Search our Database of Scientific Publications and Authors

I’m looking for a

    Details and Download Full Text PDF:
    Adequate target volume in total-body irradiation by intensity-modulated radiation therapy using helical tomotherapy: a simulation study.

    J Radiat Res 2017 Mar;58(2):210-216
    Department of Radiology, University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
    Recently, intensity-modulated radiation therapy (IMRT) has been used for total-body irradiation (TBI). Since the planning target volume (PTV) for TBI includes the surrounding air, a dose prescription to the PTV provides high fluence to the body surface. Thus with just a small set-up error, the body might be exposed to a high-fluence beam. This study aims to assess which target volume should be prescribed the dose, such as a clinical target volume (CTV) with a margin, or a CTV that excludes the surface area of the skin. Three treatment plans were created for each patient: the 5-mm clipped plan (Plan A), the 0-mm margin plan (Plan B) and the 5-mm margin plan (Plan C). The CTV was the whole body. PTVs were the CTV with the exception of 5 mm from the skin surface in Plan A, equal to the CTV in Plan B, and the CTV with a 5 mm margin in Plan C. The prescribed dose was 12 Gy in six fractions. To assess the influence of the set-up error, dose distributions were simulated on computed tomography (CT) images shifted 2 pixels (= 4.296 mm), 5 pixels (= 10.74 mm) and 10 pixels (= 21.48 mm) in the lateral direction from the original CT. With a set-up error of 10.74 mm, V110% was 8.8%, 11.1% and 23.3% in Plans A, B and C, respectively. The prescription to the PTV containing the surrounding air can be paradoxically vulnerable to a high-dose as a consequence of a small set-up error.
    PDF Download - Full Text Link
    ( Please be advised that this article is hosted on an external website not affiliated with
    Source Status ListingPossible

    Similar Publications

    Dosimetric comparison of stereotactic body radiotherapy using 4D CT and multiphase CT images for treatment planning of lung cancer: evaluation of the impact on daily dose coverage.
    Radiother Oncol 2009 Jun 26;91(3):314-24. Epub 2008 Dec 26.
    Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
    Purpose: To investigate the dosimetric impact of using 4D CT and multiphase (helical) CT images for treatment planning target definition and the daily target coverage in hypofractionated stereotactic body radiotherapy (SBRT) of lung cancer.

    Materials And Methods: For 10 consecutive patients treated with SBRT, a set of 4D CT images and three sets of multiphase helical CT scans, taken during free-breathing, end-inspiration and end-expiration breath-hold, were obtained. Three separate planning target volumes (PTVs) were created from these image sets. Read More
    Intensity-modulated radiotherapy for soft tissue sarcoma of the thigh.
    Int J Radiat Oncol Biol Phys 2004 Jul;59(3):752-9
    Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
    Purpose: Fracture of the femur is one of the late complications of adjuvant radiotherapy for patients with soft tissue sarcomas of the thigh, who receive external beam irradiation after limb-sparing surgery. When the target volume approximates the femur, it is often inevitable that a large segment of the femur will receive full prescription dose with conventional radiation techniques. We report the dosimetric feasibility of intensity- modulated radiation therapy (IMRT) techniques to achieve adequate target coverage and bone sparing. Read More
    Multi-scenario based robust intensity-modulated proton therapy (IMPT) plans can account for set-up errors more effectively in terms of normal tissue sparing than planning target volume (PTV) based intensity-modulated photon plans in the head and neck region.
    Radiat Oncol 2013 Jun 18;8:145. Epub 2013 Jun 18.
    Background: In a previous report, we compared the conformity of robust intensity-modulated proton therapy (IMPT) plans with that of helical tomotherapy plans for re-irradiations of head and neck carcinomas using a fixed set-up error of 2 mm. Here, we varied the maximum set-up errors between 0 and 5 mm and compared the robust IMPT-plans with planning target volume (PTV) based intensity-modulated photon therapy (IMRT).

    Findings: Seven patients were treated with a PTV-based tomotherapy plan. Read More
    Dosimetric influences of rotational setup errors on head and neck carcinoma intensity-modulated radiation therapy treatments.
    Med Dosim 2013 21;38(2):125-32. Epub 2012 Dec 21.
    Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA 15237, USA.
    The purpose of this work is to investigate the dosimetric influence of the residual rotational setup errors on head and neck carcinoma (HNC) intensity-modulated radiation therapy (IMRT) with routine 3 translational setup corrections and the adequacy of this routine correction. A total of 66 kV cone beam computed tomography (CBCT) image sets were acquired on the first day of treatment and weekly thereafter for 10 patients with HNC and were registered with the corresponding planning CT images, using 2 3-dimensional (3D) rigid registration methods. Method 1 determines the translational setup errors only, and method 2 determines 6-degree (6D) setup errors, i. Read More