Clinical and Translational Radiation Oncology最新文献

{"title":"Fully automatic reconstruction of prostate high-dose-rate brachytherapy interstitial needles using two-phase deep learning-based segmentation and object tracking algorithms","authors":"Mohammad Mahdi Moradi ,&nbsp;Zahra Siavashpour ,&nbsp;Soheib Takhtardeshir ,&nbsp;Eman Showkatian ,&nbsp;Ramin Jaberi ,&nbsp;Reza Ghaderi ,&nbsp;Bahram Mofid ,&nbsp;Farzad Taghizadeh-Hesary","doi":"10.1016/j.ctro.2025.100925","DOIUrl":"10.1016/j.ctro.2025.100925","url":null,"abstract":"<div><div>The critical aspect of successful brachytherapy (BT) is accurate detection of applicator/needle trajectories, which is an ongoing challenge. This study proposes a two-phase deep learning-based method to automate localization of high-dose-rate (HDR) prostate BT catheters through the patient’s CT images. The whole process is divided into two phases using two different deep neural networks. First, BT needles segmentation was accomplished through a pix2pix Generative Adversarial Neural network (pix2pix GAN). Second, a Generic Object Tracking Using Regression Networks (GOTURN) was used to predict the needle trajectories. These models were trained and tested on a clinical prostate BT dataset. Among the total 25 patients, 5 patients that consist of 592 slices was dedicated to testing sets, and the rest were used as train/validation set. The total number of needles in these slices of CT images was 8764, of which the employed pix2pix network was able to segment 98.72 % (8652 of total). Dice Similarity Coefficient (DSC) and IoU (Intersection over Union) between the network output and the ground truth were 0.95 and 0.90, respectively. Moreover, the F1-score, recall, and precision results were 0.95, 0.93, and 0.97, respectively. Regarding the location of the shafts, the proposed model has an error of 0.41 mm. The current study proposed a novel methodology to automatically localize and reconstruct the prostate HDR-BT interstitial needles through the 3D CT images. The presented method can be utilized as a computer-aided module in clinical applications to automatically detect and delineate the multi-catheters, potentially enhancing the treatment quality.</div></div>","PeriodicalId":10342,"journal":{"name":"Clinical and Translational Radiation Oncology","volume":"51 ","pages":"Article 100925"},"PeriodicalIF":2.7,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11788795/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143122573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effectiveness, toxicity and impact on quality of life of high-dose-rate brachytherapy delivered in two fractions as monotherapy in patients with prostate cancer","authors":"Johan Staby Olsén ,&nbsp;Antonis Valachis ,&nbsp;Bengt Johansson","doi":"10.1016/j.ctro.2025.100923","DOIUrl":"10.1016/j.ctro.2025.100923","url":null,"abstract":"<div><h3>Purpose</h3><div>The aim of this retrospective, single-center cohort study was to evaluate the effectiveness and safety of two-fraction high-dose-rate brachytherapy (HDR-BT) as monotherapy in a consecutive cohort of prostate cancer patients.</div></div><div><h3>Methods</h3><div>We included consecutive patients who received 28 Gy HDR-BT in two fractions (14 Gy × 2) as monotherapy during 2005 to 2021 at our institution. Eligible patients were derived from an institutional database consisting of prospectively collected data. Primary endpoint was biochemical recurrence (BCR) and secondary endpoints included toxicity (assessed through both healthcare provider and patient-reported outcomes) and quality-of-life (QoL) assessment.</div></div><div><h3>Results</h3><div>In total, 175 patients with prostate cancer (94 % classified as low- or intermediate-risk) were treated with HDR-BT during the study period with a median age of 68 years (range: 51–80), and a median follow-up of 60 months (range: 0–174). The estimated five-year cumulative BCR rate was 3.0 % (95 % Confidence Interval (CI): 0 %–13.3 %) for low-risk patients and 9.6 % (95 % CI: 4.7 %–16.7 %) for intermediate-risk patients. PSA exceeding 10 ng/mL at diagnosis was a significant risk factor for BCR (Odds Ratio (OR) = 3.29, 95 % CI: 1.01–10.67) whereas PSA of ≤0.1 ng/ml as nadir was a significant positive prognostic factor, associated with lower risk of BCR (OR = 0.11, 95 % CI: 0.03–0.33). At 12 months, 22 % of the patients had grade 2 and 3 % grade 3 urinary toxicity whereas 2 % of patients had grade 2 and none grade 3 bowel toxicity. At 12 months, 49 % of the patients with at least some erectile function before the treatment, had an impaired function.</div></div><div><h3>Conclusion</h3><div>We found that two-fraction HDR-BT as monotherapy among patients with mainly low- and intermediate-risk prostate cancer appears to be safe in terms of biochemical recurrence, with a low proportion of severe urinary and bowel toxicity.</div></div>","PeriodicalId":10342,"journal":{"name":"Clinical and Translational Radiation Oncology","volume":"51 ","pages":"Article 100923"},"PeriodicalIF":2.7,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11788793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143122572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Postoperative brachytherapy alone for 217 patients with early-stage oral cavity squamous cell carcinoma","authors":"C. Schweizer ,&nbsp;V. Strnad ,&nbsp;M. Lotter ,&nbsp;S. Kreppner ,&nbsp;R. Merten ,&nbsp;R. Fietkau ,&nbsp;A. Karius","doi":"10.1016/j.ctro.2025.100922","DOIUrl":"10.1016/j.ctro.2025.100922","url":null,"abstract":"<div><h3>Introduction</h3><div>Postoperative radiotherapy is generally recommended for pT1/2pN0 squamous cell carcinoma of the oral cavity (OSCC) if risk factors are present. Prospective studies are missing. Interventional radiotherapy offers a precise dose application. In this paper we analyze long-term efficacy and toxicity in a large single-center cohort of patients with early OSCC receiving sole postoperative brachytherapy (BT).</div></div><div><h3>Material and methods</h3><div>From 1998 to 2023, 217 patients were postoperatively treated with sole BT in our institute. The median follow-up was 110 months (range: 2–316). The primary objective was local control. Secondary outcomes were overall survival, cancer specific survival, and toxicity.</div></div><div><h3>Results</h3><div>The local recurrence rates for 12, 24, and 60 months were 7.1 %, 9.1 %, and 12.6 %. The disease-free survival was 89.7 %, 86.1 %, and 79.3 %. The overall survival rates at 12, 24, and 60 months were 94.4 %, 89.6 %, and 77.9 %. The cancer-specific survival was 97.1 %, 96.6 %, and 92.9 %, respectively. At two years, the rate of regional recurrence was 8.3 %. Patients without neck dissection had a significantly increased risk for lymph node recurrence (p = 0.025). Side effects ≥ grade 3 were seen in 14 % (30/217). 17 % (37/217) of patients developed a soft tissue necrosis (STN). Osteoradionecrosis (ORN) was seen in 7 % (15/217) of patients. A target volume &gt; 15 cm³ was significantly associated with the occurrence of STN (p = 0.011) and ORN (p = 0.004).</div></div><div><h3>Conclusions</h3><div>Postoperative interventional radiotherapy for previously not irradiated patients with early-stage OSCC is a safe and efficient treatment. Randomized trials are needed to compare these results to omission of postoperative radiotherapy as well as external beam radiotherapy.</div></div>","PeriodicalId":10342,"journal":{"name":"Clinical and Translational Radiation Oncology","volume":"51 ","pages":"Article 100922"},"PeriodicalIF":2.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Live-cell imaging and analysis of 3D spheroids in hypoxia- and radiotherapy-related research","authors":"Claire Beckers,&nbsp;Lazaros Vasilikos,&nbsp;Lorena Moor,&nbsp;Martin Pruschy","doi":"10.1016/j.ctro.2025.100920","DOIUrl":"10.1016/j.ctro.2025.100920","url":null,"abstract":"<div><div>3D spheroids are a valuable tool for investigating the interplay between hypoxia and radioresistance. However, standardized methods for visualizing normoxic and hypoxic regions within spheroids and assessing treatment responses are lacking. We developed a straightforward workflow for the analysis of spheroids based on image processing using a novel custom-written script, and flow cytometry.</div></div>","PeriodicalId":10342,"journal":{"name":"Clinical and Translational Radiation Oncology","volume":"51 ","pages":"Article 100920"},"PeriodicalIF":2.7,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11787710/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143078716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of lifetime attributable risk of post-irradiation secondary cancer of boron neutron capture therapy, proton beam therapy, and X-ray therapy for pediatric and adolescent and young adult patients","authors":"Shunsuke Suzuki ,&nbsp;Shintaro Shiba ,&nbsp;Hiroki Tanaka ,&nbsp;Masashi Yamanaka ,&nbsp;Kazuki Matsumoto ,&nbsp;Koichi Tokuuye ,&nbsp;Motoko Omura","doi":"10.1016/j.ctro.2025.100921","DOIUrl":"10.1016/j.ctro.2025.100921","url":null,"abstract":"<div><h3>Background and purpose</h3><div>This study aimed to compare the post-irradiation secondary cancer rates of boron neutron capture therapy (BNCT), proton beam therapy (PBT), and X-ray therapy (XT) in pediatric and Adolescent and Young Adult (AYA) patients with intracranial lesions.</div></div><div><h3>Materials and methods</h3><div>BNCT, PBT, and XT plans were optimized for nine pediatric and AYA patients with intracranial lesions. The BNCT dose calculation results were biologically effective dose converted. Lifetime attributable risk (LAR) was calculated using a calculation model proposed by Schneider <em>et al.</em> Statistical analysis was performed using log-linear model with mixed effects. Organs included in the radiation field were the brain, bones, and soft tissue. The difference in LAR between the three treatments for each organ and the number needed to treat (NNT), as an indicator of the number of cases required to achieve the effect of suppressing the occurrence of secondary cancers, was calculated and evaluated.</div></div><div><h3>Results</h3><div>Statistically significant differences between BNCT vs PBT and XT were confirmed for the brain, bone, soft tissue, and cumulative (P &lt; 0.0001). Significant differences were also observed in PBT and XT, with P &lt; 0.0001 for brain and cumulative, P = 0.0002 for bone, and P = 0.0281 for soft tissue. The cumulative NNT for BNCT vs. PBT, BNCT vs. XT, and PBT vs. XT were 162, 78.6, and 153, respectively.</div></div><div><h3>Conclusion</h3><div>BNCT had a significantly lower LAR compared to PBT and XT. These findings suggest the usefulness of BNCT in pediatric and AYA patients with brain tumors from the perspective of post-irradiation secondary cancer.</div></div>","PeriodicalId":10342,"journal":{"name":"Clinical and Translational Radiation Oncology","volume":"51 ","pages":"Article 100921"},"PeriodicalIF":2.7,"publicationDate":"2025-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11786841/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143078644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-term survivors with brain metastases have modest benefits from focal and systemic therapies and remain frequent despite improving treatment landscape","authors":"M. Czogalla ,&nbsp;J. Stöhr ,&nbsp;N. Gleim ,&nbsp;K. Papsdorf ,&nbsp;S. Klagges ,&nbsp;P. Hambsch ,&nbsp;T. Kuhnt ,&nbsp;F. Nägler ,&nbsp;A. Barrantes-Freer ,&nbsp;J. Wach ,&nbsp;N.H. Nicolay ,&nbsp;C. Seidel","doi":"10.1016/j.ctro.2025.100919","DOIUrl":"10.1016/j.ctro.2025.100919","url":null,"abstract":"<div><h3>Purpose</h3><div>Therapeutic options for patients with brain metastases (BM) increase. While these lead to considerable survival effects in subgroups, there is limited knowledge about characteristics, prognosticators and treatment effects in patients with BM and short survival.</div></div><div><h3>Methods</h3><div>Patients with a survival time of ≤ 6 months (short-term survivors, STS), diagnosed with BM between 2009–2021 at a large tertiary cancer center were analysed. Clinical and treatment characteristics, pathological data and causes of death were documented. Descriptive statistics, treatment-specific univariate Kaplan-Meier estimator analyses and multivariate Cox regression were performed.</div></div><div><h3>Results</h3><div>Among 1248 patients with BM, 480 (38 %) were STS. 256 STS with detailed clinical records were included in this analysis. In univariate and multivariate analysis, Karnofsky Performance Status (KPS) (p &lt; 0.001) and number of BM (p = 0.004) were prognostic. In 75 % of patients, the ds-GPA score predicted short-term survival. Use of resection with focal radiotherapy (p &lt; 0.001) and systemic treatment (p &lt; 0.001) appeared prognostically favourable compared to whole brain radiotherapy (WBRT) alone. However, survival benefits were very modest, with a median gain of 6 weeks following resection and focal radiotherapy compared to whole-brain radiotherapy, and 3 weeks from systemic treatment. Systemic tumor progression was documented as the cause of death in the majority of patients. Over the examined time period, the ratio between STS and other patients remained without significant change.</div></div><div><h3>Conclusion</h3><div>Within STS, KPS and number of BM are of prognostic relevance. There is benefit from local and systemic therapy to a limited extent. Shared and carefully discussed individual therapy decisions are necessary.</div></div>","PeriodicalId":10342,"journal":{"name":"Clinical and Translational Radiation Oncology","volume":"51 ","pages":"Article 100919"},"PeriodicalIF":2.7,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11772985/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143058134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Associations of dose to the urethra and long-term patient-reported outcomes after radiotherapy with EBRT and HDR brachytherapy boost for prostate cancer","authors":"Lars Haack ,&nbsp;David Krug ,&nbsp;Justus Domschikowski ,&nbsp;Olaf Wittenstein ,&nbsp;Severin Rodler ,&nbsp;Philipp Nuhn ,&nbsp;Christof van der Horst ,&nbsp;Claudia Schmalz ,&nbsp;Christian Schulz ,&nbsp;Oliver Blanck ,&nbsp;Frank-André Siebert ,&nbsp;Alexander Fabian","doi":"10.1016/j.ctro.2025.100918","DOIUrl":"10.1016/j.ctro.2025.100918","url":null,"abstract":"<div><h3>Purpose</h3><div>Implications of radiation dose exposure to the urethra on urinary morbidity after prostate radiotherapy are poorly understood, especially by long-term patient-reported outcomes (PRO). Therefore, our primary objective was to investigate associations of urethral dose and long-term patient-reported urinary morbidity after external beam radiotherapy and high-dose rate brachytherapy boost for prostate cancer.</div></div><div><h3>Materials and methods</h3><div>We conducted a pre-registered (<span><span>https://doi.org/10.17605/OSF.IO/A6DC3)</span><svg><path></path></svg></span> cross-sectional study at a tertiary academic center including a consecutive sample of patients being at least two years after treatment. Primary outcome measurements included urinary domains of the EPIC-26 questionnaire. Their associations with predefined urethral dose levels were assessed by univariable analyses (Pearson’s correlation) and by predefined multivariable analyses (multiple regression). Sample size calculation was based on a predefined multivariable model. A p-value &lt; 0.05 was considered statistically significant.</div></div><div><h3>Results</h3><div>Among 277 screened patients, 113 patients were alive, eligible, consented, and provided PRO. The median time passed since radiotherapy was 4 years. Per univariable analysis, a higher near maximum point dose of the urethra (D_U0.1cc) was associated with worse urinary incontinence (r = -0.32; CI = −0.48 − -0.13; p &lt; 0.001) and worse overall urinary function (r = -0.21; CI = −0.38 − -0.03; p = 0.02) of the respective EPIC-26 domains. Per predefined multivariable analysis, D_U0.1cc and urinary incontinence remained significantly associated (B = −0.005; CI = −0.008 − -0.002; p = 0.003). These associations were only present, when very high D_U0.1 cc above 137 Gy were kept in the analysis.</div></div><div><h3>Conclusions</h3><div>Very high urethral near point doses appear to be associated with worse long-term patient-reported urinary morbidity after radiotherapy for prostate cancer. Urethral dose should be considered in practice and future trials to potentially minimize long-term urinary morbidity.</div></div><div><h3>Trial registration</h3><div>The study protocol was pre-registered prior to patient accrual on the Open Science Framework (<span><span>https://doi.org/10.17605/OSF.IO/A6DC3)</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":10342,"journal":{"name":"Clinical and Translational Radiation Oncology","volume":"51 ","pages":"Article 100918"},"PeriodicalIF":2.7,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11782951/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143078643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Treatment-related toxicity, utility and patient-reported outcomes of head and neck cancer patients treated with proton therapy: A longitudinal study","authors":"Yi Hsuan Chen ,&nbsp;Michiel Kroesen ,&nbsp;Mischa Hoogeman ,&nbsp;Matthijs Versteegh ,&nbsp;Carin Uyl-de Groot ,&nbsp;Hedwig M. Blommestein","doi":"10.1016/j.ctro.2025.100913","DOIUrl":"10.1016/j.ctro.2025.100913","url":null,"abstract":"<div><h3>Objective</h3><div>In comparison to current standard photon irradiation, proton therapy (PT) significantly reduces dose to the surrounding normal tissue and therefore is expected to reduce toxicity and improve health related quality of life (HRQoL). Despite the high expectations of PT, there is very limited data on patients’ HRQoL after radiotherapy. This study evaluated HRQoL in head and neck cancer (HNC) patients receiving PT and established a robust benchmark for future comparison of PT and the radiotherapy advancements.</div></div><div><h3>Method</h3><div>A questionnaire-based (consisting of EORTC-QLQ-C30, EQ-5D, and EORTC-H&amp;N-35) prospective cohort study was performed in a Dutch proton therapy center. HNC patients who received PT between January 2020 to December 2022 were enrolled in this study. The questionnaires were distributed pre-treatment, and 0, 6, 12, 24 months post-treatment. The generalized estimating equations method was used to analyze the utility change and negative impact of the radiation-related toxicities.</div></div><div><h3>Results</h3><div>119 HNC patients were included in the study. Symptom and function scores showed the deterioration of all reported functions during the period of treatment. Most of the functions recovered within six months and improved beyond baseline. At the end of PT, the patients’ utility decreased significantly (0.12 points) compared to the baseline. The loss in utility was recovered after six months and a further improvement was seen one year after the treatment. This study further provided the estimation of the disutility of each radiation related toxicity.</div></div><div><h3>Conclusion</h3><div>The present study presented the impact of toxicity on patient’s utility over time and further confirmed it with the results of patient-reported symptom and function. This study provided estimation of each radiation-related toxicity, including xerostomia, dysphagia, mucositis, and dermatitis, which could contribute to the value assessment through economic evaluations of PT.</div></div>","PeriodicalId":10342,"journal":{"name":"Clinical and Translational Radiation Oncology","volume":"51 ","pages":"Article 100913"},"PeriodicalIF":2.7,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11787426/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143078719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relating proton LETd to biological response of parotid and submandibular glands using PSMA-PET in clinical patients","authors":"Dirk Wagenaar ,&nbsp;Vineet Mohan ,&nbsp;Johannes A. Langendijk ,&nbsp;Roel J.H.M. Steenbakkers ,&nbsp;Wouter V. Vogel ,&nbsp;Stefan Both","doi":"10.1016/j.ctro.2024.100910","DOIUrl":"10.1016/j.ctro.2024.100910","url":null,"abstract":"<div><h3>Background and purpose</h3><div>A recent study investigated the use of PSMA-PET in monitoring loss of secretory cells in salivary glands of head and neck cancer (HNC) patients. Previously, a dose–effect relation has been formulated to the PSMA-PET uptake in salivary glands. The aim of this study was to derive a proton RBE model from the PSMA-PET uptake in salivary glands after proton therapy of HNC patients.</div></div><div><h3>Materials and methods</h3><div>Six patients treated with proton therapy were included. These patients received a PET-CT scan using ⁶⁸Ga (N = 1) or ¹⁸F (N = 5) PSMA before treatment (baseline) and one month after the last fraction (follow-up). Physical dose (D), D·LET_d and the follow-up PSMA-PET scan were deformed to the baseline PET-CT using deformable image registration. Parotid and submandibular gland delineations were adjusted to include voxels which had an uptake of ≥ 5 g/ml in the baseline PSMA-PET scan.</div></div><div><h3>Results</h3><div>The average RBE-LET slope was 0.075 [0.009; 0.125] (keV/μm)^-1 (mean [95 %CI]) for parotid and submandibular glands combined. When analyzing parotid or submandibular glands separately the RBE-LET curve slope varies with two and five patients showing a positive RBE-LET slope when only analyzing parotid or submandibular glands respectively.</div></div><div><h3>Conclusion</h3><div>Our study did not find clear evidence of an increased RBE in parotid and submandibular glands with increasing LET_d. On average an LET_d effect was observed, however our sample size was too small to clearly define an RBE-LET relation. A larger cohort scanned at later time intervals could shed more light on this issue.</div></div>","PeriodicalId":10342,"journal":{"name":"Clinical and Translational Radiation Oncology","volume":"52 ","pages":"Article 100910"},"PeriodicalIF":2.7,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of tumor position displacement during end-exhalation breath-hold condition on tumor dose in lung stereotactic body radiation therapy using volumetric modulated arc therapy","authors":"Tatsuya Kamima ,&nbsp;Shunsuke Moriya ,&nbsp;Takeji Sakae ,&nbsp;Hikaru Miyauchi ,&nbsp;Yasushi Ito ,&nbsp;Kenji Tokumasu ,&nbsp;Yasuo Yoshioka","doi":"10.1016/j.ctro.2025.100916","DOIUrl":"10.1016/j.ctro.2025.100916","url":null,"abstract":"<div><h3>Background and purpose</h3><div>In lung stereotactic body radiation therapy (SBRT) using a breath-holding technique, displacement of tumor during breath-holding is rarely considered. This study used four-dimensional (4D) dose calculation with cine computed tomography (CT) to evaluate the impact of unexpected tumor position displacement during breath-holding on the target dose of lung volumetric modulated arc therapy (VMAT)-SBRT.</div></div><div><h3>Materials and methods</h3><div>This study included 20 cases for which tumor position displacement during end-exhalation breath-holding (range: 0.5–12.6 mm) was evaluated on cine CT. VMAT-SBRT plans (3D dose) were generated using treatment planning CT images (reference CT) acquired during end-exhalation breath-hold. For each plan, the 4D dose was calculated using deformable image registration of the cine CT images and was accumulated onto the reference CT. Dose metrics and the mean biologically effective dose at <span><math><mrow><mi>α</mi><mo>/</mo><mi>β</mi></mrow></math></span> = 10 (BED₁₀) for the gross tumor volume (GTV) were compared between 3D and 4D doses.</div></div><div><h3>Results</h3><div>In the 17 cases where the tumor was within the planning target volume (PTV) during breath-holding, the difference between the 3D and 4D doses was within 3 % for each dose metric. However, in 3 cases where the tumor position during breath-holding included displacement outside the PTV, both the D_98% and mean BED₁₀ of the GTV were reduced by 6.9–20.0 % and 2.1–13.8 %, respectively, in 4D doses compared to 3D doses.</div></div><div><h3>Conclusion</h3><div>Our study showed that tumor position displacements during breath-holding may lead to substantial tumor dose reduction.</div></div>","PeriodicalId":10342,"journal":{"name":"Clinical and Translational Radiation Oncology","volume":"51 ","pages":"Article 100916"},"PeriodicalIF":2.7,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11772987/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143058129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}