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  1. Article ; Online: Prospective Evaluation of Prostate and Organs at Risk Segmentation Software for MRI-based Prostate Radiation Therapy.

    Sanders, Jeremiah W / Kudchadker, Rajat J / Tang, Chad / Mok, Henry / Venkatesan, Aradhana M / Thames, Howard D / Frank, Steven J

    Radiology. Artificial intelligence

    2022  Volume 4, Issue 2, Page(s) e210151

    Abstract: The segmentation of the prostate and surrounding organs at risk (OARs) is a necessary workflow step for performing dose-volume histogram analyses of prostate radiation therapy procedures. Low-dose-rate prostate brachytherapy (LDRPBT) is a curative ... ...

    Abstract The segmentation of the prostate and surrounding organs at risk (OARs) is a necessary workflow step for performing dose-volume histogram analyses of prostate radiation therapy procedures. Low-dose-rate prostate brachytherapy (LDRPBT) is a curative prostate radiation therapy treatment that delivers a single fraction of radiation over a period of days. Prior studies have demonstrated the feasibility of fully convolutional networks to segment the prostate and surrounding OARs for LDRPBT dose-volume histogram analyses. However, performance evaluations have been limited to measures of global similarity between algorithm predictions and a reference. To date, the clinical use of automatic segmentation algorithms for LDRPBT has not been evaluated, to the authors' knowledge. The purpose of this work was to assess the performance of fully convolutional networks for prostate and OAR delineation on a prospectively identified cohort of patients who underwent LDRPBT by using clinically relevant metrics. Thirty patients underwent LDRPBT and were imaged with fully balanced steady-state free precession MRI after implantation. Custom automatic segmentation software was used to segment the prostate and four OARs. Dose-volume histogram analyses were performed by using both the original automatically generated contours and the physician-refined contours. Dosimetry parameters of the prostate, external urinary sphincter, and rectum were compared without and with the physician refinements. This study observed that physician refinements to the automatic contours did not significantly affect dosimetry parameters.
    Language English
    Publishing date 2022-01-26
    Publishing country United States
    Document type Journal Article
    ISSN 2638-6100
    ISSN (online) 2638-6100
    DOI 10.1148/ryai.210151
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Rod Withers' Data are Available Online.

    Thames, Howard D / Hunter, Nancy R / Mason, Kathy A

    International journal of radiation oncology, biology, physics

    2017  Volume 97, Issue 2, Page(s) 435–436

    Language English
    Publishing date 2017-02-01
    Publishing country United States
    Document type Editorial
    ZDB-ID 197614-x
    ISSN 1879-355X ; 0360-3016
    ISSN (online) 1879-355X
    ISSN 0360-3016
    DOI 10.1016/j.ijrobp.2016.10.014
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Uncertainty in magnetic resonance imaging-based prostate postimplant dosimetry: Results of a 10-person human observer study, and comparisons with automatic postimplant dosimetry.

    Sanders, Jeremiah W / Tang, Chad / Kudchadker, Rajat J / Venkatesan, Aradhana M / Mok, Henry / Hanania, Alexander N / Thames, Howard D / Bruno, Teresa L / Starks, Christine / Santiago, Edwin / Cunningham, Mandy / Frank, Steven J

    Brachytherapy

    2023  Volume 22, Issue 6, Page(s) 822–832

    Abstract: Purpose: Uncertainties in postimplant quality assessment (QA) for low-dose-rate prostate brachytherapy (LDRPBT) are introduced at two steps: seed localization and contouring. We quantified how interobserver variability (IoV) introduced in both steps ... ...

    Abstract Purpose: Uncertainties in postimplant quality assessment (QA) for low-dose-rate prostate brachytherapy (LDRPBT) are introduced at two steps: seed localization and contouring. We quantified how interobserver variability (IoV) introduced in both steps impacts dose-volume-histogram (DVH) parameters for MRI-based LDRPBT, and compared it with automatically derived DVH parameters.
    Methods and materials: Twenty-five patients received MRI-based LDRPBT. Seven clinical observers contoured the prostate and four organs at risk, and 4 dosimetrists performed seed localization, on each MRI. Twenty-eight unique manual postimplant QAs were created for each patient from unique observer pairs. Reference QA and automatic QA were also performed for each patient. IoV of prostate, rectum, and external urinary sphincter (EUS) DVH parameters owing to seed localization and contouring was quantified with coefficients of variation. Automatically derived DVH parameters were compared with those of the reference plans.
    Results: Coefficients of variation (CoVs) owing to contouring variability (CoV
    Conclusions: Seed localization introduces substantially less variability in postimplant QA than does contouring for MRI-based LDRPBT. While automatic seed localization may potentially help improve workflow efficiency, it has limited potential for improving the consistency and quality of postimplant dosimetry.
    MeSH term(s) Male ; Humans ; Prostate/diagnostic imaging ; Prostate/pathology ; Prostatic Neoplasms/diagnostic imaging ; Prostatic Neoplasms/radiotherapy ; Prostatic Neoplasms/pathology ; Uncertainty ; Brachytherapy/methods ; Radiotherapy Dosage ; Tomography, X-Ray Computed/methods ; Magnetic Resonance Imaging/methods
    Language English
    Publishing date 2023-09-15
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2098608-7
    ISSN 1873-1449 ; 1538-4721
    ISSN (online) 1873-1449
    ISSN 1538-4721
    DOI 10.1016/j.brachy.2023.08.001
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Sample-size calculation for preclinical dose-response experiments using heterogeneous tumour models.

    Ciecior, Willy / Ebert, Nadja / Borgeaud, Nathalie / Thames, Howard D / Baumann, Michael / Krause, Mechthild / Löck, Steffen

    Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology

    2021  Volume 158, Page(s) 262–267

    Abstract: Background: In preclinical radio-oncological research, local tumour control is considered the most relevant endpoint as it reflects the inactivation of cancer stem cells. Preclinical tumour-control assays may compare dose-response curves between ... ...

    Abstract Background: In preclinical radio-oncological research, local tumour control is considered the most relevant endpoint as it reflects the inactivation of cancer stem cells. Preclinical tumour-control assays may compare dose-response curves between different radiotherapy strategies, e.g., assessing additional targeted drugs and immunotherapeutic interventions, or between different radiation modalities. To mimic the biological heterogeneity of human tumour populations and to accommodate for approaches of personalized oncology, preclinical studies are increasingly performed combining larger panels of tumour models. For designing the study protocols and to obtain reliable results, prospective sample-size planning has to be developed that accounts for such heterogeneous cohorts.
    Methods: A Monte-Carlo-based method was developed to estimate the sample size of a comparative 1:1 two-arm prospective tumour-control assay. Based on repeated logistic regression analysis, pre-defined dose levels, assumptions on the dose-response curves of the included tumour models and on the dose-modifying factors (DMF), the power is calculated for a given number of animals per dose group.
    Results: Two applications are presented: (i) For a simple tumour-control assay with the head and neck squamous cell carcinoma (HNSCC) model FaDu, 10 animals would be required for each of 7 dose levels per arm to reveal a DMF of 1.25 with a power of 0.82 without drop out (total: 140 animals). (ii) In a more complex experiment combining six different lung tumour models to a heterogeneous population, 21 animals would be required for each of 11 dose levels per arm to reveal a DMF of 1.25 with a power of 0.81 without drop out (total: 462 animals). Analyzing the heterogeneous cohort reduces the required animal number by more than 50% compared to six individual tumour-control assays.
    Conclusion: An approach for estimating the required animal number for comparative tumour-control assays in a heterogeneous population is presented, allowing also the inclusion of different treatments as a personalized approach in the experimental arm. The software is publicly available and can be applied to plan comparisons of sigmoidal dose-response curves based on logistic regression.
    MeSH term(s) Animals ; Carcinoma, Squamous Cell ; Head and Neck Neoplasms/radiotherapy ; Humans ; Monte Carlo Method ; Prospective Studies ; Radiation Oncology ; Squamous Cell Carcinoma of Head and Neck/radiotherapy
    Language English
    Publishing date 2021-03-03
    Publishing country Ireland
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 605646-5
    ISSN 1879-0887 ; 0167-8140
    ISSN (online) 1879-0887
    ISSN 0167-8140
    DOI 10.1016/j.radonc.2021.02.032
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: The Withers Archive: online availability of H. Rodney Withers' data.

    Thames, Howard D / Hunter, Nancy R / Mason, Kathryn A

    International journal of radiation biology

    2016  Volume 92, Issue 12, Page(s) 855–857

    Abstract: We have collected lab notebooks from Rod Wither's many years of experimentation, from laboratories in Houston and Los Angeles, as well as from several of his collaborators in the USA and overseas. The contents have been digitized, and in this note we ... ...

    Abstract We have collected lab notebooks from Rod Wither's many years of experimentation, from laboratories in Houston and Los Angeles, as well as from several of his collaborators in the USA and overseas. The contents have been digitized, and in this note we explain the mechanism that has been set up to make the 'Withers Archive' available online.
    MeSH term(s) Archives/history ; Australia ; History, 20th Century ; History, 21st Century ; Manuscripts, Medical as Topic/history ; Online Systems ; Radiation Oncology/history ; Radiobiology/history ; United States
    Language English
    Publishing date 2016-12
    Publishing country England
    Document type Biography ; Historical Article ; Journal Article
    ZDB-ID 3065-x
    ISSN 1362-3095 ; 0020-7616 ; 0955-3002
    ISSN (online) 1362-3095
    ISSN 0020-7616 ; 0955-3002
    DOI 10.1080/09553002.2016.1243271
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: The Withers archive: Online availability of rod Wither's data.

    Thames, Howard D / Hunter, N R / Mason, Kathy A

    Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology

    2016  Volume 121, Issue 3, Page(s) 475–477

    Abstract: The contents of the lab notebooks of H.R. Withers have been digitized and stored as 23 excel files, a total of approximately 45 megabytes. A procedure is described whereby those interested may gain access to the data. ...

    Abstract The contents of the lab notebooks of H.R. Withers have been digitized and stored as 23 excel files, a total of approximately 45 megabytes. A procedure is described whereby those interested may gain access to the data.
    MeSH term(s) Archives ; History, 20th Century ; History, 21st Century ; Humans ; Online Systems ; Radiation Oncology/history ; Radiobiology/history ; Translational Medical Research/history ; United States
    Language English
    Publishing date 2016-12
    Publishing country Ireland
    Document type Biography ; Historical Article ; Letter
    ZDB-ID 605646-5
    ISSN 1879-0887 ; 0167-8140
    ISSN (online) 1879-0887
    ISSN 0167-8140
    DOI 10.1016/j.radonc.2016.10.004
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Proton therapy for the management of localized prostate cancer: Long-term clinical outcomes at a comprehensive cancer center.

    Sosa, Alan J / Thames, Howard D / Sanders, Jeremiah W / Choi, Seungtaek L / Nguyen, Quynh-Nhu / Mok, Henry / Ron Zhu, X / Shah, Shalin / Mayo, Lauren L / Hoffman, Karen E / Tang, Chad / Lee, Andrew K / Pugh, Thomas J / Kudchadker, Reena / Frank, Steven J

    Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology

    2023  Volume 188, Page(s) 109854

    Abstract: Background and purpose: Proton therapy (PT) has emerged as a standard-of-care treatment option for localized prostate cancer at our comprehensive cancer center. However, there are few large-scale analyses examining the long-term clinical outcomes. ... ...

    Abstract Background and purpose: Proton therapy (PT) has emerged as a standard-of-care treatment option for localized prostate cancer at our comprehensive cancer center. However, there are few large-scale analyses examining the long-term clinical outcomes. Therefore, this article aims to evaluate the long-term effectiveness and toxicity of PT in patients with localized prostate cancer.
    Materials and methods: Review of 2772 patients treated from May 2006 through January 2020. Disease risk was stratified according to National Comprehensive Cancer Network guidelines as low [LR, n = 640]; favorable-intermediate [F-IR, n = 850]; unfavorable-intermediate [U-IR, n = 851]; high [HR, n = 315]; or very high [VHR, n = 116]. Biochemical failure and toxicity were analyzed using Kaplan-Meier estimates and multivariate models.
    Results: The median patient age was 66 years; the median follow-up time was 7.0 years. Pelvic lymph node irradiation was prescribed to 28 patients (1%) (2 [0.2%] U-IR, 11 [3.5%] HR, and 15 [12.9%] VHR). The median dose was 78 Gy in 1.8-2.0 Gy(RBE) fractions. Freedom from biochemical relapse (FFBR) rates at 5 years and 10 years were 98.2% and 96.8% for the LR group; 98.3% and 93.6%, F-IR; 94.2% and 90.2%, U-IR; 94.3% and 85.2%, HR; and 86.1% and 68.5%, VHR. Two patients died of prostate cancer. Overall rates of late grade ≥ 3 GU and GI toxicity were 0.87% and 1.01%.
    Conclusions: Proton therapy for localized prostate cancer demonstrated excellent clinical outcomes in this large cohort, even among higher-risk groups with historically poor outcomes despite aggressive therapy.
    Language English
    Publishing date 2023-08-18
    Publishing country Ireland
    Document type Journal Article
    ZDB-ID 605646-5
    ISSN 1879-0887 ; 0167-8140
    ISSN (online) 1879-0887
    ISSN 0167-8140
    DOI 10.1016/j.radonc.2023.109854
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Articular cartilage scores in cranial cruciate ligament-deficient dogs with or without bucket handle tears of the medial meniscus.

    Kaufman, Kathryn / Beale, Brian S / Thames, Howard D / Saunders, W Brian

    Veterinary surgery : VS

    2017  Volume 46, Issue 1, Page(s) 120–129

    Abstract: Objective: To compare articular cartilage scores in cranial cruciate ligament (CCL)-deficient dogs with or without concurrent bucket handle tears (BHT) of the medial meniscus.: Study design: Retrospective case series.: Animals: Client-owned dogs ... ...

    Abstract Objective: To compare articular cartilage scores in cranial cruciate ligament (CCL)-deficient dogs with or without concurrent bucket handle tears (BHT) of the medial meniscus.
    Study design: Retrospective case series.
    Animals: Client-owned dogs treated with arthroscopy and tibial plateau leveling osteotomy or extracapsular repair for complete CCL rupture (290 stifles from 264 dogs).
    Methods: Medical records and arthroscopic images were reviewed. Medial femoral condyle (MFC) and medial tibial plateau (MTP) cartilage was scored using the modified Outerbridge scale. Periarticular osteophytosis (PAO) and injury to the medial meniscus were recorded. Data were analyzed using Student's t-tests, Wilcoxon rank-sum test, and Fisher's exact test for changes in the stifle based on meniscal condition, body weight, and duration of lameness.
    Results: PAO, MFC, and MTP articular cartilage scores were not significantly different in dogs with or without BHT. There were no significant differences in MFC or MTP scores when dogs were evaluated based on bodyweight and the presence or absence of a BHT. However, PAO formation was significantly increased in dogs weighing >13.6 kg and concurrent meniscal injury vs. dogs weighing <13.6 kg and concurrent meniscal injury (P < .001). Significantly more stifles with chronic lameness (40 of 89; 44.9%) had the highest PAO score of 2 reported compared to only 42 of 182 stifles (23.1%) with acute lameness (P < .001).
    Conclusion: The presence of a BHT of the medial meniscus was not associated with more severe arthroscopic articular cartilage lesions in the medial joint compartment at the time of surgery.
    MeSH term(s) Animals ; Anterior Cruciate Ligament Injuries/complications ; Anterior Cruciate Ligament Injuries/pathology ; Anterior Cruciate Ligament Injuries/surgery ; Anterior Cruciate Ligament Injuries/veterinary ; Arthroscopy/veterinary ; Dogs/injuries ; Dogs/surgery ; Female ; Injury Severity Score ; Male ; Osteotomy/veterinary ; Retrospective Studies ; Statistics, Nonparametric ; Stifle/surgery ; Tibia/surgery ; Tibial Meniscus Injuries/complications ; Tibial Meniscus Injuries/pathology ; Tibial Meniscus Injuries/surgery ; Tibial Meniscus Injuries/veterinary
    Language English
    Publishing date 2017-01
    Publishing country United States
    Document type Comparative Study ; Journal Article
    ZDB-ID 1491071-8
    ISSN 1532-950X ; 0161-3499
    ISSN (online) 1532-950X
    ISSN 0161-3499
    DOI 10.1111/vsu.12584
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Book: Fractionation in radiotherapy

    Thames, Howard D. / Hendry, Jolyon H.

    1987  

    Author's details Howard D. Thames and Jolyon H. Hendry
    Keywords Radiation Injuries / etiology ; Radiotherapy / adverse effects ; Radiotherapy Dosage ; Strahlentherapie ; Fraktionierung
    Subject Bestrahlung ; Radiotherapie ; Strahlenbehandlung ; Radioonkologie
    Size IX, 297 S. : zahlr. graph. Darst.
    Publisher Taylor & Francis
    Publishing place London u.a.
    Publishing country Great Britain
    Document type Book
    HBZ-ID HT003108055
    ISBN 0-85066-374-1 ; 978-0-85066-374-7
    Database Catalogue ZB MED Medicine, Health

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  10. Article ; Online: Computational Modeling of Micrometastatic Breast Cancer Radiation Dose Response.

    Smith, Daniel L / Debeb, Bisrat G / Thames, Howard D / Woodward, Wendy A

    International journal of radiation oncology, biology, physics

    2016  Volume 96, Issue 1, Page(s) 179–187

    Abstract: Purpose: Prophylactic cranial irradiation (PCI) involves giving radiation to the entire brain with the goals of reducing the incidence of brain metastasis and improving overall survival. Experimentally, we have demonstrated that PCI prevents brain ... ...

    Abstract Purpose: Prophylactic cranial irradiation (PCI) involves giving radiation to the entire brain with the goals of reducing the incidence of brain metastasis and improving overall survival. Experimentally, we have demonstrated that PCI prevents brain metastases in a breast cancer mouse model. We developed a computational model to expand on and aid in the interpretation of our experimental results.
    Methods and materials: MATLAB was used to develop a computational model of brain metastasis and PCI in mice. Model input parameters were optimized such that the model output would match the experimental number of metastases per mouse from the unirradiated group. An independent in vivo-limiting dilution experiment was performed to validate the model. The effect of whole brain irradiation at different measurement points after tumor cells were injected was evaluated in terms of the incidence, number of metastases, and tumor burden and was then compared with the corresponding experimental data.
    Results: In the optimized model, the correlation between the number of metastases per mouse and the experimental fits was >95. Our attempt to validate the model with a limiting dilution assay produced 99.9% correlation with respect to the incidence of metastases. The model accurately predicted the effect of whole-brain irradiation given 3 weeks after cell injection but substantially underestimated its effect when delivered 5 days after cell injection. The model further demonstrated that delaying whole-brain irradiation until the development of gross disease introduces a dose threshold that must be reached before a reduction in incidence can be realized.
    Conclusions: Our computational model of mouse brain metastasis and PCI correlated strongly with our experiments with unirradiated mice. The results further suggest that early treatment of subclinical disease is more effective than irradiating established disease.
    MeSH term(s) Animals ; Brain Neoplasms/physiopathology ; Brain Neoplasms/radiotherapy ; Brain Neoplasms/secondary ; Breast Neoplasms/physiopathology ; Breast Neoplasms/radiotherapy ; Cell Survival/radiation effects ; Computer Simulation ; Cranial Irradiation/methods ; Dose-Response Relationship, Radiation ; Mice ; Models, Biological ; Neoplasm Micrometastasis/pathology ; Neoplasm Micrometastasis/physiopathology ; Neoplasm Micrometastasis/radiotherapy ; Radiotherapy Dosage ; Radiotherapy, Computer-Assisted/methods
    Language English
    Publishing date 2016-09-01
    Publishing country United States
    Document type Journal Article
    ZDB-ID 197614-x
    ISSN 1879-355X ; 0360-3016
    ISSN (online) 1879-355X
    ISSN 0360-3016
    DOI 10.1016/j.ijrobp.2016.04.014
    Database MEDical Literature Analysis and Retrieval System OnLINE

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