Feasibility of volumetric modulated arc therapy (VMAT) for partial breast irradiation (PBI) with simultaneous integrated boost (SIB) to tumour bed was investigated. Four plans were created for 10 patients: 30 Gy/5 fractions, 26 Gy/5 fractions with 30 Gy SIB, 40.05 Gy/15 fractions, and 40.05 Gy/15 fractions with 48 Gy SIB. SIB in the 5 fraction arm had reduced ipsilateral breast dose relative to uniform dose. SIB in the 15 fraction arm had noninferior conformity compared to uniform dose. Addition of SIB did not increase other organ-at-risk doses or plan complexity. VMAT PBI with SIB was feasible for both fractionation regimens.
{"title":"Technical feasibility of delivering a simultaneous integrated boost in partial breast irradiation","authors":"Alex Burton , Tamika Cassar , Christy Glenn , Keelan Byrne","doi":"10.1016/j.phro.2024.100659","DOIUrl":"10.1016/j.phro.2024.100659","url":null,"abstract":"<div><div>Feasibility of volumetric modulated arc therapy (VMAT) for partial breast irradiation (PBI) with simultaneous integrated boost (SIB) to tumour bed was investigated. Four plans were created for 10 patients: 30 Gy/5 fractions, 26 Gy/5 fractions with 30 Gy SIB, 40.05 Gy/15 fractions, and 40.05 Gy/15 fractions with 48 Gy SIB. SIB in the 5 fraction arm had reduced ipsilateral breast dose relative to uniform dose. SIB in the 15 fraction arm had noninferior conformity compared to uniform dose. Addition of SIB did not increase other organ-at-risk doses or plan complexity. VMAT PBI with SIB was feasible for both fractionation regimens.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"32 ","pages":"Article 100659"},"PeriodicalIF":3.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533613","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}
Pub Date : 2024-10-01DOI: 10.1016/j.phro.2024.100676
Emma Skarsø Buhl , Geert Wortel , Rita Simões , Astrid Scholten , Birgitte Vrou Offersen , Stine Korreman , Tomas Janssen
Background and Purpose
This study aimed at investigating the dosimetric impact on organs at risk, when the left-sided internal mammary lymph nodes (IMN) were delineated with two interpretations of the same guideline.
Materials and Methods
The cohort consisted of 95 left-sided breast cancer patients with indication for irradiation of the CTVn_IMN treated at the Netherlands Cancer Institute (NKI). The NKI interpretation of the ESTRO guidelines was in the clinical structure sets (CTVn_IMN_NKI). A deep learning model was used as second interpretation of the guideline, based on a Danish consensus interpretation (CTVn_IMN_DK). The geometrical similarity was evaluated with the Dice Similarity Coefficient (DSC), volume, width, distance to sternal bone (SB) and maximum distance between the interpretations in the medial direction. Treatment plans were generated for both CTVn_IMNs. Mean heart dose (MHD) was correlated with the geometrical metrics.
Results
62 patients were eligible for analysis. The geometric comparison showed a median volume of 9.59 ml/7.19 ml for the CTVN_IMN_NKI/CTVn_IMN_DK along with a median DSC of 0.63. The width and distance from SB were significantly different, with a median width of 18.2 mm/14.7 mm and distance to SB of 3.4 mm/5.1 mm for CTVn_IMN_NKI/CTVn_IMN_DK. The MHD was significantly higher with the CTVn_IMN_NKI. The strongest correlation was found between MHD and maximum medial difference between the CTVn_IMN in slices where the heart was present.
Conclusions
Differences in interpretations of the CTVn_IMN delineation guidelines were found, resulting in significant differences in MHD. For the individual patients, the dosimetric differences may impact treatment decisions, underscoring the need for strong consensus across borders.
{"title":"Geometrical and dosimetrical evaluation of different interpretations of a european consensus delineation guideline for the internal mammary lymph node chain in breast cancer patients","authors":"Emma Skarsø Buhl , Geert Wortel , Rita Simões , Astrid Scholten , Birgitte Vrou Offersen , Stine Korreman , Tomas Janssen","doi":"10.1016/j.phro.2024.100676","DOIUrl":"10.1016/j.phro.2024.100676","url":null,"abstract":"<div><h3>Background and Purpose</h3><div> <!-->This study aimed at investigating the dosimetric impact on organs at risk, when the left-sided internal mammary lymph nodes (IMN) were delineated with two interpretations of the same guideline.</div></div><div><h3>Materials and Methods</h3><div> <!-->The cohort consisted of 95 left-sided breast cancer patients with indication for irradiation of the CTVn_IMN treated at the Netherlands Cancer Institute (NKI). The NKI interpretation of the ESTRO guidelines was in the clinical structure sets (CTVn_IMN_NKI). A deep learning model was used as second interpretation of the guideline, based on a Danish consensus interpretation (CTVn_IMN_DK). The geometrical similarity was evaluated with the Dice Similarity Coefficient (DSC), volume, width, distance to sternal bone (SB) and maximum distance between the interpretations in the medial direction. Treatment plans were generated for both CTVn_IMNs. Mean heart dose (MHD) was correlated with the geometrical metrics.</div></div><div><h3>Results</h3><div> <!-->62 patients were eligible for analysis. The geometric comparison showed a median volume of 9.59 ml/7.19 ml for the CTVN_IMN_NKI/CTVn_IMN_DK along with a median DSC of 0.63. The width and distance from SB were significantly different, with a median width of 18.2 mm/14.7 mm and distance to SB of 3.4 mm/5.1 mm for CTVn_IMN_NKI/CTVn_IMN_DK. The MHD was significantly higher with the CTVn_IMN_NKI. The strongest correlation was found between MHD and maximum medial difference between the CTVn_IMN in slices where the heart was present.</div></div><div><h3>Conclusions</h3><div>Differences in interpretations of the CTVn_IMN delineation guidelines were found, resulting in significant differences in MHD. For the individual patients, the dosimetric differences may impact treatment decisions, underscoring the need for strong consensus across borders.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"32 ","pages":"Article 100676"},"PeriodicalIF":3.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700258","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}
Pub Date : 2024-10-01DOI: 10.1016/j.phro.2024.100666
Marco Esposito , Riccardo Baldoni , Evy Bossuyt , Sara Bresciani , Catharine H Clark , Matthew Jones , Stephen Kry , Joseph Perry , Jeroen van de Kamer , Dirk Verellen , Nuria Jornet
Background and Purpose
With the availability of commercial electronic portal imaging detector-based in vivo dosimetry (EPID-based IVD) solutions, many radiotherapy departments are adopting this technology. However, comprehensive commissioning guidance is lacking. This study aims to provide a protocol for testing the accuracy and sensitivity of EPID-based IVD systems.
Material and methods
The protocol was tested across four institutions using two different systems. Accuracy was evaluated with homogeneous slab phantoms using different square regular fields, and clinical plans in a CIRS lung phantom. Multiple forward and back-projected algorithm implementations were assessed for different energies. Sensitivity analysis in the lung phantom examined responses to setup errors, anatomical variations, and delivery errors.
Results
In homogeneous phantoms, over 85 % of pixels passed the 5 %/2mm gamma criteria, except for the 2x2 cm2 field. In the lung phantom, all systems and implementations achieved over 95 %-pixel pass rates at the 2 %/2mm criterion for volumetric modulated arc therapy (VMAT) plans. For conformal radiation therapy (3DCRT) plans, one system implementation showed poor accuracy, with over 90 % agreement only at the 5 %/2mm criterion. Considering all systems and implementations, average sensitivity and specificity for CRT plans ranged from 0.92 and 0.42 (at 2 %/2mm) to 0.71 and 0.52 (at 5 %/2mm), while for VMAT plans ranged from 0.41 and 0.81 (at 2 %2mm) to 0.37 and 0.81 (at 5 %/2mm).
Conclusion
We successfully developed a protocol to commission EPID IDV systems. It was found that not all systems and implementations achieved satisfactory accuracy and sensitivity, emphasising the need for thorough commissioning and benchmarking.
{"title":"A commissioning protocol for portal imaging-based radiotherapy in vivo dosimetry systems","authors":"Marco Esposito , Riccardo Baldoni , Evy Bossuyt , Sara Bresciani , Catharine H Clark , Matthew Jones , Stephen Kry , Joseph Perry , Jeroen van de Kamer , Dirk Verellen , Nuria Jornet","doi":"10.1016/j.phro.2024.100666","DOIUrl":"10.1016/j.phro.2024.100666","url":null,"abstract":"<div><h3>Background and Purpose</h3><div>With the availability of commercial electronic portal imaging detector-based in vivo dosimetry (EPID-based IVD) solutions, many radiotherapy departments are adopting this technology. However, comprehensive commissioning guidance is lacking. This study aims to provide a protocol for testing the accuracy and sensitivity of EPID-based IVD systems.</div></div><div><h3>Material and methods</h3><div>The protocol was tested across four institutions using two different systems. Accuracy was evaluated with homogeneous slab phantoms using different square regular fields, and clinical plans in a CIRS lung phantom. Multiple forward and back-projected algorithm implementations were assessed for different energies. Sensitivity analysis in the lung phantom examined responses to setup errors, anatomical variations, and delivery errors.</div></div><div><h3>Results</h3><div>In homogeneous phantoms, over 85 % of pixels passed the 5 %/2mm gamma criteria, except for the 2x2 cm<sup>2</sup> field. In the lung phantom, all systems and implementations achieved over 95 %-pixel pass rates at the 2 %/2mm criterion for volumetric modulated arc therapy (VMAT) plans. For conformal radiation therapy (3DCRT) plans, one system implementation showed poor accuracy, with over 90 % agreement only at the 5 %/2mm criterion. Considering all systems and implementations, average sensitivity and specificity for CRT plans ranged from 0.92 and 0.42 (at 2 %/2mm) to 0.71 and 0.52 (at 5 %/2mm), while for VMAT plans ranged from 0.41 and 0.81 (at 2 %2mm) to 0.37 and 0.81 (at 5 %/2mm).</div></div><div><h3>Conclusion</h3><div>We successfully developed a protocol to commission EPID IDV systems. It was found that not all systems and implementations achieved satisfactory accuracy and sensitivity, emphasising the need for thorough commissioning and benchmarking.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"32 ","pages":"Article 100666"},"PeriodicalIF":3.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660814","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}
Pub Date : 2024-10-01DOI: 10.1016/j.phro.2024.100661
Audrey Cantin , Marie-Claude Lavallée , Eric Poulin , Gilion Hautvast , William Foster , Luc Beaulieu
Background and Purpose
The addition of interstitial needles to intracavitary gynecologic (GYN) high dose rate (HDR) brachytherapy has been shown to improve target coverage and organs-at-risk (OAR) sparing. However, no commercial solution allows real-time guidance of interstitial catheter placement. This phantom study aimed to evaluate the feasibility of an electromagnetic (EM) tracking system guidance workflow for GYN HDR brachytherapy treatment in a magnetic resonance imaging (MRI) and real-time transrectal ultrasound (TRUS) fusion scenario.
Materials and Methods
A clinical investigational system combining a treatment planning system and the EM tracking technology was used. The 3D T2 weighted magnetic resonance (MR) image set of a patient treated with intracavitary and interstitial HDR brachytherapy was retrospectively chosen. The MR image set was used to delineate the target and the OARs. A preplan was generated to determine needles positions in advance. The implant was reproduced in a water phantom. A 3D TRUS scan was acquired, and a rigid registration between the MR and the TRUS images was performed.
Results
The accuracy of the EM tracking system was < 1 mm for both the sagittal and the transverse modes of the TRUS probe. Contours that were delineated on the MRI were propagated on the TRUS images after the rigid registration. Needle insertion was successfully guided in real time with the EM tracking system on the TRUS live image using the MRI contours for guidance.
Conclusion
Based on this proof-of-concept, real-time EM-guidance of interstitial needle for GYN HDR brachytherapy appears to be feasible.
{"title":"Proof-of-concept of real-time electromagnetic guidance for gynecologic interstitial catheters in high dose rate brachytherapy","authors":"Audrey Cantin , Marie-Claude Lavallée , Eric Poulin , Gilion Hautvast , William Foster , Luc Beaulieu","doi":"10.1016/j.phro.2024.100661","DOIUrl":"10.1016/j.phro.2024.100661","url":null,"abstract":"<div><h3>Background and Purpose</h3><div>The addition of interstitial needles to intracavitary gynecologic (GYN) high dose rate (HDR) brachytherapy has been shown to improve target coverage and organs-at-risk (OAR) sparing. However, no commercial solution allows real-time guidance of interstitial catheter placement. This phantom study aimed to evaluate the feasibility of an electromagnetic (EM) tracking system guidance workflow for GYN HDR brachytherapy treatment in a magnetic resonance imaging (MRI) and real-time transrectal ultrasound (TRUS) fusion scenario.</div></div><div><h3>Materials and Methods</h3><div>A clinical investigational system combining a treatment planning system and the EM tracking technology was used. The 3D T2 weighted magnetic resonance (MR) image set of a patient treated with intracavitary and interstitial HDR brachytherapy was retrospectively chosen. The MR image set was used to delineate the target and the OARs. A preplan was generated to determine needles positions in advance. The implant was reproduced in a water phantom. A 3D TRUS scan was acquired, and a rigid registration between the MR and the TRUS images was performed.</div></div><div><h3>Results</h3><div>The accuracy of the EM tracking system was < 1 mm for both the sagittal and the transverse modes of the TRUS probe. Contours that were delineated on the MRI were propagated on the TRUS images after the rigid registration. Needle insertion was successfully guided in real time with the EM tracking system on the TRUS live image using the MRI contours for guidance.</div></div><div><h3>Conclusion</h3><div>Based on this proof-of-concept, real-time EM-guidance of interstitial needle for GYN HDR brachytherapy appears to be feasible.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"32 ","pages":"Article 100661"},"PeriodicalIF":3.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552814","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}
Pub Date : 2024-09-23DOI: 10.1016/j.phro.2024.100653
Eric Aliotta , Ramesh Paudyal , Alex Dresner , Amita Shukla-Dave , Nancy Lee , Laura Cerviño , Ricardo Otazo , Victoria Y. Yu
Background and purpose
Quantitative Diffusion Weighted Imaging (DWI) has potential value in guiding head and neck (HN) cancer radiotherapy. However, clinical translation has been hindered by severe distortions in standard single-shot Echo-Planar-Imaging (ssEPI) and prolonged scan time and low SNR in Turbo-Spin-Echo (ssTSE) sequences. In this study, we evaluate “multi-shot” (ms) msEPI and msTSE acquisitions in the context of HN radiotherapy.
Materials and methods
ssEPI, ssTSE, msEPI with 2 and 3 shots (2sEPI, 3sEPI), and msTSE DWI were acquired in a phantom, healthy volunteers (N=10), and patients with HN cancer (N=5) on a 3-Tesla wide-bore MRI in radiotherapy simulation RF coil setup, with matched spatial resolution (2x2x5mm) and b = 0, 200, 800 s/mm2.
Geometric distortions measured with deformable vector field (DVF) and contour analysis, apparent diffusion coefficient (ADC) values, and signal-to-noise-ratio efficiency (SNReff) were quantified for all scans.
Results
All techniques significantly (P<1x10-3) reduced distortions compared with ssEPI (DVFmean = 3.1 ± 1.3 mm). Distortions were marginally lower for msTSE (DVFmean = 1.5 ± 0.6 mm) than ssTSE (1.8 ± 0.9 mm), but were slightly higher with 2sEPI and 3sEPI (2.6 ± 1.0 mm, 2.2 ± 1.0 mm). SNReff reduced with decreasing distortion with ssEPI=21.9 ± 7.9, 2sEPI=15.1 ± 5.0, 3sEPI=12.1 ± 4.5, ssTSE=6.0 ± 1.6, and msTSE=5.7 ± 1.9 for b = 0 images. Phantom ADC values were consistent across all protocols (errors ≤ 0.03x10-3mm2/s), but in vivo ADC values were ∼ 4 % lower with msEPI and ∼ 12 % lower with ssTSE/msTSE compared with ssEPI.
Conclusions
msEPI and TSE acquisitions exhibited improved geometric distortion at the cost of SNReff and scan time. While msTSE exhibited the least distortion, 3sEPI may offer an appealing middle-ground with improved geometric fidelity but superior efficiency and in vivo ADC quantification.
{"title":"Reduced-distortion diffusion weighted imaging for head and neck radiotherapy","authors":"Eric Aliotta , Ramesh Paudyal , Alex Dresner , Amita Shukla-Dave , Nancy Lee , Laura Cerviño , Ricardo Otazo , Victoria Y. Yu","doi":"10.1016/j.phro.2024.100653","DOIUrl":"10.1016/j.phro.2024.100653","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Quantitative Diffusion Weighted Imaging (DWI) has potential value in guiding head and neck (HN) cancer radiotherapy. However, clinical translation has been hindered by severe distortions in standard single-shot Echo-Planar-Imaging (ssEPI) and prolonged scan time and low SNR in Turbo-Spin-Echo (ssTSE) sequences. In this study, we evaluate “multi-shot” (ms) msEPI and msTSE acquisitions in the context of HN radiotherapy.</div></div><div><h3>Materials and methods</h3><div>ssEPI, ssTSE, msEPI with 2 and 3 shots (2sEPI, 3sEPI), and msTSE DWI were acquired in a phantom, healthy volunteers (N=10), and patients with HN cancer (N=5) on a 3-Tesla wide-bore MRI in radiotherapy simulation RF coil setup, with matched spatial resolution (2x2x5mm) and b = 0, 200, 800 s/mm<sup>2</sup>.</div><div>Geometric distortions measured with deformable vector field (DVF) and contour analysis, apparent diffusion coefficient (ADC) values, and signal-to-noise-ratio efficiency (SNR<sub>eff</sub>) were quantified for all scans.</div></div><div><h3>Results</h3><div>All techniques significantly (P<1x10<sup>-3</sup>) reduced distortions compared with ssEPI (DVF<sub>mean</sub> = 3.1 ± 1.3 mm). Distortions were marginally lower for msTSE (DVF<sub>mean</sub> = 1.5 ± 0.6 mm) than ssTSE (1.8 ± 0.9 mm), but were slightly higher with 2sEPI and 3sEPI (2.6 ± 1.0 mm, 2.2 ± 1.0 mm). SNR<sub>eff</sub> reduced with decreasing distortion with ssEPI=21.9 ± 7.9, 2sEPI=15.1 ± 5.0, 3sEPI=12.1 ± 4.5, ssTSE=6.0 ± 1.6, and msTSE=5.7 ± 1.9 for b = 0 images. Phantom ADC values were consistent across all protocols (errors ≤ 0.03x10<sup>-3</sup>mm<sup>2</sup>/s), but <em>in vivo</em> ADC values were ∼ 4 % lower with msEPI and ∼ 12 % lower with ssTSE/msTSE compared with ssEPI.</div></div><div><h3>Conclusions</h3><div>msEPI and TSE acquisitions exhibited improved geometric distortion at the cost of SNR<sub>eff</sub> and scan time. While msTSE exhibited the least distortion, 3sEPI may offer an appealing middle-ground with improved geometric fidelity but superior efficiency and <em>in vivo</em> ADC quantification.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"32 ","pages":"Article 100653"},"PeriodicalIF":3.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326657","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}
Pub Date : 2024-09-16DOI: 10.1016/j.phro.2024.100645
Joel Poder , Peter Hoskin , Hayley Reynolds , Tsz Him Chan , Annette Haworth
Focal boost to intra-prostatic lesions (IPLs) in radiotherapy could enhance treatment efficacy. Brachytherapy (BT), delivering highly conformal dose with sharp dose gradients emerges as a potentially optimal approach for precise dose escalation to IPLs. This study aims to consolidate clinical and planning studies that implemented whole gland prostate BT and focal dose escalation to IPLs, with the view to synthesize evidence on the strategy’s effectiveness and variability. In this review, we identified nine clinical studies and ten planning/simulation studies focusing on whole gland prostate BT with IPL dose escalation. From the clinical studies, the use of whole gland prostate BT with focal dose escalation in combination with external beam radiotherapy (EBRT) appears to be a safe and effective 21 form of treatment for men with T1b – T2c prostate cancer with average five-year biochemical failure22 free survival (BFFS) of 94 % (range 81.1 %−100 %) and minimal grade three toxicities reported. Both clinical and planning studies exemplified the high level of focal dose escalation achievable using BT with a mean IPL D90 % of 132 % and 146 %, respectively (expressed as a % of the whole gland prescription dose). There was considerable variation in the reporting of clinical and technical data in the identified studies. To facilitate a more widespread and uniform adoption of the technique, recommendations on essential and desirable items to be included in future studies incorporating whole gland prostate BT with focal boost to IPLs are provided.
{"title":"A review of whole gland prostate brachytherapy with focal dose escalation to intra-prostatic lesions: Clinical efficacy and technical aspects","authors":"Joel Poder , Peter Hoskin , Hayley Reynolds , Tsz Him Chan , Annette Haworth","doi":"10.1016/j.phro.2024.100645","DOIUrl":"10.1016/j.phro.2024.100645","url":null,"abstract":"<div><div>Focal boost to intra-prostatic lesions (IPLs) in radiotherapy could enhance treatment efficacy. Brachytherapy (BT), delivering highly conformal dose with sharp dose gradients emerges as a potentially optimal approach for precise dose escalation to IPLs. This study aims to consolidate clinical and planning studies that implemented whole gland prostate BT and focal dose escalation to IPLs, with the view to synthesize evidence on the strategy’s effectiveness and variability. In this review, we identified nine clinical studies and ten planning/simulation studies focusing on whole gland prostate BT with IPL dose escalation. From the clinical studies, the use of whole gland prostate BT with focal dose escalation in combination with external beam radiotherapy (EBRT) appears to be a safe and effective 21 form of treatment for men with T1b – T2c prostate cancer with average five-year biochemical failure22 free survival (BFFS) of 94 % (range 81.1 %−100 %) and minimal grade three toxicities reported. Both clinical and planning studies exemplified the high level of focal dose escalation achievable using BT with a mean IPL D90 % of 132 % and 146 %, respectively (expressed as a % of the whole gland prescription dose). There was considerable variation in the reporting of clinical and technical data in the identified studies. To facilitate a more widespread and uniform adoption of the technique, recommendations on essential and desirable items to be included in future studies incorporating whole gland prostate BT with focal boost to IPLs are provided.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"32 ","pages":"Article 100645"},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624001155/pdfft?md5=fb857f773cb65fce3a672a8b177ccbbf&pid=1-s2.0-S2405631624001155-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311434","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}
Pub Date : 2024-09-16DOI: 10.1016/j.phro.2024.100648
Chavelli M. Kensen , Rita Simões , Anja Betgen , Lisa Wiersema , Doenja M.J. Lambregts , Femke P. Peters , Corrie A.M. Marijnen , Uulke A. van der Heide , Tomas M. Janssen
Background and purpose
In online adaptive magnetic resonance image (MRI)-guided radiotherapy (MRIgRT), manual contouring of rectal tumors on daily images is labor-intensive and time-consuming. Automation of this task is complex due to substantial variation in tumor shape and location between patients. The aim of this work was to investigate different approaches of propagating patient-specific prior information to the online adaptive treatment fractions to improve deep-learning based auto-segmentation of rectal tumors.
Materials and methods
243 T2-weighted MRI scans of 49 rectal cancer patients treated on the 1.5T MR-Linear accelerator (MR-Linac) were utilized to train models to segment rectal tumors. As benchmark, an MRI_only auto-segmentation model was trained. Three approaches of including a patient-specific prior were studied: 1. include the segmentations of fraction 1 as extra input channel for the auto-segmentation of subsequent fractions, 2. fine-tuning of the MRI_only model to fraction 1 (PSF_1) and 3. fine-tuning of the MRI_only model on all earlier fractions (PSF_cumulative). Auto-segmentations were compared to the manual segmentation using geometric similarity metrics. Clinical impact was assessed by evaluating post-treatment target coverage.
Results
All patient-specific methods outperformed the MRI_only segmentation approach. Median 95th percentile Hausdorff (95HD) were 22.0 (range: 6.1–76.6) mm for MRI_only segmentation, 9.9 (range: 2.5–38.2) mm for MRI+prior segmentation, 6.4 (range: 2.4–17.8) mm for PSF_1 and 4.8 (range: 1.7–26.9) mm for PSF_cumulative. PSF_cumulative was found to be superior to PSF_1 from fraction 4 onward (p = 0.014).
Conclusion
Patient-specific fine-tuning of automatically segmented rectal tumors, using images and segmentations from all previous fractions, yields superior quality compared to other auto-segmentation approaches.
{"title":"Incorporating patient-specific information for the development of rectal tumor auto-segmentation models for online adaptive magnetic resonance Image-guided radiotherapy","authors":"Chavelli M. Kensen , Rita Simões , Anja Betgen , Lisa Wiersema , Doenja M.J. Lambregts , Femke P. Peters , Corrie A.M. Marijnen , Uulke A. van der Heide , Tomas M. Janssen","doi":"10.1016/j.phro.2024.100648","DOIUrl":"10.1016/j.phro.2024.100648","url":null,"abstract":"<div><h3>Background and purpose</h3><p>In online adaptive magnetic resonance image (MRI)-guided radiotherapy (MRIgRT), manual contouring of rectal tumors on daily images is labor-intensive and time-consuming. Automation of this task is complex due to substantial variation in tumor shape and location between patients. The aim of this work was to investigate different approaches of propagating patient-specific prior information to the online adaptive treatment fractions to improve deep-learning based auto-segmentation of rectal tumors.</p></div><div><h3>Materials and methods</h3><p>243 T2-weighted MRI scans of 49 rectal cancer patients treated on the 1.5T MR-Linear accelerator (MR-Linac) were utilized to train models to segment rectal tumors. As benchmark, an MRI_only auto-segmentation model was trained. Three approaches of including a patient-specific prior were studied: 1. include the segmentations of fraction 1 as extra input channel for the auto-segmentation of subsequent fractions, 2. fine-tuning of the MRI_only model to fraction 1 (PSF_1) and 3. fine-tuning of the MRI_only model on all earlier fractions (PSF_cumulative). Auto-segmentations were compared to the manual segmentation using geometric similarity metrics. Clinical impact was assessed by evaluating post-treatment target coverage.</p></div><div><h3>Results</h3><p>All patient-specific methods outperformed the MRI_only segmentation approach. Median 95th percentile Hausdorff (95HD) were 22.0 (range: 6.1–76.6) mm for MRI_only segmentation, 9.9 (range: 2.5–38.2) mm for MRI+prior segmentation, 6.4 (range: 2.4–17.8) mm for PSF_1 and 4.8 (range: 1.7–26.9) mm for PSF_cumulative. PSF_cumulative was found to be superior to PSF_1 from fraction 4 onward (p = 0.014).</p></div><div><h3>Conclusion</h3><p>Patient-specific fine-tuning of automatically segmented rectal tumors, using images and segmentations from all previous fractions, yields superior quality compared to other auto-segmentation approaches.</p></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"32 ","pages":"Article 100648"},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624001180/pdfft?md5=bf30e0e5baddbf3b8635126444c1301f&pid=1-s2.0-S2405631624001180-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142239769","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}
Pub Date : 2024-09-16DOI: 10.1016/j.phro.2024.100650
Mairead Daly , Lisa McDaid , Carmel Anandadas , Andrew Brocklehurst , Ananya Choudhury , Alan McWilliam , Ganesh Radhakrishna , Cynthia L. Eccles
Background and purpose
The impact of respiratory motion management strategies for abdominal radiotherapy, such as abdominal compression (AC) and breath hold (BH), on abdominal organ at risk (OAR) delineation on magnetic resonance imaging (MRI) is unknown. This feasibility study compared the inter- and intra- observer delineation variation on MRI acquired with AC, BH for three critical abdominal OAR.
Materials and methods
T2-weighted (W) 3D MRI in free-breathing (FB) and with AC, and T1W 3D mDixon exhale BH were acquired. Four observers blinded to motion management strategy used, delineated stomach, liver, and duodenum on all MRI. One case per strategy was repeated over 6 weeks later to quantify intra-observer variation. Simultaneous truth and performance level estimation (STAPLE) contours for each OAR were generated, median and IQR mean distance to agreement (mDTA) and maximum Hausdorff distance (HD) between observer and STAPLE contours were calculated. Observers scored organ visibility on each MRI using a four-point Likert scale.
Results
A total of 27 scans including repeats were delineated. Pooled mDTA for all OARs was 1.3 mm (0.5 mm) with AC, 1.4 mm (1.0 mm) with BH, and 1.3 mm (0.5 mm) in FB. Intra-observer mDTA was highest for all organs in FB with 10.8 mm for duodenum, 1.8 mm for liver, and 2.7 mm for stomach. The pooled mean perceptual quality score value was highest for AC across organs.
Conclusions
No motion management strategy demonstrated superior similarity across OAR, emphasizing the need for personalised approaches based on individual clinical and patient factors.
{"title":"Impact of motion management strategies on abdominal organ at risk delineation for magnetic resonance-guided radiotherapy","authors":"Mairead Daly , Lisa McDaid , Carmel Anandadas , Andrew Brocklehurst , Ananya Choudhury , Alan McWilliam , Ganesh Radhakrishna , Cynthia L. Eccles","doi":"10.1016/j.phro.2024.100650","DOIUrl":"10.1016/j.phro.2024.100650","url":null,"abstract":"<div><h3>Background and purpose</h3><div>The impact of respiratory motion management strategies for abdominal radiotherapy, such as abdominal compression (AC) and breath hold (BH), on abdominal organ at risk (OAR) delineation on magnetic resonance imaging (MRI) is unknown. This feasibility study compared the inter- and intra- observer delineation variation on MRI acquired with AC, BH for three critical abdominal OAR.</div></div><div><h3>Materials and methods</h3><div>T2-weighted (W) 3D MRI in free-breathing (FB) and with AC, and T1W 3D mDixon exhale BH were acquired. Four observers blinded to motion management strategy used, delineated stomach, liver, and duodenum on all MRI. One case per strategy was repeated over 6 weeks later to quantify intra-observer variation. Simultaneous truth and performance level estimation (STAPLE) contours for each OAR were generated, median and IQR mean distance to agreement (mDTA) and maximum Hausdorff distance (HD) between observer and STAPLE contours were calculated. Observers scored organ visibility on each MRI using a four-point Likert scale.</div></div><div><h3>Results</h3><div>A total of 27 scans including repeats were delineated. Pooled mDTA for all OARs was 1.3 mm (0.5 mm) with AC, 1.4 mm (1.0 mm) with BH, and 1.3 mm (0.5 mm) in FB. Intra-observer mDTA was highest for all organs in FB with 10.8 mm for duodenum, 1.8 mm for liver, and 2.7 mm for stomach. The pooled mean perceptual quality score value was highest for AC across organs.</div></div><div><h3>Conclusions</h3><div>No motion management strategy demonstrated superior similarity across OAR, emphasizing the need for personalised approaches based on individual clinical and patient factors.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"32 ","pages":"Article 100650"},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624001209/pdfft?md5=3ca1884b9a70abce37c31b168701b85f&pid=1-s2.0-S2405631624001209-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311511","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}
Pub Date : 2024-09-14DOI: 10.1016/j.phro.2024.100649
Aly Khalifa , Jeff D. Winter , Tony Tadic , Thomas G. Purdie , Chris McIntosh
Background and purpose
No best practices currently exist for achieving high quality radiation therapy (RT) treatment plan adaptation during magnetic resonance (MR) guided RT of prostate cancer. This study validates the use of machine learning (ML) automated RT treatment plan adaptation and benchmarks it against current clinical RT plan adaptation methods.
Materials and methods
We trained an atlas-based ML automated treatment planning model using reference MR RT treatment plans (42.7 Gy in 7 fractions) from 46 patients with prostate cancer previously treated at our institution. For a held-out test set of 38 patients, retrospectively generated ML RT plans were compared to clinical human-generated adaptive RT plans for all 266 fractions. Differences in dose-volume metrics and clinical objective pass rates were evaluated using Wilcoxon tests (p < 0.05) and Exact McNemar tests (p < 0.05), respectively.
Results
Compared to clinical RT plans, ML RT plans significantly increased sparing and objective pass rates of the rectum, bladder, and left femur. The mean ± standard deviation of rectum D20 and D50 in ML RT plans were 2.5 ± 2.2 Gy and 1.6 ± 1.3 Gy lower than clinical RT plans, respectively, with 14 % higher pass rates; bladder D40 was 4.6 ± 2.9 Gy lower with a 20 % higher pass rate; and the left femur D5 was 0.8 ± 1.8 Gy lower with a 7 % higher pass rate.
Conclusions
ML automated RT treatment plan adaptation increases robustness to interfractional anatomical changes compared to current clinical adaptive RT practices by increasing compliance to treatment objectives.
{"title":"Machine learning automated treatment planning for online magnetic resonance guided adaptive radiotherapy of prostate cancer","authors":"Aly Khalifa , Jeff D. Winter , Tony Tadic , Thomas G. Purdie , Chris McIntosh","doi":"10.1016/j.phro.2024.100649","DOIUrl":"10.1016/j.phro.2024.100649","url":null,"abstract":"<div><h3>Background and purpose</h3><p>No best practices currently exist for achieving high quality radiation therapy (RT) treatment plan adaptation during magnetic resonance (MR) guided RT of prostate cancer. This study validates the use of machine learning (ML) automated RT treatment plan adaptation and benchmarks it against current clinical RT plan adaptation methods.</p></div><div><h3>Materials and methods</h3><p>We trained an atlas-based ML automated treatment planning model using reference MR RT treatment plans (42.7 Gy in 7 fractions) from 46 patients with prostate cancer previously treated at our institution. For a held-out test set of 38 patients, retrospectively generated ML RT plans were compared to clinical human-generated adaptive RT plans for all 266 fractions. Differences in dose-volume metrics and clinical objective pass rates were evaluated using Wilcoxon tests (p < 0.05) and Exact McNemar tests (p < 0.05), respectively.</p></div><div><h3>Results</h3><p>Compared to clinical RT plans, ML RT plans significantly increased sparing and objective pass rates of the rectum, bladder, and left femur. The mean ± standard deviation of rectum D20 and D50 in ML RT plans were 2.5 ± 2.2 Gy and 1.6 ± 1.3 Gy lower than clinical RT plans, respectively, with 14 % higher pass rates; bladder D40 was 4.6 ± 2.9 Gy lower with a 20 % higher pass rate; and the left femur D5 was 0.8 ± 1.8 Gy lower with a 7 % higher pass rate.</p></div><div><h3>Conclusions</h3><p>ML automated RT treatment plan adaptation increases robustness to interfractional anatomical changes compared to current clinical adaptive RT practices by increasing compliance to treatment objectives.</p></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"32 ","pages":"Article 100649"},"PeriodicalIF":3.4,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624001192/pdfft?md5=2171029966e3c5a6468365da4d535bfd&pid=1-s2.0-S2405631624001192-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142239969","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}
Proton Online Adaptive RadioTherapy (ProtOnART) harnesses the dosimetric advantage of protons and immediately acts upon anatomical changes. Here, we simulate the clinical application of delineation and planning within a ProtOnART-workflow for esophageal cancer. We aim to identify the most appropriate technique for autodelineation and evaluate full automation by replanning on autodelineated contours.
Materials and methods
We evaluated 15 patients who started treatment between 11-2022 and 01-2024, undergoing baseline and three repeat computed tomography (CT) scans in treatment position. Quantitative and qualitative evaluations compared different autodelineation methods. For Organs-at-risk (OAR) deep learning segmentation (DLS), rigid and deformable propagation from baseline to repeat CT-scans were considered. For the clinical target volume (CTV), rigid and three deformable propagation methods (default, heart as controlling structure and with focus region) were evaluated. Adaptive treatment plans with 7 mm (ATP7mm) and 3 mm (ATP3mm) setup robustness were generated using best-performing autodelineated contours. Clinical acceptance of ATPs was evaluated using goals encompassing ground-truth CTV-coverage and OAR-dose.
Results
Deformation was preferred for autodelineation of heart, lungs and spinal cord. DLS was preferred for all other OARs. For CTV, deformation with focus region was the preferred method although the difference with other deformation methods was small. Nominal ATPs passed evaluation goals for 87 % of ATP7mm and 67 % of ATP3mm. This dropped to respectively 2 % and 29 % after robust evaluation. Insufficient CTV-coverage was the main reason for ATP-rejection.
Conclusion
Autodelineation aids a ProtOnART-workflow for esophageal cancer. Currently available tools regularly require manual annotations to generate clinically acceptable ATPs.
{"title":"Autodelineation methods in a simulated fully automated proton therapy workflow for esophageal cancer","authors":"Pieter Populaire , Beatrice Marini , Kenneth Poels , Stina Svensson , Edmond Sterpin , Albin Fredriksson , Karin Haustermans","doi":"10.1016/j.phro.2024.100646","DOIUrl":"10.1016/j.phro.2024.100646","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Proton Online Adaptive RadioTherapy (ProtOnART) harnesses the dosimetric advantage of protons and immediately acts upon anatomical changes. Here, we simulate the clinical application of delineation and planning within a ProtOnART-workflow for esophageal cancer. We aim to identify the most appropriate technique for autodelineation and evaluate full automation by replanning on autodelineated contours.</div></div><div><h3>Materials and methods</h3><div>We evaluated 15 patients who started treatment between 11-2022 and 01-2024, undergoing baseline and three repeat computed tomography (CT) scans in treatment position. Quantitative and qualitative evaluations compared different autodelineation methods. For Organs-at-risk (OAR) deep learning segmentation (DLS), rigid and deformable propagation from baseline to repeat CT-scans were considered. For the clinical target volume (CTV), rigid and three deformable propagation methods (default, heart as controlling structure and with focus region) were evaluated. Adaptive treatment plans with 7 mm (ATP<sub>7mm</sub>) and 3 mm (ATP<sub>3mm</sub>) setup robustness were generated using best-performing autodelineated contours. Clinical acceptance of ATPs was evaluated using goals encompassing ground-truth CTV-coverage and OAR-dose.</div></div><div><h3>Results</h3><div>Deformation was preferred for autodelineation of heart, lungs and spinal cord. DLS was preferred for all other OARs. For CTV, deformation with focus region was the preferred method although the difference with other deformation methods was small. Nominal ATPs passed evaluation goals for 87 % of ATP<sub>7mm</sub> and 67 % of ATP<sub>3mm</sub>. This dropped to respectively 2 % and 29 % after robust evaluation. Insufficient CTV-coverage was the main reason for ATP-rejection.</div></div><div><h3>Conclusion</h3><div>Autodelineation aids a ProtOnART-workflow for esophageal cancer. Currently available tools regularly require manual annotations to generate clinically acceptable ATPs.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"32 ","pages":"Article 100646"},"PeriodicalIF":3.4,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624001167/pdfft?md5=1b1eb557e68831ef41fd49ccf36d36d0&pid=1-s2.0-S2405631624001167-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314571","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}
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