Evaluation of the peripheral dose in stereotactic radiotherapy and radiosurgery treatments

Journal Article · Thu Jul 15 00:00:00 EDT 2010 · Medical Physics

DOI:https://doi.org/10.1118/1.3447724· OSTI ID:22096717

Di Betta, Erika; Fariselli, Laura; Bergantin, Achille; Locatelli, Federica; Del Vecchio, Antonella; Broggi, Sara; Fumagalli, Maria Luisa ^[1]

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1. Department of Neurosurgery, Division of Medical Physics, Fondazione IRCCS, Istituto Neurologico C. Besta, 20133 Milano (Italy)

Purpose: The main purpose of this work was to compare peripheral doses absorbed during stereotactic treatment of a brain lesion delivered using different devices. These data were used to estimate the risk of stochastic effects. Methods: Treatment plans were created for an anthropomorphic phantom and delivered using a LINAC with stereotactic cones and a multileaf collimator, a CyberKnife system (before and after a supplemental shielding was applied), a TomoTherapy system, and a Gamma Knife unit. For each treatment, 5 Gy were prescribed to the target. Measurements were performed with thermoluminescent dosimeters inserted roughly in the position of the thyroid, sternum, upper lung, lower lung, and gonads. Results: Mean doses ranged from of 4.1 (Gamma Knife) to 62.8 mGy (LINAC with cones) in the thyroid, from 2.3 (TomoTherapy) to 30 mGy (preshielding CyberKnife) in the sternum, from 1.7 (TomoTherapy) to 20 mGy (preshielding CyberKnife) in the upper part of the lungs, from 0.98 (Gamma Knife) to 15 mGy (preshielding CyberKnife) in the lower part of the lungs, and between 0.3 (Gamma Knife) and 10 mGy (preshielding CyberKnife) in the gonads. Conclusions: The peripheral dose absorbed in the sites of interest with a 5 Gy fraction is low. Although the risk of adverse side effects calculated for 20 Gy delivered in 5 Gy fractions is negligible, in the interest of optimum patient radioprotection, further studies are needed to determine the weight of each contributor to the peripheral dose.

• OSTI ID: 22096717
• Journal Information: Medical Physics, Vol. 37, Issue 7; Other Information: (c) 2010 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
60 APPLIED LIFE SCIENCES
BRAIN
COLLIMATORS
COMPUTERIZED TOMOGRAPHY
CT-GUIDED RADIOTHERAPY
DOSIMETRY
GONADS
HAZARDS
LINEAR ACCELERATORS
LUNGS
PATIENTS
PHANTOMS
RADIATION DOSES
RADIATION PROTECTION
SHIELDING
SIDE EFFECTS
STOCHASTIC PROCESSES
SURGERY
THERMOLUMINESCENT DOSEMETERS
THYROID