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  1. Article: Investigation of in vivo source tracking error thresholds for interstitial and intra-cavitary high-dose-rate cervical brachytherapy.

    Dookie, Yashiv / Poder, Joel / Downes, Simon / Cutajar, Dean / Rosenfeld, Anatoly

    Journal of contemporary brachytherapy

    2022  Volume 14, Issue 6, Page(s) 568–581

    Abstract: Purpose: The purpose of this study was to determine a comprehensive : Material and methods: Retrospective HDR interstitial (: Results: In vivo: Conclusions: Determining the dosimetric impact of dwell position displacement provides a clinical ... ...

    Abstract Purpose: The purpose of this study was to determine a comprehensive
    Material and methods: Retrospective HDR interstitial (
    Results: In vivo
    Conclusions: Determining the dosimetric impact of dwell position displacement provides a clinical benchmark for the development of pre-treatment verification devices and an action level for real-time treatment monitoring. It was established that an
    Language English
    Publishing date 2022-12-30
    Publishing country Poland
    Document type Journal Article
    ZDB-ID 2627721-9
    ISSN 2081-2841 ; 1689-832X
    ISSN (online) 2081-2841
    ISSN 1689-832X
    DOI 10.5114/jcb.2022.123977
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: HDR prostate brachytherapy plan robustness and its effect on in-vivo source tracking error thresholds: A multi-institutional study.

    Poder, Joel / Koprivec, Dylan / Dookie, Yashiv / Howie, Andrew / Cutajar, Dean / Damato, Antonio L / Côté, Nicolas / Petasecca, Marco / Bucci, Joseph / Rosenfeld, Anatoly

    Medical physics

    2022  Volume 49, Issue 6, Page(s) 3529–3537

    Abstract: Purpose: The purpose of this study was to examine the effect of departmental planning techniques on appropriate in-vivo source tracking error thresholds for high dose rate (HDR) prostate brachytherapy (BT) treatments, and to determine if a single in- ... ...

    Abstract Purpose: The purpose of this study was to examine the effect of departmental planning techniques on appropriate in-vivo source tracking error thresholds for high dose rate (HDR) prostate brachytherapy (BT) treatments, and to determine if a single in-vivo source tracking error threshold would be appropriate for the same patient anatomy.
    Methods: The prostate, rectum, and urethra were contoured on a single patient transrectal ultrasound (TRUS) dataset. Anonymized DICOM files were disseminated to 16 departments who created an HDR prostate BT treatment plan on the dataset with a prescription dose of 15 Gy in a single fraction. Departments were asked to follow their own local treatment planning guidelines. Source positioning errors were then simulated in the 16 treatment plans and the effect on dose-volume histogram (DVH) indices calculated. Change in DVH indices were used to determine appropriate in-vivo source tracking error thresholds. Plans were considered to require intervention if the following DVH conditions occurred: prostate V100% < 90%, urethra D0.1cc > 118%, and rectumtt Dmax > 80%.
    Results: There was wide variation in appropriate in-vivo source tracking error thresholds among the 16 participating departments, ranging from 1 to 6 mm. Appropriate in-vivo source tracking error thresholds were also found to depend on the direction of the source positioning error and the endpoint. A robustness parameter was derived, and found to correlate with the sensitivity of plans to source positioning errors.
    Conclusions: A single HDR prostate BT in-vivo source tracking error threshold cannot be applied across multiple departments, even for the same patient anatomy. The burden on in-vivo source tracking devices may be eased through improving HDR prostate BT plan robustness during the plan optimisation phase.
    MeSH term(s) Brachytherapy ; Humans ; Male ; Prostate/diagnostic imaging ; Prostatic Neoplasms/diagnostic imaging ; Prostatic Neoplasms/radiotherapy ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted/methods
    Language English
    Publishing date 2022-04-19
    Publishing country United States
    Document type Journal Article ; Multicenter Study
    ZDB-ID 188780-4
    ISSN 2473-4209 ; 0094-2405
    ISSN (online) 2473-4209
    ISSN 0094-2405
    DOI 10.1002/mp.15658
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 1210: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

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  3. Article ; Online: Characterization of a flexible a-Si:H detector for in vivo dosimetry in therapeutic x-ray beams.

    Large, Matthew James / Bashiri, Aishah / Dookie, Yashiv / McNamara, Joanne / Antognini, Luca / Aziz, Saba / Calcagnile, Lucio / Caricato, Anna Paola / Catalano, Roberto / Chila, Deborah / Cirrone, Giuseppe Antonio Pablo / Croci, Tomasso / Cuttone, Giacomo / Dunand, Sylvain / Fabi, Michele / Frontini, Luca / Grimani, Catia / Ionica, Maria / Kanxheri, Keida /
    Liberali, Valentino / Maurizio, Martino / Maruccio, Giuseppe / Mazza, Giovanni / Menichelli, Mauro / Monteduro, Anna Grazia / Morozzi, Arianna / Moscatelli, Francesco / Pallotta, Stefania / Passeri, Daniele / Pedio, Maddalena / Petringa, Giada / Peverini, Francesca / Piccolo, Lorenzo / Placidi, Pisana / Quarta, Gianluca / Rizzato, Silvia / Sabbatini, Federico / Servoli, Leonello / Stabile, Alberto / Talamonti, Cinzia / Thomet, Jonathan Emanuel / Tosti, Luca / Villani, Mattia / Wheadon, Richard James / Wyrsch, Nicolas / Zema, Nicola / Petasecca, Marco

    Medical physics

    2024  

    Abstract: Background: The increasing use of complex and high dose-rate treatments in radiation therapy necessitates advanced detectors to provide accurate dosimetry. Rather than relying on pre-treatment quality assurance (QA) measurements alone, many countries ... ...

    Abstract Background: The increasing use of complex and high dose-rate treatments in radiation therapy necessitates advanced detectors to provide accurate dosimetry. Rather than relying on pre-treatment quality assurance (QA) measurements alone, many countries are now mandating the use of in vivo dosimetry, whereby a dosimeter is placed on the surface of the patient during treatment. Ideally, in vivo detectors should be flexible to conform to a patient's irregular surfaces.
    Purpose: This study aims to characterize a novel hydrogenated amorphous silicon (a-Si:H) radiation detector for the dosimetry of therapeutic x-ray beams. The detectors are flexible as they are fabricated directly on a flexible polyimide (Kapton) substrate.
    Methods: The potential of this technology for application as a real-time flexible detector is investigated through a combined dosimetric and flexibility study. Measurements of fundamental dosimetric quantities were obtained including output factor (OF), dose rate dependence (DPP), energy dependence, percentage depth dose (PDD), and angular dependence. The response of the a-Si:H detectors investigated in this study are benchmarked directly against commercially available ionization chambers and solid-state diodes currently employed for QA practices.
    Results: The a-Si:H detectors exhibit remarkable dose linearities in the direct detection of kV and MV therapeutic x-rays, with calibrated sensitivities ranging from (0.580 ± 0.002) pC/cGy to (19.36 ± 0.10) pC/cGy as a function of detector thickness, area, and applied bias. Regarding dosimetry, the a-Si:H detectors accurately obtained OF measurements that parallel commercially available detector solutions. The PDD response closely matched the expected profile as predicted via Geant4 simulations, a PTW Farmer ionization chamber and a PTW ROOS chamber. The most significant variation in the PDD performance was 5.67%, observed at a depth of 3 mm for detectors operated unbiased. With an external bias, the discrepancy in PDD response from reference data was confined to ± 2.92% for all depths (surface to 250 mm) in water-equivalent plastic. Very little angular dependence is displayed between irradiations at angles of 0° and 180°, with the most significant variation being a 7.71% decrease in collected charge at a 110° relative angle of incidence. Energy dependence and dose per pulse dependence are also reported, with results in agreement with the literature. Most notably, the flexibility of a-Si:H detectors was quantified for sample bending up to a radius of curvature of 7.98 mm, where the recorded photosensitivity degraded by (-4.9 ± 0.6)% of the initial device response when flat. It is essential to mention that this small bending radius is unlikely during in vivo patient dosimetry. In a more realistic scenario, with a bending radius of 15-20 mm, the variation in detector response remained within ± 4%. After substantial bending, the detector's photosensitivity when returned to a flat condition was (99.1 ± 0.5)% of the original response.
    Conclusions: This work successfully characterizes a flexible detector based on thin-film a-Si:H deposited on a Kapton substrate for applications in therapeutic x-ray dosimetry. The detectors exhibit dosimetric performances that parallel commercially available dosimeters, while also demonstrating excellent flexibility results.
    Language English
    Publishing date 2024-03-03
    Publishing country United States
    Document type Journal Article
    ZDB-ID 188780-4
    ISSN 2473-4209 ; 0094-2405
    ISSN (online) 2473-4209
    ISSN 0094-2405
    DOI 10.1002/mp.17013
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 1210: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

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