Three dimensional reconstruction of therapeutic carbon ion beams in phantoms using single secondary ion tracks

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21670%2F17%3A00329989" target="_blank" >RIV/68407700:21670/17:00329989 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1088/1361-6560/aa6aeb" target="_blank" >http://dx.doi.org/10.1088/1361-6560/aa6aeb</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1361-6560/aa6aeb" target="_blank" >10.1088/1361-6560/aa6aeb</a>

Result language

angličtina

Original language name

Three dimensional reconstruction of therapeutic carbon ion beams in phantoms using single secondary ion tracks

Original language description

Carbon ion beam radiotherapy enables a very localised dose deposition. However, even small changes in the patient geometry or positioning errors can significantly distort the dose distribution. A live, non-invasive monitoring system of the beam delivery within the patient is therefore highly desirable, and could improve patient treatment. We present a novel three-dimensional method for imaging the beam in the irradiated object, exploiting the measured tracks of single secondary ions emerging under irradiation. The secondary particle tracks are detected with a TimePix stack-a set of parallel pixelated semiconductor detectors. We developed a three-dimensional reconstruction algorithm based on maximum likelihood expectation maximization. We demonstrate the applicability of the new method in the irradiation of a cylindrical PMMA phantom of human head size with a carbon ion pencil beam of 226 MeV u(-1). The beam image in the phantom is reconstructed from a set of nine discrete detector positions between -80 degrees and 50 degrees from the beam axis. Furthermore, we demonstrate the potential to visualize inhomogeneities by irradiating a PMMA phantom with an air gap as well as bone and adipose tissue surrogate inserts. We successfully reconstructed a three-dimensional image of the treatment beam in the phantom from single secondary ion tracks. The beam image corresponds well to the beam direction and energy. In addition, cylindrical inhomogeneities with a diameter of 2.85 cm and density differences down to 0.3 g cm(-3) to the surrounding material are clearly visualized. This novel three-dimensional method to image a therapeutic carbon ion beam in the irradiated object does not interfere with the treatment and requires knowledge only of single secondary ion tracks. Even with detectors with only a small angular coverage, the three-dimensional reconstruction of the fragmentation points presented in this work was found to be feasible.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

30224 - Radiology, nuclear medicine and medical imaging

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physics in Medicine and Biology

ISSN

0031-9155

e-ISSN

1361-6560

Volume of the periodical

62

Issue of the periodical within the volume

June

Country of publishing house

GB - UNITED KINGDOM

Number of pages

13

Pages from-to

4884-4896

UT code for WoS article

000402376600009

EID of the result in the Scopus database

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