scholarly journals 3D Dosimetry Based on LiMgPO4 OSL Silicone Foils: Facilitating the Verification of Eye-Ball Cancer Proton Radiotherapy

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6015
Author(s):  
Michał Sądel ◽  
Jan Gajewski ◽  
Urszula Sowa ◽  
Jan Swakoń ◽  
Tomasz Kajdrowicz ◽  
...  
Keyword(s):  
Imaging System ◽  
Treatment Plan ◽  
Three Dimensional ◽  
Ccd Camera ◽  
Clinical Treatment ◽  
Planning System ◽  
Two Dimensional ◽  
Proton Radiotherapy ◽  
Medical Systems ◽  
3D Dosimetry

A direct verification of the three-dimensional (3D) proton clinical treatment plan prepared for tumor in the eyeball, using the Eclipse Ocular Proton Planning system (by Varian Medical Systems), has been presented. To achieve this, a prototype of the innovative two-dimensional (2D) circular silicone foils, made of a polymer with the embedded optically stimulated luminescence (OSL) material in powder form (LiMgPO4), and a self-developed optical imaging system, consisting of an illuminating light source and a high-sensitive CCD camera has been applied. A specially designed lifelike eyeball phantom has been used, constructed from 40 flat sheet LMP-based silicone foils stacked and placed together behind a spherical phantom made by polystyrene, all to reflect the curvature of the real eyeball. Two-dimensional OSL signals were captured and further analyzed from each single silicone foil after irradiation using a dedicated patient collimator and a 58.8 MeV modulated proton beam. The reconstructed 3D proton depth dose distribution matches very well with the clinical treatment plan, allowing for the consideration of the new OSL system for further 3D dosimetry applications within the proton radiotherapy area.

A hybrid approach for head and neck cancer using online image guidance and offline adaptive radiotherapy planning

2019 ◽  
Vol 18 (03) ◽  
pp. 271-275 ◽  
Author(s):  
Roopam Srivastava ◽  
P.K. Sharma ◽  
K.J. Maria Das ◽  
Jayanand Manjhi
Keyword(s):  
Computed Tomography ◽  
Head And Neck Cancer ◽  
Head And Neck ◽  
Neck Cancer ◽  
Dose Distribution ◽  
Treatment Plan ◽  
Planning System ◽  
Radiotherapy Planning ◽  
Treatment Planning System ◽  
Medical Systems

AbstractBackgroundThis is a prospective study to evaluate the dosimetric benefits of treatment plan adaptation for patients who had undergone repeat computed tomography (ReCT)and re-planning due to treatment-induced anatomical changes during radiotherapy.Materials and MethodsThis study involved five head and neck cancer patients who had their treatment plan modified, based on weekly thrice imaging protocol. Impact of mid-course imaging was assessed in patients using ReCT and cone beam computed tomography (CBCT)-based dose verification. Patients were imaged, apart from their initial CT, during the course of their radiation therapy with a ReCT and on board imager CBCT (Varian Medical Systems Inc., Palo Alto, CA, USA). Each CBCT/CT series was rigidly registered to the initial CT in the treatment planning system Eclipse (Varian Medical Systems Inc.) using bony landmarks. The structures were copied to the current CBCT/CT series and, where needed, manually edited slicewise. The dose distribution from the treatment plan was viewed as of the current anatomy by applying the treatment plan the CBCT/CT series, and studying the corresponding dose–volume histograms for organs at risk doses.ResultsThe reduction of parotid volumes due to weight loss was observed in all patients, which means an increase in predicted mean doses of parotid when initial CT plan was re-calculated on ReCT and CBCT (Table 1). This explains the necessity of adaptive planning. The predicted mean dose of parotid glands was increased and constraints to spinal cord and skin were exceeded, so re-planning was performed.ConclusionsThe CBCT is a useful tool to view anatomic changes in patients and get an estimate of their impact on dose distribution. Re-planning based on imaging in head and neck patients during the course of radiotherapy is mandatory to reduce side effects.

scholarly journals Making Anaglyphs in Photoshop

2005 ◽  
Vol 13 (3) ◽  
pp. 36-39 ◽  
Author(s):  
Jerry Sedgewick
Keyword(s):  
Imaging System ◽  
Three Dimensional ◽  
Ct Scans ◽  
Two Dimensional ◽  
The Right ◽  
Two Dimensional Images

In order to achieve a three dimensional appearance to a pair of two dimensional images, two off-axis images can be produced and colorized. These can be overlayed slightly apart and then viewed through glasses with two differently colored sides, one color for the left eye and another for the right eye in combinations containing red, green or blue colors. These off-axis and colorized images are referred to as anaglyphs.Off-axis images can be achieved through the use of a tilting stage on a microscope, by physically changing the position of a camera in relation to a still object, or through changing the axis of an optical stack of sections, such as what is created by confocal/CT scans. Some images lend themselves more to a 3D look both by virtue of inherent three dimensionality limited by the resolution of the imaging system.

Improvement of dose homogeneity with irregular surface compensator in whole brain radiotherapy

2016 ◽  
Vol 15 (3) ◽  
pp. 269-275
Author(s):  
H. Fujita ◽  
N. Kuwahata ◽  
H. Hattori ◽  
H. Kinoshita ◽  
H. Fukuda
Keyword(s):  
Maximum Dose ◽  
Treatment Plan ◽  
Whole Brain Radiotherapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Irregular Surface ◽  
Medical Systems ◽  
Whole Brain ◽  
Brain Radiotherapy ◽  
Dose Homogeneity

AbstractPurposeThe aim of this study was to evaluate the dosimetric aspects of whole brain radiotherapy (WBRT) using an irregular surface compensator (ISC) in contrast to conventional radiotherapy techniques.MethodsTreatment plans were devised for 20 patients. The Eclipse treatment planning system (Varian Medical Systems) was used for dose calculation. For the ISC, a fluence editor application was used to extend the range of optimal fluence. The treatment plan with the ISC was compared with the conventional technique in terms of doses in the planning target volume (PTV), dose homogeneity index (DHI), three-dimensional (3D) maximum dose, eye and lens doses and monitor unit (MU) counts required for treatment.ResultsCompared with conventional WBRT, the ISC significantly reduced the DHI, 3D maximum dose and volumes receiving 105% of the prescription dose, in addition to reducing both eye and lens doses (p<0·05 for all comparisons). In contrast, MU counts were higher for the ISC technique than for conventional WBRT (828 versus 328, p<0·01).ConclusionThe ISC technique for WBRT considerably improved the dose homogeneity in the PTV. As patients who receive WBRT have improved survival, the long-term side effects of radiotherapy are highly important.

scholarly journals Effect of smoothing on treatment plan efficiency in IMRT: eclipse Helios™ dose optimisation

2012 ◽  
Vol 11 (4) ◽  
pp. 229-238 ◽  
Author(s):  
KS Armoogum
Keyword(s):  
Organs At Risk ◽  
Treatment Plan ◽  
Intensity Modulated Radiotherapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Conformity Index ◽  
Homogeneity Index ◽  
Medical Systems ◽  
Dose Optimisation ◽  
Smoothing Parameters

AbstractBackground and purpose: This study examined the effect of varying the X–Y smoothing values on the average Leaf Pair Opening (LPO), MUFactor and total number of monitor units (MU) in a cohort of 20 prostate and head and neck (H&N) patients treated with dynamic intensity-modulated radiotherapy (IMRT).Material and methods: Plans were created using Varian Eclipse™ Treatment Planning System (TPS) version 8.9.09 (Varian Medical Systems, Palo Alto, CA). Clinically approved and dosimetrically verified plans were used as a reference plans. These were re-optimised varying the X and Y smoothing parameters from 0 to 100 in various combinations.Results: For the prostate patients, at X = 0 and Y = 0, the average LPO was 2.4 cm (σ = 0.20 cm) and 3.5 cm (σ = 0.35 cm) for X = 100 and Y = 100. For H&N, the LPO averaged over all fields increased from 1.7 cm (σ = 0.17 cm) at X = 0 and Y = 0 to 2.3 cm (σ = 0.27 cm) at X = 100 and Y = 90. The MUFactor decreased from 1.81 (σ = 0.19) at X = 0 and Y = 0 to 1.38 (σ = 0.11) at X = 100 and Y = 100 for prostates and from 1.50 (σ = 0.14) at X = 0 and Y = 0 to 1.24 (σ = 0.09) for X = 100 and Y = 90 for H&N. Total MU for prostates decreased from 1028.0 (σ = 244.6) at X = 0 and Y = 0 to 688.4 (σ = 159.3) at X = 100 and Y = 100 and from 913 (σ = 267.2) at X = 0 and Y = 0 to 696 (σ = 214.03) at X = 100 and Y = 90 for H&N.Conclusions: Increasing smoothing decreases MUFactor, decreases total MU and increases average LPO but does not greatly enhance organs at risk (OAR) sparing. The Homogeneity Index (HI) and Paddick Conformity Index (CIPAD) appear to vary little after increasing smoothing up to approximately X = 80 and Y = 70.

A SIMULATION STUDY ON DYNAMIC-SAMPLING-MODE FOR FLUORESCENCE MOLECULAR TOMOGRAPHY

2009 ◽  
Vol 02 (02) ◽  
pp. 165-177 ◽  
Author(s):  
ZHUN XU ◽  
JING BAI
Keyword(s):  
Angular Velocity ◽  
Imaging System ◽  
Optical Measurement ◽  
Three Dimensional ◽  
Ccd Camera ◽  
Dynamic Mode ◽  
Fluorescence Molecular Tomography ◽  
Fluorescence Tomography ◽  
Imaging Mode ◽  
Dynamic Sampling

Fluorescence tomography can obtain a sufficient dataset and optimal three-dimensional images when projections are captured over 360° by CCD camera. Herein a non-stop dynamic sampling mode for fluorescence tomography is proposed in an attempt to improve the optical measurement speed of the traditional imaging system and stability of the object to be imaged. A series of simulations are carried out to evaluate the accuracy of dataset acquired from the dynamic sampling mode. Reconstruction with the corresponding data obtained in the dynamic-mode process is also performed with the phantom. The results demonstrate the feasibility of such an imaging mode when the angular velocity is set to the appropriate value, thus laying the foundation for real experiments to verify the superiority in performance of this new imaging mode over the traditional one.

Integral imaging system using an electroluminescent film backlight for three-dimensional-two-dimensional convertibility and a curved structure

2009 ◽  
Vol 48 (5) ◽  
pp. 998 ◽  
Author(s):  
Jae-Hyun Jung ◽  
Yunhee Kim ◽  
Youngmin Kim ◽  
Joohwan Kim ◽  
Keehoon Hong ◽  
...  
Keyword(s):  
Imaging System ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Integral Imaging ◽  
Curved Structure

scholarly journals Evaluation of patient specific quality assurance of gated field in field radiation therapy technique using two-dimensional detector array

2020 ◽  
Author(s):  
Dražan Jaroš ◽  
Goran Kolarević ◽  
Aleksandar Kostovski ◽  
Milovan Savanović ◽  
Dejan Ćazić ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Quality Assurance ◽  
Radiation Therapy ◽  
Treatment Plan ◽  
Detector Array ◽  
Patient Specific ◽  
Two Dimensional ◽  
Palo Alto ◽  
Medical Systems ◽  
Rpm System

Introduction: Gated tangential field-in-field (FIF) technique is used to lower the dose to organs at risk for breast cancer radiotherapy (RT). In this study, the authors investigated the accuracy of the delivered treatment plan with and without gating using a two-dimensional detector array for patient-specific verification purposes.Methods: In this study, a 6MV beams were used for the merged FIF RT (forward Intensity Modulated Radiation Therapy). The respiration signals for gated FIF delivery were obtained from the one-dimensional moving phantom using the real-time position management (RPM) system (Varian Medical Systems, Palo Alto, CA). RPM system used for four-dimensional computed tomography scanner light-speed, GE is based on an infrared camera to detect motion of external 6-point marker. The beams were delivered using a Clinac iX (Varian Medical Systems, Palo Alto, CA) with the multileaf collimator Millennium 120. The MapCheck2 (SunNuclear, Florida) was used for the evaluation of treatment plans. MapCheck2 was validated through a comparison with measurements from a farmer-type ion chamber. Gated beams were delivered using a maximum dose rate with varying duty cycles and analyzed the MapCheck2 data to evaluate treatment plan delivery accuracy.Results: Results of the gamma passing rate for relative and absolute dose differences for all ungated and gated beams were between 95.1% and 100%.Conclusion: Gated FIF technique can deliver an accurate dose to a detector during gated breast cancer RT. There is no significance between gated and ungated patient-specific quality assurance (PSQA); one can use ungated PSQA for verification of treatment plan delivery

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