Physics and Imaging in Radiation Oncology最新文献

{"title":"Monte Carlo-based simulation of virtual 3 and 4-dimensional cone-beam computed tomography from computed tomography images: An end-to-end framework and a deep learning-based speedup strategy","authors":"Frederic Madesta ,&nbsp;Thilo Sentker ,&nbsp;Clemens Rohling ,&nbsp;Tobias Gauer ,&nbsp;Rüdiger Schmitz ,&nbsp;René Werner","doi":"10.1016/j.phro.2024.100644","DOIUrl":"10.1016/j.phro.2024.100644","url":null,"abstract":"<div><h3><strong>Background and purpose:</strong></h3><div>In radiotherapy, precise comparison of fan-beam computed tomography (CT) and cone-beam CT (CBCT) arises as a commonplace, yet intricate task. This paper proposes a publicly available end-to-end pipeline featuring an intrinsic deep-learning-based speedup technique for generating virtual 3D and 4D CBCT from CT images.</div></div><div><h3><strong>Materials and methods:</strong></h3><div>Physical properties, derived from CT intensity information, are obtained through automated whole-body segmentation of organs and tissues. Subsequently, Monte Carlo (MC) simulations generate CBCT X-ray projections for a full circular arc around the patient employing acquisition settings matched with a clinical CBCT scanner (modeled according to Varian TrueBeam specifications). In addition to 3D CBCT reconstruction, a 4D CBCT can be simulated with a fully time-resolved MC simulation by incorporating respiratory correspondence modeling. To address the computational complexity of MC simulations, a deep-learning-based speedup technique is developed and integrated that uses projection data simulated with a reduced number of photon histories to predict a projection that matches the image characteristics and signal-to-noise ratio of the reference simulation.</div></div><div><h3><strong>Results:</strong></h3><div>MC simulations with default parameter setting yield CBCT images with high agreement to ground truth data acquired by a clinical CBCT scanner. Furthermore, the proposed speedup technique achieves up to 20-fold speedup while preserving image features and resolution compared to the reference simulation.</div></div><div><h3><strong>Conclusion:</strong></h3><div>The presented MC pipeline and speedup approach provide an openly accessible end-to-end framework for researchers and clinicians to investigate limitations of image-guided radiation therapy workflows built on both (4D) CT and CBCT images.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624001143/pdfft?md5=a2ef1733dec9a86dd7b884c1ab4db9d1&pid=1-s2.0-S2405631624001143-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311512","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}

{"title":"Cherenkov imaging combined with scintillation dosimetry provides real-time positional and dose monitoring for radiotherapy patients with cardiac implanted electronic devices","authors":"Savannah M. Decker ,&nbsp;Allison L. Matous ,&nbsp;Rongxiao Zhang ,&nbsp;David J. Gladstone ,&nbsp;Evan K. Grove ,&nbsp;Benjamin B. Williams ,&nbsp;Michael Jermyn ,&nbsp;Shauna McVorran ,&nbsp;Lesley A. Jarvis","doi":"10.1016/j.phro.2024.100642","DOIUrl":"10.1016/j.phro.2024.100642","url":null,"abstract":"<div><h3>Background and purpose</h3><p>Cardiac implanted electronic devices (CIED) require dose monitoring during each fraction of radiotherapy, which can be time consuming and may have delayed read-out times. This study explores the potential of Cherenkov imaging combined with scintillation dosimetry as an alternative verification system.</p></div><div><h3>Methods and materials</h3><p>Time-gated, complementary metal–oxide–semiconductor (iCMOS) cameras were used to collect video images of anthropomorphic phantoms and patients undergoing radiation treatment near chest wall cardiac devices. Scintillator discs and optically stimulated luminescence dosimeters (OSLDs) were used for dose measurement. Accuracy of spatial delivery was assessed by overlaying predicted surface dose outlines derived from the treatment planning system (TPS) with the Cherenkov images. Dose measurements from OSLDs and scintillators were compared.</p></div><div><h3>Results</h3><p>In phantom studies, Cherenkov images visibly indicated when dose was delivered to the CIED as compared to non-overlapping dose deliveries. Comparison with dose overlays revealed congruence at the planned position and non-congruence when the phantom was shifted from the initial position. Absolute doses derived from scintillator discs aligned well with the OSLD measurements and TPS predictions for three different positions, measuring within 10 % for in-field positions and within 5 % for out-of-field positions. For two patients with CIEDs imaged over 18 fractions, Cherenkov imaging confirmed positional accuracy for all fractions, and dose measured by scintillator discs deviated by &lt;0.015 Gy from the OSLD measurements.</p></div><div><h3>Conclusions</h3><p>Cherenkov imaging combined with scintillation dosimetry presents an alternative methodology for CIED monitoring with the added benefit of instantly detecting deviations, enabling timely corrective actions or proper patient triage.</p></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S240563162400112X/pdfft?md5=bcc54fe1b2a9adcb0173fd6499217ee7&pid=1-s2.0-S240563162400112X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232134","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}

{"title":"Automated plan generation for prostate radiotherapy patients using deep learning and scripted optimization","authors":"Cody Church ,&nbsp;Michelle Yap ,&nbsp;Mohamed Bessrour ,&nbsp;Michael Lamey ,&nbsp;Dal Granville","doi":"10.1016/j.phro.2024.100641","DOIUrl":"10.1016/j.phro.2024.100641","url":null,"abstract":"<div><h3>Background and Purpose</h3><p>Treatment planning is a time-intensive task that could be automated. We aimed to develop a “single-click” workflow, fully deployed within a commercial treatment planning system (TPS), for autoplanning prostate radiotherapy treatment plans using predictions from a deep learning model (DLM).</p></div><div><h3>Materials and Methods</h3><p>Automatically generated treatment plans were created with a single script, executed from within a commercial TPS scripting environment, that performed two stages sequentially. Initially, a 3D dose distribution was predicted with a ResUNet DLM. The DLM was trained and validated using previously treated datasets (n = 120) which used 3D contours as inputs. Following this, dose predictions were converted into treatment plans by extracting dose-volume metrics from the predictions to use as objectives for the inverse optimizer within the TPS. An independent test dataset (n = 20) was used to evaluate the similarity between automated and clinical plans.</p></div><div><h3>Results</h3><p>For planning target volumes, the median percentage difference and interquartile range between the automatically generated plans and clinical plans were 0.4% [0.2-1.1%] for the V_100%, −0.5% [(−1.0)-(−0.2)%] for D_99% and −0.5% [(−1.0)-(−0.2)%] for D_95%. Bladder and rectum volume-at-dose objectives agreed within −6.1% [(−12.5)-0.9%]. The conversion of the DLM prediction into a treatment plan took 15 min [13-16 min].</p></div><div><h3>Conclusions</h3><p>An automatic plan generation workflow that uses a DL model with scripted optimization was fully deployed in a commercial TPS. Autoplans were compared to previously treated clinical plans and were found to be non-inferior.</p></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624001118/pdfft?md5=6fcbb63bca1c9fd02b6fc82ecbe8a942&pid=1-s2.0-S2405631624001118-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142173316","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}

{"title":"Optimising inter-patient image registration for image-based data mining in breast radiotherapy","authors":"Tanwiwat Jaikuna ,&nbsp;Fiona Wilson ,&nbsp;David Azria ,&nbsp;Jenny Chang-Claude ,&nbsp;Maria Carmen De Santis ,&nbsp;Sara Gutiérrez-Enríquez ,&nbsp;Marcel van Herk ,&nbsp;Peter Hoskin ,&nbsp;Lea Kotzki ,&nbsp;Maarten Lambrecht ,&nbsp;Zoe Lingard ,&nbsp;Petra Seibold ,&nbsp;Alejandro Seoane ,&nbsp;Elena Sperk ,&nbsp;R Paul Symonds ,&nbsp;Christopher J. Talbot ,&nbsp;Tiziana Rancati ,&nbsp;Tim Rattay ,&nbsp;Victoria Reyes ,&nbsp;Barry S. Rosenstein ,&nbsp;Eliana Vasquez Osorio","doi":"10.1016/j.phro.2024.100635","DOIUrl":"10.1016/j.phro.2024.100635","url":null,"abstract":"<div><h3>Background and purpose</h3><p>Image-based data mining (IBDM) requires spatial normalisation to reference anatomy, which is challenging in breast radiotherapy due to variations in the treatment position, breast shape and volume. We aim to optimise spatial normalisation for breast IBDM.</p></div><div><h3>Materials and methods</h3><p>Data from 996 patients treated with radiotherapy for early-stage breast cancer, recruited in the REQUITE study, were included. Patients were treated supine (n = 811), with either bilateral or ipsilateral arm(s) raised (551/260, respectively) or in prone position (n = 185). Four deformable image registration (DIR) configurations for extrathoracic spatial normalisation were tested. We selected the best-performing DIR configuration and further investigated two pathways: <em>i</em>) registering prone/supine cohorts independently and <em>ii</em>) registering all patients to a supine reference. The impact of arm positioning in the supine cohort was quantified. DIR accuracy was estimated using Normalised Cross Correlation (NCC), Dice Similarity Coefficient (DSC), mean Distance to Agreement (MDA), 95 % Hausdorff Distance (95 %HD), and inter-patient landmark registration uncertainty (ILRU).</p></div><div><h3>Results</h3><p>DIR using B-spline and normalised mutual information (NMI) performed the best across all evaluation metrics. Supine-supine registrations yielded highest accuracy (0.98 ± 0.01, 0.91 ± 0.04, 0.23 ± 0.19 cm, 1.17 ± 1.18 cm, 0.51 ± 0.26 cm for NCC, DSC, MDA, 95 %HD, and ILRU), followed by prone-prone and supine-prone registrations. Arm positioning had no significant impact on registration performance. For the best DIR strategy, uncertainty of 0.44 and 0.81 cm in the breast and shoulder regions was found.</p></div><div><h3>Conclusions</h3><p>B-spline algorithm using NMI and registered supine and prone cohorts independently provides the most optimal spatial normalisation strategy for breast IBDM.</p></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624001052/pdfft?md5=a49b0d252ac1037ec02849d1e69a131d&pid=1-s2.0-S2405631624001052-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142164668","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}

{"title":"Evaluating the effect of higher Monte Carlo statistical uncertainties on accumulated doses after daily adaptive fractionated radiotherapy in prostate cancer","authors":"Thyrza Z. Jagt,&nbsp;Tomas M. Janssen,&nbsp;Jan-Jakob Sonke","doi":"10.1016/j.phro.2024.100636","DOIUrl":"10.1016/j.phro.2024.100636","url":null,"abstract":"<div><h3>Background and purpose</h3><p>Monte Carlo (MC) based dose calculations are widely used in radiotherapy with a low statistical uncertainty, being accurate but slow. Increasing the uncertainty accelerates the calculation, but reduces quality. In online adaptive planning, however, dose is recalculated every treatment fraction, potentially decreasing the cumulative calculation error. This study aimed to evaluate the effect of higher MC statistical uncertainty in the context of daily online plan adaptation.</p></div><div><h3>Materials and methods</h3><p>For twenty prostate cancer patients, daily plans were simulated for 5 fractions and three modes of variation: rigid whole body translations, local-rigid prostate translations and local-rigid prostate rotations. For each mode and fraction, adaptive plans were generated from a clinical reference plan using three MC uncertainty values: 1 % (standard), 2 % and 3 % per plan. Dose-volume criteria were evaluated for accumulated doses, checking plan acceptability and comparing higher uncertainty plans to the standard.</p></div><div><h3>Results</h3><p>Increasing the statistical uncertainty setting from 1 % to 2–3 % caused an accumulated median target D₉₈_% reduction of 0.1 Gy, with interquartile ranges (IQRs) up to 0.12 Gy. Rectum V_35Gy increased in median up to 0.16 cm³ with IQRs up to 0.33 cm³. The bladder V_28Gy and V_32Gy showed median increases up to 0.24 %-point, with IQRs up to 0.54 %-point. Using 2 % uncertainty reduced calculation times by more than a minute for all modes of variation, with no further time gain when increasing to 3 %.</p></div><div><h3>Conclusion</h3><p>A 2–3 % MC statistical uncertainty was clinically feasible. Using a 2 % uncertainty setting reduced calculation times at the cost of limited relative dose-volume differences.</p></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624001064/pdfft?md5=a3af17f95df925315c54d13a6b199bae&pid=1-s2.0-S2405631624001064-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142148290","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}

{"title":"In vivo dosimetry with an inorganic scintillation detector during multi-channel vaginal cylinder pulsed dose-rate brachytherapy: Dosimetry for pulsed dose-rate brachytherapy","authors":"Peter D. Georgi ,&nbsp;Søren K. Nielsen ,&nbsp;Anders T. Hansen ,&nbsp;Harald Spejlborg ,&nbsp;Susanne Rylander ,&nbsp;Jacob Lindegaard ,&nbsp;Simon Buus ,&nbsp;Christian Wulff ,&nbsp;Primoz Petric ,&nbsp;Kari Tanderup ,&nbsp;Jacob G. Johansen","doi":"10.1016/j.phro.2024.100638","DOIUrl":"10.1016/j.phro.2024.100638","url":null,"abstract":"<div><h3>Background and purpose</h3><p>In vivo dosimetry is not standard in brachytherapy and some errors go undetected. The aim of this study was to evaluate the accuracy of multi-channel vaginal cylinder pulsed dose-rate brachytherapy using in vivo dosimetry.</p></div><div><h3>Materials and methods</h3><p>In vivo dosimetry data was collected during the years 2019–2022 for 22 patients (32 fractions) receiving multi-channel cylinder pulsed dose-rate brachytherapy. An inorganic scintillation detector was inserted in a cylinder channel. Each fraction was analysed as independent data sets. In vivo dosimetry-based source-tracking was used to determine the relative source-to-detector position. Measured dose was compared to planned and re-calculated source-tracking based doses. Assuming no change in organ and applicator geometry throughout treatment, the planned and source-tracking based dose distributions were compared in select volumes via γ-index analysis and dose-volume-histograms.</p></div><div><h3>Results</h3><p>The mean ± SD planned vs. measured dose deviations in the first pulse were 0.8 <span><math><mrow><mo>±</mo></mrow></math></span> 5.9 %. In 31/32 fractions the deviation was within the combined in vivo dosimetry uncertainty (averaging 9.7 %, <em>k =</em> 2) and planning dose calculation uncertainty (1.6 %, <em>k =</em> 2). The dwell-position offsets were &lt; 2 mm for 88 % of channels, with the largest being 5.1 mm (4.0 mm uncertainty, <em>k =</em> 2). 3 %/2 mm γ pass-rates averaged 97.0 % (clinical target volume (CTV)), 100.0 % (rectum), 99.9 % (bladder). The mean ± SD deviation was −1.<span><math><mrow><mn>1</mn></mrow></math></span> ± 2.9 % for CTV D98, and −0.2 ± 0.9 % and −1.2 ± 2.5 %, for bladder and rectum D2cm³ respectively, indicating good agreement between intended and delivered dose.</p></div><div><h3>Conclusions</h3><p>In vivo dosimetry verified accurate and stable dose delivery in multi-channel vaginal cylinder based pulsed dose-rate brachytherapy.</p></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624001088/pdfft?md5=e582505d93f2167330a052ddaf354c3b&pid=1-s2.0-S2405631624001088-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142164635","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}

{"title":"Investigating the use of comprehensive motion monitoring for intrafraction 3D drift assessment of hypofractionated prostate cancer patients on a 1.5T magnetic resonance imaging radiotherapy system","authors":"Georgios Tsekas,&nbsp;Cornel Zachiu,&nbsp;Gijsbert H. Bol,&nbsp;Madelon van den Dobbelsteen,&nbsp;Lieke T.C. Meijers,&nbsp;Astrid L.H.M.W. van Lier,&nbsp;Johannes C.J. de Boer,&nbsp;Bas W. Raaymakers","doi":"10.1016/j.phro.2024.100596","DOIUrl":"10.1016/j.phro.2024.100596","url":null,"abstract":"<div><p>This work investigates the use of a multi-2D cine magnetic resonance imaging-based comprehensive motion monitoring (CMM) system for the assessment of prostate intrafraction 3D drifts. The data of six healthy volunteers were analyzed and the values of a clinically-relevant registration quality factor metric exported by CMM were presented. Additionally, the CMM-derived prostate motion was compared to a 3D-based reference and the 2D-3D tracking agreement was reported. Due to the low quality of SI motion tracking (often <span><math><mrow><mo>&gt;</mo></mrow></math></span>2 mm tracking mismatch between anatomical planes) we conclude that further improvements are desirable prior to clinical introduction of CMM for prostate drift corrections.</p></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624000666/pdfft?md5=124522edf1afc0b1a2bf7c02f26cb404&pid=1-s2.0-S2405631624000666-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141408009","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}

{"title":"Motion-induced dose perturbations in photon radiotherapy and proton therapy measured by deformable liver-shaped 3D dosimeters in an anthropomorphic phantom","authors":"Simon Vindbæk ,&nbsp;Stefanie Ehrbar ,&nbsp;Esben Worm ,&nbsp;Ludvig Muren ,&nbsp;Stephanie Tanadini-Lang ,&nbsp;Jørgen Petersen ,&nbsp;Peter Balling ,&nbsp;Per Poulsen","doi":"10.1016/j.phro.2024.100609","DOIUrl":"10.1016/j.phro.2024.100609","url":null,"abstract":"<div><h3>Background and purpose</h3><p>The impact of intrafractional motion and deformations on clinical radiotherapy delivery has so far only been investigated by simulations as well as point and planar dose measurements. The aim of this study was to combine anthropomorphic 3D dosimetry with a deformable abdominal phantom to measure the influence of intra-fractional motion and gating in photon radiotherapy and evaluate the applicability in proton therapy.</p></div><div><h3>Material and methods</h3><p>An abdominal phantom was modified to hold a deformable anthropomorphic 3D dosimeter shaped as a human liver. A liver-specific photon radiotherapy and a proton pencil beam scanning therapy plan were delivered to the phantom without motion as well as with 12 mm sinusoidal motion while using either no respiratory gating or respiratory gating.</p></div><div><h3>Results</h3><p>Using the stationary irradiation as reference the local 3 %/2 mm 3D gamma index pass rate of the motion experiments in the planning target volume (PTV) was above 97 % (photon) and 78 % (proton) with gating whereas it was below 74 % (photon) and 45 % (proton) without gating.</p></div><div><h3>Conclusions</h3><p>For the first time a high-resolution deformable anthropomorphic 3D dosimeter embedded in a deformable abdominal phantom was applied for experimental validation of both photon and proton treatments of targets exhibiting respiratory motion. It was experimentally shown that gating improves dose coverage and the geometrical accuracy for both photon radiotherapy and proton therapy.</p></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624000794/pdfft?md5=4d59bb653313cf7c63ec5bcea269a7c2&pid=1-s2.0-S2405631624000794-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141693852","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}

{"title":"ESTRO-EPTN radiation dosimetry guidelines for the acquisition of proton pencil beam modelling data","authors":"Carles Gomà ,&nbsp;Katrin Henkner ,&nbsp;Oliver Jäkel ,&nbsp;Stefano Lorentini ,&nbsp;Giuseppe Magro ,&nbsp;Alfredo Mirandola ,&nbsp;Lorenzo Placidi ,&nbsp;Michele Togno ,&nbsp;Marie Vidal ,&nbsp;Gloria Vilches-Freixas ,&nbsp;Jörg Wulff ,&nbsp;Sairos Safai","doi":"10.1016/j.phro.2024.100621","DOIUrl":"10.1016/j.phro.2024.100621","url":null,"abstract":"<div><p>Proton therapy (PT) is an advancing radiotherapy modality increasingly integrated into clinical settings, transitioning from research facilities to hospital environments. A critical aspect of the commissioning of a proton pencil beam scanning delivery system is the acquisition of experimental beam data for accurate beam modelling within the treatment planning system (TPS). These guidelines describe in detail the acquisition of proton pencil beam modelling data. First, it outlines the intrinsic characteristics of a proton pencil beam—energy distribution, angular-spatial distribution and particle number. Then, it lists the input data typically requested by TPSs. Finally, it describes in detail the set of experimental measurements recommended for the acquisition of proton pencil beam modelling data—integrated depth-dose curves, spot maps in air, and reference dosimetry. The rigorous characterization of these beam parameters is essential for ensuring the safe and precise delivery of proton therapy treatments.</p></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624000915/pdfft?md5=0fa6cb1d2915fda28631a4c64d021428&pid=1-s2.0-S2405631624000915-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141953364","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}

{"title":"Diffusion-weighted magnetic resonance imaging as an early prognostic marker of chemoradiotherapy response in squamous cell carcinoma of the anus: An individual patient data meta-analysis","authors":"Bettina A. Hanekamp ,&nbsp;Pradeep S. Virdee ,&nbsp;Vicky Goh ,&nbsp;Michael Jones ,&nbsp;Rasmus Hvass Hansen ,&nbsp;Helle Hjorth Johannesen ,&nbsp;Anselm Schulz ,&nbsp;Eva Serup-Hansen ,&nbsp;Marianne G. Guren ,&nbsp;Rebecca Muirhead","doi":"10.1016/j.phro.2024.100618","DOIUrl":"10.1016/j.phro.2024.100618","url":null,"abstract":"<div><h3>Background and purpose</h3><p>Squamous cell carcinoma of the anus (SCCA) can recur after chemoradiotherapy (CRT). Early prediction of treatment response is crucial for individualising treatment. Existing data on radiological biomarkers is limited and contradictory. We performed an individual patient data <em>meta</em>-analysis (IPM) of four prospective trials investigating whether diffusion-weighted (DW) magnetic resonance imaging (MRI) in weeks two to three of CRT predicts treatment failure in SCCA.</p></div><div><h3>Material and methods</h3><p>Individual patient data from four trials, including paired DW-MRI at baseline and during CRT, were combined into one dataset. The association between ADC volume histogram parameters and treatment failure (locoregional and any failure) was assessed using logistic regression. Pre-defined analysis included categorising patients into a change in the mean ADC of the delineated tumour volume above and below 20%.</p></div><div><h3>Results</h3><p>The study found that among all included 142 patients, 11.3 % (n = 16) had a locoregional treatment failure. An ADC mean change of &lt;20 % and &gt;20 % resulted in a locoregional failure rate of 16.7 % and 8.0 %, respectively. However, no other ADC-based histogram parameter was associated with locoregional or any treatment failure.</p></div><div><h3>Conclusions</h3><p>DW-MRI standard parameters, as an isolated biomarker, were not found to be associated with increased odds of treatment failure in SCCA in this IPM. Radiological biomarker investigations involve multiple steps and can result in heterogeneous data. In future, it is crucial to include radiological biomarkers in large prospective trials to minimize heterogeneity and maximize learning.</p></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2405631624000885/pdfft?md5=0b0fd195e8d85c337304013d5ccb91b3&pid=1-s2.0-S2405631624000885-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141951685","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}