuki Takei , Hitoshi Ishikawa

Background and purpose

Radiotherapy for localized prostate cancer often targets the entire prostate with a uniform dose despite the presence of high-risk dominant intraprostatic lesions (DILs). This study investigated the feasibility of focal dose-averaged linear energy transfer (LET_d) boost for prostate carbon-ion radiotherapy to deposit higher LET_d to DILs while ensuring desired relative biological effectiveness weighted dose coverage to targets and sparing organs at risk (OARs).

Materials and methods

A retrospective planning study was conducted on 15 localized prostate cancer cases. The DILs were identified on multiparametric MRI and used to define the boost target (PTV_boost). Two treatment plans were designed for each patient: 1) conventional plan optimized by the single-field uniform dose technique, and 2) boost plan optimized by the multifield optimization and LET painting technique, to achieve LET_d boost within the PTV_boost. Dose and LET_d metrics of the targets and OARs were compared between the two plans.

Results

Compared to the conventional plans, the boost plans delivered clinically acceptable dose coverage (D_90% and D_50%) to the target (PTV2) within 1% differences while significantly increasing the minimum LET_d by 16 ∼ 24 keV/μm for the PTV_boost (63.9 ± 2.8 vs. 44.0 ± 1.3 keV/μm, p < 0.001). Furthermore, these improvements were consistent across all cases, irrespective of their anatomical features, including the boost volume’s size, location, and shape.

Conclusion

Focal LET_d boost was a feasible strategy for prostate carbon-ion radiotherapy. This investigation demonstrated its superiority in delivering LET_d boost without depending on tumor location and volume across different cases.

{"title":"Optimizing the dose-averaged linear energy transfer for the dominant intraprostatic lesions in high-risk localized prostate cancer patients","authors":"Bo Zhao , Nobuyuki Kanematsu , Shuri Aoki , Shinichiro Mori , Hideyuki Mizuno , Takamitsu Masuda , Hideyuki Takei , Hitoshi Ishikawa","doi":"10.1016/j.phro.2025.100727","DOIUrl":"10.1016/j.phro.2025.100727","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Radiotherapy for localized prostate cancer often targets the entire prostate with a uniform dose despite the presence of high-risk dominant intraprostatic lesions (DILs). This study investigated the feasibility of focal dose-averaged linear energy transfer (LET<sub>d</sub>) boost for prostate carbon-ion radiotherapy to deposit higher LET<sub>d</sub> to DILs while ensuring desired relative biological effectiveness weighted dose coverage to targets and sparing organs at risk (OARs).</div></div><div><h3>Materials and methods</h3><div>A retrospective planning study was conducted on 15 localized prostate cancer cases. The DILs were identified on multiparametric MRI and used to define the boost target (PTV<sub>boost</sub>). Two treatment plans were designed for each patient: 1) conventional plan optimized by the single-field uniform dose technique, and 2) boost plan optimized by the multifield optimization and LET painting technique, to achieve LET<sub>d</sub> boost within the PTV<sub>boost</sub>. Dose and LET<sub>d</sub> metrics of the targets and OARs were compared between the two plans.</div></div><div><h3>Results</h3><div>Compared to the conventional plans, the boost plans delivered clinically acceptable dose coverage (D<sub>90%</sub> and D<sub>50%</sub>) to the target (PTV2) within 1% differences while significantly increasing the minimum LET<sub>d</sub> by 16 ∼ 24 keV/μm for the PTV<sub>boost</sub> (63.9 ± 2.8 vs. 44.0 ± 1.3 keV/μm, p < 0.001). Furthermore, these improvements were consistent across all cases, irrespective of their anatomical features, including the boost volume’s size, location, and shape.</div></div><div><h3>Conclusion</h3><div>Focal LET<sub>d</sub> boost was a feasible strategy for prostate carbon-ion radiotherapy. This investigation demonstrated its superiority in delivering LET<sub>d</sub> boost without depending on tumor location and volume across different cases.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"33 ","pages":"Article 100727"},"PeriodicalIF":3.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthetic Computed Tomography generation using deep-learning for female pelvic radiotherapy planning

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-01-01 DOI: 10.1016/j.phro.2025.100719

Rachael Tulip , Sebastian Andersson , Robert Chuter , Spyros Manolopoulos

Synthetic Computed Tomography (sCT) is required to provide electron density information for MR-only radiotherapy. Deep-learning (DL) methods for sCT generation show improved dose congruence over other sCT generation methods (e.g. bulk density). Using 30 female pelvis datasets to train a cycleGAN-inspired DL model, this study found mean dose differences between a deformed planning CT (dCT) and sCT were 0.2 % (D98 %). Three Dimensional Gamma analysis showed a mean of 90.4 % at 1 %/1mm. This study showed accurate sCTs (dose) can be generated from routinely available T2 spin echo sequences without the need for additional specialist sequences.

引用次数: 0

Nontoxic generalized patient shielding devices for total skin electron therapy

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-01-01 DOI: 10.1016/j.phro.2025.100697

Clinton Gibson, Joseph B. Schulz, Amy Yu, Piotr Dubrowski, Lawrie Skinner

This study evaluates alternative shielding materials to lead for protecting the scalp and nails during total skin electron irradiation. We tested a silicone helmet, tungsten-doped silicone mittens, and planar aluminum and copper shields. The helmet and mittens were created using 3D modeling software and fused filament fabrication printing, while the planar shields were machined and assembled with printed hardware. Transmission measurements showed transmission rates of 4.5%–6.8% for the mittens, 5.8%–9.1% for the helmet, and 7.5% for the planar shields. The silicone-based devices improve comfort and usability, and slight design changes can enhance coverage and application.

引用次数: 0

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