Venkatraman Pitchaikannu P | Bharathiyar University (original) (raw)

Papers by Venkatraman Pitchaikannu P

Radiotherapy and Oncology

Response to ''Comments on whole lung irradiation as a novel treatment for COVID-19: Final results... more Response to ''Comments on whole lung irradiation as a novel treatment for COVID-19: Final results of the prospective randomized trial (WINCOVID trial)"

The traditional vehicle-based and vision based drowsy detection become apparent only after the dr... more The traditional vehicle-based and vision based drowsy detection become apparent only after the driver starts to sleep, which is often too late to prevent an accident. In this proposed project a buzzer with low power consumption, is placed near the driver which would wake up the driver while he falls asleep while driving. The EEGsensor senses the brain signals and also the eye blink of the driver using ADS1299, and the entire device is operated using an Op-amp TLV 2760. The EEG signal is converted to digital using ADS1299 Analog front end and the output is acquired using MSP430G2553. The speed of the car will be varied according to the EEG signals. If the car slows down the indication is displayed at the back of the car using a LED display. Thus a sensor able to detect the activities and components of brain is important for comprehensive care and analysis of body conditions. The Low cost embedded drowsy driver detection system determines the sensor result and if it is below or above ...

Radiotherapy and Oncology, 2022

Radiotherapy and Oncology

The objective of this study is to evaluate the neutron shielding effects of materials, bricks and... more The objective of this study is to evaluate the neutron shielding effects of materials, bricks and polyethylene by using an Am-Be neutron source room for radiation protection.

The objective of this study is to verify the alpha dose rate, calculated using various statistica... more The objective of this study is to verify the alpha dose rate, calculated using various statistical methods and its comparison with the alpha counting system generated data.

The objective of this study is to fabricate a novel PCB technology based 2D ion detector for sing... more The objective of this study is to fabricate a novel PCB technology based 2D ion detector for single ion registration in Nanodosimetry.

Three Gas-Electron-Multiplier tracking detectors with an active area of 10 cm × 10 cm and a two-d... more Three Gas-Electron-Multiplier tracking detectors with an active area of 10 cm × 10 cm and a two-dimensional, laser-etched orthogonal strip readout have been tested extensively in particle beams at the Meson Test Beam Facility at Fermilab. These detectors used GEM foils produced by Tech-Etch, Inc. They showed an efficiency in excess of 95% and spatial resolution better than 70 µm. The influence of the angle of incidence of particles on efficiency and spatial resolution was studied in detail.

Future measurements of the flavor-separated spin structure of the proton via parity-violating W b... more Future measurements of the flavor-separated spin structure of the proton via parity-violating W boson production at RHIC require an upgrade of the forward tracking system of the STAR detector. This upgrade will allow the reconstruction of the charge sign of electrons and positrons produced from decaying W bosons. A design based on six large area triple GEM disks using GEM foils produced by Tech-Etch Inc. has emerged as a cost-effective solution to provide the necessary tracking precision. We report first results from a beam test of three test detectors using Tech-Etch produced GEM foils and a laser etched two dimensional strip readout. The detectors show good operational stability, high efficiency and a spacial resolution of around 70 µm or better, exceeding the requirements for the forward tracking upgrade. The influence of the angle of incidence of the particles on the spatial resolution of the detectors has also been studied in detail.

Computers & Geosciences, 2011

Chang'E-1 (abbreviation CE-1), China's first Moon-orbiting spacecraft launched in 2007, carried e... more Chang'E-1 (abbreviation CE-1), China's first Moon-orbiting spacecraft launched in 2007, carried equipment called the Solar Wind Ion Detector (abbreviation SWID), which sent back tens of gigabytes of solar wind ion differential number flux data. These data are essential for furthering our understanding of the cislunar space environment. However, to fully comprehend and analyze these data presents considerable difficulties, not only because of their huge size (57 GB), but also because of their complexity. Therefore, a new 3D visualization method is developed to give a more intuitive representation than traditional 1D and 2D visualizations, and in particular to offer a better indication of the direction of the incident ion differential number flux and the relative spatial position of CE-1 with respect to the Sun, the Earth, and the Moon. First, a coordinate system named Selenocentric Solar Ecliptic (SSE) which is more suitable for our goal is chosen, and solar wind ion differential number flux vectors in SSE are calculated from Geocentric Solar Ecliptic System (GSE) and Moon Center Coordinate (MCC) coordinates of the spacecraft, and then the ion differential number flux distribution in SSE is visualized in 3D space. This visualization method is integrated into an interactive visualization analysis software tool named vtSWIDs, developed in MATLAB, which enables researchers to browse through numerous records and manipulate the visualization results in real time. The tool also provides some useful statistical analysis functions, and can be easily expanded.

Journal of The American Society for Mass Spectrometry, 2007

Proteomic profiling involves identification and quantification of protein components in complex b... more Proteomic profiling involves identification and quantification of protein components in complex biological systems. Most of the mass profiling studies performed with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) have been restricted to peptides and small proteins (<20 kDa) because the sensitivity of the standard ion detectors decreases with increasing ion mass. Here we perform a protein profiling study of the snake venom Sistrurus miliarius barbouri, comparing 2D gel electrophoresis and reversed-phase high-performance liquid chromatography (HPLC) with a high mass cryodetector MALDI-TOF instrument (Macromizer), whose detector displays an uniform sensitivity with mass. Our results show that such MS approach can render superior analysis of protein complexity compared with that obtained with the electrophoretic and chromatographic approaches. The summation of ion impacts allows relative quantification of different proteins, and the number of ion counts correlates with the peak areas in the reversed-phase HPLC. Furthermore, the sensitivity reached with the high mass cryodetection MS technology clearly exceeds the detection limit of standard high-sensitivity staining methods.

Physica Medica, 2007

A 2D array (PTW, type 10024), equipped with 729 vented plane parallel ion-chambers, has been cali... more A 2D array (PTW, type 10024), equipped with 729 vented plane parallel ion-chambers, has been calibrated as a detector for the in vivo comparison between measured and predicted portal doses for head–neck tumors. The comparison of absolute portal doses measured to ones predicted by a commercial treatment planning system within the field of view of the CT scanner, can help the delivered dose verification during different treatment fractions, in particular when the patient's present weight loss.This paper reports the preliminary results of the comparison of the portal doses measured by a PTW 2D array during several radiotherapy fractions and the predicted portal doses for seven patients undergoing head–neck tumor radiotherapy. The gamma index analysis supplied an agreement of more than 95% of the dose-point Pγ > 95% within acceptance criteria, in terms of dose difference, ΔDmax, and distance-agreement, Δdmax, equal to 5% and 4 mm, respectively. After the third week, one patient showed a decrease of Pγ values due to the markedly reduced patient's thickness. Even if the spatial resolution of the 2D array was 1 cm, there were two advantages in the use of this 2D array as a portal dose device for IMRT quality control. The first one was the use of a stable and efficient absolute dosimeter for in vivo verification, although its construction and behavior for other gantry angles need to be tested, and the second one was the time efficiency in verifying the correct dose delivery in several fractions of the therapy.This study presents acceptance criteria for the comparison of TPS-predicted portal dose images with in vivo 2D ion-chamber measurements for IMRT. In particular, portal dose measurements offer clues for additional studies as to which indicators can signal the need for replanning during treatment.

In the present paper, we describe the development of Long Wave Infrared (8-12 μm) linear and 2-D ... more In the present paper, we describe the development of Long Wave Infrared (8-12 μm) linear and 2-D IR FPA detectors using HgCdTe for use in thermal imagers and IIR seekers. In this direction, Solid State Physics Laboratory(SSPL) (DRDO) tried to concentrate initially in the bulk growth and characterization of HgCdTe during the early eighties. Some efforts were then made to develop a LWIR photoconductive type MCT array in linear configuration with the IRFPA processed on bulk MCT crystals grown in the laboratory. Non availability of quality epilayers with the required specification followed by the denial of supply of CdTe, CdZnTe and even high purity Te by advanced countries, forced us to shift our efforts during early nineties towards development of 60 element PC IR detectors. High performance linear PC arrays were developed. A novel horizontal casting procedure was evolved for growing high quality bulk material using solid state recrystallization technique. Efforts for ultra purification of Te to 7N purity with the help of a sister concern has made it possible to have this material indigenously. Having succeded in the technology for growing single crystalline CdZnTe with (111) orientation and LPE growth of HgCdTe epilayers on CdZnTe substrates an attempt was made to establish the fabrication of 2D short PV arrays showing significant IR response. Thus a detailed technological knowhow for passivation, metallization, ion implanted junction formation, etc. was generated. Parallel work on the development of a matching CCD Mux readout in silicon by Semiconductor Complex Limited was also completed which was tested first in stand-alone mode followed by integration with IRFPAs through indigenously-developed indium bumps. These devices were integrated into an indigenously fabricated glass dewar cooled by a self-developed JT minicooler. In recent years, the LPE (Liquid Phase Epitaxy) growth from Terich route has been standardized for producing epitaxial layers with high compositional and thickness uniformity leading to a respectable stage of maturity in FPA technology.

Velocity map imaging of ions and electrons using electrostatic lenses: Application in photoelectr... more Velocity map imaging of ions and electrons using electrostatic lenses: Application in photoelectron and photofragment ion imaging of molecular oxygen. [Review of Scientific Instruments 68, 3477 (1997)]. André TJB Eppink, David H. Parker. Abstract. ...

Medical Physics, 2006

The Gafchromic EBT was recently introduced in film dosimetry for external beam therapy (EBT). The... more The Gafchromic EBT was recently introduced in film dosimetry for external beam therapy (EBT). The high spatial resolution, weak energy dependence, and near-tissue equivalence of EBT films make them suitable for measurement of dose distributions in radiotherapy, especially intensity-modulated radiation therapy (IMRT). Starting with a sensitometric curve and dose uncertainty relative to the flatbed scanner, the goal of this study was to find an efficient method of correcting for light scattering, and to compare dose distribution supplied by Gafchromic EBT with the distribution obtained with a 2D ion-chamber detector system. Light scattering was analyzed for different levels of dose, and was found to depend on the red-scale value as well as the position of the pixel on the scanner. Many &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;uniform&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; films were exposed at different levels of dose to create a two-dimensional matrix correction to take this effect into account. The dose distribution obtained for three clinical beams (10 x 10, 15 x 15 cm open fields and 12 x 12 cm wedge 60 degrees field) were in agreement with those supplied by the 2D array. Gamma index &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1 (using 5 mm distance and 5% dose as constraints) for the three fields considered was reached in an average of 98% of the points.

Zeitschrift Fur Medizinische Physik

3D dose reconstruction is a verification of the delivered absorbed dose. Our aim was to describe ... more 3D dose reconstruction is a verification of the delivered absorbed dose. Our aim was to describe and evaluate a 3D dose reconstruction method applied to phantoms in the context of narrow beams. A solid water phantom and a phantom containing a bone-equivalent material were irradiated on a 6 MV linac. The transmitted dose was measured by using one array of a 2D ion chamber detector. The dose reconstruction was obtained by an iterative algorithm. A phantom set-up error and organ interfraction motion were simulated to test the algorithm sensitivity.In all configurations convergence was obtained within three iterations. A local reconstructed dose agreement of at least 3% / 3 mm with respect to the planned dose was obtained, except in a few points of the penumbra. The reconstructed primary fluences were consistent with the planned ones, which validates the whole reconstruction process. The results validate our method in a simple geometry and for narrow beams. The method is sensitive to a set-up error of a heterogeneous phantom and interfraction heterogeneous organ motion.3D-Dosis-Rekonstruktion gilt als Verifikation der übertragenen absorbierten Dosis. Unser Ziel ist die 3D-Dosis-Rekonstruktionsmethode für schmale Strahlen, ausprobiert an Phantomen, zu beschreiben und zu bemessen. Ein Wasseräquivalentphantom und ein Phantom, das knochenähnliches Material enthält, wurden mit einem 6-MV-Linac bestrahlt. Die durchstrahlte Dosis wurde mit einer Reihe von einem Ionisationskammermatrixdetektor gemessen. Die Dosisrekonstruktion wurde durch einen iterativen Algorithmus erreicht. Fehler in Phantomeinstellung und Organinterfraktionsbewegung wurden simuliert um die Algorithmus-Empfindlichkeit zu prüfen.In allen Konfigurationen wurde der Algorithmus innerhalb von drei Iterationen konvergiert. Eine lokale Dosisübereinstimmung mit der geplanten Dosis von mindestens 3% / 3 mm wurde erreicht, mit der Ausnahme von wenigen Punkten in der Penumbra. Die rekonstruierten Primärfluenzen waren mit den geplanten vereinbart, was der gesamte Rekonstruktionsprozess bestätigt. Die Ergebnisse bestätigen unsere Methode in dem Fall eine einfache Geometrie und schmale Strahlen. Die Methode ist empfindlich gegenüber Einstellungsfehlern eines heterogenen Phantoms und Organinterfraktionsbewegung.

Radiotherapy and Oncology

Response to ''Comments on whole lung irradiation as a novel treatment for COVID-19: Final results... more Response to ''Comments on whole lung irradiation as a novel treatment for COVID-19: Final results of the prospective randomized trial (WINCOVID trial)"

The traditional vehicle-based and vision based drowsy detection become apparent only after the dr... more The traditional vehicle-based and vision based drowsy detection become apparent only after the driver starts to sleep, which is often too late to prevent an accident. In this proposed project a buzzer with low power consumption, is placed near the driver which would wake up the driver while he falls asleep while driving. The EEGsensor senses the brain signals and also the eye blink of the driver using ADS1299, and the entire device is operated using an Op-amp TLV 2760. The EEG signal is converted to digital using ADS1299 Analog front end and the output is acquired using MSP430G2553. The speed of the car will be varied according to the EEG signals. If the car slows down the indication is displayed at the back of the car using a LED display. Thus a sensor able to detect the activities and components of brain is important for comprehensive care and analysis of body conditions. The Low cost embedded drowsy driver detection system determines the sensor result and if it is below or above ...

Radiotherapy and Oncology, 2022

Radiotherapy and Oncology

The objective of this study is to evaluate the neutron shielding effects of materials, bricks and... more The objective of this study is to evaluate the neutron shielding effects of materials, bricks and polyethylene by using an Am-Be neutron source room for radiation protection.

The objective of this study is to verify the alpha dose rate, calculated using various statistica... more The objective of this study is to verify the alpha dose rate, calculated using various statistical methods and its comparison with the alpha counting system generated data.

The objective of this study is to fabricate a novel PCB technology based 2D ion detector for sing... more The objective of this study is to fabricate a novel PCB technology based 2D ion detector for single ion registration in Nanodosimetry.

Three Gas-Electron-Multiplier tracking detectors with an active area of 10 cm × 10 cm and a two-d... more Three Gas-Electron-Multiplier tracking detectors with an active area of 10 cm × 10 cm and a two-dimensional, laser-etched orthogonal strip readout have been tested extensively in particle beams at the Meson Test Beam Facility at Fermilab. These detectors used GEM foils produced by Tech-Etch, Inc. They showed an efficiency in excess of 95% and spatial resolution better than 70 µm. The influence of the angle of incidence of particles on efficiency and spatial resolution was studied in detail.

Future measurements of the flavor-separated spin structure of the proton via parity-violating W b... more Future measurements of the flavor-separated spin structure of the proton via parity-violating W boson production at RHIC require an upgrade of the forward tracking system of the STAR detector. This upgrade will allow the reconstruction of the charge sign of electrons and positrons produced from decaying W bosons. A design based on six large area triple GEM disks using GEM foils produced by Tech-Etch Inc. has emerged as a cost-effective solution to provide the necessary tracking precision. We report first results from a beam test of three test detectors using Tech-Etch produced GEM foils and a laser etched two dimensional strip readout. The detectors show good operational stability, high efficiency and a spacial resolution of around 70 µm or better, exceeding the requirements for the forward tracking upgrade. The influence of the angle of incidence of the particles on the spatial resolution of the detectors has also been studied in detail.

Computers & Geosciences, 2011

Chang'E-1 (abbreviation CE-1), China's first Moon-orbiting spacecraft launched in 2007, carried e... more Chang'E-1 (abbreviation CE-1), China's first Moon-orbiting spacecraft launched in 2007, carried equipment called the Solar Wind Ion Detector (abbreviation SWID), which sent back tens of gigabytes of solar wind ion differential number flux data. These data are essential for furthering our understanding of the cislunar space environment. However, to fully comprehend and analyze these data presents considerable difficulties, not only because of their huge size (57 GB), but also because of their complexity. Therefore, a new 3D visualization method is developed to give a more intuitive representation than traditional 1D and 2D visualizations, and in particular to offer a better indication of the direction of the incident ion differential number flux and the relative spatial position of CE-1 with respect to the Sun, the Earth, and the Moon. First, a coordinate system named Selenocentric Solar Ecliptic (SSE) which is more suitable for our goal is chosen, and solar wind ion differential number flux vectors in SSE are calculated from Geocentric Solar Ecliptic System (GSE) and Moon Center Coordinate (MCC) coordinates of the spacecraft, and then the ion differential number flux distribution in SSE is visualized in 3D space. This visualization method is integrated into an interactive visualization analysis software tool named vtSWIDs, developed in MATLAB, which enables researchers to browse through numerous records and manipulate the visualization results in real time. The tool also provides some useful statistical analysis functions, and can be easily expanded.

Journal of The American Society for Mass Spectrometry, 2007

Proteomic profiling involves identification and quantification of protein components in complex b... more Proteomic profiling involves identification and quantification of protein components in complex biological systems. Most of the mass profiling studies performed with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) have been restricted to peptides and small proteins (<20 kDa) because the sensitivity of the standard ion detectors decreases with increasing ion mass. Here we perform a protein profiling study of the snake venom Sistrurus miliarius barbouri, comparing 2D gel electrophoresis and reversed-phase high-performance liquid chromatography (HPLC) with a high mass cryodetector MALDI-TOF instrument (Macromizer), whose detector displays an uniform sensitivity with mass. Our results show that such MS approach can render superior analysis of protein complexity compared with that obtained with the electrophoretic and chromatographic approaches. The summation of ion impacts allows relative quantification of different proteins, and the number of ion counts correlates with the peak areas in the reversed-phase HPLC. Furthermore, the sensitivity reached with the high mass cryodetection MS technology clearly exceeds the detection limit of standard high-sensitivity staining methods.

Physica Medica, 2007

A 2D array (PTW, type 10024), equipped with 729 vented plane parallel ion-chambers, has been cali... more A 2D array (PTW, type 10024), equipped with 729 vented plane parallel ion-chambers, has been calibrated as a detector for the in vivo comparison between measured and predicted portal doses for head–neck tumors. The comparison of absolute portal doses measured to ones predicted by a commercial treatment planning system within the field of view of the CT scanner, can help the delivered dose verification during different treatment fractions, in particular when the patient's present weight loss.This paper reports the preliminary results of the comparison of the portal doses measured by a PTW 2D array during several radiotherapy fractions and the predicted portal doses for seven patients undergoing head–neck tumor radiotherapy. The gamma index analysis supplied an agreement of more than 95% of the dose-point Pγ > 95% within acceptance criteria, in terms of dose difference, ΔDmax, and distance-agreement, Δdmax, equal to 5% and 4 mm, respectively. After the third week, one patient showed a decrease of Pγ values due to the markedly reduced patient's thickness. Even if the spatial resolution of the 2D array was 1 cm, there were two advantages in the use of this 2D array as a portal dose device for IMRT quality control. The first one was the use of a stable and efficient absolute dosimeter for in vivo verification, although its construction and behavior for other gantry angles need to be tested, and the second one was the time efficiency in verifying the correct dose delivery in several fractions of the therapy.This study presents acceptance criteria for the comparison of TPS-predicted portal dose images with in vivo 2D ion-chamber measurements for IMRT. In particular, portal dose measurements offer clues for additional studies as to which indicators can signal the need for replanning during treatment.

In the present paper, we describe the development of Long Wave Infrared (8-12 μm) linear and 2-D ... more In the present paper, we describe the development of Long Wave Infrared (8-12 μm) linear and 2-D IR FPA detectors using HgCdTe for use in thermal imagers and IIR seekers. In this direction, Solid State Physics Laboratory(SSPL) (DRDO) tried to concentrate initially in the bulk growth and characterization of HgCdTe during the early eighties. Some efforts were then made to develop a LWIR photoconductive type MCT array in linear configuration with the IRFPA processed on bulk MCT crystals grown in the laboratory. Non availability of quality epilayers with the required specification followed by the denial of supply of CdTe, CdZnTe and even high purity Te by advanced countries, forced us to shift our efforts during early nineties towards development of 60 element PC IR detectors. High performance linear PC arrays were developed. A novel horizontal casting procedure was evolved for growing high quality bulk material using solid state recrystallization technique. Efforts for ultra purification of Te to 7N purity with the help of a sister concern has made it possible to have this material indigenously. Having succeded in the technology for growing single crystalline CdZnTe with (111) orientation and LPE growth of HgCdTe epilayers on CdZnTe substrates an attempt was made to establish the fabrication of 2D short PV arrays showing significant IR response. Thus a detailed technological knowhow for passivation, metallization, ion implanted junction formation, etc. was generated. Parallel work on the development of a matching CCD Mux readout in silicon by Semiconductor Complex Limited was also completed which was tested first in stand-alone mode followed by integration with IRFPAs through indigenously-developed indium bumps. These devices were integrated into an indigenously fabricated glass dewar cooled by a self-developed JT minicooler. In recent years, the LPE (Liquid Phase Epitaxy) growth from Terich route has been standardized for producing epitaxial layers with high compositional and thickness uniformity leading to a respectable stage of maturity in FPA technology.

Velocity map imaging of ions and electrons using electrostatic lenses: Application in photoelectr... more Velocity map imaging of ions and electrons using electrostatic lenses: Application in photoelectron and photofragment ion imaging of molecular oxygen. [Review of Scientific Instruments 68, 3477 (1997)]. André TJB Eppink, David H. Parker. Abstract. ...

Medical Physics, 2006

The Gafchromic EBT was recently introduced in film dosimetry for external beam therapy (EBT). The... more The Gafchromic EBT was recently introduced in film dosimetry for external beam therapy (EBT). The high spatial resolution, weak energy dependence, and near-tissue equivalence of EBT films make them suitable for measurement of dose distributions in radiotherapy, especially intensity-modulated radiation therapy (IMRT). Starting with a sensitometric curve and dose uncertainty relative to the flatbed scanner, the goal of this study was to find an efficient method of correcting for light scattering, and to compare dose distribution supplied by Gafchromic EBT with the distribution obtained with a 2D ion-chamber detector system. Light scattering was analyzed for different levels of dose, and was found to depend on the red-scale value as well as the position of the pixel on the scanner. Many &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;uniform&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; films were exposed at different levels of dose to create a two-dimensional matrix correction to take this effect into account. The dose distribution obtained for three clinical beams (10 x 10, 15 x 15 cm open fields and 12 x 12 cm wedge 60 degrees field) were in agreement with those supplied by the 2D array. Gamma index &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1 (using 5 mm distance and 5% dose as constraints) for the three fields considered was reached in an average of 98% of the points.

Zeitschrift Fur Medizinische Physik

3D dose reconstruction is a verification of the delivered absorbed dose. Our aim was to describe ... more 3D dose reconstruction is a verification of the delivered absorbed dose. Our aim was to describe and evaluate a 3D dose reconstruction method applied to phantoms in the context of narrow beams. A solid water phantom and a phantom containing a bone-equivalent material were irradiated on a 6 MV linac. The transmitted dose was measured by using one array of a 2D ion chamber detector. The dose reconstruction was obtained by an iterative algorithm. A phantom set-up error and organ interfraction motion were simulated to test the algorithm sensitivity.In all configurations convergence was obtained within three iterations. A local reconstructed dose agreement of at least 3% / 3 mm with respect to the planned dose was obtained, except in a few points of the penumbra. The reconstructed primary fluences were consistent with the planned ones, which validates the whole reconstruction process. The results validate our method in a simple geometry and for narrow beams. The method is sensitive to a set-up error of a heterogeneous phantom and interfraction heterogeneous organ motion.3D-Dosis-Rekonstruktion gilt als Verifikation der übertragenen absorbierten Dosis. Unser Ziel ist die 3D-Dosis-Rekonstruktionsmethode für schmale Strahlen, ausprobiert an Phantomen, zu beschreiben und zu bemessen. Ein Wasseräquivalentphantom und ein Phantom, das knochenähnliches Material enthält, wurden mit einem 6-MV-Linac bestrahlt. Die durchstrahlte Dosis wurde mit einer Reihe von einem Ionisationskammermatrixdetektor gemessen. Die Dosisrekonstruktion wurde durch einen iterativen Algorithmus erreicht. Fehler in Phantomeinstellung und Organinterfraktionsbewegung wurden simuliert um die Algorithmus-Empfindlichkeit zu prüfen.In allen Konfigurationen wurde der Algorithmus innerhalb von drei Iterationen konvergiert. Eine lokale Dosisübereinstimmung mit der geplanten Dosis von mindestens 3% / 3 mm wurde erreicht, mit der Ausnahme von wenigen Punkten in der Penumbra. Die rekonstruierten Primärfluenzen waren mit den geplanten vereinbart, was der gesamte Rekonstruktionsprozess bestätigt. Die Ergebnisse bestätigen unsere Methode in dem Fall eine einfache Geometrie und schmale Strahlen. Die Methode ist empfindlich gegenüber Einstellungsfehlern eines heterogenen Phantoms und Organinterfraktionsbewegung.