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Sample records for 3d treatment planning

  1. 49: 3-D treatment planning. 3

    For practical 3-D treatment planning, one of the most important perspectives to be used is the 'beam's-eye-view' (BEV), since it displays the relationship of the target volume with the proposed radiation beams. Several BEV features comprise the 3-D planning system U-MPlan, including BEV displays which include contour and shaded solid surfaces of defined anatomy, block entry using joystick and digitizer tablet, automatic block and multi-leaf collimator design, output of block coordinates to hard copy devices, direct output to a computer-controlled block and compensator cutter, use of video digitized radiographs as a backdrop for the BEV graphics, image analysis of digitized films, complete image correlation between BEV-type imaging and CT, MR, PET, etc., and a photon dose calculation algorithm which makes accurate and fast calculations in BEV planes and under blocks. The correlation and use of radiographs and other BEV-type images with CT-type information allows a new degree of precision to be incorporated into radiation therapy planning. 9 refs.; 3 figs

  2. 64: 3-D treatment planning. 4

    A full function brachytherapy treatment planning program has been developed as part of the 3-D treatment planning system U-MPlan. This program integrates more conventional brachytherapy planning with multi-modality imaging. As a result, source locations can be derived from and displayed over a variety of images including CT, MR, and digitized radiographs. Derived three-dimensional anatomical data can be used to help in designing and evaluating dose distributions. Cross-sectional calculational planes can be defined relative to the anatomy or modified to be oriented with respect to the implant symmetry. Special utilities are provided for designing stereotactic brain implants. Calculational results can be viewed both two- and three-dimensionally relative to axonometric views of image cross-sections and derived anatomical structures. Isodose surfaces can be generated and displayed as well as dose displays across anatomical surfaces. Dose-volume histograms and composite or subtracted plans can be used to evaluate and/or compare rival plans. 5 refs.; 4 figs

  3. 3-D CT for cardiovascular treatment planning

    Wildermuth, S.; Leschka, S.; Duru, F.; Alkadhi, H. [Inst. for Diagnostic Radiology, Univ. Hospital Zurich (Switzerland)

    2005-11-15

    The recently developed 64-slice CT scanner together with the use of 2-D and 3-D reconstructions can aid the cardiovascular surgeon and interventional radiologist in visualizing exact geometric relationships to plan and execute complex procedures via minimally invasive or standard approaches.Cardiac 64-slice CT considerably benefits from the high temporal and spatial resolution allowing the reliable depiction of small coronary segments. Similarly, abdominal vascular 64-slice CT became possible within short examination times and allowing an optimal arterial contrast bolus exploitation. We demonstrate four representative cardiac and abdominal examples using the new 64-slice CT technology which reveal the impact of the new scanner generation for cardiovascular treatment planning. (orig.)

  4. 3D volume visualization in remote radiation treatment planning

    Yun, David Y.; Garcia, Hong-Mei C.; Mun, Seong K.; Rogers, James E.; Tohme, Walid G.; Carlson, Wayne E.; May, Stephen; Yagel, Roni

    1996-03-01

    This paper reports a novel applications of 3D visualization in an ARPA-funded remote radiation treatment planning (RTP) experiment, utilizing supercomputer 3D volumetric modeling power and NASA ACTS (Advanced Communication Technology Satellite) communication bandwidths at the Ka-band range. The objective of radiation treatment is to deliver a tumorcidal dose of radiation to a tumor volume while minimizing doses to surrounding normal tissues. High performance graphics computers are required to allow physicians to view a 3D anatomy, specify proposed radiation beams, and evaluate the dose distribution around the tumor. Supercomputing power is needed to compute and even optimize dose distribution according to pre-specified requirements. High speed communications offer possibilities for sharing scarce and expensive computing resources (e.g., hardware, software, personnel, etc.) as well as medical expertise for 3D treatment planning among hospitals. This paper provides initial technical insights into the feasibility of such resource sharing. The overall deployment of the RTP experiment, visualization procedures, and parallel volume rendering in support of remote interactive 3D volume visualization will be described.

  5. Orthodontic treatment plan changed by 3D images

    Clinical application of CBCT is most often enforced in dental phenomenon of impacted teeth, hyperodontia, transposition, ankyloses or root resorption and other pathologies in the maxillofacial area. The goal, we put ourselves, is to show how the information from 3D images changes the protocol of the orthodontic treatment. The material, we presented six our clinical cases and the change in the plan of the treatment, which has used after analyzing the information carried on the three planes of CBCT. These cases are casuistic in the orthodontic practice and require individual approach to each of them during their analysis and decision taken. The discussion made by us is in line with reveal of the impacted teeth, where we need to evaluate their vertical depth and mediodistal ratios with the bond structures. At patients with hyperodontia, the assessment is of outmost importance to decide which of the teeth to be extracted and which one to be arranged into the dental arch. The conclusion we make is that diagnostic information is essential for decisions about treatment plan. The exact graphs will lead to better treatment plan and more predictable results. (authors) Key words: CBCT. IMPACTED CANINES. HYPERODONTIA. TRANSPOSITION

  6. Towards real-time 3D ultrasound planning and personalized 3D printing for breast HDR brachytherapy treatment

    Two different end-to-end procedures were tested for real-time planning in breast HDR brachytherapy treatment. Both methods are using a 3D ultrasound (3DUS) system and a freehand catheter optimization algorithm. They were found fast and efficient. We demonstrated a proof-of-concept approach for personalized real-time guidance and planning to breast HDR brachytherapy treatments

  7. Audit of 3D conformal radiotherapy treatment planning systems

    Background. Treatment planning systems (TPSs) are an essential part of modern radiotherapy equipment where radiation dose distribution and number of Monitor Units (MU) necessary to achieve it are calculated. Therefore, proper commissioning, implementation and application of TPSs are essential to ensure accurate dose delivery to the patient, and to minimize the possibility of accidental exposure. IAEA is supporting national and sub-regional TPS audit activities as a new initiative to improve the quality and safety of radiotherapy in Member States. The audit methodology is based on the outcome of the IAEA coordinated research project E2.40.13 'Development of procedures for quality assurance for dosimetry calculation in radiotherapy'. The pilot runs have been conducted in the Baltic States and Hungarian hospitals. Methodology. The methodology for the audit focuses on the dosimetric aspects of the treatment planning and delivery processes of radiotherapy, for high-energy photon beams. It assesses the important part of the external beam radiotherapy workflow - from patient data acquisition and treatment planning to dose delivery. The audit procedure is based on the use of a CIRS thorax phantom Model 002LFC (Norfolk, VA). The phantom has a body made of plastic water, lung equivalent material and bone equivalent material sections and has 10 holes to hold interchangeable rod inserts for an ionization chamber. The phantom has a set of calibrated electron density reference plugs that enable the verification of the Hounsfield units/electron density (HU/ ED) conversion procedure. Computed tomography (CT) is used to image the phantom and the images are transferred to a TPS where planning and dose calculations take place. The clinical test cases cover a range of basic treatment techniques used in 3D conformal radiotherapy (CRT). The tests are structured so that at first, the dose distributions for single beams are considered, then standard multiple field techniques are used, and

  8. Commissioning and acceptance testing of Cadplan plus- a 3D treatment planning system

    3D treatment planning systems are finding wide acceptance in the radiotherapy community due to their improved dose calculation accuracy as well as the 3D visualization tools. Cadplan plus, a 3D treatment planning system from Varian, has been commissioned at the Tata Memorial Hospital in accordance to various international guidelines

  9. Dosimetric evaluation of 3D treatment planning system

    The computerized treatment planning system plays a major role in radiation therapy in delivering correct radiation dose to the patients with in 65% as recommended by the ICRU. A Plato V2.7.2 Treatment Planning System (Nucletron B.V.) was installed at Dr. Kamakshi Memorial Hospital with external and brachytherapy software. It is connected with Siemens CT scan (Emotion Duo) via Ocriten anatomical Modeling system. The present paper investigates the Dosimetric performance of the TPS with three-Dimensional dose calculation algorithm using the basic beam data measured for 6MV X-rays. Nine numbers of test cases were created according to the TRS 430 and are used to test the TPS, in a homogeneous water phantom. These cases involve simple field arrangements as well as the presence of a low-density material in the beam to resemble an air inhomogeneity. Absolute dose measurements were performed for the each case with the MU calculation given by the TPS, the measured dose is compared with that of the corresponding TPS calculations yields difference with in 3.39% for all simple test cases, for complex test cases in the presence of inhomogeneity or beam modifiers a maximum deviation of 6.25% was observed. In conclusion, observed deviations are well with in the set tolerance level

  10. Evaluation of isocenter reproducibility in telemedicine of 3D-radiotherapy treatment planning

    Hirota, Saeko; Tsujino, Kayoko; Kimura, Kouji; Takada, Yoshiki; Hishikawa, Yoshio; Kono, Michio [Hyogo Medical Center for Adults, Akashi (Japan); Soejima, Toshinori; Kodama, Akihisa

    2000-09-01

    To evaluate the utility in telemedicine of Three-Dimensional Radiotherapy Treatment Planning (tele-3D-RTP) and to examine the accuracy of isocenter reproducibility in its offline trial. CT data of phantoms and patients in the satellite hospital were transferred to our hospital via floppy-disk and 3D-radiotherapy plans were generated by 3D-RTP computer in our hospital. Profile data of CT and treatment beams in the satellite hospital were pre-installed into the computer. Tele-3D-RTPs were performed in 3 phantom plans and 14 clinical plans for 13 patients. Planned isocenters were well reproduced, especially in the immobilized head and neck/brain tumor cases, whose 3D-vector of aberration was 1.96{+-}1.38 (SD) mm. This teletherapy system is well applicable for practical use and can provides cost-reduction through sharing the resources of expensive equipment and radiation oncologists. (author)

  11. Evaluation of isocenter reproducibility in telemedicine of 3D-radiotherapy treatment planning

    To evaluate the utility in telemedicine of Three-Dimensional Radiotherapy Treatment Planning (tele-3D-RTP) and to examine the accuracy of isocenter reproducibility in its offline trial. CT data of phantoms and patients in the satellite hospital were transferred to our hospital via floppy-disk and 3D-radiotherapy plans were generated by 3D-RTP computer in our hospital. Profile data of CT and treatment beams in the satellite hospital were pre-installed into the computer. Tele-3D-RTPs were performed in 3 phantom plans and 14 clinical plans for 13 patients. Planned isocenters were well reproduced, especially in the immobilized head and neck/brain tumor cases, whose 3D-vector of aberration was 1.96±1.38 (SD) mm. This teletherapy system is well applicable for practical use and can provides cost-reduction through sharing the resources of expensive equipment and radiation oncologists. (author)

  12. Review of 3D image data calibration for heterogeneity correction in proton therapy treatment planning.

    Zhu, Jiahua; Penfold, Scott N

    2016-06-01

    Correct modelling of the interaction parameters of patient tissues is of vital importance in proton therapy treatment planning because of the large dose gradients associated with the Bragg peak. Different 3D imaging techniques yield different information regarding these interaction parameters. Given the rapidly expanding interest in proton therapy, this review is written to make readers aware of the current challenges in accounting for tissue heterogeneities and the imaging systems that are proposed to tackle these challenges. A summary of the interaction parameters of interest in proton therapy and the current and developmental 3D imaging techniques used in proton therapy treatment planning is given. The different methods to translate the imaging data to the interaction parameters of interest are reviewed and a summary of the implementations in several commercial treatment planning systems is presented. PMID:27115163

  13. Procedure for creating a three-dimensional (3D) model for superficial hyperthermia treatment planning

    To make a patient- and treatment-specific computed tomography (CT) scan and to create a three-dimensional (3D) patient model for superficial hyperthermia treatment planning (SHTP). Patients with recurrent breast adenocarcinoma in previously irradiated areas referred for radiotherapy (RT) and hyperthermia (HT) treatment and giving informed consent were included. After insertion of the thermometry catheters in the treatment area, a CT scan in the treatment position was made. A total of 26 patients have been, thus far, included in the study. During the study period, five types of adjustments were made to the procedure: (1) marking the RT field with radioopaque markers, (2) making the CT scan after the first HT treatment instead of before, (3) using an air- and foam-filled (dummy) water bolus, (4) a change to radiolucent catheters for which radioopaque markers were needed, and (5) marking the visible/palpable extent of the tumor with radioopaque markers, if necessary. With these adjustments, all necessary information is visible on the CT scan. Each CT slice was automatically segmented into muscle, fat, bone, and air. RT field, catheters, applicators, and tumor lesions, if indicated, were outlined manually using the segmentation program iSeg. Next the model was imported into SEMCAD X, a 3D electromagnetic field simulator. Using the final procedure to obtain a patient- and treatment-specific CT scan, it is possible to create a 3D model for SHTP.

  14. Procedure for creating a three-dimensional (3D) model for superficial hyperthermia treatment planning

    Linthorst, Marianne; Drizdal, Tomas; Joosten, Hans; Rhoon, Gerard C. van; Zee, Jacoba van der [Hyperthermia Unit, Rotterdam (Netherlands). Erasmus MC Rotterdam

    2011-12-15

    To make a patient- and treatment-specific computed tomography (CT) scan and to create a three-dimensional (3D) patient model for superficial hyperthermia treatment planning (SHTP). Patients with recurrent breast adenocarcinoma in previously irradiated areas referred for radiotherapy (RT) and hyperthermia (HT) treatment and giving informed consent were included. After insertion of the thermometry catheters in the treatment area, a CT scan in the treatment position was made. A total of 26 patients have been, thus far, included in the study. During the study period, five types of adjustments were made to the procedure: (1) marking the RT field with radioopaque markers, (2) making the CT scan after the first HT treatment instead of before, (3) using an air- and foam-filled (dummy) water bolus, (4) a change to radiolucent catheters for which radioopaque markers were needed, and (5) marking the visible/palpable extent of the tumor with radioopaque markers, if necessary. With these adjustments, all necessary information is visible on the CT scan. Each CT slice was automatically segmented into muscle, fat, bone, and air. RT field, catheters, applicators, and tumor lesions, if indicated, were outlined manually using the segmentation program iSeg. Next the model was imported into SEMCAD X, a 3D electromagnetic field simulator. Using the final procedure to obtain a patient- and treatment-specific CT scan, it is possible to create a 3D model for SHTP.

  15. In-house quality check of external beam plans using 3D treatment planning systems - a DVH comparison.

    Kumar, Ayyalasomayajula Anil; Akula, Roopa Rani; Ayyangar, Komanduri; P, Krishna Reddy; Vuppu, Srinivas; Narayana, P V Lakshmi; Rao, A Durga Prasada

    2016-01-01

    This paper presents a new approach towards the quality assurance of external beam plans using in-house-developed DICOM import and export software in a clinical setup. The new approach is different from what is currently used in most clinics, viz., only MU and point dose are verified. The DICOM-RT software generates ASCII files to import/export structure sets, treatment beam data, and dose-volume histo-grams (DVH) from one treatment planning system (TPS) to the other. An efficient and reliable 3D planning system, ROPS, was used for verifying the accuracy of treatment plans and treatment plan parameters. With the use of this new approach, treatment plans planned using Varian Eclipse planning system were exported to ROPS planning system. Important treatment and dosimetrical data, such as the beam setup accuracy, target dose coverage, and dose to critical structures, were also quantitatively verified using DVH comparisons. Two external beam plans with diverse photon energies were selected to test the new approach. The satisfactory results show that the new approach is feasible, easy to use, and can be used as an adjunct test for patient treatment quality check. PMID:27167271

  16. New customized patient repositioning system for use in three dimensional (3D) treatment planning and radiotherapy

    Purpose/Objective: To develop a safe and easy method for customized patient repositioning and immobilization prior to 3-D treatment planning and during precise radiotherapy. Materials and methods: The new material consists of impression material, and covering material to fix and hold the impression. The impression material is composed of numerous effervescent polystyrene beads (3.1 mm in diameter) coated by polymerizing substance, urethane prepolymer. When being wet, the material beads adhere to each other due to polymelization, and it is hardened in 5 to 10 minutes. Within one hour the mold is sufficiently dry to be used for treatment planning utilizing computed tomography(CT). The physical characteristics of the material, the subjective comfort of the patient, the reduction in time required for repositioning in the treatment of the head and neck tumors, and the reduction in patient movement in the treatment of the breast cancers were investigated. Results: During the hardening stage, the maximum temperature of the material was 33 deg. C. Non-toxic CO2 gas was produced and evaporated from the covering fabric. The mold, with a density of 0.095, was strong enough to endure compression, flexure, and scratching. In the healthy volunteers, no sensitivity to the skin was observed after 12 hours' attachment to the skin. The CT number of the material was less than minus 800, and no build-up effect was demonstrated in megavoltage photon therapy. Various molds were made and used as neck rest adjunctive to thermoplastic face mask, whole body cast, and arm rest (Figure). A questionnaire survey administered to 59 patients with brain, head and neck tumors, and to 18 patients with breast cancers, revealed that subjective comfort was markedly improved (90.9%) of improved (9.1%) by virtue of the new material. In the treatment of head and neck tumors, the mean time and SD for repositioning were 61.1 ± 13.6 seconds with the ready-made neck-rest and 49.4 ± 8.4 seconds with the

  17. Quality control of dose volume histogram computation characteristics of 3D treatment planning systems

    Panitsa, E.; Rosenwald, J. C.; Kappas, C.

    1998-10-01

    Detailed quality control (QC) protocols are a necessity for modern radiotherapy departments. The established QC protocols for treatment planning systems (TPS) do not include recommendations on the advanced features of three-dimensional (3D) treatment planning, like the dose volume histograms (DVH). In this study, a test protocol for DVH characteristics was developed. The protocol assesses the consistency of the DVH computation to the dose distribution calculated by the same TPS by comparing DVH parameters with values obtained by the isodose distributions. The computation parameters (such as the dimension of the computation grid) that are applied to the TPS during the tests are not fixed but set by the user as if the test represents a typical clinical case. Six commercial TPS were examined with this protocol within the frame of the EC project Dynarad (Biomed I). The results of the intercomparison prove the consistency of the DVH results to the isodose values for most of the examined TPS. However, special attention should be paid when working with cases of adverse conditions such as high dose gradient regions. In these cases, higher errors are derived, especially when an insufficient number of dose calculation points are used for the DVH computation.

  18. The choice of optimal radiotherapy technique for locally advanced maxillary carcinoma using 3d treatment planning system

    Mileusnić Dušan

    2004-01-01

    Full Text Available Aim. To compare the isodose distribution of three radiotherapy techniques for locally advanced maxillary sinus carcinoma and analyze the potential of three-dimensional (3D conformal radiotherapy planning in order to determine the optimal technique for target dose delivery, and spare uninvolved healthy tissue structures. Methods. Computed tomography (CT scans of fourteen patients with T3-T4, N0, M0 maxillary sinus carcinoma were acquired and transferred to 3D treatment planning system (3D-TPS. The target volume and uninvolved dose limiting structures were contoured on axial CT slices throughout the volume of interest combining three variants of treatment plans (techniques for each patient: 1. A conventional two-dimensional (2D treatment plan with classically shaped one anterior two lateral opposite fields and two types of 3D conformal radiotherapy plans were compared for each patient. 2. Three-dimensional standard (3D-S plan one anterior + two lateral opposite coplanar fields, which outlines were shaped with multileaf collimator (MLC according to geometric information based on 3D reconstruction of target volume and organs at risk as seen in the beam eye's view (BEV projection. 3. Three-dimensional non-standard (3D-NS plan: one anterior + two lateral noncoplanar fields, which outlines were shaped in the same manner as in 3D-S plans. The planning parameters for target volumes and the degree of neurooptic structures and parotid glands protection were evaluated for all three techniques. Comparison of plans and treatment techniques was assessed by isodose distribution, dose statistics and dose-volume histograms. Results. The most enhanced conformity of the dose delivered to the target volume was achieved with 3D-NS technique, and significant differences were found comparing 3D-NS vs. 2D (Dmax: p<0,05 Daver: p<0,01; Dmin: p<0,05; V90: p<0,05, and V95: p<0,01, as well as 3D-NS vs. 3D-S technique (Dmin: p<0,05; V90: p<0,05, and V95: p<0,01, while there

  19. Large area 3-D optical coherence tomography imaging of lumpectomy specimens for radiation treatment planning

    Wang, Cuihuan; Kim, Leonard; Barnard, Nicola; Khan, Atif; Pierce, Mark C.

    2016-02-01

    Our long term goal is to develop a high-resolution imaging method for comprehensive assessment of tissue removed during lumpectomy procedures. By identifying regions of high-grade disease within the excised specimen, we aim to develop patient-specific post-operative radiation treatment regimens. We have assembled a benchtop spectral-domain optical coherence tomography (SD-OCT) system with 1320 nm center wavelength. Automated beam scanning enables "sub-volumes" spanning 5 mm x 5 mm x 2 mm (500 A-lines x 500 B-scans x 2 mm in depth) to be collected in under 15 seconds. A motorized sample positioning stage enables multiple sub-volumes to be acquired across an entire tissue specimen. Sub-volumes are rendered from individual B-scans in 3D Slicer software and en face (XY) images are extracted at specific depths. These images are then tiled together using MosaicJ software to produce a large area en face view (up to 40 mm x 25 mm). After OCT imaging, specimens were sectioned and stained with HE, allowing comparison between OCT image features and disease markers on histopathology. This manuscript describes the technical aspects of image acquisition and reconstruction, and reports initial qualitative comparison between large area en face OCT images and HE stained tissue sections. Future goals include developing image reconstruction algorithms for mapping an entire sample, and registering OCT image volumes with clinical CT and MRI images for post-operative treatment planning.

  20. Clinical evaluation of 3D/3D MRI-CBCT automatching on brain tumors for online patient setup verification - A step towards MRI-based treatment planning

    Buhl, Sune K.; Duun-Christensen, Anne Katrine; Kristensen, Brian H.;

    2010-01-01

    undergoing postoperative radiotherapy for malignant brain tumors received a weekly CBCT. In total 18 scans was matched with both CT and MRI as reference. The CBCT scans were acquired using a Clinac iX 2300 linear accelerator (Varian Medical Systems) with an On-Board Imager (OBI). Results. For the phantom......Background. Magnetic Resonance Imaging (MRI) is often used in modern day radiotherapy (RT) due to superior soft tissue contrast. However, treatment planning based solely on MRI is restricted due to e. g. the limitations of conducting online patient setup verification using MRI as reference. In this...... study 3D/3D MRI-Cone Beam CT (CBCT) automatching for online patient setup verification was investigated. Material and methods. Initially, a multi-modality phantom was constructed and used for a quantitative comparison of CT-CBCT and MRI-CBCT automatching. Following the phantom experiment three patients...

  1. Integration method of 3D MR spectroscopy into treatment planning system for glioblastoma IMRT dose painting with integrated simultaneous boost

    Ken Soléakhéna

    2013-01-01

    Full Text Available Abstract Background To integrate 3D MR spectroscopy imaging (MRSI in the treatment planning system (TPS for glioblastoma dose painting to guide simultaneous integrated boost (SIB in intensity-modulated radiation therapy (IMRT. Methods For sixteen glioblastoma patients, we have simulated three types of dosimetry plans, one conventional plan of 60-Gy in 3D conformational radiotherapy (3D-CRT, one 60-Gy plan in IMRT and one 72-Gy plan in SIB-IMRT. All sixteen MRSI metabolic maps were integrated into TPS, using normalization with color-space conversion and threshold-based segmentation. The fusion between the metabolic maps and the planning CT scans were assessed. Dosimetry comparisons were performed between the different plans of 60-Gy 3D-CRT, 60-Gy IMRT and 72-Gy SIB-IMRT, the last plan was targeted on MRSI abnormalities and contrast enhancement (CE. Results Fusion assessment was performed for 160 transformations. It resulted in maximum differences p  Conclusions Delivering standard doses to conventional target and higher doses to new target volumes characterized by MRSI and CE is now possible and does not increase dose to organs at risk. MRSI and CE abnormalities are now integrated for glioblastoma SIB-IMRT, concomitant with temozolomide, in an ongoing multi-institutional phase-III clinical trial. Our method of MR spectroscopy maps integration to TPS is robust and reliable; integration to neuronavigation systems with this method could also improve glioblastoma resection or guide biopsies.

  2. Testing of treatment planning system in aspect of transitioning from 3-D to IMRT

    measurement. The difference was less than 1% in simple geometries and up to 5% in complex geometries with heterogeneity. To apply an IMRT plan to a patient, one needs to verify it beforehand. As a patient-specific test we chose to perform absolute dose measurements in several critical points for single multisegment field and total dose measurements in water phantom in vertical and horizontal mode for all beams. Good agreement of calculation and measurements led us to transit from 2-D to 3-D conformal radiotherapy and to begin introducing IMRT in our clinical practice. To use IMRT in clinical practice more extensively, we need to work out a patient-specific QA protocol. In spite of the absence of required equipment and software for this QA we consider the use of IMRT in clinical practice possible because we made a basic set of tests. (author)

  3. Integration method of 3D MR spectroscopy into treatment planning system for glioblastoma IMRT dose painting with integrated simultaneous boost

    To integrate 3D MR spectroscopy imaging (MRSI) in the treatment planning system (TPS) for glioblastoma dose painting to guide simultaneous integrated boost (SIB) in intensity-modulated radiation therapy (IMRT). For sixteen glioblastoma patients, we have simulated three types of dosimetry plans, one conventional plan of 60-Gy in 3D conformational radiotherapy (3D-CRT), one 60-Gy plan in IMRT and one 72-Gy plan in SIB-IMRT. All sixteen MRSI metabolic maps were integrated into TPS, using normalization with color-space conversion and threshold-based segmentation. The fusion between the metabolic maps and the planning CT scans were assessed. Dosimetry comparisons were performed between the different plans of 60-Gy 3D-CRT, 60-Gy IMRT and 72-Gy SIB-IMRT, the last plan was targeted on MRSI abnormalities and contrast enhancement (CE). Fusion assessment was performed for 160 transformations. It resulted in maximum differences <1.00 mm for translation parameters and ≤1.15° for rotation. Dosimetry plans of 72-Gy SIB-IMRT and 60-Gy IMRT showed a significantly decreased maximum dose to the brainstem (44.00 and 44.30 vs. 57.01 Gy) and decreased high dose-volumes to normal brain (19 and 20 vs. 23% and 7 and 7 vs. 12%) compared to 60-Gy 3D-CRT (p < 0.05). Delivering standard doses to conventional target and higher doses to new target volumes characterized by MRSI and CE is now possible and does not increase dose to organs at risk. MRSI and CE abnormalities are now integrated for glioblastoma SIB-IMRT, concomitant with temozolomide, in an ongoing multi-institutional phase-III clinical trial. Our method of MR spectroscopy maps integration to TPS is robust and reliable; integration to neuronavigation systems with this method could also improve glioblastoma resection or guide biopsies

  4. A discussion panel on 3-D treatment planning systems, presently available and in clinical use in Europe

    In recent years a number of treatment planning systems (TPS) have become available on the market that may be called 3-D. What makes a system truly 3-D is that: a. the viewing of the patient, the beam set-up and of the dose distribution is 3-D, which regards display in any plane through the patient and in 3-D perspective images; b. the possibilities of treatment technique and field shaping are 3-D, which means complete flexibility in beam set-up, block design and/or multi-leaf-collimator setting; c. the dose distributions are 3-D, which concerns the modelling of the beams, the patient, the interaction of both and the choice of dose matrix. Important aspects that determine the quality of a TPS are: a. the accuracy of the dose calculations; b. the speed of display and of various computations; c. the speed and flexibility of menu-handling and d. data management and safety issues. Items that regard the workload of starting-up and running of the system are: a. the amount of experimental data and efforts required for customizing beams; b. the level of software QA, documentation and support provided by the vendor and c. the user-friendliness of the TPS in general for physician, treatment planner and physicist. In this session clinical users of various systems will report on how well their TPS performs on the listed 3-D functionality, quality aspects and workload items. In order to enable easy comparison of the systems, the reports will be presented according to a specific format based on the above listings. The aim is to inform present and future users of 3-D TPS on the features and limitations of what is presently available, on what is under development and on what is still to be desired

  5. SU-E-T-03: 3D GPU-Accelerated Secondary Checks of Radiation Therapy Treatment Plans

    Purpose: Redundant treatment verifications in conformal and intensity-modulated radiation therapy techniques are traditionally performed with single point calculations. New solutions can replace these checks with 3D treatment plan verifications. This work describes a software tool (Mobius3D, Mobius Medical Systems) that uses a GPU-accelerated collapsed cone algorithm to perform 3D independent verifications of TPS calculations. Methods: Mobius3D comes with reference beam models for common linear accelerators. The system uses an independently developed collapsed cone algorithm updated with recent enhancements. 144 isotropically-spaced cones are used for each voxel for calculations. These complex calculations can be sped up by using GPUs. Mobius3D calculate dose using DICOM information coming from TPS (CT, RT Struct, RT Plan RT Dose). DVH-metrics and 3D gamma tests can be used to compare both TPS and secondary calculations. 170 patients treated with all common techniques as 3DCFRT (including wedged), static and dynamic IMRT and VMAT have been successfully verified with this solution. Results: Calculation times are between 3–5 minutes for 3DCFRT treatments and 15–20 for most complex dMLC and VMAT plans. For all PTVs mean dose and 90% coverage differences are (1.12±0.97)% and (0.68±1.19)%, respectively. Mean dose discrepancies for all OARs is (0.64±1.00)%. 3D gamma (global, 3%/3 mm) analysis shows a mean passing rate of (97.8 ± 3.0)% for PTVs and (99.0±3.0)% for OARs. 3D gamma pasing rate for all voxels in CT has a mean value of (98.5±1.6)%. Conclusion: Mobius3D is a powerful tool to verify all modalities of radiation therapy treatments. Dose discrepancies calculated by this system are in good agreement with TPS. The use of reference beam data results in time savings and can be used to avoid the propagation of errors in original beam data into our QA system. GPU calculations permit enhanced collapsed cone calculations with reasonable calculation times

  6. SU-E-T-03: 3D GPU-Accelerated Secondary Checks of Radiation Therapy Treatment Plans

    Clemente, F; Perez, C [Hospital Central de la Defensa Gomez Ulla, Madrid, Madrid (Spain)

    2014-06-01

    Purpose: Redundant treatment verifications in conformal and intensity-modulated radiation therapy techniques are traditionally performed with single point calculations. New solutions can replace these checks with 3D treatment plan verifications. This work describes a software tool (Mobius3D, Mobius Medical Systems) that uses a GPU-accelerated collapsed cone algorithm to perform 3D independent verifications of TPS calculations. Methods: Mobius3D comes with reference beam models for common linear accelerators. The system uses an independently developed collapsed cone algorithm updated with recent enhancements. 144 isotropically-spaced cones are used for each voxel for calculations. These complex calculations can be sped up by using GPUs. Mobius3D calculate dose using DICOM information coming from TPS (CT, RT Struct, RT Plan RT Dose). DVH-metrics and 3D gamma tests can be used to compare both TPS and secondary calculations. 170 patients treated with all common techniques as 3DCFRT (including wedged), static and dynamic IMRT and VMAT have been successfully verified with this solution. Results: Calculation times are between 3–5 minutes for 3DCFRT treatments and 15–20 for most complex dMLC and VMAT plans. For all PTVs mean dose and 90% coverage differences are (1.12±0.97)% and (0.68±1.19)%, respectively. Mean dose discrepancies for all OARs is (0.64±1.00)%. 3D gamma (global, 3%/3 mm) analysis shows a mean passing rate of (97.8 ± 3.0)% for PTVs and (99.0±3.0)% for OARs. 3D gamma pasing rate for all voxels in CT has a mean value of (98.5±1.6)%. Conclusion: Mobius3D is a powerful tool to verify all modalities of radiation therapy treatments. Dose discrepancies calculated by this system are in good agreement with TPS. The use of reference beam data results in time savings and can be used to avoid the propagation of errors in original beam data into our QA system. GPU calculations permit enhanced collapsed cone calculations with reasonable calculation times.

  7. Treatment planning for image-guided neuro-vascular interventions using patient-specific 3D printed phantoms

    Russ, M.; O'Hara, R.; Setlur Nagesh, S. V.; Mokin, M.; Jimenez, C.; Siddiqui, A.; Bednarek, D.; Rudin, S.; Ionita, C.

    2015-03-01

    Minimally invasive endovascular image-guided interventions (EIGIs) are the preferred procedures for treatment of a wide range of vascular disorders. Despite benefits including reduced trauma and recovery time, EIGIs have their own challenges. Remote catheter actuation and challenging anatomical morphology may lead to erroneous endovascular device selections, delays or even complications such as vessel injury. EIGI planning using 3D phantoms would allow interventionists to become familiarized with the patient vessel anatomy by first performing the planned treatment on a phantom under standard operating protocols. In this study the optimal workflow to obtain such phantoms from 3D data for interventionist to practice on prior to an actual procedure was investigated. Patientspecific phantoms and phantoms presenting a wide range of challenging geometries were created. Computed Tomographic Angiography (CTA) data was uploaded into a Vitrea 3D station which allows segmentation and resulting stereo-lithographic files to be exported. The files were uploaded using processing software where preloaded vessel structures were included to create a closed-flow vasculature having structural support. The final file was printed, cleaned, connected to a flow loop and placed in an angiographic room for EIGI practice. Various Circle of Willis and cardiac arterial geometries were used. The phantoms were tested for ischemic stroke treatment, distal catheter navigation, aneurysm stenting and cardiac imaging under angiographic guidance. This method should allow for adjustments to treatment plans to be made before the patient is actually in the procedure room and enabling reduced risk of peri-operative complications or delays.

  8. Treatment Planning for Image-Guided Neuro-Vascular Interventions Using Patient-Specific 3D Printed Phantoms

    Russ, M; O’Hara, R.; Setlur Nagesh, S.V.; Mokin, M.; Jimenez, C.; Siddiqui, A.; Bednarek, D.; Rudin, S; C. Ionita

    2015-01-01

    Minimally invasive endovascular image-guided interventions (EIGIs) are the preferred procedures for treatment of a wide range of vascular disorders. Despite benefits including reduced trauma and recovery time, EIGIs have their own challenges. Remote catheter actuation and challenging anatomical morphology may lead to erroneous endovascular device selections, delays or even complications such as vessel injury. EIGI planning using 3D phantoms would allow interventionists to become familiarized ...

  9. Evaluation of 3D pre-treatment verification for volumetric modulated arc therapy plan in head region

    Ruangchan, S.; Oonsiri, S.; Suriyapee, S.

    2016-03-01

    The development of pre-treatment QA tools contributes to the three dimension (3D) dose verification using the calculation software with the measured planar dose distribution. This research is aimed to evaluate the Sun Nuclear 3DVH software with Thermo luminescence dosimeter (TLD) measurement. The two VMAT patient plans (2.5 arcs) of 6 MV photons with different PTV locations were transferred to the Rando phantom images. The PTV of the first plan located in homogeneous area and vice versa in the second plan. For treatment planning process, the Rando phantom images were employed in optimization and calculation with the PTV, brain stem, lens and TLD position contouring. The verification plans were created, transferred to the ArcCHECK for measurement and calculated the 3D dose using 3DVH software. The range of the percent dose differences in both PTV and organ at risk (OAR) between TLD and 3DVH software of the first and the second plans were -2.09 to 3.87% and -1.39 to 6.88%, respectively. The mean percent dose differences for the PTV were 1.62% and 3.93% for the first and the second plans, respectively. In conclusion, the 3DVH software results show good agreement with TLD when the tumor located in the homogeneous area.

  10. Validation of an IMRT beam model using a secondary treatment planning system as a 3D dosimeter

    A treatment planning system IMRT beam model is usually validated using phantom-based measurement, however this will not detect errors related to patient anatomy and inhomogeneity. In this study a secondary treatment system (CMS XIO) was used as a 3D dosimeter to verify an IMRT beam model recently commissioned in a Philips Pinnacle treatment planning system. Data sets from three head-neck and two prostate patients previously treated were utilised. The IMRT plans for these patients were planned in Pinnacle and transferred to XIO. The dose at each voxel in the patient volume was calculated in both XIO and Pinnacle. The 2D dose gamma maps for three orthogonal planes passing through the isocenter were calculated with a criteria of 3%/3mm. The mean gamma pass rate for all patients was 96.86% with maximum and minimum values of 99.6% and 95%. One coronal dose plane at 5.5 cm depth in the phantom was also measured and compared with dose calculated by the Pinnacle IMRT beam model using same gamma criteria. The measured mean gamma pass rate for this coronal plane dose was 96.7% with maximum and minimum of 98.41% and 95.3%. This was comparable with the gamma map pass rates for the three orthogonal dose planes calculated by XIO for the patient data. A secondary treatment planning system was shown to provide a supplementary verification tool based on calculation-based 3D dosimetry using patient anatomy.

  11. Nasopharyngeal carcinoma. Treatment planning with IMRT and 3D conformal radiotherapy

    Kristensen, Claus A; Kjaer-Kristoffersen, Flemming; Sapru, Wendy;

    2007-01-01

    significantly improved with IMRT compared to 3D-CRT. One-year loco-regional control, distant metastasis-free survival, and overall survival were 79%, 72%, and 80%. Two patients have had recurrence in the clinical target volume (CTV) only and seven patients have relapsed in distant organs and/or in head...

  12. Dosimetric verification of a dedicated 3D treatment planning system for episcleral plaque therapy

    Purpose: Episcleral plaque therapy (EPT) is applied in the management of some malignant ocular tumors. A customized configuration of typically 4 to 20 radioactive seeds is fixed in a gold plaque, and the plaque is sutured to the scleral surface corresponding to the basis of the intraocular tumor, allowing for a localized radiation dose delivery to the tumor. Minimum target doses as high as 100 Gy are directed at malignant tumor sites close to critical normal tissues (e.g., optic disc and macula). Precise dosimetry is therefore fundamental for judging both the risk for normal tissue toxicity and tumor dose prescription. This paper describes the dosimetric verification of a commercially available dedicated treatment planning system (TPS) for EPT when realistic multiple-seed configurations are applied. Materials and Methods: The TPS Bebig Plaque Simulator is used to plan EPT at our institution. Relative dose distributions in a water phantom, including central axis depth dose and off-axis dose profiles for three different plaques, the University of Southern California (USC) No. 9 and the Collaborative Ocular Melanoma Study (COMS) 12-mm and 20-mm plaques, were measured with a diode detector. Each plaque was arranged with realistic multiple 125I seed configurations. The measured dose distributions were compared to the corresponding dose profiles calculated with the TPS. All measurements were corrected for the angular sensitivity variation of the diode. Results: Single-seed dose distributions measured with our dosimetry setup agreed with previously published data within 3%. For the three multiple-seed plaque configurations, the measured and calculated dose distributions were in good agreement. For the central axis depth doses, the agreement was within 4%, whereas deviations up to 11% were observed in single points far off-axis. Conclusions: The Bebig Plaque Simulator is a reliable TPS for calculating relative dose distributions around realistic multiple 125I seed

  13. Comparison between the ideal reference dose level and the actual reference dose level from clinical 3D radiotherapy treatment plans

    Purpose: Retrospective study of 3D clinical treatment plans based on radiobiological considerations in the choice of the reference dose level from tumor dose-volume histograms. Methods and materials: When a radiation oncologist evaluates the 3D dose distribution calculated by a treatment planning system, a decision must be made on the percentage dose level at which the prescribed dose should be delivered. Much effort is dedicated to deliver a dose as uniform as possible to the tumor volume. However due to the presence of critical organs, the result may be a rather inhomogeneous dose distribution throughout the tumor volume. In this study we use a formulation of tumor control probability (TCP) based on the linear quadratic model and on a parameter, the F factor. The F factor allows one to write TCP, from the heterogeneous dose distribution (TCP{(εj,Dj)}), as a function of TCP under condition of homogeneous irradiation of tumor volume (V) with dose D (TCP(V,D)). We used the expression of the F factor to calculate the 'ideal' percentage dose level (iDLr) to be used as reference level for the prescribed dose D delivery, so as to render TCP{(εj,Dj)} equal to TCP(V,D). The 3D dose distributions of 53 clinical treatment plans were re-evaluated to derive the iDLr and to compare it with the one (DtpL) to which the dose was actually administered. Results: For the majority of prostate treatments, we observed a low overdosing following the choice of a DtpL lower than the iDLr. While for the breast and head-and-neck treatments, the method showed that in many cases we underdosed choosing a DtpL greater than the iDLr. The maximum difference between the iDLr and the DtpL was -3.24% for one of the head-and-neck treatments. Conclusions: Using the TCP model, the probability of tumor control is compromised following an incorrect choice of DtpL; so we conclude that the application of the F factor is an effective tool and clinical aid to derive the optimal reference dose level from

  14. Commissioning of a 3D image-based treatment planning system for high-dose-rate brachytherapy of cervical cancer.

    Kim, Yongbok; Modrick, Joseph M; Pennington, Edward C; Kim, Yusung

    2016-01-01

    The objective of this work is to present commissioning procedures to clinically implement a three-dimensional (3D), image-based, treatment-planning system (TPS) for high-dose-rate (HDR) brachytherapy (BT) for gynecological (GYN) cancer. The physical dimensions of the GYN applicators and their values in the virtual applicator library were varied by 0.4 mm of their nominal values. Reconstruction uncertainties of the titanium tandem and ovoids (T&O) were less than 0.4 mm on CT phantom studies and on average between 0.8-1.0 mm on MRI when compared with X-rays. In-house software, HDRCalculator, was developed to check HDR plan parameters such as independently verifying active tandem or cylinder probe length and ovoid or cylinder size, source calibration and treatment date, and differences between average Point A dose and prescription dose. Dose-volume histograms were validated using another independent TPS. Comprehensive procedures to commission volume optimization algorithms and process in 3D image-based planning were presented. For the difference between line and volume optimizations, the average absolute differences as a percentage were 1.4% for total reference air KERMA (TRAK) and 1.1% for Point A dose. Volume optimization consistency tests between versions resulted in average absolute differences in 0.2% for TRAK and 0.9 s (0.2%) for total treatment time. The data revealed that the optimizer should run for at least 1 min in order to avoid more than 0.6% dwell time changes. For clinical GYN T&O cases, three different volume optimization techniques (graphical optimization, pure inverse planning, and hybrid inverse optimization) were investigated by comparing them against a conventional Point A technique. End-to-end testing was performed using a T&O phantom to ensure no errors or inconsistencies occurred from imaging through to planning and delivery. The proposed commissioning procedures provide a clinically safe implementation technique for 3D image-based TPS for HDR

  15. Heart dose reduction in breast cancer treatment with simultaneous integrated boost. Comparison of treatment planning and dosimetry for a novel hybrid technique and 3D-CRT

    The present study compares in silico treatment plans of clinically established three-dimensional conformal radiotherapy (3D-CRT) with a hybrid technique consisting of intensity-modulated radiotherapy (IMRT) and volumetric modulated arc radiotherapy (VMAT) during normally fractionated radiation of mammary carcinomas with simultaneous integrated boost on the basis of dose-volume histogram (DVH) parameters. Radiation treatment planning was performed with a hybrid and a 3D-CRT treatment plan for 20 patients. Hybrid plans were implemented with two tangential IMRT fields and a VMAT field in the angular range of the tangents. Verification of the plan was performed with a manufacturer-independent measurement system consisting of a detector array and rotation unit. The mean values of the heart dose for the entire patient collective were 3.6 ± 2.5 Gy for 3D-CRT and 2.9 ± 2.1 Gy for the hybrid technique (p < 0.01). For the left side (n = 10), the mean values for the left anterior descending artery were 21.8 ± 7.4 Gy for 3D-CRT and 17.6 ± 7.4 Gy for the hybrid technique (p < 0.01). The mean values of the ipsilateral lung were 11.9 ± 1.6 Gy for 3D-CRT and 10.5 ± 1.3 Gy for the hybrid technique (p < 0.01). Calculated dose distributions in the hybrid arm were in good accordance with measured dose (on average 95.6 ± 0.5 % for γ < 1 and 3 %/3 mm). The difference of the mean treatment time per fraction was 7 s in favor of 3D-CRT. Compared with the established 3D-CRT technique, the hybrid technique allows for a decrease in dose, particularly of the mean heart and lung dose with comparable target volume acquisition and without disadvantageous low-dose load of contralateral structures. Uncomplicated implementation of the hybrid technique was demonstrated in this context. The hybrid technique combines the advantages of tangential IMRT with the superior sparing of organs at risk by VMAT. (orig.)

  16. Dosimetric impact of different CT datasets for stereotactic treatment planning using 3D conformal radiotherapy or volumetric modulated arc therapy

    Oechsner, Markus; Odersky, Leonhard; Berndt, Johannes; Combs, Stephanie Elisabeth; Wilkens, Jan Jakob; DUMA, MARCIANA NONA

    2015-01-01

    Background The purpose of this study was to assess the impact on dose to the planning target volume (PTV) and organs at risk (OAR) by using four differently generated CT datasets for dose calculation in stereotactic body radiotherapy (SBRT) of lung and liver tumors. Additionally, dose differences between 3D conformal radiotherapy and volumetric modulated arc therapy (VMAT) plans calculated on these CT datasets were determined. Methods Twenty SBRT patients, ten lung cases and ten liver cases, ...

  17. Usefulness of US-CT 3D dual imaging for the planning and monitoring of hepatocellular carcinoma treatment using HIFU

    Purpose: We evaluated the safety and usefulness of high-intensity focused ultrasound (HIFU) assisted by ultrasound-computed tomography three-dimensional (US-CT 3D) dual imaging for the treatment of hepatocellular carcinoma (HCC). Materials and methods: HIFU ablation was performed in 13 patients with small HCC (≤3 lesions, ≤3 cm in diameter). The HIFU system (Chongqing Haifu Tech) was used under ultrasound guidance. By transferring the sagittal or axial plane of the 3D US and the CT volume data into the ZioM900, multiplanar reconstruction images were displayed in a manner resembling conventional monitor US to assist the HIFU treatment. Results: Overall, 69% (9/13) of the patients in whom good visualization using B-mode sonography could not be obtained because of the influence of multi-reflections, rib shadows, and unclear tumor margins were successfully treated under the guidance of US-CT 3D dual imaging. In 5 of the 13 patients, multi-reflections were responsible for the poor visualization. In 2 cases, the tumor was poorly visualized because of a rib shadow. In one case, the margin of the tumor was too unclear to be detected using ultrasography. The 3D US images obtained as part of the US-CT 3D dual imaging had a high resolution and were useful for examining the area of HCC invasion and for determining the extent of the ablation area. The CT images, which are not influenced by bone shadows or multi-reflections, were useful for detecting the tumors and for visualizing the presence of the intestines in the sonication zone. HIFU treatments were successfully performed in all the patients with the assistance of US-CT 3D dual imaging. Conclusion: US-CT 3D dual imaging is useful for HIFU treatment for HCC, compensating for the occasionally poor visualization provided by US monitor.

  18. Post-mastectomy radiotherapy in Denmark: From 2D to 3D treatment planning guidelines of The Danish Breast Cancer Cooperative Group

    Thomsen, Mette Skovhus; Berg, Martin; Nielsen, Hanne M.;

    2008-01-01

    , it was investigated whether it was possible to find a treatment technique alternative to the one recommended by the Danish Breast Cancer Cooperative Group (DBCG). A dosimetric comparison of a combined photon/electron 3-field technique (3F) and a partial wide tangent technique (PWT) was carried out on individual......This paper describes the procedure of changing from 2D to 3D treatment planning guidelines for post-mastectomy radiotherapy in Denmark. The aim of introducing 3D planning for post-mastectomy radiotherapy was to optimize the target coverage and minimize the dose to the normal tissues. Initially...... to 3F. It was concluded that PWT was an appropriate choice of technique for future radiation treatment of post-mastectomy patients. A working group was formed and guidelines for 3D planning were developed during a series of workshops where radiation oncologists and physicists from all radiotherapy...

  19. Guidelines for radiation oncology centres in AFRA Member States intending to make a transition from 2-D to 3-D treatment planning and delivery

    The IAEA Regional Technical Cooperation Project RAF/6/031 on Medical Physics in Support of Cancer Management aims to strengthen national and regional medical physics capabilities to sustain radiotherapy treatments in the AFRA1 Member States. In particular, it aims at increasing the number of qualified medical physicists in the region as well as improving the level of medical physics by establishing regional training and continuous development programmes. Eighteen National Project Coordinators (NPCs) nominated by participating AFRA Member States are engaged in the project. RAF/6/031 was approved by the IAEA in 2005 for an initial five year duration. A coordination meeting is held every two years where the NPCs and IAEA Technical and Project Management Officers establish the project's training and development programmes. During the first coordination meeting at Cape Town in November 2005, it was decided to convene a Task Force Meeting to review the status of treatment planning in radiotherapy in AFRA Member States and prepare a guidance document on the transition from 2-D to 3-D treatment planning. This Task Force Meeting took place at the IAEA's Headquarters in Vienna on 23-26 April 2007. The resulting guidance document highlights the milestones that have to be achieved by radiotherapy centres routinely implementing 2-D computerized treatment planning before making a transition to 3-D treatment planning and delivery. The implementation of 3-D planning by radiotherapy centres that have not yet met these milestones could lead to serious mistakes in treatments. A self-assessment questionnaire was also prepared during the Task Force Meeting. Member States that are planning to make a transition to 3-D planning are advised to assess their existing capabilities through this questionnaire. The same questionnaire could also be useful for the IAEA staff and external experts when assessing the readiness of a radiotherapy centre to make a safe and effective transition to 3-D

  20. A Comparative Analysis for Verification of IMRT and VMAT Treatment Plans using a 2-D and 3-D Diode Array

    Dance, Michael J.

    With the added complexity of current radiation treatment dose delivery modalities such as IMRT (Intensity Modulated Radiation Therapy) and VMAT (Volumetric Modulated Arc Therapy), quality assurance (QA) of these plans become multifaceted and labor intensive. To simplify the patient specific quality assurance process, 2D or 3D diode arrays are used to measure the radiation fluence for IMRT and VMAT treatments which can then be quickly and easily compared against the planned dose distribution. Because the arrays that can be used for IMRT and VMAT patient-specific quality assurance are of different geometry (planar vs. cylindrical), the same IMRT or VMAT treatment plan measured by two different arrays could lead to different measured radiation fluences, regardless of the output and performance of linear accelerator. Thus, the purpose of this study is to compare patient specific QA results as measured by the MapCHECK 2 and ArcCHECK diode arrays for the same IMRT and VMAT treatment plans to see if one diode array consistently provides a closer comparison to reference data. Six prostate and three thoracic spine IMRT treatment plans as well as three prostate and three thoracic spine VMAT treatment plans were produced. Radiotherapy plans for this study were generated using the Pinnacle TPS v9.6 (Philips Radiation Oncology Systems, Fitchburg, WI) using 6 MV, 6 MV FFF, and 10 MV x-ray beams from a Varian TrueBeam linear accelerator (Varian Medical Systems, Palo Alto, CA) with a 120-millenium multi-leaf collimator (MLC). Each IMRT and VMAT therapy plan was measured on Sun Nuclear's MapCHECK 2 and ArcCHECK diode arrays. IMRT measured data was compared with planned dose distribution using Sun Nuclear's 3DVH quality assurance software program using gamma analysis and dose-volume histograms for target volumes and critical structures comparison. VMAT arc plans measured on the MapCHECK 2 and ArcCHECK were compared using beam-by-beam analysis with the gamma evaluation method with

  1. Planning for brachytherapy using a 3D-simulation model

    A 3D-simulation model made with a milling system was applied to HDR-brachytherapy. The 3D-simulation model is used to simulate the 3D-structure of the lesion and the surrounding organs before the actual catheterization for brachytherapy. The first case was recurrent prostatic cancer in a 61-year-old man. The other case was lymph node recurrence of a 71-year-old woman's upper gum cancer. In both cases, the 3D-simulation model was very useful to simulate the 3D-conformation, to plan the treatment process and to avoid the risk accompanying treatment. (author)

  2. The benefit of individualized custom bolus in the postmastectomy radiation therapy: numerical analysis with 3-D treatment planning

    Cho, Jae Ho; Cho, Kwang Hwan; Keum, Ki Chang; Han, Yong Yih; Kim, Yong Bae; Chu, Sung Sil; Suh, Chang Ok [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    2003-03-01

    To reduce the irradiation dose to the lungs and heart in the case of chest wall irradiation using an oppositional electron beam, we used an individualized custom bolus, which was precisely designed to compensate for the differences in chest wall thickness. The benefits were evaluated by comparing the normal tissue complication probabilities (NTCPs) and dose statistics both with and without boluses Boluses were made, and their effects evaluated in ten patients treated using the reverse hockey-stick technique. The electron beam energy was determined so as to administer 80% of the irradiation prescription dose to the deepest lung-chest wall border, which was usually located at the internal mammary lymph node chain. An individualized custom bolus was prepared to compensate for a chest wall thinner than the prescription depth by meticulously measuring the chest wall thickness at 1 cm{sup 2} intervals on the planning CT images. A second planning CT was obtained overlying the individualized custom bolus for each patient's chest wall. 3-D treatment planning was performed using ADAC-Pinnacle{sup 3} for all patients with and without bolus, NTCPs based on 'the Lyman-Kutcher' model were analyzed and the mean, maximum, minimum doses, V{sub 50} and V{sub 95} for the heart and lungs were computed. The average NTCPs in the ipsilateral lung showed a statistically significant reduction (p<0.01), from 80.2{+-}3.43% to 47.7{+-}4.61%, with the use of the individualized custom boluses. The mean lung irradiation dose to the ipsilateral lung was also significantly reduced by about 430 cGy from 2757 cGy to 2,327 cGy (p<0.01). The V{sub 50} and V{sub 95} in the ipsilateral lung markedly decreased from the averages of 54.5 and 17.4% to 45.3 and 11.0%, respectively. The V{sub 50} and V{sub 95} in the heart also decreased from the averages of 16.8 and 6.1% to 9.8% and 2.2%, respectively. The NTCP in the contralateral lung and the heart were 0%, even for the cases with no bolus

  3. Commissioning of 3D treatment planning system Helax TMS 6.1 for Co-60 Machine Gammatron-3

    The commissioning process has the following aims: 1) To compare the calculated beam characteristics with measured data; 2) To assess the performance of Treatment Planning Systems (TPS) according to criteria of acceptance, i.e. limits of accuracy; 3) To observe and record under what conditions the TPS is acceptable or not acceptable; 4) To monitor the use of the TPS and ensure that the standards of acceptance are maintained. The equipment used for the test measurements was: the Automatic Water Phantom System PTW MP3 with water phantom (70/60/50 cm), ionization chamber type PTW 31002- 0.125 cm3 and electrometer Tandem. Analysis of depth dose data for squire fields shows a good agreement between measured and TPS data, in the case when the calculated Percentage Depth Doses (PDDs) are obtained at different set-up from that used for the reference input data. The tendency of calculating narrower dose profiles from Helax TMS, most pronounced for maximum 16x16 field size, was found out. As a result, an underestimating of dose in the penumbra regions is observed. This is of great importance in the case of adjacent fields and when the radiation field is close to the organ at risk. For these cases, one should take note of unacceptable performance of Helax TMS, when one of the radiation field size is 16 cm or close to it. The results from other tests show good agreement between measured and calculated data. It should be noted that this is not a complete commissioning of TPS and more test (for oblique incidence, inhomogeneities, complex field shapes, 3-D calculations) should be preformed

  4. Heart dose reduction in breast cancer treatment with simultaneous integrated boost. Comparison of treatment planning and dosimetry for a novel hybrid technique and 3D-CRT

    Joest, Vincent; Kretschmer, Matthias; Sabatino, Marcello; Wuerschmidt, Florian; Dahle, Joerg; Lorenzen, Joern [Radiological Alliance, Hamburg (Germany); Ueberle, Friedrich [University of Applied Sciences, Faculty Life Sciences, Hamburg (Germany)

    2015-09-15

    The present study compares in silico treatment plans of clinically established three-dimensional conformal radiotherapy (3D-CRT) with a hybrid technique consisting of intensity-modulated radiotherapy (IMRT) and volumetric modulated arc radiotherapy (VMAT) during normally fractionated radiation of mammary carcinomas with simultaneous integrated boost on the basis of dose-volume histogram (DVH) parameters. Radiation treatment planning was performed with a hybrid and a 3D-CRT treatment plan for 20 patients. Hybrid plans were implemented with two tangential IMRT fields and a VMAT field in the angular range of the tangents. Verification of the plan was performed with a manufacturer-independent measurement system consisting of a detector array and rotation unit. The mean values of the heart dose for the entire patient collective were 3.6 ± 2.5 Gy for 3D-CRT and 2.9 ± 2.1 Gy for the hybrid technique (p < 0.01). For the left side (n = 10), the mean values for the left anterior descending artery were 21.8 ± 7.4 Gy for 3D-CRT and 17.6 ± 7.4 Gy for the hybrid technique (p < 0.01). The mean values of the ipsilateral lung were 11.9 ± 1.6 Gy for 3D-CRT and 10.5 ± 1.3 Gy for the hybrid technique (p < 0.01). Calculated dose distributions in the hybrid arm were in good accordance with measured dose (on average 95.6 ± 0.5 % for γ < 1 and 3 %/3 mm). The difference of the mean treatment time per fraction was 7 s in favor of 3D-CRT. Compared with the established 3D-CRT technique, the hybrid technique allows for a decrease in dose, particularly of the mean heart and lung dose with comparable target volume acquisition and without disadvantageous low-dose load of contralateral structures. Uncomplicated implementation of the hybrid technique was demonstrated in this context. The hybrid technique combines the advantages of tangential IMRT with the superior sparing of organs at risk by VMAT. (orig.) [German] Die vorliegende Studie vergleicht ''in silico

  5. Continuous table acquisition MRI for radiotherapy treatment planning: Distortion assessment with a new extended 3D volumetric phantom

    Purpose: Accurate geometry is required for radiotherapy treatment planning (RTP). When considering the use of magnetic resonance imaging (MRI) for RTP, geometric distortions observed in the acquired images should be considered. While scanner technology and vendor supplied correction algorithms provide some correction, large distortions are still present in images, even when considering considerably smaller scan lengths than those typically acquired with CT in conventional RTP. This study investigates MRI acquisition with a moving table compared with static scans for potential geometric benefits for RTP. Methods: A full field of view (FOV) phantom (diameter 500 mm; length 513 mm) was developed for measuring geometric distortions in MR images over volumes pertinent to RTP. The phantom consisted of layers of refined plastic within which vitamin E capsules were inserted. The phantom was scanned on CT to provide the geometric gold standard and on MRI, with differences in capsule location determining the distortion. MRI images were acquired with two techniques. For the first method, standard static table acquisitions were considered. Both 2D and 3D acquisition techniques were investigated. With the second technique, images were acquired with a moving table. The same sequence was acquired with a static table and then with table speeds of 1.1 mm/s and 2 mm/s. All of the MR images acquired were registered to the CT dataset using a deformable B-spline registration with the resulting deformation fields providing the distortion information for each acquisition. Results: MR images acquired with the moving table enabled imaging of the whole phantom length while images acquired with a static table were only able to image 50%–70% of the phantom length of 513 mm. Maximum distortion values were reduced across a larger volume when imaging with a moving table. Increased table speed resulted in a larger contribution of distortion from gradient nonlinearities in the through

  6. Continuous table acquisition MRI for radiotherapy treatment planning: Distortion assessment with a new extended 3D volumetric phantom

    Walker, Amy, E-mail: aw554@uowmail.edu.au; Metcalfe, Peter [Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia and Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia); Liney, Gary [Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia); Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia); South West Clinical School, University of New South Wales, Sydney, NSW 2170 (Australia); Holloway, Lois [Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia); Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia); South West Clinical School, University of New South Wales, Sydney, NSW 2170 (Australia); Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Dowling, Jason; Rivest-Henault, David [Commonwealth Scientific and Industrial Research Organisation, Australian E-Health Research Centre, Herston, QLD 4029 (Australia)

    2015-04-15

    Purpose: Accurate geometry is required for radiotherapy treatment planning (RTP). When considering the use of magnetic resonance imaging (MRI) for RTP, geometric distortions observed in the acquired images should be considered. While scanner technology and vendor supplied correction algorithms provide some correction, large distortions are still present in images, even when considering considerably smaller scan lengths than those typically acquired with CT in conventional RTP. This study investigates MRI acquisition with a moving table compared with static scans for potential geometric benefits for RTP. Methods: A full field of view (FOV) phantom (diameter 500 mm; length 513 mm) was developed for measuring geometric distortions in MR images over volumes pertinent to RTP. The phantom consisted of layers of refined plastic within which vitamin E capsules were inserted. The phantom was scanned on CT to provide the geometric gold standard and on MRI, with differences in capsule location determining the distortion. MRI images were acquired with two techniques. For the first method, standard static table acquisitions were considered. Both 2D and 3D acquisition techniques were investigated. With the second technique, images were acquired with a moving table. The same sequence was acquired with a static table and then with table speeds of 1.1 mm/s and 2 mm/s. All of the MR images acquired were registered to the CT dataset using a deformable B-spline registration with the resulting deformation fields providing the distortion information for each acquisition. Results: MR images acquired with the moving table enabled imaging of the whole phantom length while images acquired with a static table were only able to image 50%–70% of the phantom length of 513 mm. Maximum distortion values were reduced across a larger volume when imaging with a moving table. Increased table speed resulted in a larger contribution of distortion from gradient nonlinearities in the through

  7. SU-C-BRE-01: 3D Conformal Micro Irradiation Results of Four Treatment Sites for Preclinical Small Animal and Clinical Treatment Plans

    Price, S; Yaddanapudi, S [Washington University School of Medicine, Saint Louis, MO (United States); Rangaraj, D; Izaguirre, E [Scott and White Hospital, Temple, TX (United States)

    2014-06-15

    Purpose: Small animal irradiation can provide preclinical insights necessary for clinical advancement. In order to provide clinically relevant data, these small animal irradiations must be designed such that the treatment methods and results are comparable to clinical protocols, regardless of variations in treatment size and modality. Methods: Small animal treatments for four treatment sites (brain, liver, lung and spine) were investigated, accounting for change in treatment energy and target size. Up to five orthovoltage (300kVp) beams were used in the preclinical treatments, using circular, square, and conformal tungsten apertures, based on the treatment site. Treatments were delivered using the image guided micro irradiator (microIGRT). The plans were delivered to a mouse sized phantom and dose measurements in axial and coronal planes were performed using radiochromic film. The results of the clinical and preclinical protocols were characterized in terms of conformality number, CTV coverage, dose nonuniformity ratio, and organ at risk sparing. Results: Preclinical small animal treatment conformality was within 1–16% of clinical results for all treatment sites. The volume of the CTV receiving 100% of the prescription dose was typically within 10% of clinical values. The dose non-uniformity was consistently higher for preclinical treatments compared to clinical treatments, indicating hot spots in the target. The ratios of the mean dose in the target to the mean dose in an organ at risk were comparable if not better for preclinical versus clinical treatments. Finally, QUANTEC dose constraints were applied and the recommended morbidity limits were satisfied in each small animal treatment site. Conclusion: We have shown that for four treatment sites, preclinical 3D conformal small animal treatments can be clinically comparable if clinical protocols are followed. Using clinical protocols as the standard, preclinical irradiation methods can be altered and iteratively

  8. SU-C-213-04: Application of Depth Sensing and 3D-Printing Technique for Total Body Irradiation (TBI) Patient Measurement and Treatment Planning

    Purpose: To develop and validate an innovative method of using depth sensing cameras and 3D printing techniques for Total Body Irradiation (TBI) treatment planning and compensator fabrication. Methods: A tablet with motion tracking cameras and integrated depth sensing was used to scan a RANDOTM phantom arranged in a TBI treatment booth to detect and store the 3D surface in a point cloud (PC) format. The accuracy of the detected surface was evaluated by comparison to extracted measurements from CT scan images. The thickness, source to surface distance and off-axis distance of the phantom at different body section was measured for TBI treatment planning. A 2D map containing a detailed compensator design was calculated to achieve uniform dose distribution throughout the phantom. The compensator was fabricated using a 3D printer, silicone molding and tungsten powder. In vivo dosimetry measurements were performed using optically stimulated luminescent detectors (OSLDs). Results: The whole scan of the anthropomorphic phantom took approximately 30 seconds. The mean error for thickness measurements at each section of phantom compare to CT was 0.44 ± 0.268 cm. These errors resulted in approximately 2% dose error calculation and 0.4 mm tungsten thickness deviation for the compensator design. The accuracy of 3D compensator printing was within 0.2 mm. In vivo measurements for an end-to-end test showed the overall dose difference was within 3%. Conclusion: Motion cameras and depth sensing techniques proved to be an accurate and efficient tool for TBI patient measurement and treatment planning. 3D printing technique improved the efficiency and accuracy of the compensator production and ensured a more accurate treatment delivery

  9. SU-C-213-04: Application of Depth Sensing and 3D-Printing Technique for Total Body Irradiation (TBI) Patient Measurement and Treatment Planning

    Lee, M; Suh, T [Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of); Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of); Han, B; Xing, L [Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, CA (United States); Jenkins, C [Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, CA (United States); Department of Mechanical Engineering, Stanford University, Palo Alto, CA (United States)

    2015-06-15

    Purpose: To develop and validate an innovative method of using depth sensing cameras and 3D printing techniques for Total Body Irradiation (TBI) treatment planning and compensator fabrication. Methods: A tablet with motion tracking cameras and integrated depth sensing was used to scan a RANDOTM phantom arranged in a TBI treatment booth to detect and store the 3D surface in a point cloud (PC) format. The accuracy of the detected surface was evaluated by comparison to extracted measurements from CT scan images. The thickness, source to surface distance and off-axis distance of the phantom at different body section was measured for TBI treatment planning. A 2D map containing a detailed compensator design was calculated to achieve uniform dose distribution throughout the phantom. The compensator was fabricated using a 3D printer, silicone molding and tungsten powder. In vivo dosimetry measurements were performed using optically stimulated luminescent detectors (OSLDs). Results: The whole scan of the anthropomorphic phantom took approximately 30 seconds. The mean error for thickness measurements at each section of phantom compare to CT was 0.44 ± 0.268 cm. These errors resulted in approximately 2% dose error calculation and 0.4 mm tungsten thickness deviation for the compensator design. The accuracy of 3D compensator printing was within 0.2 mm. In vivo measurements for an end-to-end test showed the overall dose difference was within 3%. Conclusion: Motion cameras and depth sensing techniques proved to be an accurate and efficient tool for TBI patient measurement and treatment planning. 3D printing technique improved the efficiency and accuracy of the compensator production and ensured a more accurate treatment delivery.

  10. IMRT and 3D conformal radiotherapy with or without elective nodal irradiation in locally advanced NSCLC. A direct comparison of PET-based treatment planning

    Fleckenstein, Jochen; Kremp, Katharina; Kremp, Stephanie; Palm, Jan; Ruebe, Christian [Saarland University Medical School, Department of Radiotherapy and Radiation Oncology, Homburg/Saar (Germany)

    2016-02-15

    The potential of intensity-modulated radiation therapy (IMRT) as opposed to three-dimensional conformal radiotherapy (3D-CRT) is analyzed for two different concepts of fluorodeoxyglucose positron emission tomography (FDG PET)-based target volume delineation in locally advanced non-small cell lung cancer (LA-NSCLC): involved-field radiotherapy (IF-RT) vs. elective nodal irradiation (ENI). Treatment planning was performed for 41 patients with LA-NSCLC, using four different planning approaches (3D-CRT-IF, 3D-CRT-ENI, IMRT-IF, IMRT-ENI). ENI included a boost irradiation after 50 Gy. For each plan, maximum dose escalation was calculated based on prespecified normal tissue constraints. The maximum prescription dose (PD), tumor control probability (TCP), conformal indices (CI), and normal tissue complication probabilities (NTCP) were analyzed. IMRT resulted in statistically significant higher prescription doses for both target volume concepts as compared with 3D-CRT (ENI: 68.4 vs. 60.9 Gy, p < 0.001; IF: 74.3 vs. 70.1 Gy, p < 0.03). With IMRT-IF, a PD of at least 66 Gy was achieved for 95 % of all plans. For IF as compared with ENI, there was a considerable theoretical increase in TCP (IMRT: 27.3 vs. 17.7 %, p < 0.00001; 3D-CRT: 20.2 vs. 9.9 %, p < 0.00001). The esophageal NTCP showed a particularly good sparing with IMRT vs. 3D-CRT (ENI: 12.3 vs. 30.9 % p < 0.0001; IF: 15.9 vs. 24.1 %; p < 0.001). The IMRT technique and IF target volume delineation allow a significant dose escalation and an increase in TCP. IMRT results in an improved sparing of OARs as compared with 3D-CRT at equivalent dose levels. (orig.) [German] Das Potenzial der intensitaetsmodulierten Strahlentherapie (IMRT) soll im Rahmen der FDG-PET basierten Bestrahlungsplanung des lokal fortgeschrittenen nichtkleinzelligen Bronchialkarzinoms (LA-NSCLC) fuer 2 Zielvolumenansaetze (Involved-Field-Bestrahlung, IF) sowie elektive Nodalbestrahlung (ENI) geprueft und mit der 3-D-konformalen Strahlentherapie (3-D

  11. Adaptation, Commissioning, and Evaluation of a 3D Treatment Planning System for High-Resolution Small-Animal Irradiation.

    Jeong, Jeho; Chen, Qing; Febo, Robert; Yang, Jie; Pham, Hai; Xiong, Jian-Ping; Zanzonico, Pat B; Deasy, Joseph O; Humm, John L; Mageras, Gig S

    2016-06-01

    Although spatially precise systems are now available for small-animal irradiations, there are currently limited software tools available for treatment planning for such irradiations. We report on the adaptation, commissioning, and evaluation of a 3-dimensional treatment planning system for use with a small-animal irradiation system. The 225-kV X-ray beam of the X-RAD 225Cx microirradiator (Precision X-Ray) was commissioned using both ion-chamber and radiochromic film for 10 different collimators ranging in field size from 1 mm in diameter to 40 × 40 mm(2) A clinical 3-dimensional treatment planning system (Metropolis) developed at our institution was adapted to small-animal irradiation by making it compatible with the dimensions of mice and rats, modeling the microirradiator beam orientations and collimators, and incorporating the measured beam data for dose calculation. Dose calculations in Metropolis were verified by comparison with measurements in phantoms. Treatment plans for irradiation of a tumor-bearing mouse were generated with both the Metropolis and the vendor-supplied software. The calculated beam-on times and the plan evaluation tools were compared. The dose rate at the central axis ranges from 74 to 365 cGy/min depending on the collimator size. Doses calculated with Metropolis agreed with phantom measurements within 3% for all collimators. The beam-on times calculated by Metropolis and the vendor-supplied software agreed within 1% at the isocenter. The modified 3-dimensional treatment planning system provides better visualization of the relationship between the X-ray beams and the small-animal anatomy as well as more complete dosimetric information on target tissues and organs at risk. It thereby enhances the potential of image-guided microirradiator systems for evaluation of dose-response relationships and for preclinical experimentation generally. PMID:25948321

  12. The role of F-18 FDG-PET for 3-D radiation treatment planning of non-small cell lung cancer - first results of a prospective study

    To determine the role of F-18 FDG-PET in 3-D-radiation therapy planning, findings in 27 patients, studied by both, PET and CT, were analyzed prospectively. All patients were first examined by helical CT and F-18 FDG-PET. The PET data were iteratively reconstructed into 3-D images and image fusion with CT data was applied. First, based on CT data, the planning target volumes (PTV) and the volumes of organs at risk were generated. In a second step, the transversal slices of CT and PET were matched. Then, based on PET data, new target volumes were generated. Treatment plans for radiation therapy were calculated on CT-based and PET-based planning target volumes. If PET results were used additionally for the 3-D-planning procedure of radiation therapy, the planning target volume could be reduced in a range of 3-21% as compared with conventional imaging methods, e.g., PET allowed differentiation between tumor and atelectasis resulting in smaller PTV. The dose volume histograms of the PET-based treatment plans showed a reduction of dose to the organs at risk, e.g., Vlung (20 Gy) could be reduced by 5% to 17%. In 2 patients, the boost volume based on PET findings was larger than the one based on CT, since PET detected lymph node metastases being of normal size in CT (<1 cm). PET can provide important complementary metabolic information to morphological imaging modalities for an exact localization of nodal involvement and the extent of the primary tumor. Due to smaller PTV, radiation therapy could be delivered with less toxicity in most patients. Using metabolic tumor localization by PET additionally to anatomic delineation by CT scan, a better tumor control may be achieved. Further studies are required to proof this concept. (orig.)

  13. 3D-conformal Accelerated Partial Breast Irradiation treatment planning: the value of surgical clips in the delineation of the lumpectomy cavity

    Accurate localisation of the lumpectomy cavity (LC) volume is one of the most critical points in 3D-conformal Partial breast irradiation (3D-APBI) treatment planning because the irradiated volume is restricted to a small breast volume. Here, we studied the role of the placement of surgical clips at the 4 cardinal points of the lumpectomy cavity in target delineation. Forty CT-based 3D-APBI plans were retrieved on which a total of 4 radiation oncologists, two trainee and two experienced physicians, outlined the lumpectomy cavity. The inter-observer variability of LC contouring was assessed when the CTV was defined as the delineation that encompassed both surgical clips and remodelled breast tissue. The conformity index of tumour bed delineation was significantly improved by the placement of surgical clips within the LC (median at 0.65). Furthermore, a better conformity index of LC was observed according to the experience of the physicians (median CI = 0.55 for trainee physicians vs 0.65 for experienced physicians). The placement of surgical clips improved the accuracy of lumpectomy cavity delineation in 3D-APBI. However, a learning curve is needed to improve the conformity index of the lumpectomy cavity

  14. A probabilistic approach using deformable organ models for automatic definition of normal anatomical structures for 3D treatment planning

    priori (prior) information and 2) a likelihood function. In Bayesian terminology, the energy functions in the model represent a priori information. The likelihood function is computed from the image data and can take the form of geometric measurements obtained at the skeleton and boundary points. The best match is obtained by deforming the model to optimize the posterior probability. Results : A 2D implementation of the approach was tested on CT slices through the liver and kidneys and on MRI slices through the ventricles of the brain. Automatic segmentation was successful in all cases. When the model is matched against several slices, the slice that best matches the model corresponds to the slice with the greatest posterior probability. This finding is a demonstration of object recognition. Moreover abnormalities in shape, e.g., protrusions or indentations not represented in the model, can be recognized and localized by analyzing local values of the posterior probability. Conclusion : The method for combining the model and image data warps the model to conform to the image data while preserving neighbor relationships in the model, stabilizing the localization of the object boundary region in the presence of noise, contrast gradients, and poor contrast resolution. Therefore the method is robust and the results are reproducible and user independent. The success of initial studies is encouraging and extension to 3D is planned using more sophisticated models that capture statistical variations in organ shape across a population of images

  15. CT guided brachytherapy: a new approach in 3D treatment planning of interstitial implant in oral cancer with mHDR

    The definition of target volume is uniquely critical for the success of interstitial implant in brachytherapy as the dose falls off very rapidly beyond the reference volume. The conventional practice of defining GTV and PTV on the basis of orthogonal radiograph not only have the infirmity of defining 3D volume on the basis of 2D information, but also does not address the dynamic situation prevalent in such implants. The ICRU-58 recommendation illustrates the evaluation of treatment plan for elucidating the Mean central dose (MCD), Minimum Target Dose, Homogenity index, Treated Volume, High dose regions, Low dose regions, reference volume, irradiated volume etc. In this presentation an attempt has been made to compare the conventional planning method based on orthogonal radiograph with the image guided approach where multislice CT scanner capable of generation of 3D volumetric information has been utilized for definition of GTV and PTV before each fraction in conformity of ICRU-58. This paper thus explores the possibility of CT based planning in implementation of ICRU-58 in improving the 3D information for reducing the dose to the organ at risk and enhancing the biological effectiveness in the target volume

  16. Development of a fast 3D treatment planning platform for clinical interstitial microwave hyperthermia within free-hand obliquely implanted HDR catheters

    Scott, Serena J.; Salgaonkar, Vasant A.; Prakash, Punit; Curto, Sergio; Hsu, I.-Chow; Diederich, Chris J.

    2015-03-01

    A treatment planning platform for interstitial microwave hyperthermia was developed for practical, free-hand clinical implants. Such implants, consisting of non-parallel, moderately curved antennas with varying insertion depths, are used in HDR brachytherapy for treating locally advanced cancer. Numerical models for commercially available MA251 antennas (915 MHz, BSD Medical) were developed in COMSOL Multiphysics, a finite element analysis software package. To expedite treatment planning, electric fields, power deposition and temperature rises were computed for a single straight antenna in 2D axisymmetric geometry. A precomputed library of electric field and temperature solutions was created for a range of insertion depths (5-12 cm) and blood perfusion rates (0.5-5 kg/m3/s). 3D models of multiple antennas and benchtop phantoms experiments using temperature-sensitive liquid crystal paper to monitor heating by curved antennas were performed for comparative evaluation of the treatment planning platform. A patient-customizable hyperthermia treatment planning software package was developed in MATLAB with capabilities to interface with a commercial radiation therapy planning platform (Oncentra, Nucleotron), import patient and multicatheter implant geometries, calculate insertion depths, and perform hyperthermia planning with antennas operating in asynchronous or synchronous mode. During asynchronous operation, the net power deposition and temperature rises were approximated as a superposition sum of the respective quantities for one single antenna. During synchronous excitation, a superposition of complex electrical fields was performed with appropriate phasing to compute power deposition. Electric fields and temperatures from the pre-computed single-antenna library were utilized following appropriate non-rigid coordinate transformations. Comparison to 3D models indicated that superposition of electric fields around parallel antennas is valid when they are at least 15 mm

  17. Dosimetric evaluation of a commercial 3-D treatment planning system using Report 55 b AAPM Task Group 23

    A relevant part of radiotherapy treatment planning system QA concerns dose calculation verification. Report 55 by AAPM TG-23 is an instrument for performing dosimetric evaluation of treatment planning systems in case of external photon beams. It was employed by different groups in three radiotherapy departments for controlling performances of RTPS CadPlan Varian-Dosetek, versions 2.7.9, 3.0.6 and 3. 1. 1. Once the basic data of the AAPM 4 MV and 18 MV X-ray units had been converted into the CadPlan format and the AAPM units configured, the whole set of TG23 tests were carried out on three different systems. According to Report 55. comparisons between values measured by TG-23 and calculated by RTPS were made in terms of dose at selected points and radiological field width at different depths. As far as dose is concerned, 266 data were compared for 4 MV and 297 for Is MV. Ninety-five-point-nine percent of dose deviations for 4 MV and 92.6% for 18 MV are less than 2%. Most of the relevant discrepancies for both energies occur in a test case where dose has to be calculated under a long narrow block centred on the beam axis. Deviations as much as 6.1 % for 4 MV and - 7.5% for 18 MV were obsessed in points at 1 cm depth under the block. Poor results were also observed in the rectangular field 25 x 5. in points outside the field edges under collimators. As regards radiological field width. 58 out of 64 comparisons for 4 MV occurred in the range ± 2 mm. For 18 MV the biggest deviation was - 2.2 mm. The TG-23 tests demonstrated that the accuracy of the RTPS in dose calculation is good in most of the typical radiotherapy applications. Our results are better than those recently published for other RTPS. The TG-23 package turned out to be an effective instrument for QA and calculation verification. as well as being a powerful method for training purpose in configuring and using a RTPS (author.)

  18. Verification of methodology for QUASAR phantoms used for quality assurance of non dosimetric parameters of 3D treatment planning systems

    In cooperation with 6 radiotherapeutic workplaces, Czech methodology for quality assurance of non-dosimetric parameters with QUASAR phantoms was verified. None of checked treatment planning systems (TPS) showed heavy problem that would be a reason for demotion of TPS from clinical process although sometimes the tolerances were exceeded. The verification of methodology caused the tolerance modification in some reasoned cases against the original value that was recommended in the methodology made by phantom producer. Deviations that exceed recommended tolerance needn't necessarily indicate wrong function of TPS. Often the measurement of dimensions and distances with software tools or structures contouring is very subjective. It is highly important to aim attention to accuracy while contouring volumes in TPS. In any case the users should know limitations and drifts of their TPS. (authors)

  19. Image-Based 3D Treatment Planning for Vaginal Cylinder Brachytherapy: Dosimetric Effects of Bladder Filling on Organs at Risk

    Purpose: To investigate the dosimetric effects of bladder filling on organs at risk (OARs) using three-dimensional image-based treatment planning for vaginal cylinder brachytherapy. Methods and Materials: Twelve patients with endometrial or cervical cancer underwent postoperative high–dose rate vaginal cylinder brachytherapy. For three-dimensional planning, patients were simulated by computed tomography with an indwelling catheter in place (empty bladder) and with 180 mL of sterile water instilled into the bladder (full bladder). The bladder, rectum, sigmoid, and small bowel (OARs) were contoured, and a prescription dose was generated for 10 to 35 Gy in 2 to 5 fractions at the surface or at 5 mm depth. For each OAR, the volume dose was defined by use of two different criteria: the minimum dose value in a 2.0-cc volume receiving the highest dose (D2cc) and the dose received by 50% of the OAR volume (D50%). International Commission on Radiation Units and Measurements (ICRU) bladder and rectum point doses were calculated for comparison. The cylinder-to-bowel distance was measured using the shortest distance from the cylinder apex to the contoured sigmoid or small bowel. Statistical analyses were performed with paired t tests. Results: Mean bladder and rectum D2cc values were lower than their respective ICRU doses. However, differences between D2cc and ICRU doses were small. Empty vs. full bladder did not significantly affect the mean cylinder-to-bowel distance (0.72 vs. 0.92 cm, p = 0.08). In contrast, bladder distention had appreciable effects on bladder and small bowel volume dosimetry. With a full bladder, the mean small bowel D2cc significantly decreased from 677 to 408 cGy (p = 0.004); the mean bladder D2cc did not increase significantly (1,179 cGy vs. 1,246 cGy, p = 0.11). Bladder distention decreased the mean D50% for both the bladder (441 vs. 279 cGy, p = 0.001) and the small bowel (168 vs. 132 cGy, p = 0.001). Rectum and sigmoid volume doses were not

  20. Image-Based 3D Treatment Planning for Vaginal Cylinder Brachytherapy: Dosimetric Effects of Bladder Filling on Organs at Risk

    Hung, Jennifer; Shen Sui; De Los Santos, Jennifer F. [Department of Radiation Oncology, University of Alabama Medical Center, Birmingham, AL (United States); Kim, Robert Y., E-mail: rkim@uabmc.edu [Department of Radiation Oncology, University of Alabama Medical Center, Birmingham, AL (United States)

    2012-07-01

    Purpose: To investigate the dosimetric effects of bladder filling on organs at risk (OARs) using three-dimensional image-based treatment planning for vaginal cylinder brachytherapy. Methods and Materials: Twelve patients with endometrial or cervical cancer underwent postoperative high-dose rate vaginal cylinder brachytherapy. For three-dimensional planning, patients were simulated by computed tomography with an indwelling catheter in place (empty bladder) and with 180 mL of sterile water instilled into the bladder (full bladder). The bladder, rectum, sigmoid, and small bowel (OARs) were contoured, and a prescription dose was generated for 10 to 35 Gy in 2 to 5 fractions at the surface or at 5 mm depth. For each OAR, the volume dose was defined by use of two different criteria: the minimum dose value in a 2.0-cc volume receiving the highest dose (D{sub 2cc}) and the dose received by 50% of the OAR volume (D{sub 50%}). International Commission on Radiation Units and Measurements (ICRU) bladder and rectum point doses were calculated for comparison. The cylinder-to-bowel distance was measured using the shortest distance from the cylinder apex to the contoured sigmoid or small bowel. Statistical analyses were performed with paired t tests. Results: Mean bladder and rectum D{sub 2cc} values were lower than their respective ICRU doses. However, differences between D{sub 2cc} and ICRU doses were small. Empty vs. full bladder did not significantly affect the mean cylinder-to-bowel distance (0.72 vs. 0.92 cm, p = 0.08). In contrast, bladder distention had appreciable effects on bladder and small bowel volume dosimetry. With a full bladder, the mean small bowel D{sub 2cc} significantly decreased from 677 to 408 cGy (p = 0.004); the mean bladder D{sub 2cc} did not increase significantly (1,179 cGy vs. 1,246 cGy, p = 0.11). Bladder distention decreased the mean D{sub 50%} for both the bladder (441 vs. 279 cGy, p = 0.001) and the small bowel (168 vs. 132 cGy, p = 0.001). Rectum

  1. Dosimetric evaluation of a commercial 3D treatment planning system using the AAPM Task Group 23 test package.

    Casanova Borca, Valeria; Pasquino, Massimo; Bresciani, Sara; Catuzzo, Paola; Ozzello, Franca; Tofani, Santi

    2005-03-01

    The accuracy of the dose calculation algorithm is one of the most critical steps in assessing the radiotherapy treatment to achieve the 5% accuracy in dose delivery, which represents the suggested limit to increase the complication-free local control of tumor. We have used the AAPM Task Group 23 (TG-23) test package for clinical photon external beam therapy to evaluate the accuracy of the new version of the PLATO TPS algorithm. The comparison between tabulated values and calculated ones has been performed for 266 and 297 dose values for the 4 and 18 MV photon beams, respectively. Dose deviations less than 2% were found in the 98.5%- and 90.6% analyzed dose points for the two considered energies, respectively. Larger deviations were obtained for both energies, in large dose gradients, such as the build-up region or near the field edges and blocks. As far as the radiological field width is concerned, 64 points were analyzed for both the energies: 53 points (83%) and 64 points (100%) were within +/-2 millimeters for the 4 and 18 MV photon beams, respectively. The results show the good accuracy of the algorithm either in simple geometry beam conditions or in complex ones, in homogeneous medium, and in the presence of inhomogeneities, for low and high energy beams. Our results fit well the data reported by several authors related to the calculation accuracy of different treatment planning systems (TPSs) (within a mean value of 0.7% and 1.2% for 4 and 18 MV respectively). The TG-23 test package can be considered a powerful instrument to evaluate dose calculation accuracy, and as such may play an important role in a quality assurance program related to the commissioning of a new TPS. PMID:15839346

  2. Data analysis tools for 3D dosimetry: the use of CERR as a platform to integrate and compare measurements and treatment planning information

    CERR, the Computational Environment for Radiotherapy Research, is a mature Matlab-based application that allows users to visualize and analyze 3D treatment planning data exported using standard protocols from clinical treatment planning systems. In this presentation we will give an in-depth discussion of the use of CERR as a tool to analyze measurements compared to expected treatment planning systems. Extensions to CERR allow for straightforward import and registration of experimental data with the planning data. These tools allow users to compare the match between measurement and treatment planning calculation in detail, as provided by profile plots and other tools. Custom Matlab scripts can also be developed, providing complete flexibility in analysis methods. In addition, several offshoot tools have been developed by our group to facilitate dosimetric data analysis, including: A film QA tool, developed under a contract for the Radiological Physics Center (RPC), and a Monte Carlo recalculation tool, also developed under the same contract for the RPC. The film QA tool is meant to facilitate the analysis of film that is irradiated in a phantom. The tool provides a simple method for registering pin-marked points on film to corresponding points in a CT-scanned phantom. Similarly, the locations of point dosimeters can be found. Once registered, data can be compared with the expected treatment plan, interpolated from the converted CERR plan. The dose-distance gamma function is available to quantify agreement. We will discuss the ways these tools can be used to support dosimetry research. All the software discussed here is being made available under open-source licensing.

  3. WE-F-16A-06: Using 3D Printers to Create Complex Phantoms for Dose Verification, Quality Assurance, and Treatment Planning System Commissioning in Radiotherapy

    Purpose: To use 3D printers to design and construct complex geometrical phantoms for commissioning treatment planning systems, dose calculation algorithms, quality assurance (QA), dose delivery, and patient dose verifications. Methods: In radiotherapy, complex geometrical phantoms are often required for dose verification, dose delivery and calculation algorithm validation. Presently, fabrication of customized phantoms is limited due to time, expense and challenges in machining of complex shapes. In this work, we designed and utilized 3D printers to fabricate two phantoms for QA purposes. One phantom includes hills and valleys (HV) for verification of intensity modulated radiotherapy for photons, and protons (IMRT and IMPT). The other phantom includes cylindrical cavities (CC) of various sizes for dose verification of inhomogeneities. We evaluated the HV phantoms for an IMPT beam, and the CC phantom to study various inhomogeneity configurations using photon, electron, and proton beams. Gafcromic ™ films were used to quantify the dose distributions delivered to the phantoms. Results: The HV phantom has dimensions of 12 cm × 12 cm and consists of one row and one column of five peaks with heights ranging from 2 to 5 cm. The CC phantom has a size 10 cm × 14 cm and includes 6 cylindrical cavities with length of 7.2 cm and diameters ranging from 0.6 to 1.2 cm. The IMPT evaluation using the HV phantom shows good agreement as compared to the dose distribution calculated with treatment planning system. The CC phantom also shows reasonable agreements for using different algorithms for each beam modalities. Conclusion: 3D printers with submillimiter resolutions are capable of printing complex phantoms for dose verification and QA in radiotherapy. As printing costs decrease and the technology becomes widely available, phantom design and construction will be readily available to any clinic for testing geometries that were not previously feasible

  4. Automatic Segmentation of the Eye in 3D Magnetic Resonance Imaging: A Novel Statistical Shape Model for Treatment Planning of Retinoblastoma

    Ciller, Carlos, E-mail: carlos.cillerruiz@unil.ch [Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne (Switzerland); Ophthalmic Technology Group, ARTORG Center of the University of Bern, Bern (Switzerland); Centre d’Imagerie BioMédicale, University of Lausanne, Lausanne (Switzerland); De Zanet, Sandro I.; Rüegsegger, Michael B. [Ophthalmic Technology Group, ARTORG Center of the University of Bern, Bern (Switzerland); Department of Ophthalmology, Inselspital, Bern University Hospital, Bern (Switzerland); Pica, Alessia [Department of Radiation Oncology, Inselspital, Bern University Hospital, Bern (Switzerland); Sznitman, Raphael [Ophthalmic Technology Group, ARTORG Center of the University of Bern, Bern (Switzerland); Department of Ophthalmology, Inselspital, Bern University Hospital, Bern (Switzerland); Thiran, Jean-Philippe [Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne (Switzerland); Signal Processing Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne (Switzerland); Maeder, Philippe [Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne (Switzerland); Munier, Francis L. [Unit of Pediatric Ocular Oncology, Jules Gonin Eye Hospital, Lausanne (Switzerland); Kowal, Jens H. [Ophthalmic Technology Group, ARTORG Center of the University of Bern, Bern (Switzerland); Department of Ophthalmology, Inselspital, Bern University Hospital, Bern (Switzerland); and others

    2015-07-15

    Purpose: Proper delineation of ocular anatomy in 3-dimensional (3D) imaging is a big challenge, particularly when developing treatment plans for ocular diseases. Magnetic resonance imaging (MRI) is presently used in clinical practice for diagnosis confirmation and treatment planning for treatment of retinoblastoma in infants, where it serves as a source of information, complementary to the fundus or ultrasonographic imaging. Here we present a framework to fully automatically segment the eye anatomy for MRI based on 3D active shape models (ASM), and we validate the results and present a proof of concept to automatically segment pathological eyes. Methods and Materials: Manual and automatic segmentation were performed in 24 images of healthy children's eyes (3.29 ± 2.15 years of age). Imaging was performed using a 3-T MRI scanner. The ASM consists of the lens, the vitreous humor, the sclera, and the cornea. The model was fitted by first automatically detecting the position of the eye center, the lens, and the optic nerve, and then aligning the model and fitting it to the patient. We validated our segmentation method by using a leave-one-out cross-validation. The segmentation results were evaluated by measuring the overlap, using the Dice similarity coefficient (DSC) and the mean distance error. Results: We obtained a DSC of 94.90 ± 2.12% for the sclera and the cornea, 94.72 ± 1.89% for the vitreous humor, and 85.16 ± 4.91% for the lens. The mean distance error was 0.26 ± 0.09 mm. The entire process took 14 seconds on average per eye. Conclusion: We provide a reliable and accurate tool that enables clinicians to automatically segment the sclera, the cornea, the vitreous humor, and the lens, using MRI. We additionally present a proof of concept for fully automatically segmenting eye pathology. This tool reduces the time needed for eye shape delineation and thus can help clinicians when planning eye treatment and confirming the extent of the tumor.

  5. Automatic Segmentation of the Eye in 3D Magnetic Resonance Imaging: A Novel Statistical Shape Model for Treatment Planning of Retinoblastoma

    Purpose: Proper delineation of ocular anatomy in 3-dimensional (3D) imaging is a big challenge, particularly when developing treatment plans for ocular diseases. Magnetic resonance imaging (MRI) is presently used in clinical practice for diagnosis confirmation and treatment planning for treatment of retinoblastoma in infants, where it serves as a source of information, complementary to the fundus or ultrasonographic imaging. Here we present a framework to fully automatically segment the eye anatomy for MRI based on 3D active shape models (ASM), and we validate the results and present a proof of concept to automatically segment pathological eyes. Methods and Materials: Manual and automatic segmentation were performed in 24 images of healthy children's eyes (3.29 ± 2.15 years of age). Imaging was performed using a 3-T MRI scanner. The ASM consists of the lens, the vitreous humor, the sclera, and the cornea. The model was fitted by first automatically detecting the position of the eye center, the lens, and the optic nerve, and then aligning the model and fitting it to the patient. We validated our segmentation method by using a leave-one-out cross-validation. The segmentation results were evaluated by measuring the overlap, using the Dice similarity coefficient (DSC) and the mean distance error. Results: We obtained a DSC of 94.90 ± 2.12% for the sclera and the cornea, 94.72 ± 1.89% for the vitreous humor, and 85.16 ± 4.91% for the lens. The mean distance error was 0.26 ± 0.09 mm. The entire process took 14 seconds on average per eye. Conclusion: We provide a reliable and accurate tool that enables clinicians to automatically segment the sclera, the cornea, the vitreous humor, and the lens, using MRI. We additionally present a proof of concept for fully automatically segmenting eye pathology. This tool reduces the time needed for eye shape delineation and thus can help clinicians when planning eye treatment and confirming the extent of the tumor

  6. Comparison of 2D and 3D Imaging and Treatment Planning for Postoperative Vaginal Apex High-Dose Rate Brachytherapy for Endometrial Cancer

    Russo, James K. [Department of Radiation Oncology, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina (United States); Armeson, Kent E. [Division of Biostatistics and Epidemiology, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina (United States); Richardson, Susan, E-mail: srichardson@radonc.wustl.edu [Department of Radiation Oncology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri (United States)

    2012-05-01

    Purpose: To evaluate bladder and rectal doses using two-dimensional (2D) and 3D treatment planning for vaginal cuff high-dose rate (HDR) in endometrial cancer. Methods and Materials: Ninety-one consecutive patients treated between 2000 and 2007 were evaluated. Seventy-one and 20 patients underwent 2D and 3D planning, respectively. Each patient received six fractions prescribed at 0.5 cm to the superior 3 cm of the vagina. International Commission on Radiation Units and Measurements (ICRU) doses were calculated for 2D patients. Maximum and 2-cc doses were calculated for 3D patients. Organ doses were normalized to prescription dose. Results: Bladder maximum doses were 178% of ICRU doses (p < 0.0001). Two-cubic centimeter doses were no different than ICRU doses (p = 0.22). Two-cubic centimeter doses were 59% of maximum doses (p < 0.0001). Rectal maximum doses were 137% of ICRU doses (p < 0.0001). Two-cubic centimeter doses were 87% of ICRU doses (p < 0.0001). Two-cubic centimeter doses were 64% of maximum doses (p < 0.0001). Using the first 1, 2, 3, 4 or 5 fractions, we predicted the final bladder dose to within 10% for 44%, 59%, 83%, 82%, and 89% of patients by using the ICRU dose, and for 45%, 55%, 80%, 85%, and 85% of patients by using the maximum dose, and for 37%, 68%, 79%, 79%, and 84% of patients by using the 2-cc dose. Using the first 1, 2, 3, 4 or 5 fractions, we predicted the final rectal dose to within 10% for 100%, 100%, 100%, 100%, and 100% of patients by using the ICRU dose, and for 60%, 65%, 70%, 75%, and 75% of patients by using the maximum dose, and for 68%, 95%, 84%, 84%, and 84% of patients by using the 2-cc dose. Conclusions: Doses to organs at risk vary depending on the calculation method. In some cases, final dose accuracy appears to plateau after the third fraction, indicating that simulation and planning may not be necessary in all fractions. A clinically relevant level of accuracy should be determined and further research conducted to address

  7. Improved Surgery Planning Using 3-D Printing: a Case Study.

    Singhal, A J; Shetty, V; Bhagavan, K R; Ragothaman, Ananthan; Shetty, V; Koneru, Ganesh; Agarwala, M

    2016-04-01

    The role of 3-D printing is presented for improved patient-specific surgery planning. Key benefits are time saved and surgery outcome. Two hard-tissue surgery models were 3-D printed, for orthopedic, pelvic surgery, and craniofacial surgery. We discuss software data conversion in computed tomography (CT)/magnetic resonance (MR) medical image for 3-D printing. 3-D printed models save time in surgery planning and help visualize complex pre-operative anatomy. Time saved in surgery planning can be as much as two thirds. In addition to improved surgery accuracy, 3-D printing presents opportunity in materials research. Other hard-tissue and soft-tissue cases in maxillofacial, abdominal, thoracic, cardiac, orthodontics, and neurosurgery are considered. We recommend using 3-D printing as standard protocol for surgery planning and for teaching surgery practices. A quick turnaround time of a 3-D printed surgery model, in improved accuracy in surgery planning, is helpful for the surgery team. It is recommended that these costs be within 20 % of the total surgery budget. PMID:27303117

  8. 3D conformal planning using low segment multi-criteria IMRT optimization

    Khan, Fazal

    2014-01-01

    Purpose: To evaluate automated multicriteria optimization (MCO)-- designed for intensity modulated radiation therapy (IMRT), but invoked with limited segmentation -- to efficiently produce high quality 3D conformal treatment (3D-CRT) plans. Methods: Ten patients previously planned with 3D-CRT were replanned with a low-segment inverse multicriteria optimized technique. The MCO-3D plans used the same number of beams, beam geometry and machine parameters of the corresponding 3D plans, but were limited to an energy of 6 MV. The MCO-3D plans were optimized using a fluence-based MCO IMRT algorithm and then, after MCO navigation, segmented with a low number of segments. The 3D and MCO-3D plans were compared by evaluating mean doses to individual organs at risk (OARs), mean doses to combined OARs, homogeneity indexes (HI), monitor units (MUs), physician preference, and qualitative assessments of planning time and plan customizability. Results: The MCO-3D plans significantly reduced the OAR mean doses and monitor unit...

  9. Dosimetric Comparison of Volumetric Modulated Arc Therapy, Static Field Intensity Modulated Radiation Therapy, and 3D Conformal Planning for the Treatment of a Right-Sided Reconstructed Chest Wall and Regional Nodal Case

    Vishruta A. Dumane

    2014-01-01

    Full Text Available We compared 3D conformal planning, static field intensity modulated radiation therapy (IMRT, and volumetric modulated arc therapy (VMAT to investigate the suitable treatment plan and delivery method for a right-sided reconstructed chest wall and nodal case. The dose prescribed for the reconstructed chest wall and regional nodes was 50.4 Gy. Plans were compared for target coverage and doses of the lungs, heart, contralateral breast, and healthy tissue. All plans achieved acceptable coverage of the target and IMNs. The best right lung sparing achieved with 3D was a V20 Gy of 31.09%. Compared to it, VMAT reduced the same by 10.85% and improved the CI and HI over 3D by 18.75% and 2%, respectively. The ipsilateral lung V5 Gy to V20 Gy decreased with VMAT over IMRT by as high as 17.1%. The contralateral lung V5 Gy was also lowered with VMAT compared to IMRT by 16.22%. The MU and treatment beams were lowered with VMAT over IMRT by 30% and 10, respectively, decreasing the treatment time by >50%. VMAT was the treatment plan and delivery method of choice for this case due to a combination of improved lung sparing and reduced treatment time without compromising target coverage.

  10. 3D root canal modeling for advanced endodontic treatment

    Hong, Shane Y.; Dong, Janet

    2002-06-01

    More than 14 million teeth receive endodontic (root canal) treatment annually. Before a clinician's inspection and diagnosis, destructive access preparation by removing teeth crown and dentin is usually needed. This paper presents a non-invasive method for accessing internal tooth geometry by building 3-D tooth model from 2-D radiographic and endoscopic images to be used for an automatic prescription system of computer-aided treatment procedure planning, and for the root canal preparation by an intelligent micro drilling machine with on-line monitoring. It covers the techniques specific for dental application in the radiographic images acquirement, image enhancement, image segmentation and feature recognition, distance measurement and calibration, merging 2D image into 3D mathematical model representation and display. Included also are the methods to form references for irregular teeth geometry and to do accurately measurement with self-calibration.

  11. Integrating 3D visualisation in landscape design and environmental planning

    Lange, E.; Hehl-Lange, S.

    2006-07-01

    Information is a key element in environmental decision making. In landscape and environmental planning, information can be presented in a number of ways, ranging from texts and statistics to realistic representations such as 3D visualisations. We assume that 3D visualisations of scenarios for landscape changes are a key element for informed decision making. In order to assess the role of 3D visualisation in the planning and decision making process, we have examined three case studies related to generating energy (i.e., hydro power, reclamation of a brown coal surface mine, and wind turbines). In the early 1990s when 3D visualisation technology was just becoming more widely available, the application was typically limited to large infrastructure projects that were often subject to an environmental impact assessment. At that time 3D visualisation was only used to show the results of the planning and decision making process. There are indications that this is now changing towards integrating visualisation already in the earliest planning steps. Such integration allows both planning experts and the public to engage on equal footing in the entire planning and decision making process.

  12. PLANNING AND CONTROL OF 3-D NANO-MANIPULATION

    Li Guangyong; Xi Ning; Wang Yuechao; Yu Mengmeng; Fung Wai-Keung

    2004-01-01

    The use of atomic force microscope (AFM) as a nanomanipulator has been evolving for various kinds of nano-manipulation tasks. Due to the bow effect of the piezo scanner of the AFM,the AFM space is different from the Cartesian space. Traditional nanomanipulation based on AFM is only a 2-D operation and does not consider the bow effect of the piezotube. In this paper, different 3-D nanomanipulation tasks using AFM such as nanolithography, pushing and cutting have been discussed.3-D path planning is performed directly in the AFM space and the 3-D paths are generated based on the 3-D topography information of the surface represented in the AFM space. This approach can avoid the mappings between the AFM space and Cartesian space in planning. By following the generated motion paths, the tip can either follow the topography of the surface or move across the surface by avoiding collision with bumps. Nanomanipulation using this method can be considered as the "true"3-D operations since the cantilever tip can be controlled to follow any desired 3-D trajectory within the range of AFM space. The experimental study shows the effectiveness of the planning and control scheme.

  13. A Hybrid 3D Path Planning Algorithm for UAVs

    Ortiz-Arroyo, Daniel

    2016-01-01

    This paper presents a hybrid method for path planning in 3D spaces. We propose an improvement to a near-optimal 2D off-line algorithm and a flexible normalized on-line fuzzy controller to find shortest paths. Our method, targeted to low altitude domains, is simple and efficient. Our preliminary resu...

  14. A Hybrid 3D Path Planning Method for UAVs

    Ortiz-Arroyo, Daniel

    2015-01-01

    This paper presents a hybrid method for path planning in 3D spaces. We propose an improvement to a near-optimal 2D off-line algorithm and a flexible normalized on-line fuzzy controller to find shortest paths. Our method, targeted to low altitude domains, is simple and efficient. Our preliminary resu...

  15. First impressions of 3D visual tools and dose volume histograms for plan evaluation

    Converting from 2D to 3D treatment planning offers numerous challenges. The practices that have evolved in the 2D environment may not be applicable when translated into the 3D environment. One such practice is the methods used to evaluate a plan. In 2D planning a plane by plane comparison method is generally practiced. This type of evaluation method would not be appropriate for plans produced by a 3D planning system. To this end 3D dose displays and Dose Volume Histograms (DVHs) have been developed to facilitate the evaluation of such plans. A survey was conducted to determine the impressions of Radiation Therapists as they used these tools for the first time. The survey involved comparing a number of plans for a small group of patients and selecting the best plan for each patient. Three evaluation methods were assessed. These included the traditional plane by plane, 3D dose display, and DVHs. Those surveyed found the DVH to be the easiest of the three methods to use, with the 3D display being the next easiest. Copyright (1999) Blackwell Science Pty Ltd

  16. Survey of Robot 3D Path Planning Algorithms

    Liang Yang

    2016-01-01

    Full Text Available Robot 3D (three-dimension path planning targets for finding an optimal and collision-free path in a 3D workspace while taking into account kinematic constraints (including geometric, physical, and temporal constraints. The purpose of path planning, unlike motion planning which must be taken into consideration of dynamics, is to find a kinematically optimal path with the least time as well as model the environment completely. We discuss the fundamentals of these most successful robot 3D path planning algorithms which have been developed in recent years and concentrate on universally applicable algorithms which can be implemented in aerial robots, ground robots, and underwater robots. This paper classifies all the methods into five categories based on their exploring mechanisms and proposes a category, called multifusion based algorithms. For all these algorithms, they are analyzed from a time efficiency and implementable area perspective. Furthermore a comprehensive applicable analysis for each kind of method is presented after considering their merits and weaknesses.

  17. 3D Image Modelling and Specific Treatments in Orthodontics Domain

    Dionysis Goularas

    2007-01-01

    Full Text Available In this article, we present a 3D specific dental plaster treatment system for orthodontics. From computer tomography scanner images, we propose first a 3D image modelling and reconstruction method of the Mandible and Maxillary based on an adaptive triangulation allowing management of contours meant for the complex topologies. Secondly, we present two specific treatment methods directly achieved on obtained 3D model allowing the automatic correction for the setting in occlusion of the Mandible and the Maxillary, and the teeth segmentation allowing more specific dental examinations. Finally, these specific treatments are presented via a client/server application with the aim of allowing a telediagnosis and treatment.

  18. VISIPLAN 3D ALARA planning and communication tool

    Human operations are required in nuclear installation, during maintenance, outage, repair and decommissioning. This leads to the exposure of the worker to radiation. It is clear that these operations must be performed according to the ALARA principle (to reduce the dose As Low As Reasonably Achievable). The person responsible for planning the job needs to evaluate different scenarios based on the exposure of the worker. This involves the manipulation of a lot of information specific to the work place such as the geometry, materials, radiological and technical boundary conditions to assess the dose. A lot of communication between the ALARA stakeholders is needed during this pre-job study. A communication that can be cumbersome and tedious when based on written documents and paper plans. The use of 3D calculation and simulation tools provide a solution to this problem. They provide an excellent means to make the above mentioned process more efficient and effective by calculating and visualising the environment and the associated radiological risk. The VISIPLAN 3D ALARA planning tool is developed and designed by SCK-CEN as a dose assessment tool enabling the user to calculate the dose in a 3D environment for work scenarios. This software is very successful in the ALARA field. At present 22 companies in Europe use the VISIPLAN software in the field of dose assessment in maintenance and decommissioning. Recent developments and applications are discussed

  19. Displacement of structures in the thorax from expiration to inspiration as estimated by computed tomography and a 3-D treatment planning system

    Purpose/Objective: The spread of image based three dimensional treatment planning and conformal radiotherapy have brought new attention to the problems of patient motion during treatment. Recent studies of the effects of breathing on the motion of internal structures have led to the suggestion that gated irradiation might improve the therapeutic benefits of conformal therapy. In the present work we investigate the displacement of tumor and other structures in the thorax with breathing in order to assess further the potential benefit of gating in the treatment of lung tumors. Materials and Methods: Thoracic CT scans were obtained for patients immediately after inspiration and after expiration. Tumor positions were assessed by computing the centers of the outlined volumes for both inspiration and expiration. Effects of breathing motion along the longitudinal direction were evaluated by using a three dimensional treatment planning system to measure the distances between scans where the top of the diaphragm was present. Displacement within the transverse direction was assessed by measuring the positions of the field skin markers, the aorta and the esophagus. Results: Movement of the centers of the tumor volumes as computed by reconstructed volumes was measured to be 0.7-1.2cm. The magnitude of this movement was greatest for tumors in the mid to lower region of the lung and was primarily in the direction of superior to inferior combined with anterior to posterior. Displacement of the diaphragm ranged 1-3 cm with breathing. Displacement of the aorta and esophagus was measured to be 0.2-1.5 cm. Movement of these structures was only analyzed transversely and showed displacement to the patients' left and posterior upon expiration. The magnitude did not appear to correlate with position relative to the diaphragm. Patients with less diaphragm movement also had smaller tidal volumes and conversely, patients with larger diaphragm displacement had greater tidal volumes

  20. SU-E-T-538: Lung SBRT Dosimetric Comparison of 3D Conformal and RapidArc Planning

    Purpose: Dose distributions of RapidArc Plan can be quite different from standard 3D conformal radiation therapy. SBRT plans can be optimized with high conformity or mimic the 3D conformal treatment planning with very high dose in the center of the tumor. This study quantifies the dosimetric differences among 3D conformal plan; flattened beam and FFF beam RapidArc Plans for lung SBRT. Methods: Five lung cancer patients treated with 3D non-coplanar SBRT were randomly selected. All the patients were CT scanned with 4DCT to determine the internal target volume. Abdominal compression was applied to minimize respiratory motion for SBRT patients. The prescription dose was 48 Gy in 4 fractions. The PTV coverage was optimized by two groups of objective function: one with high conformity, another mimicking 3D conformal dose distribution with high dose in the center of PTV. Optimization constraints were set to meet the criteria of the RTOG-0915 protocol. All VMAT plans were optimized with the RapidArc technique using four full arcs in Eclipse treatment planning system. The RapidArc SBRT plans with flattened 6MV beam and 6MV FFF beam were generated and dosimetric results were compared with the previous treated 3D non-coplanar plans. Results: All the RapidArc plans with flattened beam and FFF beam had similar results for the PTV and OARs. For the high conformity optimization group, The DVH of PTV exhibited a steep dose fall-off outside the PTV compared to the 3D non-coplanar plan. However, for the group mimicking the 3D conformal target dose distribution, although the PTV is very similar to the 3D conformal plan, the ITV coverage is better than 3D conformal plan. Conclusion: Due to excellent clinical experiences of 3D conformal SBRT treatment, the Rapid Arc optimization mimicking 3D conformal planning may be suggested for clinical use

  1. Bladder and rectum dose define 3D treatment planning for cervix cancer brachytherapy comparison of dose volume histograms for organ contour and organ wall contour

    Kim, Jong Won [Myongji Hospital, Gangneong (Korea, Republic of); Kim, Jong Won; Kim, Dae Hyun; Choi, Joon Yong [The Catholic Univ. of Korea College of Medicine, Seoul (Korea, Republic of); Choi, Joon Yong [Dongguk Univ. Medical Center, Seoul (Korea, Republic of); Won, Yeong Jin [Inje Univ. lsan Paik Hospital, Goyang (Korea, Republic of)

    2012-12-15

    To analyze the correlation between dose volume histograms(DVH) based on organ outer wall contour and organ wall delineation for bladder and rectum, and to compare the doses to these organs with the absorbed doses at the bladder and rectum. Individual CT based brachytherapy treatment planning was performed in 13 patients with cervical cancer as part of a prospective comparative trial. The external contours and the organ walls were delineated for the bladder and rectum in order to compute the corresponding dose volume histograms. The minimum dose in 0.1 cm{sup 3}, 1 cm{sup 3}, 2 cm{sup 3}, 5 cm{sup 3}, 10 cm{sup 3} volumes receiving the highest dose were compared with the absorbed dose at the rectum and bladder reference point. Results: The bladder and rectal doses derived from organ outer wall contour and computed for volumes of 2 cm{sup 3}, provided a good estimate for the doses computed for the organ wall contour only. This correspondence was no longer true when large volumes were considered. For clinical applications, when volumes smaller than 5 cm{sup 2} are considered, the dose.volume histograms computed from external organ contours for the bladder and rectum can be used instead of dose.volume histograms computed for the organ walls only. External organ contours are indeed easier to obtain. The dose at the ICRU rectum reference point provides a good estimate of the rectal dose computed for volumes smaller than 2 cm{sup 2} only for a midline position of the rectum. The ICRU bladder reference point provides a good estimate of the dose computed for the bladder wall only in cases of appropriate balloon position.

  2. Pediatric deformity treatment update, including 3D correction concepts%Pediatric deformity treatment update,including 3D correction concepts

    Randal R. Betz; Patrick J. Cahill; Joshua M. Pahys; Amer F. Samdani

    2011-01-01

    The purpose of this article is to highlight some of the new developments in the treatment of adolescent idiopathic scoliosis,including 3D correction of deformity,posterior and minimally invasive surgery,and fusionless strategies.

  3. Characterization of HDR Ir-192 source for 3D planning system

    Fonseca, Gabriel P.; Yoriyaz, Helio; Antunes, Paula C.G.; Siqueira, Paulo T.D., E-mail: gabriel.fonseca@usp.b, E-mail: hyoriyaz@ipen.b, E-mail: ptsiquei@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Rubo, Rodrigo [Universidade de Sao Paulo (HC/FMUSP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Servico de Radioterapia; Minamisawa, Renato A., E-mail: renato.minamisawa@psi.c [Paul Scherrer Institut (PSI), Villigen (Switzerland); Ferreira, Louise A. [Universidade Estadual de Maringa (UEM), PR (Brazil). Fac. de Medicina

    2011-07-01

    Brachytherapy treatment involves surgical or cavitary insertion of radioactive sources for diseases treatments, such as: lung, gynecologic or prostate cancer. This technique has great ability to administer high doses to the tumor, with adjacent normal tissue preservation equal or better than external beam radiation therapy. Several innovations have been incorporated in this treatment technique, such as, 3D treatment planning system and computer guided sources. In detriment to scientific advances there are no protocols that relate dose with tumor volume, organs or A point, established by ICRU38 and used to prescribe dose in treatment planning system. Several international studies, like as EMBRACE, the multicentre international study, has been trying to correlate the dose volume using 3D planning systems and medical images, as those obtained by CT or MRI, to establish treatment protocols. With the objective of analyzing the 3D dose distribution, a micro Selectron-HDR remote afterloading device for high dose-rate (HDR) was characterized in the present work. Through the data provided by the manufacturer the source was simulated, using the MCNP5 code to calculate American Association of Physicists in Medicine Task Group No. 43 report (AAPM TG43) specified parameters. The simulations have shown great agreement when compared to the ONCENTRA planning system results and those provided by literature. The micro Selectron-HDR remote afterloading device will be utilized to simulate 3D dose distribution through CT images processed by an auxiliary software which process DICOM images. (author)

  4. A linguistic geometry for 3D strategic planning

    Stilman, Boris

    1995-01-01

    This paper is a new step in the development and application of the Linguistic Geometry. This formal theory is intended to discover the inner properties of human expert heuristics, which have been successful in a certain class of complex control systems, and apply them to different systems. In this paper we investigate heuristics extracted in the form of hierarchical networks of planning paths of autonomous agents. Employing Linguistic Geometry tools the dynamic hierarchy of networks is represented as a hierarchy of formal attribute languages. The main ideas of this methodology are shown in this paper on the new pilot example of the solution of the extremely complex 3D optimization problem of strategic planning for the space combat of autonomous vehicles. This example demonstrates deep and highly selective search in comparison with conventional search algorithms.

  5. Dose Verification of Stereotactic Radiosurgery Treatment for Trigeminal Neuralgia with Presage 3D Dosimetry System

    Wang, Z; Thomas, A; Newton, J; Ibbott, G; Deasy, J; Oldham, M, E-mail: Zhiheng.wang@duke.ed

    2010-11-01

    Achieving adequate verification and quality-assurance (QA) for radiosurgery treatment of trigeminal-neuralgia (TGN) is particularly challenging because of the combination of very small fields, very high doses, and complex irradiation geometries (multiple gantry and couch combinations). TGN treatments have extreme requirements for dosimetry tools and QA techniques, to ensure adequate verification. In this work we evaluate the potential of Presage/Optical-CT dosimetry system as a tool for the verification of TGN distributions in high-resolution and in 3D. A TGN treatment was planned and delivered to a Presage 3D dosimeter positioned inside the Radiological-Physics-Center (RPC) head and neck IMRT credentialing phantom. A 6-arc treatment plan was created using the iPlan system, and a maximum dose of 80Gy was delivered with a Varian Trilogy machine. The delivered dose to Presage was determined by optical-CT scanning using the Duke Large field-of-view Optical-CT Scanner (DLOS) in 3D, with isotropic resolution of 0.7mm{sup 3}. DLOS scanning and reconstruction took about 20minutes. 3D dose comparisons were made with the planning system. Good agreement was observed between the planned and measured 3D dose distributions, and this work provides strong support for the viability of Presage/Optical-CT as a highly useful new approach for verification of this complex technique.

  6. Dose Verification of Stereotactic Radiosurgery Treatment for Trigeminal Neuralgia with Presage 3D Dosimetry System

    Wang, Z.; Thomas, A.; Newton, J.; Ibbott, G.; Deasy, J.; Oldham, M.

    2010-11-01

    Achieving adequate verification and quality-assurance (QA) for radiosurgery treatment of trigeminal-neuralgia (TGN) is particularly challenging because of the combination of very small fields, very high doses, and complex irradiation geometries (multiple gantry and couch combinations). TGN treatments have extreme requirements for dosimetry tools and QA techniques, to ensure adequate verification. In this work we evaluate the potential of Presage/Optical-CT dosimetry system as a tool for the verification of TGN distributions in high-resolution and in 3D. A TGN treatment was planned and delivered to a Presage 3D dosimeter positioned inside the Radiological-Physics-Center (RPC) head and neck IMRT credentialing phantom. A 6-arc treatment plan was created using the iPlan system, and a maximum dose of 80Gy was delivered with a Varian Trilogy machine. The delivered dose to Presage was determined by optical-CT scanning using the Duke Large field-of-view Optical-CT Scanner (DLOS) in 3D, with isotropic resolution of 0.7mm3. DLOS scanning and reconstruction took about 20minutes. 3D dose comparisons were made with the planning system. Good agreement was observed between the planned and measured 3D dose distributions, and this work provides strong support for the viability of Presage/Optical-CT as a highly useful new approach for verification of this complex technique.

  7. Dose Verification of Stereotactic Radiosurgery Treatment for Trigeminal Neuralgia with Presage 3D Dosimetry System

    Achieving adequate verification and quality-assurance (QA) for radiosurgery treatment of trigeminal-neuralgia (TGN) is particularly challenging because of the combination of very small fields, very high doses, and complex irradiation geometries (multiple gantry and couch combinations). TGN treatments have extreme requirements for dosimetry tools and QA techniques, to ensure adequate verification. In this work we evaluate the potential of Presage/Optical-CT dosimetry system as a tool for the verification of TGN distributions in high-resolution and in 3D. A TGN treatment was planned and delivered to a Presage 3D dosimeter positioned inside the Radiological-Physics-Center (RPC) head and neck IMRT credentialing phantom. A 6-arc treatment plan was created using the iPlan system, and a maximum dose of 80Gy was delivered with a Varian Trilogy machine. The delivered dose to Presage was determined by optical-CT scanning using the Duke Large field-of-view Optical-CT Scanner (DLOS) in 3D, with isotropic resolution of 0.7mm3. DLOS scanning and reconstruction took about 20minutes. 3D dose comparisons were made with the planning system. Good agreement was observed between the planned and measured 3D dose distributions, and this work provides strong support for the viability of Presage/Optical-CT as a highly useful new approach for verification of this complex technique.

  8. Dosimetric analysis of 3D image-guided HDR brachytherapy planning for the treatment of cervical cancer: is point A-based dose prescription still valid in image-guided brachytherapy?

    Kim, Hayeon; Beriwal, Sushil; Houser, Chris; Huq, M Saiful

    2011-01-01

    The purpose of this study was to analyze the dosimetric outcome of 3D image-guided high-dose-rate (HDR) brachytherapy planning for cervical cancer treatment and compare dose coverage of high-risk clinical target volume (HRCTV) to traditional Point A dose. Thirty-two patients with stage IA2-IIIB cervical cancer were treated using computed tomography/magnetic resonance imaging-based image-guided HDR brachytherapy (IGBT). Brachytherapy dose prescription was 5.0-6.0 Gy per fraction for a total 5 fractions. The HRCTV and organs at risk (OARs) were delineated following the GYN GEC/ESTRO guidelines. Total doses for HRCTV, OARs, Point A, and Point T from external beam radiotherapy and brachytherapy were summated and normalized to a biologically equivalent dose of 2 Gy per fraction (EQD2). The total planned D90 for HRCTV was 80-85 Gy, whereas the dose to 2 mL of bladder, rectum, and sigmoid was limited to 85 Gy, 75 Gy, and 75 Gy, respectively. The mean D90 and its standard deviation for HRCTV was 83.2 ± 4.3 Gy. This is significantly higher (p IGBT in HDR cervical cancer treatment needs advanced concept of evaluation in dosimetry with clinical outcome data about whether this approach improves local control and/or decreases toxicities. PMID:20488690

  9. VAM3D-CG configuration management plan

    The VAM3D-CG computer code has been licensed for use at Hanford, from HydroGeologic, Inc., of Herndon, VA. Version 2.4b has been installed on the 3200GWW workstations, and is currently under configuration management. The purpose of this report is to describe the installation and configuration management of VAM3D-CG on the Hanford Computer System. VAM3D-CG is written in standard FORTRAN F77

  10. Real-time 3D dose calculation and display: a tool for plan optimization

    Purpose: Both human and computer optimization of treatment plans have advantages; humans are much better at global pattern recognition, and computers are much better at detailed calculations. A major impediment to human optimization of treatment plans by manipulation of beam parameters is the long time required for feedback to the operator on the effectiveness of a change in beam parameters. Our goal was to create a real-time dose calculation and display system that provides the planner with immediate (fraction of a second) feedback with displays of three-dimensional (3D) isodose surfaces, digitally reconstructed radiographs (DRRs), dose-volume histograms, and/or a figure of merit (FOM) (i.e., a single value plan score function). This will allow the experienced treatment planner to optimize a plan by adjusting beam parameters based on a direct indication of plan effectiveness, the FOM value, and to use 3D display of target, critical organs, DRRs, and isodose contours to guide changes aimed at improving the FOM value. Methods and Materials: We use computer platforms that contain easily utilized parallel processors and very tight coupling between calculation and display. We ported code running on a network of two workstations and an array of transputers to a single multiprocessor workstation. Our current high-performance graphics workstation contains four 150-MHz processors that can be readily used in a shared-memory multithreaded calculation. Results: When a 10 x 10-cm beam is moved, using an 8-mm dose grid, the full 3D dose matrix is recalculated using a Bentley-Milan-type dose calculation algorithm, and the 3D dose surface display is then updated, all in < 0.1 s. A 64 x 64-pixel DRR calculation can be performed in < 0.1 s. Other features, such as automated aperture calculation, are still required to make real-time feedback practical for clinical use. Conclusion: We demonstrate that real-time plan optimization using general purpose multiprocessor workstations is a

  11. 3D-image-guided high-dose-rate intracavitary brachytherapy for salvage treatment of locally persistent nasopharyngeal carcinoma

    Ren, Yu-Feng; Cao, Xin-Ping; Xu, Jia; Ye, Wei-Jun; Gao, Yuan-Hong; Teh, Bin S.; Wen, Bi-Xiu

    2013-01-01

    Background To evaluate the therapeutic benefit of 3D-image-guided high-dose-rate intracavitary brachytherapy (3D-image-guided HDR-BT) used as a salvage treatment of intensity modulated radiation therapy (IMRT) in patients with locally persistent nasopharyngeal carcinoma (NPC). Methods Thirty-two patients with locally persistent NPC after full dose of IMRT were evaluated retrospectively. 3D-image-guided HDR-BT treatment plan was performed on a 3D treatment planning system (PLATO BPS 14.2). The...

  12. A comprehensive EPID-based 3D validation technique for TrueBeam-delivered VMAT plans

    Purpose: To develop and validate a pre-treatment EPI dosimetry method on Varian TrueBeam linacs using continuous imaging, with reconstruction in a 3D cylindrical phantom geometry. Methods: Delivery of VMAT plans with continuous imaging is currently possible only in Research Mode on TrueBeam linacs, with images acquired in a proprietary format. An earlier technique was adapted to take advantage of technical improvements in EPID delivery, and was tested under various acquisition conditions. The dosimetry of VMAT plans was evaluated at isocentre and within patient volumes that had been transferred to the virtual phantom. Results: Approximately 60 portal image projections per arc were found to be adequate for 3D reconstruction in phantom volumes of 28cm diameter. Twelve prostate, CNS and Head and Neck deliveries were evaluated in Research mode relative to the corresponding Eclipse (v.10) treatment plans, and to measurements on an ArcCheck device in Treatment mode. Mean dose differences at isocentre were within 2% for the three-way comparison, and in PTV volumes were within 1% (s.d. 1%). However, some discrepancies were observed in ArcCheck results that may be related to the small dimensions of certain VMAT apertures. Conclusions: EPI dosimetry with 3D dose reconstruction is an accurate, comprehensive and efficient pre-treatment validation technique for VMAT delivery. Although currently limited to a research mode on TrueBeam, it has the potential to be implemented for clinical use.

  13. A comprehensive EPID-based 3D validation technique for TrueBeam-delivered VMAT plans

    Ansbacher, W.; Gagne, I. M.; Swift, C.-L.

    2014-03-01

    Purpose: To develop and validate a pre-treatment EPI dosimetry method on Varian TrueBeam linacs using continuous imaging, with reconstruction in a 3D cylindrical phantom geometry. Methods: Delivery of VMAT plans with continuous imaging is currently possible only in Research Mode on TrueBeam linacs, with images acquired in a proprietary format. An earlier technique was adapted to take advantage of technical improvements in EPID delivery, and was tested under various acquisition conditions. The dosimetry of VMAT plans was evaluated at isocentre and within patient volumes that had been transferred to the virtual phantom. Results: Approximately 60 portal image projections per arc were found to be adequate for 3D reconstruction in phantom volumes of 28cm diameter. Twelve prostate, CNS and Head & Neck deliveries were evaluated in Research mode relative to the corresponding Eclipse (v.10) treatment plans, and to measurements on an ArcCheck device in Treatment mode. Mean dose differences at isocentre were within 2% for the three-way comparison, and in PTV volumes were within 1% (s.d. 1%). However, some discrepancies were observed in ArcCheck results that may be related to the small dimensions of certain VMAT apertures. Conclusions: EPI dosimetry with 3D dose reconstruction is an accurate, comprehensive and efficient pre-treatment validation technique for VMAT delivery. Although currently limited to a research mode on TrueBeam, it has the potential to be implemented for clinical use.

  14. Treatment planning systems

    All aspects of treatment planning in radiotherapy are discussed in detail. Included are, among others, machine data and their acquisition, photon dose calculations and tests thereof, criteria of acceptability, sources of uncertainties, from 2D to 3D and from 3D to IMRT, dosimetric measurements for RTP validation, frequency of QA tests and suggested tolerances for TPS, time and staff requirements, model based segmentation, multi-dimensional radiotherapy (MDCRT), and biological IMRT process. (P.A.)

  15. 3D freehand ultrasound for medical assistance in diagnosis and treatment of breast cancer: preliminary results

    Torres, Fabian; Fanti, Zian; Arambula Cosío, F.

    2013-11-01

    Image-guided interventions allow the physician to have a better planning and visualization of a procedure. 3D freehand ultrasound is a non-invasive and low-cost imaging tool that can be used to assist medical procedures. This tool can be used in the diagnosis and treatment of breast cancer. There are common medical practices that involve large needles to obtain an accurate diagnosis and treatment of breast cancer. In this study we propose the use of 3D freehand ultrasound for planning and guiding such procedures as core needle biopsy and radiofrequency ablation. The proposed system will help the physician to identify the lesion area, using image-processing techniques in the 3D freehand ultrasound images, and guide the needle to this area using the information of position and orientation of the surgical tools. We think that this system can upgrade the accuracy and efficiency of these procedures.

  16. Development of a High Resolution 3D Infant Stomach Model for Surgical Planning

    Chaudry, Qaiser; Raza, S. Hussain; Lee, Jeonggyu; Xu, Yan; Wulkan, Mark; Wang, May D.

    Medical surgical procedures have not changed much during the past century due to the lack of accurate low-cost workbench for testing any new improvement. The increasingly cheaper and powerful computer technologies have made computer-based surgery planning and training feasible. In our work, we have developed an accurate 3D stomach model, which aims to improve the surgical procedure that treats the infant pediatric and neonatal gastro-esophageal reflux disease (GERD). We generate the 3-D infant stomach model based on in vivo computer tomography (CT) scans of an infant. CT is a widely used clinical imaging modality that is cheap, but with low spatial resolution. To improve the model accuracy, we use the high resolution Visible Human Project (VHP) in model building. Next, we add soft muscle material properties to make the 3D model deformable. Then we use virtual reality techniques such as haptic devices to make the 3D stomach model deform upon touching force. This accurate 3D stomach model provides a workbench for testing new GERD treatment surgical procedures. It has the potential to reduce or eliminate the extensive cost associated with animal testing when improving any surgical procedure, and ultimately, to reduce the risk associated with infant GERD surgery.

  17. I-125 ROPES eye plaque dosimetry: Validation of a commercial 3D ophthalmic brachytherapy treatment planning system and independent dose calculation software with GafChromic{sup ®} EBT3 films

    Poder, Joel; Corde, Stéphanie [Department of Radiation Oncology, Prince of Wales Hospital, Randwick, NSW 2031 (Australia)

    2013-12-15

    Purpose: The purpose of this study was to measure the dose distributions for different Radiation Oncology Physics and Engineering Services, Australia (ROPES) type eye plaques loaded with I-125 (model 6711) seeds using GafChromic{sup ®} EBT3 films, in order to verify the dose distributions in the Plaque Simulator™ (PS) ophthalmic 3D treatment planning system. The brachytherapy module of RADCALC{sup ®} was used to independently check the dose distributions calculated by PS. Correction factors were derived from the measured data to be used in PS to account for the effect of the stainless steel ROPES plaque backing on the 3D dose distribution.Methods: Using GafChromic{sup ®} EBT3 films inserted in a specially designed Solid Water™ eye ball phantom, dose distributions were measured three-dimensionally both along and perpendicular to I-125 (model 6711) loaded ROPES eye plaque's central axis (CAX) with 2 mm depth increments. Each measurement was performed in full scatter conditions both with and without the stainless steel plaque backing attached to the eye plaque, to assess its effect on the dose distributions. Results were compared to the dose distributions calculated by Plaque Simulator™ and checked independently with RADCALC{sup ®}.Results: The EBT3 film measurements without the stainless steel backing were found to agree with PS and RADCALC{sup ®} to within 2% and 4%, respectively, on the plaque CAX. Also, RADCALC{sup ®} was found to agree with PS to within 2%. The CAX depth doses measured using EBT3 film with the stainless steel backing were observed to result in a 4% decrease relative to when the backing was not present. Within experimental uncertainty, the 4% decrease was found to be constant with depth and independent of plaque size. Using a constant dose correction factor of T= 0.96 in PS, where the calculated dose for the full water scattering medium is reduced by 4% in every voxel in the dose grid, the effect of the plaque backing was

  18. I-125 ROPES eye plaque dosimetry: Validation of a commercial 3D ophthalmic brachytherapy treatment planning system and independent dose calculation software with GafChromic® EBT3 films

    Purpose: The purpose of this study was to measure the dose distributions for different Radiation Oncology Physics and Engineering Services, Australia (ROPES) type eye plaques loaded with I-125 (model 6711) seeds using GafChromic® EBT3 films, in order to verify the dose distributions in the Plaque Simulator™ (PS) ophthalmic 3D treatment planning system. The brachytherapy module of RADCALC® was used to independently check the dose distributions calculated by PS. Correction factors were derived from the measured data to be used in PS to account for the effect of the stainless steel ROPES plaque backing on the 3D dose distribution.Methods: Using GafChromic® EBT3 films inserted in a specially designed Solid Water™ eye ball phantom, dose distributions were measured three-dimensionally both along and perpendicular to I-125 (model 6711) loaded ROPES eye plaque's central axis (CAX) with 2 mm depth increments. Each measurement was performed in full scatter conditions both with and without the stainless steel plaque backing attached to the eye plaque, to assess its effect on the dose distributions. Results were compared to the dose distributions calculated by Plaque Simulator™ and checked independently with RADCALC®.Results: The EBT3 film measurements without the stainless steel backing were found to agree with PS and RADCALC® to within 2% and 4%, respectively, on the plaque CAX. Also, RADCALC® was found to agree with PS to within 2%. The CAX depth doses measured using EBT3 film with the stainless steel backing were observed to result in a 4% decrease relative to when the backing was not present. Within experimental uncertainty, the 4% decrease was found to be constant with depth and independent of plaque size. Using a constant dose correction factor of T= 0.96 in PS, where the calculated dose for the full water scattering medium is reduced by 4% in every voxel in the dose grid, the effect of the plaque backing was accurately modeled in the planning system. Off

  19. 'Optimized' 3-D planning by simple means. An example

    Aim: A treatment technique favorable for linacs with asymmetric jaws, which combines cranio-caudal matching fields with fields enclosing the whole target volume, is investigated with respect to field matching and sparing of normal tissue and organs at risk. Patient and methods: For a pelvic target volume rapidly varying in cranio-caudal direction a 5-field technique was planned with individually weighted and blocked fields. Three fields adjoining in cranio-caudal direction were completed by 2 fields enclosing the whole target volume. The matching line was measured and calculated with helax TMS copyright. Furthermore, a 4-field box and opposing fields were planned. The dose-volume histograms for target, bladder, intestine and soft tissue were exported. Normal tissue complication probability and tumor control probability, respectively, were calculated for all techniques. Results: In the region of the matching line the summation of the measured normalized curves resulted in relative dose maxima of 6.0% (caudal) and 4.5% (cranial), respectively. For fields enclosing the whole target volume the dose maxima in the region of the matching line decreased to 2.0% (caudal) and 1.8% (cranial), respectively. For the dose profiles calculated with Helax TMS copyright no overdose was found. The 5-field technique with adjoining fields results in a better sparing of the organs at risk compared to the other techniques, wheres the tumor control remains the same. Conclusions: In specific cases a technique with cranio-caudal adjoining fields can be recommended with respect to sparing of normal tissue and organs at risk. (orig.)

  20. Path planning for complex 3D multilevel environments

    Leonel DEUSDADO; Fernandes, António Ramires; Belo, Orlando

    2010-01-01

    The continuous development of graphics hardware is contributing to the creation of 3D virtual worlds with high level of detail, from models of large urban areas, to complete infrastructures, such as residential buildings, stadiums, industrial settings or archaeological sites, to name just a few. Adding virtual humans or avatars adds an extra touch to the visualization providing an enhanced perception of the spaces, namely adding a...

  1. 3D-Printing of Arteriovenous Malformations for Radiosurgical Treatment: Pushing Anatomy Understanding to Real Boundaries.

    Conti, Alfredo; Pontoriero, Antonio; Iatì, Giuseppe; Marino, Daniele; La Torre, Domenico; Vinci, Sergio; Germanò, Antonino; Pergolizzi, Stefano; Tomasello, Francesco

    2016-01-01

    Radiosurgery of arteriovenous malformations (AVMs) is a challenging procedure. Accuracy of target volume contouring is one major issue to achieve AVM obliteration while avoiding disastrous complications due to suboptimal treatment. We describe a technique to improve the understanding of the complex AVM angioarchitecture by 3D prototyping of individual lesions. Arteriovenous malformations of ten patients were prototyped by 3D printing using 3D rotational angiography (3DRA) as a template. A target volume was obtained using the 3DRA; a second volume was obtained, without awareness of the first volume, using 3DRA and the 3D-printed model. The two volumes were superimposed and the conjoint and disjoint volumes were measured. We also calculated the time needed to perform contouring and assessed the confidence of the surgeons in the definition of the target volumes using a six-point scale. The time required for the contouring of the target lesion was shorter when the surgeons used the 3D-printed model of the AVM (p=0.001). The average volume contoured without the 3D model was 5.6 ± 3 mL whereas it was 5.2 ± 2.9 mL with the 3D-printed model (p=0.003). The 3D prototypes proved to be spatially reliable. Surgeons were absolutely confident or very confident in all cases that the volume contoured using the 3D-printed model was plausible and corresponded to the real boundaries of the lesion. The total cost for each case was 50 euros whereas the cost of the 3D printer was 1600 euros. 3D prototyping of AVMs is a simple, affordable, and spatially reliable procedure that can be beneficial for radiosurgery treatment planning. According to our preliminary data, individual prototyping of the brain circulation provides an intuitive comprehension of the 3D anatomy of the lesion that can be rapidly and reliably translated into the target volume. PMID:27335707

  2. Preparing diagnostic 3D images for image registration with planning CT images

    Purpose: Pre-radiotherapy (pre-RT) tomographic images acquired for diagnostic purposes often contain important tumor and/or normal tissue information which is poorly defined or absent in planning CT images. Our two years of clinical experience has shown that computer-assisted 3D registration of pre-RT images with planning CT images often plays an indispensable role in accurate treatment volume definition. Often the only available format of the diagnostic images is film from which the original 3D digital data must be reconstructed. In addition, any digital data, whether reconstructed or not, must be put into a form suitable for incorporation into the treatment planning system. The purpose of this investigation was to identify all problems that must be overcome before this data is suitable for clinical use. Materials and Methods: In the past two years we have 3D-reconstructed 300 diagnostic images from film and digital sources. As a problem was discovered we built a software tool to correct it. In time we collected a large set of such tools and found that they must be applied in a specific order to achieve the correct reconstruction. Finally, a toolkit (ediScan) was built that made all these tools available in the proper manner via a pleasant yet efficient mouse-based user interface. Results: Problems we discovered included different magnifications, shifted display centers, non-parallel image planes, image planes not perpendicular to the long axis of the table-top (shearing), irregularly spaced scans, non contiguous scan volumes, multiple slices per film, different orientations for slice axes (e.g. left-right reversal), slices printed at window settings corresponding to tissues of interest for diagnostic purposes, and printing artifacts. We have learned that the specific steps to correct these problems, in order of application, are: Also, we found that fast feedback and large image capacity (at least 2000 x 2000 12-bit pixels) are essential for practical application

  3. Modification of a 3D-planning system for use with a multileaf collimator

    Recently, the Philips SL25 linear accelerator of the Radiotherapy Department at the University Hospital of Gent was retro-fitted with a multileaf collimator (MLC). To allow treatment planning with the MLC, the currently use GRATISTM 3D-planning system (developed by G. Sherouse) needed some adaptations, using the C source code. The virtual Simulator section was extended so that the leaves are graphically set in the Beams Eye View. The leaves can be set manually or automatically, based on a previously defined margin around the target. Once the leaves are set, a data file is created for each beam, containing the leaf settings. This file is finally transferred to the MLC computer over the network or by disk. The entire process does not require any manual transfer of leaf settings, not only adding a time-saving but also an error preventing factor to the GRATISTM 3D-planning system. Measurements to verify the accuracy of the adaptations to the planning system are addressed

  4. Modification of a 3D-planning system for use with a multileaf collimator

    Van Duyse, B. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; Colle, C.; De Wagter, C.; De Neve, W.

    1995-12-01

    Recently, the Philips SL25 linear accelerator of the Radiotherapy Department at the University Hospital of Gent was retro-fitted with a multileaf collimator (MLC). To allow treatment planning with the MLC, the currently use GRATISTM 3D-planning system (developed by G. Sherouse) needed some adaptations, using the C source code. The virtual Simulator section was extended so that the leaves are graphically set in the Beams Eye View. The leaves can be set manually or automatically, based on a previously defined margin around the target. Once the leaves are set, a data file is created for each beam, containing the leaf settings. This file is finally transferred to the MLC computer over the network or by disk. The entire process does not require any manual transfer of leaf settings, not only adding a time-saving but also an error preventing factor to the GRATISTM 3D-planning system. Measurements to verify the accuracy of the adaptations to the planning system are addressed.

  5. Experiment for Integrating Dutch 3d Spatial Planning and Bim for Checking Building Permits

    van Berlo, L.; Dijkmans, T.; Stoter, J.

    2013-09-01

    This paper presents a research project in The Netherlands in which several SMEs collaborated to create a 3D model of the National spatial planning information. This 2D information system described in the IMRO data standard holds implicit 3D information that can be used to generate an explicit 3D model. The project realized a proof of concept to generate a 3D spatial planning model. The team used the model to integrate it with several 3D Building Information Models (BIMs) described in the open data standard Industry Foundation Classes (IFC). Goal of the project was (1) to generate a 3D BIM model from spatial planning information to be used by the architect during the early design phase, and (2) allow 3D checking of building permits. The team used several technologies like CityGML, BIM clash detection and GeoBIM to explore the potential of this innovation. Within the project a showcase was created with a part of the spatial plan from the city of The Hague. Several BIM models were integrated in the 3D spatial plan of this area. A workflow has been described that demonstrates the benefits of collaboration between the spatial domain and the AEC industry in 3D. The research results in a showcase with conclusions and considerations for both national and international practice.

  6. Variation of treatment planning parameters (D90 HR-CTV, D2cc for OAR) for cervical cancer tandem ring brachytherapy in a multicentre setting: Comparison of standard planning and 3D image guided optimisation based on a joint protocol for dose-volume constraints

    Purpose: To perform a qualitative and quantitative comparison of different treatment planning methods used in different centres for MRI-based brachytherapy (BT) of cervical cancer. Materials and methods: Two representative patients with advanced cervical cancer (1 'limited volume case'; 1 'extensive volume case') were planned for brachytherapy (BT) with a tandem-ring applicator by six different centres. During a workshop all centres produced an institutional standard plan and an MRI-based adaptive treatment plan for each case. Optimisation was based on the fractionation schedule (HDR, PDR) and method according to the institutional protocol. Results: The loading pattern, dwell times, shape of the point A isodose varied considerably between institutional standard plans, as did dose-volume parameters for high risk CTV (HR-CTV) and also for the D2cc for OAR, violating the dose-volume constraints in many situations. During optimisation, the centres stayed as close as possible to the standard loading pattern and dwell times. The dose distributions and dose-volume parameters between the plans from the different centres became much more comparable after optimisation. The prescribed dose to the HR-CTV could be achieved in the limited volume case by all centres, in the extensive case only if additional needles were applied. Conclusion: Treatment planning for gynaecologic brachytherapy based on different traditions shows less variation in regard to target coverage and OAR dose, when 3D image-based optimisation is performed with a uniform prescription protocol.

  7. VMAT planning and verification of delivery and dosimetry using the 3-D delta4 dosimetry system

    VMAT can provide advantages over IMRT and 3DCRT, by reducing treatment delivery time and total number of monitor units, as well as improving dose conformity. VMAT plans produced using Oncentra MasterPlan (Nucletron) and delivered with an Elekta Synergy linac were evaluated. Verification dosimetry measurements were earned out as part of a pre-clinical commissioning programme, using a Semiflex ionisation chamber in a CIRS humanoid pelvis phantom, and using a ScandiDos Delta system. The Delta incorporates two orthogonal 2D arrays of semiconductor diodes, enabling assessment of delivered dose distributions in 3D. These techniques have been previously verified during an on-going development of IMRT pre-treatment verification dosimetry that has evolved from film to the Delta arrays

  8. Interaction model for 3D cutting in maxillofacial surgery planning

    Neumann, Patrick; Siebert, Dirk; Schulz, Armin; Faulkner, Gabriele; Krauss, Manfred; Tolxdorff, Thomas

    1999-05-01

    Our main research work is the realization of a completely computer-based maxillofacial surgery planning system. An important step toward this goal is the availability of virtual tools for the surgeon to interactively define bone segments from skull and jaw bones. The easy-to-handle user interface employs visual and force-feedback devices to define subvolumes of a patient's volume dataset. The defined subvolumes together with their spatial arrangements lead to an operation plan. We have evaluated modern low-cost, force- feedback devices with regard to their ability to emulate the surgeon's working procedure.

  9. Simulation of 3D-CRT treatment for lung cancer

    In radiotherapy treatment for lung cancer, occurs doses deposition in healthy organs. During the treatment planning are calculated some doses due to photons. This dose deposition in healthy organs could induce to the appearance of new cancers foci. The aim of this study was to analyze the equivalent doses in healthy organs of a patient treated by radiotherapy for lung cancer. In order to calculate the doses, was done a computer simulation of radiotherapy treatment for lung cancer, adopting database of the treatment performed by INCA. To perform the simulation was used several tools, among them, the radiation transport code MCNPX, in which was shaped the radiotherapy room and the head from the linear accelerator Varian 2300 C / D, the patient was simulated by Voxel male phantom in Rex,and the treatment protocol adopted considers a beam with energy of 6 MV focusing on three gantry tilt angles (0 deg, 180 deg and 45 deg). In addition, there was variation in the opening of the radiation field according to the angle of inclination. The results of this study point to the organs close to the irradiated area are predominantly affected by the dose due to photons, affecting organs from different body systems, such as esophagus, heart, thymus, spine and lymph nodes. The calculated values demonstrating that the angle of 0 deg was the most responsible for the deposit of unwanted dose. The results showed that the simulations in this paper is developed in accordance with the planning data described in different studies and literature. (author)

  10. Simulation of 3D-CRT treatment for lung cancer

    Thalhofer, Jardel L.; Silva, Ademir X. da; Junior, Juraci R.P., E-mail: jardellt@yahoo.com.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil); Rebello, Wilson F., E-mail: rebello@ime.eb.br [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear; Correa, Samanda C.A., E-mail: samandacristine@uezo.rj.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Souza, Edmilson M., E-mail: emonteiro@nuclear.ufrj.br [Centro Universitario da Zona Oeste (UEZO), Rio de Janeiro, RJ (Brazil). Colegiado de Comutacao e Matematica; Batista, Delano V.S., E-mail: delano@inca.gov.br [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    In radiotherapy treatment for lung cancer, occurs doses deposition in healthy organs. During the treatment planning are calculated some doses due to photons. This dose deposition in healthy organs could induce to the appearance of new cancers foci. The aim of this study was to analyze the equivalent doses in healthy organs of a patient treated by radiotherapy for lung cancer. In order to calculate the doses, was done a computer simulation of radiotherapy treatment for lung cancer, adopting database of the treatment performed by INCA. To perform the simulation was used several tools, among them, the radiation transport code MCNPX, in which was shaped the radiotherapy room and the head from the linear accelerator Varian 2300 C / D, the patient was simulated by Voxel male phantom in Rex,and the treatment protocol adopted considers a beam with energy of 6 MV focusing on three gantry tilt angles (0 deg, 180 deg and 45 deg). In addition, there was variation in the opening of the radiation field according to the angle of inclination. The results of this study point to the organs close to the irradiated area are predominantly affected by the dose due to photons, affecting organs from different body systems, such as esophagus, heart, thymus, spine and lymph nodes. The calculated values demonstrating that the angle of 0 deg was the most responsible for the deposit of unwanted dose. The results showed that the simulations in this paper is developed in accordance with the planning data described in different studies and literature. (author)

  11. Domestic comparison of radiation treatment techniques for breast cancer: 3D-CRT, IMRT and VMAT

    The purpose of this study is to compare method in the treatment of breast cancer using dose index. And, it is to find the optimized treatment technique to the patient. The phantom filled with tissue-equivalent material were used simulation and treatment as techniques of 3D-CRT, IMRT, VMAT was planned using Eclipse v10. By using HI(homogeneity index), CI(Conformity index), OE (Organ equivalent dose), EAR(Excess Absolute Risk), were assessed for each treatment plans. HI and CI of 3D-CRT, IMRT, VMAT were calculated 16.89, 11.21, 9.55 and 0.59, 0.61, 0.83. The organ average doses of Lt lung, Rt lung, liver, heart, esophagus, cord, Lt breast, trachea and stomach were 0.01 ∼ 2.02 Gy, 0.36 ∼ 5.01 Gy, 0.25 ∼ 2.49 Gy, 0.14 ∼ 6.92 Gy, 0.03 ∼ 2.02 Gy, 0.01 ∼ 1.06 Gy, 0.25 ∼ 6.08 Gy, 0.08 ∼ 0.59 Gy, 0.01 ∼ 1.34 Gy, respectively. The OED, EAR of the IMRT and VMAT show higher than 3D-CRT. As the result of this study, we could confirm being higher dose index(HI, CI) in IMRT and VMAT than 3D-CRT, but doses of around normal organs was higher IMRT, VMAT than 3D-CRT

  12. Domestic comparison of radiation treatment techniques for breast cancer: 3D-CRT, IMRT and VMAT

    Lee, Bo Ram; Yoon, Myong Geun [Dept. of Bio-convergence Engineering, College of Health Science, Korea University, Seoul (Korea, Republic of); Lee, Sun Young [Dept. of Radiation Oncology, Yusung Sun Medical Center, Daejeon (Korea, Republic of)

    2013-09-15

    The purpose of this study is to compare method in the treatment of breast cancer using dose index. And, it is to find the optimized treatment technique to the patient. The phantom filled with tissue-equivalent material were used simulation and treatment as techniques of 3D-CRT, IMRT, VMAT was planned using Eclipse v10. By using HI(homogeneity index), CI(Conformity index), OE (Organ equivalent dose), EAR(Excess Absolute Risk), were assessed for each treatment plans. HI and CI of 3D-CRT, IMRT, VMAT were calculated 16.89, 11.21, 9.55 and 0.59, 0.61, 0.83. The organ average doses of Lt lung, Rt lung, liver, heart, esophagus, cord, Lt breast, trachea and stomach were 0.01 ∼ 2.02 Gy, 0.36 ∼ 5.01 Gy, 0.25 ∼ 2.49 Gy, 0.14 ∼ 6.92 Gy, 0.03 ∼ 2.02 Gy, 0.01 ∼ 1.06 Gy, 0.25 ∼ 6.08 Gy, 0.08 ∼ 0.59 Gy, 0.01 ∼ 1.34 Gy, respectively. The OED, EAR of the IMRT and VMAT show higher than 3D-CRT. As the result of this study, we could confirm being higher dose index(HI, CI) in IMRT and VMAT than 3D-CRT, but doses of around normal organs was higher IMRT, VMAT than 3D-CRT.

  13. SU-E-T-393: Investigation of Hot Spots in Tomotherapy 3D Conformal Breast Plan

    Chen, Q; Siebers, J; Khandelwal, S [University of Virginia, Charlottesville, VA (United States)

    2014-06-01

    Purpose: The purpose of this study is to determine the root-cause of hotspots inherent to Tomotherapy static beam 3D conformal radiotherapy (3DCRT) for breast treatment. ASTRO (ref here) recommends that IMRT be avoided for breast treatments. Despite Tomotherapy's inherent IMRT-like optimization and delivery, our experience at a Tomotherapy-only site has been that Tomotherapy 3DCRT fail to produce a clinically acceptable plan for 79% of our breast patients. Hot-spots have been one of the major obstacles. Methods: Eight lumpectomy patients were planned according to RTOG-1005 specification. Two or four tangential beams were used for 3DCRT breast planning. To spare the contralateral breast and ipsilateral lung, part of the PTV was not covered by the primary beam, yielding adjacent hot-spots. We hypothesize that the planning system creates hotspots adjacent to the cold spots to yield scatter radiation dose compensation in the blocked region. Various phantom and patient setup were used to test the hypothesis. Results: Hot spots outside of PTV in the range of 135% - 174% were observed for patient plan. It is confirmed that the PTV partial block causes the adjacent hot spot. The root cause is the optimizer quadratic objective function over- weighs improving the cold spot. The IMRT flexibility offered by Tomotherapy is counter-productive in static-beam 3DCRT breast treatment. For phantom case, as the Modulation-Factor increases from 1.1 to 5, the hot spot increases from 110% to 300%. Limiting the 3DCRT intensity modulation is shown to produce clinically acceptable plan. Conclusion: Most of the hot spots in Tomotherapy 3DCRT breast plan originate from the planning-system optimizer attempting to cover PTV cold spots rather than from the beam energy. Altering the objective function could improve clinical acceptability of static beam Tomotherapy 3DCRT.

  14. 3D planning in the reconstruction of maxillofacial defects

    Schepers, Rutger Hendrik

    2016-01-01

    Resection of a tumor in the upper- or lower jaw often results in a large defect, because with the tumor resection also an adjacent part of the jaw is resected. The most favorable treatment for large defects is the combination of a bony free vascularized graft to reconstruct the defect with implants to retain prosthetic constructions. The Free vascularized Fibula Flap (FFF) is a versatile flap that commonly is used to reconstruct such bony and soft tissue defects. It is shown that oral rehabil...

  15. Evaluation of field development plans using 3-D reservoir modelling

    Seifert, D.; Lewis, J.J.M. [Heriot-Watt Univ., Edinburgh (United Kingdom); Newbery, J.D.H. [Conoco, UK Ltd., Aberdeen (United Kingdom)] [and others

    1997-08-01

    Three-dimensional reservoir modelling has become an accepted tool in reservoir description and is used for various purposes, such as reservoir performance prediction or integration and visualisation of data. In this case study, a small Northern North Sea turbiditic reservoir was to be developed with a line drive strategy utilising a series of horizontal producer and injector pairs, oriented north-south. This development plan was to be evaluated and the expected outcome of the wells was to be assessed and risked. Detailed analyses of core, well log and analogue data has led to the development of two geological {open_quotes}end member{close_quotes} scenarios. Both scenarios have been stochastically modelled using the Sequential Indicator Simulation method. The resulting equiprobable realisations have been subjected to detailed statistical well placement optimisation techniques. Based upon bivariate statistical evaluation of more than 1000 numerical well trajectories for each of the two scenarios, it was found that the wells inclinations and lengths had a great impact on the wells success, whereas the azimuth was found to have only a minor impact. After integration of the above results, the actual well paths were redesigned to meet external drilling constraints, resulting in substantial reductions in drilling time and costs.

  16. Application of 3D Printing in the Surgical Planning of Trimalleolar Fracture and Doctor-Patient Communication

    Long Yang

    2016-01-01

    Full Text Available To evaluate the effect of 3D printing in treating trimalleolar fractures and its roles in physician-patient communication, thirty patients with trimalleolar fractures were randomly divided into the 3D printing assisted-design operation group (Group A and the no-3D printing assisted-design group (Group B. In Group A, 3D printing was used by the surgeons to produce a prototype of the actual fracture to guide the surgical treatment. All patients underwent open reduction and internal fixation. A questionnaire was designed for doctors and patients to verify the verisimilitude and effectiveness of the 3D-printed prototype. Meanwhile, the operation time and the intraoperative blood loss were compared between the two groups. The fracture prototypes were accurately printed, and the average overall score of the verisimilitude and effectiveness of the 3D-printed prototypes was relatively high. Both the operation time and the intraoperative blood loss in Group A were less than those in Group B (P<0.05. Patient satisfaction using the 3D-printed prototype and the communication score were 9.3±0.6 points. A 3D-printed prototype can faithfully reflect the anatomy of the fracture site; it can effectively help the doctors plan the operation and represent an effective tool for physician-patient communication.

  17. Application of 3D Printing in the Surgical Planning of Trimalleolar Fracture and Doctor-Patient Communication

    Yang, Long; Shang, Xian-Wen; Fan, Jian-Nan; He, Zhi-Xu; Wang, Jian-Ji; Liu, Miao; Zhuang, Yong

    2016-01-01

    To evaluate the effect of 3D printing in treating trimalleolar fractures and its roles in physician-patient communication, thirty patients with trimalleolar fractures were randomly divided into the 3D printing assisted-design operation group (Group A) and the no-3D printing assisted-design group (Group B). In Group A, 3D printing was used by the surgeons to produce a prototype of the actual fracture to guide the surgical treatment. All patients underwent open reduction and internal fixation. A questionnaire was designed for doctors and patients to verify the verisimilitude and effectiveness of the 3D-printed prototype. Meanwhile, the operation time and the intraoperative blood loss were compared between the two groups. The fracture prototypes were accurately printed, and the average overall score of the verisimilitude and effectiveness of the 3D-printed prototypes was relatively high. Both the operation time and the intraoperative blood loss in Group A were less than those in Group B (P < 0.05). Patient satisfaction using the 3D-printed prototype and the communication score were 9.3 ± 0.6 points. A 3D-printed prototype can faithfully reflect the anatomy of the fracture site; it can effectively help the doctors plan the operation and represent an effective tool for physician-patient communication. PMID:27446944

  18. A Pipeline for 3D Multimodality Image Integration and Computer-assisted Planning in Epilepsy Surgery

    Nowell, Mark; Rodionov, Roman; Zombori, Gergely; Sparks, Rachel; Rizzi, Michele; Ourselin, Sebastien; Miserocchi, Anna; McEvoy, Andrew; Duncan, John

    2016-01-01

    Epilepsy surgery is challenging and the use of 3D multimodality image integration (3DMMI) to aid presurgical planning is well-established. Multimodality image integration can be technically demanding, and is underutilised in clinical practice. We have developed a single software platform for image integration, 3D visualization and surgical planning. Here, our pipeline is described in step-by-step fashion, starting with image acquisition, proceeding through image co-registration, manual segmen...

  19. Measurements of non-target organ doses using MOSFET dosemeters for selected IMRT and 3D CRT radiation treatment procedures.

    Wang, Brian; Xu, X George

    2008-01-01

    Many expressed concerns about the potential increase in second cancer risk from the widespread shift to intensity-modulated radiation therapy (IMRT) techniques from traditional 3-D conformal radiation treatment (3D CRT). This paper describes the study on in-phantom measurements of radiation doses in organ sites away from the primary tumour target. The measurements involved a RANDO((R)) phantom and Metal Oxide Semiconductor Field Effect Transistor dosemeters for selected 3D CRT and IMRT treatment plans. Three different treatment plans, 4-field 3D CRT, 6-field 3D CRT and 7-field IMRT for the prostate, were considered in this study. Steps to reconstruct organ doses from directly measured data were also presented. The dosemeter readings showed that the doses decrease as the distances increase for all treatment plans. At 40 cm from the prostate target, doses were <1% of the therapeutic dose. At this location, however, the IMRT plan resulted in an absorbed dose from photons, that is a factor of 3-5 higher than the 3D CRT treatment plans. This increase on absorbed dose is due to the increased exposure time for delivering the IMRT plan. The total monitor unit (MU) was 2850 for the IMRT case, while the MU was 1308 and 1260 for 6-field and 4-field 3D CRT cases, respectively. Findings from this case study involving the prostate treatments agree with those from previous studies that IMRT indeed delivers higher photon doses to locations that are away from the primary target. PMID:17627959

  20. Development of 3-D Radiosurgery Planning System Using IBM Personal Computer

    Recently, stereotactic radiosurgery plan is required with the information of 3-D image and dose distribution. A project has been doing if developing LINAC based stereotactic radiosurgery since April 1991. The purpose of this research is to develop 3-D radiosurgery planning system using personal computer. The procedure of this research is based on two steps. The first step is to develop 3-D localization system, which input the image information of the patient, coordinate transformation, the position and shape of target, and patient contour into computer system using CT image and stereotactic frame. The second step is to develop 3-D dose planning system, which compute dose distribution on image plane, display on high resolution monitor both isodose distribution and patient image simultaneously and develop menu-driven planning system. This prototype of radiosurgery planning system was applied recently for several clinical cases. It was shown that our planning system is fast, accurate and efficient while making it possible to handle various kinds of image modalities such as angiography, CT and MRI. It makes it possible to develop general 3-D planning system using beam eye view or CT simulation in radiation therapy in future

  1. Accuracy of 3D Virtual Planning of Corrective Osteotomies of the Distal Radius.

    Stockmans, Filip; Dezillie, Marleen; Vanhaecke, Jeroen

    2013-11-01

    Corrective osteotomies of the distal radius for symptomatic malunion are time-tested procedures that rely on accurate corrections. Patients with combined intra- and extra-articular malunions present a challenging deformity. Virtual planning and patient-specific instruments (PSIs) to transfer the planning into the operating room have been used both to simplify the surgery and to make it more accurate. This report focuses on the clinically achieved accuracy in four patients treated between 2008 and 2012 with virtual planning and PSIs for a combined intra- and extraarticular malunion of the distal radius. The accuracy of the correction is quantified by comparing the virtual three-dimensional (3D) planning model with the postoperative 3D bone model. For the extraarticular malunion the 3D volar tilt, 3D radial inclination and 3D ulnar variance are measured. The volar tilt is undercorrected in all cases with an average of -6 ± 6°. The average difference between the postoperative and planned 3D radial inclination was -1 ± 5°. The average difference between the postoperative and planned 3D ulnar variances is 0 ± 1 mm. For the evaluation of the intraarticular malunion, both the arc method of measurement and distance map measurement are used. The average postoperative maximum gap is 2.1 ± 0.9 mm. The average maximum postoperative step-off is 1.3 ± 0.4 mm. The average distance between the postoperative and planned articular surfaces is 1.1 ± 0.6 mm as determined in the distance map measurement. There is a tendency to achieve higher accuracy as experience builds up, both on the surgeon's side and on the design engineering side. We believe this technology holds the potential to achieve consistent accuracy of very complex corrections. PMID:24436834

  2. Application of 3D Printing in the Surgical Planning of Trimalleolar Fracture and Doctor-Patient Communication.

    Yang, Long; Shang, Xian-Wen; Fan, Jian-Nan; He, Zhi-Xu; Wang, Jian-Ji; Liu, Miao; Zhuang, Yong; Ye, Chuan

    2016-01-01

    To evaluate the effect of 3D printing in treating trimalleolar fractures and its roles in physician-patient communication, thirty patients with trimalleolar fractures were randomly divided into the 3D printing assisted-design operation group (Group A) and the no-3D printing assisted-design group (Group B). In Group A, 3D printing was used by the surgeons to produce a prototype of the actual fracture to guide the surgical treatment. All patients underwent open reduction and internal fixation. A questionnaire was designed for doctors and patients to verify the verisimilitude and effectiveness of the 3D-printed prototype. Meanwhile, the operation time and the intraoperative blood loss were compared between the two groups. The fracture prototypes were accurately printed, and the average overall score of the verisimilitude and effectiveness of the 3D-printed prototypes was relatively high. Both the operation time and the intraoperative blood loss in Group A were less than those in Group B (P communication score were 9.3 ± 0.6 points. A 3D-printed prototype can faithfully reflect the anatomy of the fracture site; it can effectively help the doctors plan the operation and represent an effective tool for physician-patient communication. PMID:27446944

  3. 3D Visualization for Pre-operative Planning of Orthopedic Surgery

    Steen, Alexander; Widegren, Marcus

    2013-01-01

    This report presents a master thesis on 3D visualization for pre-operation planning of orthopedic surgery done for Sectra Medical Systems AB. The focus is on visualizing clinically relevant data for planning a Total Hip Replacement (THR). The thesis includes a pre-study and the implementation of a prototype using the Sectra IDS7 workstation.

  4. 3-Phase Recognition Approach to Pseudo 3D Building Generation from 2D Floor Plan

    Moloo, Raj Kishen; Auleear, Abu Salmaan

    2011-01-01

    Nowadays three dimension (3D) architectural visualisation has become a powerful tool in the conceptualisation, design and presentation of architectural products in the construction industry, providing realistic interaction and walkthrough on engineering products. Traditional ways of implementing 3D models involves the use of specialised 3D authoring tools along with skilled 3D designers with blueprints of the model and this is a slow and laborious process. The aim of this paper is to automate this process by simply analyzing the blueprint document and generating the 3D scene automatically. For this purpose we have devised a 3-Phase recognition approach to pseudo 3D building generation from 2D floor plan and developed a software accordingly. Our 3-phased 3D building system has been implemented using C, C++ and OpenCV library [24] for the Image Processing module; The Save Module generated an XML file for storing the processed floor plan objects attributes; while the Irrlitch [14] game engine was used to impleme...

  5. The superiority of hybrid-volumetric arc therapy (VMAT) technique over double arcs VMAT and 3D-conformal technique in the treatment of locally advanced non-small cell lung cancer – A planning study

    Purpose: To compare the dosimetric performance of three different treatment techniques – conformal radiotherapy (CRT), double arcs volumetric modulated arc therapy (RapidArc, RA) and Hybrid-RapidArc (H-RA) for locally-advanced non-small cell lung cancer (NSCLC). Material and methods: CRT, RA and H-RA plans were optimized for 24 stage III NSCLC patients. The target prescription dose was 60 Gy. CRT consisted of 5–7 coplanar fields, while RA comprised of two 204o arcs. H-RA referred to two 204o arcs plus 2 static fields, which accounted for approximately half of the total dose. The plans were optimized to fulfill the departmental plan acceptance criteria. Results: RA and H-RA yielded a 20% better conformity compared with CRT. Lung volume receiving >20 Gy (V20) and mean lung dose (MLD) were the lowest in H-RA (V20 1.7% and 2.1% lower, MLD 0.59 Gy and 0.41 Gy lower than CRT and RA respectively) without jeopardizing the low-dose lung volume (V5). H-RA plans gave the lowest mean maximum spinal cord dose (34.4 Gy, 3.9 Gy < CRT and 2.2 Gy < RA plans) and NTCP of lung. Higher average MU per fraction (addition 52.4 MU) was observed with a reduced treatment time compared with CRT plans. Conclusion: The H-RA technique was superior in dosimetric outcomes for treating locally-advanced NSCLC compared to CRT and RA.

  6. Computer-Assisted Hepatocellular Carcinoma Ablation Planning Based on 3-D Ultrasound Imaging.

    Li, Kai; Su, Zhongzhen; Xu, Erjiao; Guan, Peishan; Li, Liu-Jun; Zheng, Rongqin

    2016-08-01

    To evaluate computer-assisted hepatocellular carcinoma (HCC) ablation planning based on 3-D ultrasound, 3-D ultrasound images of 60 HCC lesions from 58 patients were obtained and transferred to a research toolkit. Compared with virtual manual ablation planning (MAP), virtual computer-assisted ablation planning (CAP) consumed less time and needle insertion numbers and exhibited a higher rate of complete tumor coverage and lower rate of critical structure injury. In MAP, junior operators used less time, but had more critical structure injury than senior operators. For large lesions, CAP performed better than MAP. For lesions near critical structures, CAP resulted in better outcomes than MAP. Compared with MAP, CAP based on 3-D ultrasound imaging was more effective and achieved a higher rate of complete tumor coverage and a lower rate of critical structure injury; it is especially useful for junior operators and with large lesions, and lesions near critical structures. PMID:27126243

  7. Web-based 3-D GIS and its applications for pipeline planning and construction

    Tao, V.; Wang, T.Q.K. [Calgary Univ., Calgary, AB (Canada). Dept. of Geomatics Engineering

    2000-07-01

    The many benefits that web-based 3D geographical information system (GIS) technology can bring to pipeline planning and construction was discussed. GIS can effectively integrate and manage a variety of data sources including geological, geographical, environmental, engineering and socioeconomic data. The third dimension of geospatial data is also very significant for pipeline planning, construction and maintenance which explains the increased demand for the development of a 3D GIS for pipeline applications. The Internet has made it possible to integrate GIS, visualization and distributed object computing technologies for a web-based 3D GIS. While this offers many advantages, it also poses several technical challenges. The technology allows users to access, manipulate and analyze geospatial objects remotely. This has positive implications for pipeline operating companies in their collaborative decision making for large pipeline projects that cover large areas with multiple landowners and different government sections. The technology will enhance their capability and productivity by making it possible to run their operations more efficiently. The Department of Geomatics Engineering at the University of Calgary has developed a web-based 3D GIS, GeoEye 3D prototype using a pure Java solution. The system is based on an advanced client/server model for visualization, manipulation and analysis of spatial data such as 3D terrain, wells, linear objects such as roads or pipelines and solid objects such as buildings. The system can be linked to other databases for spatial inquiry. 7 refs., 3 figs.

  8. 3D-image-guided high-dose-rate intracavitary brachytherapy for salvage treatment of locally persistent nasopharyngeal carcinoma

    To evaluate the therapeutic benefit of 3D-image-guided high-dose-rate intracavitary brachytherapy (3D-image-guided HDR-BT) used as a salvage treatment of intensity modulated radiation therapy (IMRT) in patients with locally persistent nasopharyngeal carcinoma (NPC). Thirty-two patients with locally persistent NPC after full dose of IMRT were evaluated retrospectively. 3D-image-guided HDR-BT treatment plan was performed on a 3D treatment planning system (PLATO BPS 14.2). The median dose of 16 Gy was delivered to the 100% isodose line of the Gross Tumor Volume. The whole procedure was well tolerated under local anesthesia. The actuarial 5-y local control rate for 3D-image-guided HDR-BT was 93.8%, patients with early-T stage at initial diagnosis had 100% local control rate. The 5-y actuarial progression-free survival and distant metastasis-free survival rate were 78.1%, 87.5%. One patient developed and died of lung metastases. The 5-y actuarial overall survival rate was 96.9%. Our results showed that 3D-image-guided HDR-BT would provide excellent local control as a salvage therapeutic modality to IMRT for patients with locally persistent disease at initial diagnosis of early-T stage NPC

  9. Computer assisted 3D pre-operative planning tool for femur fracture orthopedic surgery

    Gamage, Pavan; Xie, Sheng Quan; Delmas, Patrice; Xu, Wei Liang

    2010-02-01

    Femur shaft fractures are caused by high impact injuries and can affect gait functionality if not treated correctly. Until recently, the pre-operative planning for femur fractures has relied on two-dimensional (2D) radiographs, light boxes, tracing paper, and transparent bone templates. The recent availability of digital radiographic equipment has to some extent improved the workflow for preoperative planning. Nevertheless, imaging is still in 2D X-rays and planning/simulation tools to support fragment manipulation and implant selection are still not available. Direct three-dimensional (3D) imaging modalities such as Computed Tomography (CT) are also still restricted to a minority of complex orthopedic procedures. This paper proposes a software tool which allows orthopedic surgeons to visualize, diagnose, plan and simulate femur shaft fracture reduction procedures in 3D. The tool utilizes frontal and lateral 2D radiographs to model the fracture surface, separate a generic bone into the two fractured fragments, identify the pose of each fragment, and automatically customize the shape of the bone. The use of 3D imaging allows full spatial inspection of the fracture providing different views through the manipulation of the interactively reconstructed 3D model, and ultimately better pre-operative planning.

  10. A Pipeline for 3D Multimodality Image Integration and Computer-assisted Planning in Epilepsy Surgery.

    Nowell, Mark; Rodionov, Roman; Zombori, Gergely; Sparks, Rachel; Rizzi, Michele; Ourselin, Sebastien; Miserocchi, Anna; McEvoy, Andrew; Duncan, John

    2016-01-01

    Epilepsy surgery is challenging and the use of 3D multimodality image integration (3DMMI) to aid presurgical planning is well-established. Multimodality image integration can be technically demanding, and is underutilised in clinical practice. We have developed a single software platform for image integration, 3D visualization and surgical planning. Here, our pipeline is described in step-by-step fashion, starting with image acquisition, proceeding through image co-registration, manual segmentation, brain and vessel extraction, 3D visualization and manual planning of stereoEEG (SEEG) implantations. With dissemination of the software this pipeline can be reproduced in other centres, allowing other groups to benefit from 3DMMI. We also describe the use of an automated, multi-trajectory planner to generate stereoEEG implantation plans. Preliminary studies suggest this is a rapid, safe and efficacious adjunct for planning SEEG implantations. Finally, a simple solution for the export of plans and models to commercial neuronavigation systems for implementation of plans in the operating theater is described. This software is a valuable tool that can support clinical decision making throughout the epilepsy surgery pathway. PMID:27286266

  11. A Pipeline for 3D Multimodality Image Integration and Computer-assisted Planning in Epilepsy Surgery

    Nowell, Mark; Rodionov, Roman; Zombori, Gergely; Sparks, Rachel; Rizzi, Michele; Ourselin, Sebastien; Miserocchi, Anna; McEvoy, Andrew; Duncan, John

    2016-01-01

    Epilepsy surgery is challenging and the use of 3D multimodality image integration (3DMMI) to aid presurgical planning is well-established. Multimodality image integration can be technically demanding, and is underutilised in clinical practice. We have developed a single software platform for image integration, 3D visualization and surgical planning. Here, our pipeline is described in step-by-step fashion, starting with image acquisition, proceeding through image co-registration, manual segmentation, brain and vessel extraction, 3D visualization and manual planning of stereoEEG (SEEG) implantations. With dissemination of the software this pipeline can be reproduced in other centres, allowing other groups to benefit from 3DMMI. We also describe the use of an automated, multi-trajectory planner to generate stereoEEG implantation plans. Preliminary studies suggest this is a rapid, safe and efficacious adjunct for planning SEEG implantations. Finally, a simple solution for the export of plans and models to commercial neuronavigation systems for implementation of plans in the operating theater is described. This software is a valuable tool that can support clinical decision making throughout the epilepsy surgery pathway. PMID:27286266

  12. An investigation of PRESAGE® 3D dosimetry for IMRT and VMAT radiation therapy treatment verification

    The purpose of this work was to characterize three formulations of PRESAGE® dosimeters (DEA-1, DEA-2, and DX) and to identify optimal readout timing and procedures for accurate in-house 3D dosimetry. The optimal formulation and procedure was then applied for the verification of an intensity modulated radiation therapy (IMRT) and a volumetric modulated arc therapy (VMAT) treatment technique. PRESAGE® formulations were studied for their temporal stability post-irradiation, sensitivity, and linearity of dose response. Dosimeters were read out using a high-resolution optical-CT scanner. Small volumes of PRESAGE® were irradiated to investigate possible differences in sensitivity for large and small volumes (‘volume effect’). The optimal formulation and read-out technique was applied to the verification of two patient treatments: an IMRT plan and a VMAT plan. A gradual decrease in post-irradiation optical-density was observed in all formulations with DEA-1 exhibiting the best temporal stability with less than 4% variation between 2–22 h post-irradiation. A linear dose response at the 4 h time point was observed for all formulations with an R2 value >0.99. A large volume effect was observed for DEA-1 with sensitivity of the large dosimeter being ∼63% less than the sensitivity of the cuvettes. For the IMRT and VMAT treatments, the 3D gamma passing rates for 3%/3 mm criteria using absolute measured dose were 99.6 and 94.5% for the IMRT and VMAT treatments, respectively. In summary, this work shows that accurate 3D dosimetry is possible with all three PRESAGE® formulations. The optimal imaging windows post-irradiation were 3–24 h, 2–6 h, and immediately for the DEA-1, DEA-2, and DX formulations, respectively. Because of the large volume effect, small volume cuvettes are not yet a reliable method for calibration of larger dosimeters to absolute dose. Finally, PRESAGE® is observed to be a useful method of 3D verification when careful consideration

  13. Difference in the Set-up Margin between 2D Conventional and 3D CT Based Planning in Patients with Early Breast Cancer

    Jo, Sun Mi; Chun, Mi Sun; Kim, Mi Hwa; Oh, Young Taek; Noh, O Kyu [Ajou University School of Medicine, Seoul (Korea, Republic of); Kang, Seung Hee [Inje University, Ilsan Paik Hospital, Ilsan (Korea, Republic of)

    2010-11-15

    Simulation using computed tomography (CT) is now widely available for radiation treatment planning for breast cancer. It is an important tool to help define the tumor target and normal tissue based on anatomical features of an individual patient. In Korea, most patients have small sized breasts and the purpose of this study was to review the margin of treatment field between conventional two-dimensional (2D) planning and CT based three-dimensional (3D) planning in patients with small breasts. Twenty-five consecutive patients with early breast cancer undergoing breast conservation therapy were selected. All patients underwent 3D CT based planning with a conventional breast tangential field design. In 2D planning, the treatment field margins were determined by palpation of the breast parenchyma (In general, the superior: base of the clavicle, medial: midline, lateral: mid - axillary line, and inferior margin: 2 m below the inflamammary fold). In 3D planning, the clinical target volume (CTV) ought to comprise all glandular breast tissue, and the PTV was obtained by adding a 3D margin of 1 cm around the CTV except in the skin direction. The difference in the treatment field margin and equivalent field size between 2D and 3D planning were evaluated. The association between radiation field margins and factors such as body mass index, menopause status, and bra size was determined. Lung volume and heart volume were examined on the basis of the prescribed breast radiation dose and 3D dose distribution. The margins of the treatment field were smaller in the 3D planning except for two patients. The superior margin was especially variable (average, 2.5 cm; range, -2.5 to 4.5 cm; SD, 1.85). The margin of these targets did not vary equally across BMI class, menopause status, or bra size. The average irradiated lung volume was significantly lower for 3D planning. The average irradiated heart volume did not decrease significantly. The use of 3D CT based planning reduced the

  14. Individualized Surgical Approach Planning for Petroclival Tumors Using a 3D Printer.

    Muelleman, Thomas John; Peterson, Jeremy; Chowdhury, Naweed Iffat; Gorup, Jason; Camarata, Paul; Lin, James

    2016-06-01

    Objectives To determine the utility of three-dimensional (3D) printed models in individualized petroclival tumor resection planning by measuring the fidelity of printed anatomical structures and comparing tumor exposure afforded by different approaches. Design Case series and review of the literature. Setting Tertiary care center. Participants Three patients with petroclival lesions. Main Outcome Measures Subjective opinion of access by neuro-otologists and neurosurgeons as well as surface area of tumor exposure. Results Surgeons found the 3D models of each patient's skull and tumor useful for preoperative planning. Limitations of individual surgical approaches not identified through preoperative imaging were apparent after 3D models were evaluated. Significant variability in exposure was noted between models for similar or identical approaches. A notable drawback is that our printing process did not replicate mastoid air cells. Conclusions We found that 3D modeling is useful for individualized preoperative planning for approaching petroclival tumors. Our printing techniques did produce authentic replicas of the tumors in relation to bony structures. PMID:27175320

  15. Combined photogrammetry and 3-D CAD for plant documentation and planning of refits

    Meticulous advance planning and erection studies using a three-dimensional computer-aided design model of the plant area concerned can reduce the problem that unexpected events during a plant refit will prolong the required inspection period. This presupposes that a 3-D CAD scale model of the running plant has been generated. A method is described with which the as-built condition of the plant area is converted into a 3-D CAD model by combining photogrammetry with 3-D CAD. The minimum amount of time required for in-plant surveying and the completeness and clarity of results are the special advantages of this method in comparison with other measurement techniques. Selected applications are presented. (orig.)

  16. Development of tactile floor plan for the blind and the visually impaired by 3D printing technique

    Raša Urbas

    2016-07-01

    Full Text Available The aim of the research was to produce tactile floor plans for blind and visually impaired people for the use in the museum. For the production of tactile floor plans 3D printing technique was selected among three different techniques. 3D prints were made of white and colored ABS polymer materials. Development of different elements of tactile floor plans, as well as the problems and the solutions during 3D printing, are described in the paper.

  17. Renal Tumor Cryoablation Planning. The Efficiency of Simulation on Reconstructed 3D CT Scan

    Ciprian Valerian LUCAN

    2010-12-01

    Full Text Available Introduction & Objective: Nephron-sparing surgical techniques risks are related to tumor relationships with adjacent anatomic structures. Complexity of the renal anatomy drives the interest to develop tools for 3D reconstruction and surgery simulation. The aim of the article was to assess the simulation on reconstructed 3D CT scan used for planning the cryoablation. Material & Method: A prospective randomized study was performed between Jan. 2007 and July 2009 on 27 patients who underwent retroperitoneoscopic T1a renal tumors cryoablation (RC. All patients were assessed preoperatively by CT scan, also used for 3D volume rendering. In the Gr.A, the patients underwent surgery planning by simulation on 3D CT scan. In the Gr.B., patients underwent standard RC. The two groups were compared in terms of surgical time, bleeding, postoperative drainage, analgesics requirement, hospital stay, time to socio-professional reintegration. Results: Fourteen patients underwent preoperative cryoablation planning (Gr.A and 13 patients underwent standard CR (Gr.B. All parameters analyzed were shorter in the Gr.A. On multivariate logistic regression, only shortens of the surgical time (138.79±5.51 min. in Gr.A. vs. 140.92±5.54 min in Gr.B. and bleeding (164.29±60.22 mL in Gr.A. vs. 215.38±100.80 mL in Gr.B. achieved statistical significance (p<0.05. The number of cryoneedles assessed by simulation had a 92.52% accuracy when compared with those effectively used. Conclusions: Simulation of the cryoablation using reconstructed 3D CT scan improves the surgical results. The application used for simulation was able to accurately assess the number of cryoneedles required for tumor ablation, their direction and approach.

  18. Using Stereoscopic 3D Technologies for the Diagnosis and Treatment of Amblyopia in Children

    Gargantini, Angelo

    2011-01-01

    The 3D4Amb project aims at developing a system based on the stereoscopic 3D techonlogy, like the NVIDIA 3D Vision, for the diagnosis and treatment of amblyopia in young children. It exploits the active shutter technology to provide binocular vision, i.e. to show different images to the amblyotic (or lazy) and the normal eye. It would allow easy diagnosis of amblyopia and its treatment by means of interactive games or other entertainment activities. It should not suffer from the compliance problems of the classical treatment, it is suitable to domestic use, and it could at least partially substitute occlusion or patching of the normal eye.

  19. Gap-filling methods for 3D PlanTIS data

    The range of positron emitters and their labeled compounds have led to high-resolution PET scanners becoming widely used, not only in clinical and pre-clinical studies but also in plant studies. A high-resolution PET scanner, plant tomographic imaging system (PlanTIS), was designed to study metabolic and physiological functions of plants noninvasively. The gantry of the PlanTIS scanner has detector-free regions. Even when the gantry of the PlanTIS is rotated during the scan, these regions result in missing sinogram bins in the acquired data. Missing data need to be estimated prior to the analytical image reconstructions in order to avoid artifacts in the final reconstructed images. In this study, we propose three gap-filling methods for estimation of the unique gaps existing in the 3D PlanTIS sinogram data. The 3D sinogram data were gap-filled either by linear interpolation in the transaxial planes or by the bicubic interpolation method (proposed for the ECAT high-resolution research tomograph) in the transradial planes or by the inpainting method in the transangular planes. Each gap-filling method independently compensates for slices in one of three orthogonal sinogram planes (transaxial, transradial and transangular planes). A 3D numerical Shepp-Logan phantom and the NEMA image quality phantom were used to evaluate the methods. The gap-filled sinograms were reconstructed using the analytical 3D reprojection (3DRP) method. The NEMA phantom sinograms were also reconstructed by the iterative reconstruction method, ordered subsets maximum a posteriori one step late (OSMAPOSL), to compare the results of gap filling followed by 3DRP with the results of OSMAPOSL reconstruction without gap filling. The three methods were evaluated quantitatively (by mean square error and coefficients of variation) over the selected regions of the 3D numerical Shepp-Logan phantom at eight different Poisson noise levels. Moreover, the NEMA phantom scan data were used in visual assessments

  20. Investigations on the quality of manual image segmentation in 3D radiotherapy planning

    In 3D radiotherapy planning image segmentation plays an important role in the definition process of target volume and organs at risk. Here, we present a method to quantify the technical precision of the manual image segmentation process. To validate our method we developed a virtual phantom consisting of several geometrical objects of changing form and contrast, which should be contoured by volunteers using the TOMAS tool for manual segmentation of the Heidelberg VOXELPLAN system. The results of this examination are presented. (orig.)

  1. Options in virtual 3D, optical-impression-based planning of dental implants.

    Reich, Sven; Kern, Thomas; Ritter, Lutz

    2014-01-01

    If a 3D radiograph, which in today's dentistry often consists of a CBCT dataset, is available for computerized implant planning, the 3D planning should also consider functional prosthetic aspects. In a conventional workflow, the CBCT is done with a specially produced radiopaque prosthetic setup that makes the desired prosthetic situation visible during virtual implant planning. If an exclusively digital workflow is chosen, intraoral digital impressions are taken. On these digital models, the desired prosthetic suprastructures are designed. The entire datasets are virtually superimposed by a "registration" process on the corresponding structures (teeth) in the CBCTs. Thus, both the osseous and prosthetic structures are visible in one single 3D application and make it possible to consider surgical and prosthetic aspects. After having determined the implant positions on the computer screen, a drilling template is designed digitally. According to this design (CAD), a template is printed or milled in CAM process. This template is the first physically extant product in the entire workflow. The article discusses the options and limitations of this workflow. PMID:25098158

  2. Clinical application of 3D imaging for assessment of treatment outcomes

    Cevidanes, Lucia H.C.; Oliveira, Ana Emilia Figueiredo; Grauer, Dan; Styner, Martin; Proffit, William R.

    2011-01-01

    This paper outlines the clinical application of CBCT for assessment of treatment outcomes, and discusses current work to superimpose digital dental models and 3D photographs. Superimposition of CBCTs on stable structures of reference now allow assessment of 3D dental, skeletal and soft tissue changes for both growing and non-growing patients. Additionally, we describe clinical findings from CBCT superimpositions in assessment of surgery and skeletal anchorage treatment.

  3. Optimization of spine surgery planning with 3D image templating tools

    Augustine, Kurt E.; Huddleston, Paul M.; Holmes, David R., III; Shridharani, Shyam M.; Robb, Richard A.

    2008-03-01

    The current standard of care for patients with spinal disorders involves a thorough clinical history, physical exam, and imaging studies. Simple radiographs provide a valuable assessment but prove inadequate for surgery planning because of the complex 3-dimensional anatomy of the spinal column and the close proximity of the neural elements, large blood vessels, and viscera. Currently, clinicians still use primitive techniques such as paper cutouts, pencils, and markers in an attempt to analyze and plan surgical procedures. 3D imaging studies are routinely ordered prior to spine surgeries but are currently limited to generating simple, linear and angular measurements from 2D views orthogonal to the central axis of the patient. Complex spinal corrections require more accurate and precise calculation of 3D parameters such as oblique lengths, angles, levers, and pivot points within individual vertebra. We have developed a clinician friendly spine surgery planning tool which incorporates rapid oblique reformatting of each individual vertebra, followed by interactive templating for 3D placement of implants. The template placement is guided by the simultaneous representation of multiple 2D section views from reformatted orthogonal views and a 3D rendering of individual or multiple vertebrae enabling superimposition of virtual implants. These tools run efficiently on desktop PCs typically found in clinician offices or workrooms. A preliminary study conducted with Mayo Clinic spine surgeons using several actual cases suggests significantly improved accuracy of pre-operative measurements and implant localization, which is expected to increase spinal procedure efficiency and safety, and reduce time and cost of the operation.

  4. Multi-modality fusion of CT, 3D ultrasound, and tracked strain images for breast irradiation planning

    Foroughi, Pezhman; Csoma, Csaba; Rivaz, Hassan; Fichtinger, Gabor; Zellars, Richard; Hager, Gregory; Boctor, Emad

    2009-02-01

    Breast irradiation significantly reduces the risk of recurrence of cancer. There is growing evidence suggesting that irradiation of only the involved area of the breast, partial breast irradiation (PBI), is as effective as whole breast irradiation. Benefits of PBI include shortened treatment time, and perhaps fewer side effects as less tissue is treated. However, these benefits cannot be realized without precise and accurate localization of the lumpectomy cavity. Several studies have shown that accurate delineation of the cavity in CT scans is very challenging and the delineated volumes differ dramatically over time and among users. In this paper, we propose utilizing 3D ultrasound (3D-US) and tracked strain images as complementary modalities to reduce uncertainties associated with current CT planning workflow. We present the early version of an integrated system that fuses 3D-US and real-time strain images. For the first time, we employ tracking information to reduce the noise in calculation of strain image by choosing the properly compressed frames and to position the strain image within the ultrasound volume. Using this system, we provide the tools to retrieve additional information from 3D-US and strain image alongside the CT scan. We have preliminarily evaluated our proposed system in a step-by-step fashion using a breast phantom and clinical experiments.

  5. The advantage of 3D conformal treatment of lumbar spine metastases in comparison to traditional PA or AP-PA techniques: restoring an intermediate niche of therapeutic sophistication

    To evaluate the effect of the 3D radiation field design on normal tissues compared with commonly used appositional fields in patients with lumbar spine metastases. Ten comparative treatment plans for radiation of lumbar spine metastases were compared for posterior and anterior- posterior fields with 3D plans. The PTV coverage in all comparative plans was similar. V 15 of the bowel in 3D, AP-PA and PA plans was 6.7 Gy (SD 6.47), 39.8 Gy (SD 11.4) and 37.3 Gy (SD15.7), respectively (p < 0.0001). The mean dose to both kidneys was 9.6 Gy (SD 4.8), 4.1 Gy (SD 3.9) and 4.6 Gy (SD 4.4) for appropriate plans (p = 0.002). Maximal dose to the spinal cord was 30.6 Gy (SD 2.1), 33.1 Gy (SD 9.8) and 37.7 Gy (SD 2) for 3D, AP-PA and PA plans. 3D conformal treatment planning of lumbar vertebral metastases was significantly better in term of bowel and spinal cord exposure compared to AP-PA and PA techniques. The exposure of the kidneys in 3D plans, while greater than in the comparative plans, did not violate accepted dose-volume thresholds

  6. Volumetric modulated arc planning for lung stereotactic body radiotherapy using conventional and unflattened photon beams: a dosimetric comparison with 3D technique

    Frequently, three-dimensional (3D) conformal beams are used in lung cancer stereotactic body radiotherapy (SBRT). Recently, volumetric modulated arc therapy (VMAT) was introduced as a new treatment modality. VMAT techniques shorten delivery time, reducing the possibility of intrafraction target motion. However dose distributions can be quite different from standard 3D therapy. This study quantifies those differences, with focus on VMAT plans using unflattened photon beams. A total of 15 lung cancer patients previously treated with 3D or VMAT SBRT were randomly selected. For each patient, non-coplanar 3D, coplanar and non-coplanar VMAT and flattening filter free VMAT (FFF-VMAT) plans were generated to meet the same objectives with 50 Gy covering 95% of the PTV. Two dynamic arcs were used in each VMAT plan. The couch was set at ± 5° to the 0° straight position for the two non-coplanar arcs. Pinnacle version 9.0 (Philips Radiation Oncology, Fitchburg WI) treatment planning system with VMAT capabilities was used. We analyzed the conformity index (CI), which is the ratio of the total volume receiving at least the prescription dose to the target volume receiving at least the prescription dose; the conformity number (CN) which is the ratio of the target coverage to CI; and the gradient index (GI) which is the ratio of the volume of 50% of the prescription isodose to the volume of the prescription isodose; as well as the V20, V5, and mean lung dose (MLD). Paired non-parametric analysis of variance tests with post-tests were performed to examine the statistical significance of the differences of the dosimetric indices. Dosimetric indices CI, CN and MLD all show statistically significant improvement for all studied VMAT techniques compared with 3D plans (p < 0.05). V5 and V20 show statistically significant improvement for the FFF-VMAT plans compared with 3D (p < 0.001). GI is improved for the FFF-VMAT and the non-coplanar VMAT plans (p < 0.01 and p < 0.05 respectively

  7. Improved 3D limit-cycle navigation method for path planning quad rotor

    Quad rotors as a type of rotary wing aerial vehicle must planned their flight path effectively and avoid any disturbance to complete their mission. The extension of 2D limit-cycle navigation into 3D, made it possible to apply for aerial vehicle. The extended limit-cycle has been introduced, but it generate unsuitable path in certain condition. In this research, rendering the obstacle into a cylinder will generate the efficient path and provide the best way in avoiding stationary obstacle. By defining obstacle position, a simulation and performance study is done using limit-cycle characteristic method. The simulations results illustrated the path generation using improved 3D limit cycle with different obstacle condition

  8. Autoblocking dose-limiting normal structures within a radiation treatment field: 3-D computer optimization of 'unconventional' field arrangements

    Purpose/Objective: To demonstrate that one can obtain a homogeneous dose distribution within a specified gross tumor volume (GTV) while severely limiting the dose to a structure surrounded by that tumor volume. We present three clinical examples below. Materials and Methods: Using planning CT scans from previously treated patients, we designed variety of radiation treatment plans in which the dose-critical normal structure was blocked, even if it meant blocking some of the tumor. To deal with the resulting dose inhomogeneities within the tumor, we introduced 3D compensation. Examples presented here include (1) blocking the spinal cord segment while treating an entire vertebral body, (2) blocking both kidneys while treating the entire peritoneal cavity, and (3) blocking one parotid gland while treating the oropharynx in its entirety along with regional nodes. A series of multiple planar and non-coplanar beam templates with automatic anatomic blocking and field shaping were designed for each scenario. Three-dimensional compensators were designed that gave the most homogeneous dose-distribution for the GTV. For each beam, rays were cast from the beam source through a 2D compensator grid and out through the tumor. The average tumor dose along each ray was then used to adjust the compensator thickness over successive iterations to achieve a uniform average dose. DVH calculations for the GTV, normal structures, and the 'auto-blocked' structure were made and used for inter-plan comparisons. Results: These optimized treatment plans successfully decreased dose to the dose-limiting structure while at the same time preserving or even improving the dose distribution to the tumor volume as compared to traditional treatment plans. Conclusion: The use of 3D compensation allows one to obtain dose distributions that are, theoretically, at least, far superior to those in common clinical use. Sensible beam templates, auto-blocking, auto-field shaping, and 3D compensators form a

  9. Verification of Rapid Arc™ planning with AAA algorithm using an inhomogeneous 3D phantom

    New technologies have been developed to improve the quality assurance of the planning with modulated beams. One way to deal with the high costs of the dosimetry equipment was to develop a 3D phantom, using TLDs and radiochromic film, designed by the Radiotherapy Quality Program of INCa. The calculus was done using the AAA algorithm with heterogeneity correction, making the phantom rather heterogeneous. Five measurements related to the Rapid Arc™ planning were taken, once there was the phantom CT for optimization. The purpose of this work is a 3D verification of the dose distribution in the heterogeneous phantom. The mean deviation in planning target volumes was lower than ±5%. On the other side, the results dispersion for the others heterogeneities was higher, the maximum mean deviation obtained, for example, for the heterogeneity related to the bladder, was 7.41%. The maximum standard deviation found for both cases was around 9% for the target heterogeneity and 11% for the other heterogeneities. The phantom might be an interesting tool in order to verify the Rapid Arc™ planning, however, more statistical data is necessary as to achieve better results for the analysis of dose distribution. (author)heterogeneous phantom. The mean deviation in planning target volumes was lower than ±5%. On the other side, the results dispersion for the others heterogeneities was higher, the maximum mean deviation obtained, for example, for the heterogeneity related to the bladder, was 7.41%. The maximum standard deviation found for both cases was around 9% for the target heterogeneity and 11% for the other heterogeneities. The phantom might be an interesting tool in order to verify the Rapid Arc™ planning, however, more statistical data is necessary as to achieve better results for the analysis of dose distribution. (author)

  10. Digital holographic microscopy for imaging growth and treatment response in 3D tumor models

    Li, Yuyu; Petrovic, Ljubica; Celli, Jonathan P.; Yelleswarapu, Chandra S.

    2014-03-01

    While three-dimensional tumor models have emerged as valuable tools in cancer research, the ability to longitudinally visualize the 3D tumor architecture restored by these systems is limited with microscopy techniques that provide only qualitative insight into sample depth, or which require terminal fixation for depth-resolved 3D imaging. Here we report the use of digital holographic microscopy (DHM) as a viable microscopy approach for quantitative, non-destructive longitudinal imaging of in vitro 3D tumor models. Following established methods we prepared 3D cultures of pancreatic cancer cells in overlay geometry on extracellular matrix beds and obtained digital holograms at multiple timepoints throughout the duration of growth. The holograms were digitally processed and the unwrapped phase images were obtained to quantify nodule thickness over time under normal growth, and in cultures subject to chemotherapy treatment. In this manner total nodule volumes are rapidly estimated and demonstrated here to show contrasting time dependent changes during growth and in response to treatment. This work suggests the utility of DHM to quantify changes in 3D structure over time and suggests the further development of this approach for time-lapse monitoring of 3D morphological changes during growth and in response to treatment that would otherwise be impractical to visualize.

  11. Enhancing photogrammetric 3d city models with procedural modeling techniques for urban planning support

    This paper presents a workflow to increase the level of detail of reality-based 3D urban models. It combines the established workflows from photogrammetry and procedural modeling in order to exploit distinct advantages of both approaches. The combination has advantages over purely automatic acquisition in terms of visual quality, accuracy and model semantics. Compared to manual modeling, procedural techniques can be much more time effective while maintaining the qualitative properties of the modeled environment. In addition, our method includes processes for procedurally adding additional features such as road and rail networks. The resulting models meet the increasing needs in urban environments for planning, inventory, and analysis

  12. PACS-based interface for 3D anatomical structure visualization and surgical planning

    Koehl, Christophe; Soler, Luc; Marescaux, Jacques

    2002-05-01

    The interpretation of radiological image is routine but it remains a rather difficult task for physicians. It requires complex mental processes, that permit translation from 2D slices into 3D localization and volume determination of visible diseases. An easier and more extensive visualization and exploitation of medical images can be reached through the use of computer-based systems that provide real help from patient admission to post-operative followup. In this way, we have developed a 3D visualization interface linked to a PACS database that allows manipulation and interaction on virtual organs delineated from CT-scan or MRI. This software provides the 3D real-time surface rendering of anatomical structures, an accurate evaluation of volumes and distances and the improvement of radiological image analysis and exam annotation through a negatoscope tool. It also provides a tool for surgical planning allowing the positioning of an interactive laparoscopic instrument and the organ resection. The software system could revolutionize the field of computerized imaging technology. Indeed, it provides a handy and portable tool for pre-operative and intra-operative analysis of anatomy and pathology in various medical fields. This constitutes the first step of the future development of augmented reality and surgical simulation systems.

  13. Usefulness of 3D-fast-SPGR MR image for gamma knife radiosurgery planning

    Yamada, Yasushi; Mori, Yoshimasa; Kobayashi, Tatsuya; Koshikawa, Tokiko [Komaki City Hospital, Aichi (Japan)

    2001-12-01

    Optimal stereotactic radiosurgery depends on accurate definition of the target and surrounding structures on neuroimaging. The recently developed 3D-Fast-SPGR magnetic resonance (MR) imaging provides high-resolution images of brain anatomy. We investigated various parameters in 3D-Fast-SPGR images both in experimental phantom studies and in assessment of clinical cases of cerebral arteriovenous malformation (AVM) and trigeminal neuralgia. In addition, we investigated the accuracy of coordinates in 3D-Fast-SPGR images. In phantom study, the signal-to-noise ratio (SNR) was best at TE=minimum full and band width (BW)=16 kHz. Contrast ratio between 1.0 mmol/l gadolinium (Gd) solution (compatible with contrast-enhanced vessels) and 0.2 mmol/l Gd solution (compatible with brain parenchyma) was largest at TE=minimum and band width=32 kHz. However, in clinical images of patients, shorter TE (minimum) more clearly reveals feeding arteries as high-intensity vessels without low-intensity flow voids in the assessment of AVMs and identifies arteries pressing against the trigeminal nerve in trigeminal neurlgia cases. We recommend parameters of TE=minimum, band width=16 kHz, TR=19.5 ms, TE=4.2 ms, and FA=25 degrees for radiosurgery dose planning in cases of AVM or trigeminal neuralgia. We also checked the accuracy of each coordinate obtained on 3D-Fast-SPGR axial images. Around the center of Leksell stereotactic G-frame (x=50-150, y=50-150, z=70-130), the error of x-coordinates was 0.48 {+-}0.12 mm, that of y-coordinates was 0.36{+-}0.1 mm, and that of z-coordinates was 0.62{+-}0.38 mm. The error was minimum at the center (x=100, y=100, and z=100). In conclusion, 3D-Fast-SPGR MR imaging is a fast, non-invasive, accurate imaging method for stereotactic radiosurgery. It provides useful information on vascular and parenchymal brain anatomy for optimal dose planning, especially in cases of AVM and trigeminal neuralgia. We believe that it can be used with confidence as the sole

  14. Usefulness of 3D-fast-SPGR MR image for gamma knife radiosurgery planning

    Optimal stereotactic radiosurgery depends on accurate definition of the target and surrounding structures on neuroimaging. The recently developed 3D-Fast-SPGR magnetic resonance (MR) imaging provides high-resolution images of brain anatomy. We investigated various parameters in 3D-Fast-SPGR images both in experimental phantom studies and in assessment of clinical cases of cerebral arteriovenous malformation (AVM) and trigeminal neuralgia. In addition, we investigated the accuracy of coordinates in 3D-Fast-SPGR images. In phantom study, the signal-to-noise ratio (SNR) was best at TE=minimum full and band width (BW)=16 kHz. Contrast ratio between 1.0 mmol/l gadolinium (Gd) solution (compatible with contrast-enhanced vessels) and 0.2 mmol/l Gd solution (compatible with brain parenchyma) was largest at TE=minimum and band width=32 kHz. However, in clinical images of patients, shorter TE (minimum) more clearly reveals feeding arteries as high-intensity vessels without low-intensity flow voids in the assessment of AVMs and identifies arteries pressing against the trigeminal nerve in trigeminal neuralgia cases. We recommend parameters of TE=minimum, band width=16 kHz, TR=19.5 ms, TE=4.2 ms, and FA=25 degrees for radiosurgery dose planning in cases of AVM or trigeminal neuralgia. We also checked the accuracy of each coordinate obtained on 3D-Fast-SPGR axial images. Around the center of Leksell stereotactic G-frame (x=50-150, y=50-150, z=70-130), the error of x-coordinates was 0.48 ±0.12 mm, that of y-coordinates was 0.36±0.1 mm, and that of z-coordinates was 0.62±0.38 mm. The error was minimum at the center (x=100, y=100, and z=100). In conclusion, 3D-Fast-SPGR MR imaging is a fast, non-invasive, accurate imaging method for stereotactic radiosurgery. It provides useful information on vascular and parenchymal brain anatomy for optimal dose planning, especially in cases of AVM and trigeminal neuralgia. We believe that it can be used with confidence as the sole imaging

  15. 3D printed cardiac phantom for procedural planning of a transcatheter native mitral valve replacement

    Izzo, Richard L.; O'Hara, Ryan P.; Iyer, Vijay; Hansen, Rose; Meess, Karen M.; Nagesh, S. V. Setlur; Rudin, Stephen; Siddiqui, Adnan H.; Springer, Michael; Ionita, Ciprian N.

    2016-03-01

    3D printing an anatomically accurate, functional flow loop phantom of a patient's cardiac vasculature was used to assist in the surgical planning of one of the first native transcatheter mitral valve replacement (TMVR) procedures. CTA scans were acquired from a patient about to undergo the first minimally-invasive native TMVR procedure at the Gates Vascular Institute in Buffalo, NY. A python scripting library, the Vascular Modeling Toolkit (VMTK), was used to segment the 3D geometry of the patient's cardiac chambers and mitral valve with severe stenosis, calcific in nature. A stereolithographic (STL) mesh was generated and AutoDesk Meshmixer was used to transform the vascular surface into a functioning closed flow loop. A Stratasys Objet 500 Connex3 multi-material printer was used to fabricate the phantom with distinguishable material features of the vasculature and calcified valve. The interventional team performed a mock procedure on the phantom, embedding valve cages in the model and imaging the phantom with a Toshiba Infinix INFX-8000V 5-axis Carm bi-Plane angiography system. Results: After performing the mock-procedure on the cardiac phantom, the cardiologists optimized their transapical surgical approach. The mitral valve stenosis and calcification were clearly visible. The phantom was used to inform the sizing of the valve to be implanted. Conclusion: With advances in image processing and 3D printing technology, it is possible to create realistic patientspecific phantoms which can act as a guide for the interventional team. Using 3D printed phantoms as a valve sizing method shows potential as a more informative technique than typical CTA reconstruction alone.

  16. Comparison of 3D conformal radiotherapy vs. intensity modulated radiation therapy (IMRT) of a stomach cancer treatment;Comparacion dosimetrica de radioterapia conformal 3D versus radioterapia de intensidad modulada (IMRT) de un tratamiento de cancer de estomago

    Bernui de V, Maria Giselle; Cardenas, Augusto; Vargas, Carlos [Hospital Nacional Carlos Alberto Seguin Escobedo (ESSALUD), Arequipa (Peru). Servicio de Radioterapia

    2009-07-01

    The purpose of this work was to compare the dosimetry in 3D Conformal Radiotherapy with Intensity Modulated Radiation Therapy (IMRT) in a treatment of stomach cancer. For this comparison we selected a patient who underwent subtotal gastrectomy and D2 dissection for a T3N3 adenocarcinoma Mx ECIIIB receiving treatment under the scheme Quimio INT 0116 - in adjuvant radiotherapy. In the treatment plan was contouring the Clinical Target Volume (CTV) and the Planning Target Volume (PTV) was generated from the expansion of 1cm of the CTV, the risky organs contouring were: the liver, kidneys and spinal cord, according to the consensus definition of volumes in gastric cancer. The 3D Conformal Radiotherapy planning is carried out using 6 half beams following the Leong Trevol technique; for the IMRT plan was used 8 fields, the delivery technique is step-and-shoot. In both cases the fields were coplanar, isocentric and the energy used was 18 MV. Intensity Modulated Radiation Therapy (IMRT), in this case has proved to be a good treatment alternative to the technique of 3D Conformal Radiotherapy; the dose distributions with IMRT have better coverage of PTV and positions of the hot spots, as well as the kidneys volume that received higher doses to 2000 cGy is lower, but the decrease in dose to the kidneys is at the expense of increased dose in other organs like the liver. (author)

  17. The role of 3D Helical CT in the reconstructive treatment of maxillofacial cancers

    Purpose of this work is to investigate the role of Helical CT and the usefulness of three-dimensional (3D) imaging for pre-operative planning and follow-up of reconstructive maxillofacial surgery with alloplastic material in neoplastic disease involving this region. From 1996 to 1999 eleven patients were examined with Helical CT and 3D images for planning of maxillofacial plastic and reconstructive surgery for advanced cancer of this anatomically complex region. A 3D-modulated titanium mesh (100%) or micro nets was used to rebuild the anterior surface of maxillary bone and the orbital floor. The mesh was cut to the appropriate size and shape and curved where necessary. Within the residual sinusal cavity a siliconed filling was used surmounting an acrylic prosthesis with dental arch to rebuild the palate. A rehydrated bovine pericardium was affixed and moduled on the borders in two cases only. Three-dimensionally reconstructed CT images were obtained preoperatively and at least 6 months postoperatively in all patients. The images were generated on a computer workstation using the shaded surface display (SSD) software with threshold values ranging 425 to 630 HU, and a more closed window for the imaging of titanium mesh/bone interface in the post surgical follow-up. It was obtained an excellent complete spatial depiction of maxillo facial region both before and after surgery, with no artefacts so important as to affect the 3D reconstruction process and the image quality. Together with the head-neck surgical team it could be worked for preoperative planning through CT scans by different 3D points of view. The 3D reconstructed follow-up scans showed good filling of the defect in the area where the titanium mesh had been used. Then efficacious bone modelling and good biocompatibility of the alloplastic material were seen in all patients, with no inflammatory reactions. Titanium is a well-known material, which is widely used for cranioplasty. It is a radiolucent, non

  18. Modelling and validation for total body irradiation using a 3D planning system

    Pinnacle treatment planning system has been successfully commissioned for total body irradiation and will be used for patient treatments in near future. The actual dose delivered to patients will be monitored with TLDs and diode array and the agreement with the prescribed dose will be further investigated

  19. Dose assessment and dose optimisation in decommissioning using the VISIPLAN 3D ALARA planning tool

    The optimisation of radiological protection of the workers in nuclear industry is an important part of the safety culture especially in the field of decommissioning where we are confronted with a radioactive environment that is in the process of constant change. The application of the ALARA concept (to keep exposures As Low As Reasonably Achievable) is not always straightforward in such cases. A good ALARA pre-job study must be performed and should contain predicted doses in the work area and investigate the effects of geometry, material, source or work position changes. This information provides a quantitative basis to select between various alternative work scenario's for a specific operation. In order to handle this information SCK-CEN developed the VISIPLAN 3D ALARA planning tool. This PC-based tool makes it possible to create and edit work scenarios taking into account worker positions and subsequent geometry and source distribution changes in a 3D environment. The presentation will show the current status of the tool and its application to the decommissioning of the BR3 reactor and other installations. New developments will also be presented regarding the geometric and radioactive characterisation of a decommissioning site. The use of human motion simulation tools in ALARA assessment will also be discussed. This will show how new developments of software and measurement tools can help dealing with the new challenges of decommissioning in the field of dose optimization. (authors)

  20. Surgical Planning by 3D Printing for Primary Cardiac Schwannoma Resection.

    Son, Kuk Hui; Kim, Kun-Woo; Ahn, Chi Bum; Choi, Chang Hu; Park, Kook Yang; Park, Chul Hyun; Lee, Jae-Ik; Jeon, Yang Bin

    2015-11-01

    We report herein a case of benign cardiac schwannoma in the interatrial septum. A 42-year-old woman was transferred from a clinic because of cardiomegaly as determined by chest X-ray. A transthoracic echocardiography and chest computed tomography examination revealed a huge mass in the pericardium compressing the right atrium, superior vena cava (SVC), left atrium, and superior pulmonary vein. To confirm that the tumor originated from either heart or mediastinum, cine magnetic resonance imaging was performed, but the result was not conclusive. To facilitate surgical planning, we used 3D printing. Using a printed heart model, we decided that tumor resection under cardiopulmonary bypass (CPB) through sternotomy would be technically feasible. At surgery, a huge tumor in the interatrial septum was confirmed. By incision on the atrial roof between the aorta and SVC, tumor enucleation was performed successfully under CPB. Pathology revealed benign schwannoma. The patient was discharged without complication. 3D printing of the heart and tumor was found to be helpful when deciding optimal surgical approach. PMID:26446661

  1. Experimental evaluations of the accuracy of 3D and 4D planning in robotic tracking stereotactic body radiotherapy for lung cancers

    Chan, Mark K. H. [Department of Clinical Oncology, The University of Hong Kong and Department of Clinical Oncology, Tuen Mun Hospital, Hong Kong Special Administrative Region, 999077 (Hong Kong); Kwong, Dora L. W.; Ng, Sherry C. Y. [Department of Clinical Oncology, Queen Mary Hospital, Hong Kong Special Administrative Region, 999077 (Hong Kong); Tong, Anthony S. M.; Tam, Eric K. W. [Theresa Po CyberKnife Center, Hong Kong Special Administrative Region, 999077 (Hong Kong)

    2013-04-15

    Purpose: Due to the complexity of 4D target tracking radiotherapy, the accuracy of this treatment strategy should be experimentally validated against established standard 3D technique. This work compared the accuracy of 3D and 4D dose calculations in respiration tracking stereotactic body radiotherapy (SBRT). Methods: Using the 4D planning module of the CyberKnife treatment planning system, treatment plans for a moving target and a static off-target cord structure were created on different four-dimensional computed tomography (4D-CT) datasets of a thorax phantom moving in different ranges. The 4D planning system used B-splines deformable image registrations (DIR) to accumulate dose distributions calculated on different breathing geometries, each corresponding to a static 3D-CT image of the 4D-CT dataset, onto a reference image to compose a 4D dose distribution. For each motion, 4D optimization was performed to generate a 4D treatment plan of the moving target. For comparison with standard 3D planning, each 4D plan was copied to the reference end-exhale images and a standard 3D dose calculation was followed. Treatment plans of the off-target structure were first obtained by standard 3D optimization on the end-exhale images. Subsequently, they were applied to recalculate the 4D dose distributions using DIRs. All dose distributions that were initially obtained using the ray-tracing algorithm with equivalent path-length heterogeneity correction (3D{sub EPL} and 4D{sub EPL}) were recalculated by a Monte Carlo algorithm (3D{sub MC} and 4D{sub MC}) to further investigate the effects of dose calculation algorithms. The calculated 3D{sub EPL}, 3D{sub MC}, 4D{sub EPL}, and 4D{sub MC} dose distributions were compared to measurements by Gafchromic EBT2 films in the axial and coronal planes of the moving target object, and the coronal plane for the static off-target object based on the {gamma} metric at 5%/3mm criteria ({gamma}{sub 5%/3mm}). Treatment plans were considered

  2. 3D Path Planning for Autonomous Aerial Vehicles in Constrained Spaces

    Schøler, Flemming

    . The primary contributions of this thesis are an approximate path planner and a geodesic path planner. Both planners are model independent and operate on the surface of the configuration space to identify a length minimizing path. The approximate planner determines an approximated shortest path by building...... the path to find a collision free trajectory that is more appropriate for flight. The geodesic planner relates to wavefront-type planning, and identifies continuously differentiable geodesic paths as parametric equations determined by surface primitives given from the configuration space. Consequently......, this planner uses a more analytical approach since it relies on combinations of optimal curves. Both planners operate on an explicit description of the configuration space in a work space containing 3D obstacles. A method was developed that generates convex configuration space obstacles from any point clouds...

  3. Treating benign optic nerve tumors with a 3-D conformal plan

    A 68 year old male patient presented for radiation therapy for treatment of a benign tumor, a glioma of his left optic nerve. The radiation oncologist intended to prescribe 52.2 Gy to the planning target volume, while maintaining a maximum of 54 Gy to the optic nerves and the optic chiasm and a maximum of 40–45 Gy to the globes in order to minimize the possibility of damaging the optic system, which is especially important as this is a benign tumor. The dosimetrist devised a conformal non-coplanar three-dimensional plan with a slightly weighted forward planning component. This plan was created in approximately 15 minutes after the critical organs and the targets were delineated and resulted in an extremely conformal and homogenous plan, treating the target while sparing the nearby critical structures. This approach can also be extended to other tumors in the brain - benign or malignant

  4. Mechanically assisted 3D ultrasound for pre-operative assessment and guiding percutaneous treatment of focal liver tumors

    Sadeghi Neshat, Hamid; Bax, Jeffery; Barker, Kevin; Gardi, Lori; Chedalavada, Jason; Kakani, Nirmal; Fenster, Aaron

    2014-03-01

    Image-guided percutaneous ablation is the standard treatment for focal liver tumors deemed inoperable and is commonly used to maintain eligibility for patients on transplant waitlists. Radiofrequency (RFA), microwave (MWA) and cryoablation technologies are all delivered via one or a number of needle-shaped probes inserted directly into the tumor. Planning is mostly based on contrast CT/MRI. While intra-procedural CT is commonly used to confirm the intended probe placement, 2D ultrasound (US) remains the main, and in some centers the only imaging modality used for needle guidance. Corresponding intraoperative 2D US with planning and other intra-procedural imaging modalities is essential for accurate needle placement. However, identification of matching features of interest among these images is often challenging given the limited field-of-view (FOV) and low quality of 2D US images. We have developed a passive tracking arm with a motorized scan-head and software tools to improve guiding capabilities of conventional US by large FOV 3D US scans that provides more anatomical landmarks that can facilitate registration of US with both planning and intra-procedural images. The tracker arm is used to scan the whole liver with a high geometrical accuracy that facilitates multi-modality landmark based image registration. Software tools are provided to assist with the segmentation of the ablation probes and tumors, find the 2D view that best shows the probe(s) from a 3D US image, and to identify the corresponding image from planning CT scans. In this paper, evaluation results from laboratory testing and a phase 1 clinical trial for planning and guiding RFA and MWA procedures using the developed system will be presented. Early clinical results show a comparable performance to intra-procedural CT that suggests 3D US as a cost-effective alternative with no side-effects in centers where CT is not available.

  5. Sci—Sat AM: Stereo — 01: 3D Pre-treatment Dose Verification for Stereotactic Body Radiation Therapy Patients

    Asuni, G; Beek, T van; Van Utyven, E [Medical Physics Department, CancerCare Manitoba, Winnipeg, Manitoba (Canada); McCowan, P [Medical Physics Department, CancerCare Manitoba, Winnipeg, Manitoba (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba (Canada); McCurdy, B.M.C. [Medical Physics Department, CancerCare Manitoba, Winnipeg, Manitoba (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba (Canada); Department of Radiology, University of Manitoba, Winnipeg Manitoba (Canada)

    2014-08-15

    Radical treatment techniques such as stereotactic body radiation therapy (SBRT) are becoming popular and they involve delivery of large doses in fewer fractions. Due to this feature of SBRT, a high-resolution, pre-treatment dose verification method that makes use of a 3D patient representation would be appropriate. Such a technique will provide additional information about dose delivered to the target volume(s) and organs-at-risk (OARs) in the patient volume compared to 2D verification methods. In this work, we investigate an electronic portal imaging device (EPID) based pre-treatment QA method which provides an accurate reconstruction of the 3D-dose distribution in the patient model. Customized patient plans are delivered ‘in air’ and the portal images are collected using the EPID in cine mode. The images are then analysed to determine an estimate of the incident energy fluence. This is then passed to a collapsed-cone convolution dose algorithm which reconstructs a 3D patient dose estimate on the CT imaging dataset. To date, the method has been applied to 5 SBRT patient plans. Reconstructed doses were compared to those calculated by the TPS. Reconstructed mean doses were mostly within 3% of those in the TPS. DVHs of target volumes and OARs compared well. The Chi pass rates using 3%/3mm in the high dose region are greater than 97% in all cases. These initial results demonstrate clinical feasibility and utility of a robust, efficient, effective and convenient pre-treatment QA method using EPID. Research sponsored in part by Varian Medical Systems.

  6. Sci—Sat AM: Stereo — 01: 3D Pre-treatment Dose Verification for Stereotactic Body Radiation Therapy Patients

    Radical treatment techniques such as stereotactic body radiation therapy (SBRT) are becoming popular and they involve delivery of large doses in fewer fractions. Due to this feature of SBRT, a high-resolution, pre-treatment dose verification method that makes use of a 3D patient representation would be appropriate. Such a technique will provide additional information about dose delivered to the target volume(s) and organs-at-risk (OARs) in the patient volume compared to 2D verification methods. In this work, we investigate an electronic portal imaging device (EPID) based pre-treatment QA method which provides an accurate reconstruction of the 3D-dose distribution in the patient model. Customized patient plans are delivered ‘in air’ and the portal images are collected using the EPID in cine mode. The images are then analysed to determine an estimate of the incident energy fluence. This is then passed to a collapsed-cone convolution dose algorithm which reconstructs a 3D patient dose estimate on the CT imaging dataset. To date, the method has been applied to 5 SBRT patient plans. Reconstructed doses were compared to those calculated by the TPS. Reconstructed mean doses were mostly within 3% of those in the TPS. DVHs of target volumes and OARs compared well. The Chi pass rates using 3%/3mm in the high dose region are greater than 97% in all cases. These initial results demonstrate clinical feasibility and utility of a robust, efficient, effective and convenient pre-treatment QA method using EPID. Research sponsored in part by Varian Medical Systems

  7. SU-E-T-77: Comparison of 2D and 3D Gamma Analysis in Patient-Specific QA for Prostate VMAT Plans

    Clemente, F; Perez, C [Hospital Central de la Defensa Gomez Ulla, Madrid, Madrid (Spain)

    2014-06-01

    Purpose: Patient-specific QA procedures for IMRT and VMAT are traditionally performed by comparing TPS calculations with measured single point values and plane dose distributions by means of gamma analysis. New QA devices permit us to calculate 3D dose distributions on patient anatomy as redundant secondary check and reconstruct it from measurements taken with 2D and 3D detector arrays. 3D dose calculations allow us to perform DVH-based comparisons with clinical relevance, as well as 3D gamma analysis. One of these systems (Compass, IBA Dosimetry) combines traditional 2D with new anatomical-based 3D gamma analysis. This work shows the ability of this system by comparing 2D and 3D gamma analysis in pre-treatment QA for several VMAT prostate plans. Methods: Compass is capable of calculating dose as secondary check from DICOM TPS data and reconstructing it from measurements taken by a 2D ion chamber array (MatriXX Evolution, IBA Dosimetry). Both 2D and 3D gamma tests are available to compare calculated and reconstructed dose in Compass with TPS RT Dose. Results: 15 VMAT prostate plans have been measured with Compass. Dose is reconstructed with Compass for these plans. 2D gamma comparisons can be done for any plane from dose matrix. Mean gamma passing rates for isocenter planes (axial, coronal, sagittal) are (99.7±0.2)%, (99.9±0.1)%, (99.9±0.1)% for reconstructed dose planes. 3D mean gamma passing rates are (98.5±1.7)% for PTVs, (99.1±1.5)% for rectum, (100.0±0.0)% for bladder, (99.6±0.7)% for femoral heads and (98.1±4.1)% for penile bulb. Conclusion: Compass is a powerful tool to perform a complete pre-treatment QA analysis, from 2D techniques to 3D DVH-based techniques with clinical relevance. All reported values for VMAT prostate plans are in good agreement with TPS values. This system permits us to ensure the accuracy in the delivery of VMAT treatments completing a full patient-specific QA program.

  8. Physical-dosimetric enabling a dual linear accelerator 3D planning systems for radiotherapy

    The process of commissioning clinical linear accelerator requires a dual comprehensive study of the therapeutic beam parameters, both photons Electron. All information gained by measuring physical and dosimetric these beams must be analyzed, processed and refined for further modeling in computer-based treatment planning (RTPS). Of professionalism of this process will depend on the accuracy and precision of the calculations the prescribed doses. This paper aims to demonstrate availability clinical linear accelerator system-RTPS with late radiotherapy treatments shaped beam of photons and electrons. (author)

  9. A framework for inverse planning of beam-on times for 3D small animal radiotherapy using interactive multi-objective optimisation

    Advances in precision small animal radiotherapy hardware enable the delivery of increasingly complicated dose distributions on the millimeter scale. Manual creation and evaluation of treatment plans becomes difficult or even infeasible with an increasing number of degrees of freedom for dose delivery and available image data. The goal of this work is to develop an optimisation model that determines beam-on times for a given beam configuration, and to assess the feasibility and benefits of an automated treatment planning system for small animal radiotherapy.The developed model determines a Pareto optimal solution using operator-defined weights for a multiple-objective treatment planning problem. An interactive approach allows the planner to navigate towards, and to select the Pareto optimal treatment plan that yields the most preferred trade-off of the conflicting objectives. This model was evaluated using four small animal cases based on cone-beam computed tomography images. Resulting treatment plan quality was compared to the quality of manually optimised treatment plans using dose-volume histograms and metrics.Results show that the developed framework is well capable of optimising beam-on times for 3D dose distributions and offers several advantages over manual treatment plan optimisation. For all cases but the simple flank tumour case, a similar amount of time was needed for manual and automated beam-on time optimisation. In this time frame, manual optimisation generates a single treatment plan, while the inverse planning system yields a set of Pareto optimal solutions which provides quantitative insight on the sensitivity of conflicting objectives. Treatment planning automation decreases the dependence on operator experience and allows for the use of class solutions for similar treatment scenarios. This can shorten the time required for treatment planning and therefore increase animal throughput. In addition, this can improve treatment standardisation and

  10. Virtual film technique used in 3d and step-shot IMRT planning check

    Full text: A virtual film technique developed and used in segmented field dose reconstruction for IMRT planning dose distribution check. Film dosimetry analysis is commonly used for the isodose curve comparison but the result can be affected by film dosimetry technical problems, and the film processing also takes a significant amount of workload. This study is focused on using digital image technique to reconstruct dose distribution for a 3D plan by mapping water-scanning data on screen in black and white intensity value, and by simulating the film analysis process to plot equivalent Isodose curve for the planning Isodose comparison check. In-house developed software is used to select the TPR (Tissue-Phantom Ratio) and OCR (Off Central-Axis Ratio) data for different beam field types and sizes; each point dose of the field is interpolated and converted into the greyscale pixel value. The location of the pixel is calculated by the triangular function according to the beam entry position and gantry/collimator angles. After each segment field is processed, the program gathers all the segments and overlays the greyscale value pixel by pixel for all the segments into a combined map. The background value is calibrated to match the water scan curve background level. The penumbra slope is adjusted by an interpolated divergent angle according to the OAD (Off Central-Axis Distance) of the field. A normal film dosimetry analysis can then be performed to plot the Isodose curves. By comparing some typical fields with both single beam and segmented IMRT fields, with the point dose checked by ionization measurement, the central point dose discrepancy is within ±2% and the maximum 3-5% for a random point using TLD technique. Compare the Isodose overlaying result to planning curves for both perpendicular and lateral beam. Although the curve shape for the virtual film viewed is more artificial compared with real film, the results are easier to compare for the quantity analysis with

  11. Planning and Implementing a 3D Printing Service in an Academic Library

    Gonzalez, Sara Russell; Bennett, Denise Beaubien

    2014-01-01

    Initiating a 3D printing service in an academic library goes beyond justification of its value and gaining the necessary library and administrative support. Additional aspects such as policies, environmental safety, training, publicizing, maintenance, and scope of service must be considered. This article provides a guide to developing a 3D print…

  12. Proton radiation therapy (prt) for pediatric optic pathway gliomas: comparison with 3d planned conventional photons and a standard photon technique

    Purpose: Following adequate therapy, excellent long-term survival rates can be achieved for patients with optic pathway gliomas. Therefore, avoidance of treatment-related functional long-term sequelae is of utmost importance. Optimized sparing of normal tissue is of primary concern in the development of new treatment modalities. The present study compares proton radiation therapy (PRT) with a three-dimensional (3D)-planned multiport photon and a lateral beam photon technique for localized and extensive optic pathway tumors. Methods and Materials: Between February 1992 and November 1997, seven children with optic pathway gliomas underwent PRT. For this study, we computed proton, 3D photon, and lateral photon plans based on the same CT data sets, and using the same treatment planning software for all plans. Radiation exposure for normal tissue and discrete organs at risk was quantified based on dose-volume histograms. Results: Gross tumor volume (GTV) ranged from 3.9 cm3 to 127.2 cm3. Conformity index (relation of encompassing isodose to GTV volume) was 2.3 for protons, 2.9 for 3D photons, and 7.3 for lateral photons. The relative increase of normal tissue (NT) encompassed at several isodose levels in relation to NT encompassed by the 95% proton isodose volume was computed. Relative NT volume of proton plan isodoses at the 95%, 90%, 80%, 50%, and 25% isodose level increased from 1 to 1.6, 2.8, 6.4, to a maximum of 13.3. Relative volumes for 3D photons were 1.6, 2.4, 3.8, 11.5, and 34.8. Lateral plan relative values were 6, 8.3, 11.5, 19.2, and 26.8. Analysis for small (3) and larger (> 80 cm3) tumors showed that protons encompassed the smallest volumes of NT at all isodose levels. Comparable conformity and high-dose gradient were achieved for proton and 3D photon plans in small tumors. However, with increasing tumor volume and complexity, differences became larger. At the 50% isodose level, 3D photons were superior to lateral photons for small tumors; this advantage

  13. Results of the European research project 'Improving the effectiveness of cancer treatment with 3D Brachytherapy'

    The project iMERA + T2.J06 'Improving the effectiveness of cancer treatment using 3D brachytherapy' was solved in the period 2008-2011 in collaboration of metrology institutes from 10 European Union countries, including participation of the Czech Republic. Its main objective was to create a means to ensure metrological quantity absorbed dose in water from brachyterapeutical (BT) sources enabling more accurate assessment of therapeutic benefit than using existing dosimetry protocols that are based on the quantity kerma in the air. This project is discussed.

  14. Sampling-Based Sweep Planning to Exploit Local Planarity in the Inspection of Complex 3d Structures

    Englot, Brendan J.; Hover, Franz S.

    2012-01-01

    We present a hybrid algorithm that plans feasible paths for 100% sensor coverage of complex 3D structures. The structures to be inspected are segmented to isolate planar areas, and back-and-forth sweep paths are generated to view as much of these planar areas as possible while avoiding collision. A randomized planning procedure fills in the remaining gaps in coverage. The problem of selecting an order to traverse the elements of the inspection is solved by reduction to the traveling salesman ...

  15. Treatment of left sided breast cancer for a patient with funnel chest: Volumetric-modulated arc therapy vs. 3D-CRT and intensity-modulated radiotherapy

    This case study presents a rare case of left-sided breast cancer in a patient with funnel chest, which is a technical challenge for radiation therapy planning. To identify the best treatment technique for this case, 3 techniques were compared: conventional tangential fields (3D conformal radiotherapy [3D-CRT]), intensity-modulated radiotherapy (IMRT), and volumetric-modulated arc therapy (VMAT). The plans were created for a SynergyS® (Elekta, Ltd, Crawley, UK) linear accelerator with a BeamModulator™ head and 6-MV photons. The planning system was Oncentra Masterplan® v3.3 SP1 (Nucletron BV, Veenendal, Netherlands). Calculations were performed with collapsed cone algorithm. Dose prescription was 50.4 Gy to the average of the planning target volume (PTV). PTV coverage and homogeneity was comparable for all techniques. VMAT allowed reducing dose to the ipsilateral organs at risk (OAR) and the contralateral breast compared with IMRT and 3D-CRT: The volume of the left lung receiving 20 Gy was 19.3% for VMAT, 26.1% for IMRT, and 32.4% for 3D-CRT. In the heart, a D15% of 9.7 Gy could be achieved with VMAT compared with 14 Gy for IMRT and 46 Gy for 3D-CRT. In the contralateral breast, D15% was 6.4 Gy for VMAT, 8.8 Gy for IMRT, and 10.2 Gy for 3D-CRT. In the contralateral lung, however, the lowest dose was achieved with 3D-CRT with D10% of 1.7 Gy for 3D-CRT, and 6.7 Gy for both IMRT and VMAT. The lowest number of monitor units (MU) per 1.8-Gy fraction was required by 3D-CRT (192 MU) followed by VMAT (518 MU) and IMRT (727 MU). Treatment time was similar for 3D-CRT (3 min) and VMAT (4 min) but substantially increased for IMRT (13 min). VMAT is considered the best treatment option for the presented case of a patient with funnel chest. It allows reducing dose in most OAR without compromising target coverage, keeping delivery time well below 5 minutes

  16. Steering in loco-regional deep hyperthermia: evaluation of common practice with 3D-planning

    Full text: Radiotherapy plus hyperthermia is standard treatment for locally advanced cervical cancer. In our unit the hyperthermia treatment of these patients is performed with a BSD 2000 3D deep hyperthermia system. In order to apply loco-regional deep hyperthermia at a maximum dose level, protocolized SAR steering is used to optimize tumor temperatures, avoid toxicity and minimize complaints due to local overheating. SAR steering is the term we use to address all changes in antenna settings that affect the distribution of dissipated power. The protocol used to guide SAR steering reflects an empirical strategy based on the experience gathered over the last decade. With the availability of sophisticated codes to predict patient specific EM fields, we are now able to prospectively evaluate the effectiveness of the applied amplitude and phase settings, and of the steering protocol. In this study, we evaluate the effect of prescribed steering actions in a patient model according to the treatment protocol. In particular, we assess the effectiveness of both phase and amplitude steering to control power dissipation at the tumor location and at the surface. From the simulations it is clear that the SAR focus within the pelvis falls apart in three different maxima. One located at the ventral side and associated with the os pubis, one located at the backside and associated with the lumbosacral vertebrae, and one in the middle associated with the tumor volume. Instead of continuously shifting the SAR focus, both phase- and amplitude steering in the AP direction merely changes the ratio of dissipated power in the three different areas. To elucidate the difference between phase and amplitude steering in the AP direction, we divide our patient model in three regions of interest. These regions are indicated as front (f), middle (m) and back (b). For these regions total integrated power absorption was calculated at a range of phase and amplitude settings. In figure 1a the ratio

  17. A 3D technique for simulation of irregular electron treatment fields using a digital camera

    Cerrobend inserts, which define electron field apertures, are manufactured at our institution using perspex templates. Contours are reproduced manually on these templates at the simulator from the field outlines drawn on the skin or mask of a patient. A previously reported technique for simulation of electron treatment fields uses a digital camera to eliminate the need for such templates. However, avoidance of the image distortions introduced by non-flat surfaces on which the electron field outlines were drawn could only be achieved by limiting the application of this technique to surfaces which were flat or near flat. We present a technique that employs a digital camera and allows simulation of electron treatment fields contoured on an anatomical surface of an arbitrary three-dimensional (3D) shape, such as that of the neck, extremities, face, or breast. The procedure is fast, accurate, and easy to perform

  18. Biologically relevant 3D tumor arrays: treatment response and the importance of stromal partners

    Rizvi, Imran; Celli, Jonathan P.; Xu, Feng; Evans, Conor L.; Abu-Yousif, Adnan O.; Muzikansky, Alona; Elrington, Stefan A.; Pogue, Brian W.; Finkelstein, Dianne M.; Demirci, Utkan; Hasan, Tayyaba

    2011-02-01

    The development and translational potential of therapeutic strategies for cancer is limited, in part, by a lack of biological models that capture important aspects of tumor growth and treatment response. It is also becoming increasingly evident that no single treatment will be curative for this complex disease. Rationally-designed combination regimens that impact multiple targets provide the best hope of significantly improving clinical outcomes for cancer patients. Rapidly identifying treatments that cooperatively enhance treatment efficacy from the vast library of candidate interventions is not feasible, however, with current systems. There is a vital, unmet need to create cell-based research platforms that more accurately mimic the complex biology of human tumors than monolayer cultures, while providing the ability to screen therapeutic combinations more rapidly than animal models. We have developed a highly reproducible in vitro three-dimensional (3D) tumor model for micrometastatic ovarian cancer (OvCa), which in conjunction with quantitative image analysis routines to batch-process large datasets, serves as a high throughput reporter to screen rationally-designed combination regimens. We use this system to assess mechanism-based combination regimens with photodynamic therapy (PDT), which sensitizes OvCa to chemo and biologic agents, and has shown promise in clinic trials. We show that PDT synergistically enhances carboplatin efficacy in a sequence dependent manner. In printed heterocellular cultures we demonstrate that proximity of fibroblasts enhances 3D tumor growth and investigate co-cultures with endothelial cells. The principles described here could inform the design and evaluation of mechanism-based therapeutic options for a broad spectrum of metastatic solid tumors.

  19. Solid works 3D

    This book explains modeling of solid works 3D and application of 3D CAD/CAM. The contents of this book are outline of modeling such as CAD and 2D and 3D, solid works composition, method of sketch, writing measurement fixing, selecting projection, choosing condition of restriction, practice of sketch, making parts, reforming parts, modeling 3D, revising 3D modeling, using pattern function, modeling necessaries, assembling, floor plan, 3D modeling method, practice floor plans for industrial engineer data aided manufacturing, processing of CAD/CAM interface.

  20. Computerized radiation treatment planning

    Following a general introduction, a chain consisting of three computer programs which has been developed for treatment planning of external beam radiotherapy without manual intervention is described. New score functions used for determination of optimal incidence directions are presented and the calculation of the position of the isocentre for each optimum combination of incidence directions is explained. A description of how a set of applicators, covering fields with dimensions of 4 to 20 cm, for the 6 to 20 MeV electron beams of a MEL SL75-20 linear accelerator was developed, is given. A computer program for three dimensional electron beam treatment planning is presented. A microprocessor based treatment planning system for the Selectron remote controlled afterloading system for intracavitary radiotherapy is described. The main differences in treatment planning procedures for external beam therapy with neutrons instead of photons is discussed. A microprocessor based densitometer for plotting isodensity lines in film dosimetry is described. A computer program for dose planning of brachytherapy is presented. Finally a general discussion about the different aspects of computerized treatment planning as presented in this thesis is given. (Auth.)

  1. QA of treatment planning systems

    Protocols for commissioning and performance of treatment planning systems have been proposed and performed at several occasions. These tests are valuable, but it is evident that we need a more comprehensive QA for the planning systems. International bodies are working on this subject today, and recommendations will soon appear. However, very little results and experiences are published from running QA protocols. In our department we have been using an in house 2D system for many years, and as both developer and user we needed a QA protocol. Two years ago we bought a commercial 3D system, and a new QA protocol had to be set up for this situation. This protocol include: 1) description of duties for responsible persons, 2) education/competence levels for users, 3) acceptance tests for both system and treatment unit data, and 4) constancy tests for the same. Experience so far reveals that a QA protocol is necessary for use of sophisticated 3D systems, even though no error in the system itself have been found that would have given erroneous dosage. Clear definitions of who is responsible for the different aspects of using the system has proven essential. An introductory course have to be given to all new users to avoid misuse. Acceptance tests of system is necessary, not only to accept the system but also to learn how to use it correctly and detect its limitations. Acceptance tests of basic treatment unit data is mandatory before they can be taken into clinical use. Also constancy tests have proven necessary when modifications are done. The experience with such a protocol gives lot of input back to the manufacturer too. It also raises principal questions about what should be checked and what is the responsibility of the manufacturers. More details will be presented in the meeting

  2. Surgical treatment of kyphosis in children with scheuermann’s diseaseusing 3D-CT navigation

    Sergei Valentinovich Vissarionov

    2015-03-01

    Full Text Available The purpose of the study is to describe features of the surgical technique for correction of kyphotic deformity of the spine and to analyze the results of surgical treatment of juvenile kyphosis in children with the use of 3D-CT navigation.— Materials and methods. We observed 11 patientsaged 14-17 years old (2 girls and 9 boys with kyphoticdeformity of the spine, developed on the backgroundof Scheuermann’s disease. The deformity amount aver-aged 73,9° (60 to 90°. Surgery was performed fromthe combined access, carring out discapophysectomyand corporodesis on top of kyphosis and fixing mul-tibasic corrective metal construction. For the insertionof pedicle screws we used 3D-CT navigation.— The results. After surgery kyphosis value decreasedto 32,6° (20 to 45°, the deformity correction averaged41,3° (30 to 50°. Hybrid systems were placed in 5 pa-tients, total transpedicular fixation - in 6 children.Number of fixed vertebrae with hybrid metal construc-tions averaged 14 (13 to 15, in patients with total pediclefixation - 13 (12 to 14. In all cases we observed the correct position of pedicle support elements. Postopera- tive follow-up period was from 1 year and 5 months to5 years and 4 months, on average - 3 years 5 months. The loss of the result achieved in the long-term follow- up period was observed in patients with hybrid metal constructions and averaged 7,2° (4 to 9°.— Conclusion. The use of pedicle screws for thecorrection of juvenile kyphosis in children allows forthe effective correction of the deformity, restoring thephysiological profiles of the spine, eliminating post-operative progression of curvature, and reducing thelength of metal fixation and save the result achievedin the long-term follow-up. The use of active optical3D-CT navigation allows carring out a correct inser-tion of pedicle screws in the vertebral bodies in chil-dren with juvenile kyphosis.— Keywords: Scheuermann’s disease, juvenile ky-phosis, transpedicular

  3. Advantages of three-dimensional treatment planning in radiation therapy

    This study was designed to demonstrate the feasibility of three-dimensional (3-D) treatment planning in-patients maxilla, breast, bladder, and lung tumors to explore its potential therapeutic advantage over the traditional dimensional (2-D) approach in these diseases. Conventional two-dimensional (2-D) treatment planning was compared to three-dimensional (3-D) treatment planning. In five selected disease sites, plans calculated with both types of treatment planning were compared. The (3-D) treatment planning system used in this work TMS version 5.1 B from helax AB is based on a monte Carlo-based pencil beam model. The other treatment planning system (2-D 0, introduced in this study was the multi data treatment planning system version 2.35. For the volumes of interest; quality of dose distribution concerning homogeneity in the target volume and the isodose distribution in organs at risk, was discussed. Qualitative and quantitative comparisons between the two planning systems were made using dose volume histograms (DVH's) . For comparisons of dose distributions in real-patient cases, differences ranged from 0.8% to 6.4% for 6 MV, while in case of 18 MV photon, it ranged from 1,8% to 6.5% and was within -+3 standard deviations for the dose between the two planning systems.Dose volume histogram (DVH) shows volume reduction of the radiation-related organs at risk 3-D planning

  4. Combining supine MRI and 3D optical scanning for improved surgical planning of breast conserving surgeries

    Pallone, Matthew J.; Poplack, Steven P.; Barth, Richard J., Jr.; Paulsen, Keith D.

    2012-02-01

    Image-guided wire localization is the current standard of care for the excision of non-palpable carcinomas during breast conserving surgeries (BCS). The efficacy of this technique depends upon the accuracy of wire placement, maintenance of the fixed wire position (despite patient movement), and the surgeon's understanding of the spatial relationship between the wire and tumor. Notably, breast shape can vary significantly between the imaging and surgical positions. Despite this method of localization, re-excision is needed in approximately 30% of patients due to the proximity of cancer to the specimen margins. These limitations make wire localization an inefficient and imprecise procedure. Alternatively, we investigate a method of image registration and finite element (FE) deformation which correlates preoperative supine MRIs with 3D optical scans of the breast surface. MRI of the breast can accurately define the extents of very small cancers. Furthermore, supine breast MR reduces the amount of tissue deformation between the imaging and surgical positions. At the time of surgery, the surface contour of the breast may be imaged using a handheld 3D laser scanner. With the MR images segmented by tissue type, the two scans are approximately registered using fiducial markers present in both acquisitions. The segmented MRI breast volume is then deformed to match the optical surface using a FE mechanical model of breast tissue. The resulting images provide the surgeon with 3D views and measurements of the tumor shape, volume, and position within the breast as it appears during surgery which may improve surgical guidance and obviate the need for wire localization.

  5. Completion of treatment planning

    The outline of the lecture included the following topics: entering prescription; plan printout; print and transfer DDR; segment BEV; export to R and V; physician approval; and second check. Considerable attention, analysis and discussion. The summary is as follows: Treatment planning completion is a very responsible process which requires maximum attention; Should be independently checked by the planner, physicist, radiation oncologist and a therapist; Should not be done in a last minute rush; Proper communication between team members; Properly set procedure should prevent propagation of an error by one individual to the treatment: the error should be caught by somebody else. (P.A.)

  6. 3D Road-Mapping in the Endovascular Treatment of Cerebral Aneurysms and Arteriovenous Malformations

    Rossitti, S.; Pfister, M

    2009-01-01

    3D road-mapping with syngo iPilot was used as an additional tool for assessing cerebral aneurysms and arteriovenous malformations (AVMs) for endovascular therapy. This method provides accurate superimposition of a live fluoroscopic image (native or vascular road-map) and its matching 2D projection of the 3D data set, delivering more anatomic information on one additional display. In the endovascular management of cases with complex anatomy, 3D road-mapping provides excellent image quality at ...

  7. Volumetric Next-best-view Planning for 3D Object Reconstruction with Positioning Error

    J. Irving Vasquez-Gomez

    2014-10-01

    Full Text Available Three-dimensional (3D object reconstruction is the process of building a 3D model of a real object. This task is performed by taking several scans of an object from different locations (views. Due to the limited field of view of the sensor and the object’s self-occlusions, it is a difficult problem to solve. In addition, sensor positioning by robots is not perfect, making the actual view different from the expected one. We propose a next best view (NBV algorithm that determines each view to reconstruct an arbitrary object. Furthermore, we propose a method to deal with the uncertainty in sensor positioning. The algorithm fulfills all the constraints of a reconstruction process, such as new information, positioning constraints, sensing constraints and registration constraints. Moreover, it improves the scan’s quality and reduces the navigation distance. The algorithm is based on a search-based paradigm where a set of candidate views is generated and then each candidate view is evaluated to determine which one is the best. To deal with positioning uncertainty, we propose a second stage which re-evaluates the views according to their neighbours, such that the best view is that which is within a region of the good views. The results of simulation and comparisons with previous approaches are presented.

  8. A unified framework for 3D radiation therapy and IMRT planning: plan optimization in the beamlet domain by constraining or regularizing the fluence map variations

    The purpose of this work is to demonstrate that physical constraints on fluence gradients in 3D radiation therapy (RT) planning can be incorporated into beamlet optimization explicitly by direct constraint on the spatial variation of the fluence maps or implicitly by using total-variation regularization (TVR). The former method forces the fluence to vary in accordance with the known form of a wedged field and latter encourages the fluence to take the known form of the wedged field by requiring the derivatives of the fluence maps to be piece-wise constant. The performances of the proposed methods are evaluated by using a brain cancer case and a head and neck case. It is found that both approaches are capable of providing clinically sensible 3D RT solutions with monotonically varying fluence maps. For currently available 3D RT delivery schemes based on the use of customized physical or dynamic wedges, constrained optimization seems to be more useful because the optimized fields are directly deliverable. Working in the beamlet domain provides a natural way to model the spatial variation of the beam fluence. The proposed methods take advantage of the fact that 3D RT is a special form of intensity-modulated radiation therapy (IMRT) and finds the optimal plan by searching for fields with a certain type of spatial variation. The approach provides a unified framework for 3D CRT and IMRT plan optimization. (note)

  9. Radiotherapy treatment planning

    A teaching text on external beam radiotherapy treatment planning is presented. Chapters are included on machines, radiation units, the physics of a single radiation field, the multiple-field isodose curve pattern, electron beam therapy, manual addition of isodose curves and dose calculation methods. (U.K.)

  10. Sci—Sat AM: Stereo — 06: Dosimetric Comparison of 3D Conformai, Flattened and Flattening Filter-Free TrueBeam RapidArc Planning for Lung SBRT

    Jiang, Runqing; Zhan, Lixin; Osei, Ernest [Grand River Regional Cancer Center, Grand River Hospital, Kitchener, Ontario (Canada)

    2014-08-15

    The major advantages of the VMAT SBRT plans compared to the conventional 3D conformai plan include faster delivery and improved target dose conformity. This study quantifies the dosimetric differences among 3D conformai plan; flattened beam and flattening filter-free (FFF) beam RapidArc Plans for lung SBRT. Five early stage lung cancer patients with various tumor positions and sizes previously treated with 3D non-coplanar SBRT were randomly selected. 4DCT was used for each patient to determine the internal target volume. Abdominal compression was applied to minimize respiratory motion for SBRT patients. For treatment planning, a 5 mm margin was given to the ITV to generate a planning target volume. The prescription dose was 48 Gy in 4 fractions and normalized to 95% of the PTV. Organs at risk (OAR) included spinal cord, esophagus, heart, trachea, bilateral lung, and great vessels. Optimization constraints were set to meet the criteria of the RTOG-0915 protocol. All VMAT plans were optimized with the RapidArc technique using two full arcs in Eclipse treatment planning system. The RapidArc SBRT plans with flattened 6MV beam and 6MV FFF beam were generated and dosimetric results were compared with the previous treated 3D non-coplanar plans. RapidArc plans demonstrated better conformity to target, sharper dose fall-off in normal tissues and lower dose to normal lung and other OARs than the 3D conformai plans. RapidArc SBRT for FFF beam showed comparable target conformity, adequate tumor dose, and clinically acceptable DVHs of OARs to flattened beams and significantly reduced treatment delivery time.

  11. Sci—Sat AM: Stereo — 06: Dosimetric Comparison of 3D Conformai, Flattened and Flattening Filter-Free TrueBeam RapidArc Planning for Lung SBRT

    The major advantages of the VMAT SBRT plans compared to the conventional 3D conformai plan include faster delivery and improved target dose conformity. This study quantifies the dosimetric differences among 3D conformai plan; flattened beam and flattening filter-free (FFF) beam RapidArc Plans for lung SBRT. Five early stage lung cancer patients with various tumor positions and sizes previously treated with 3D non-coplanar SBRT were randomly selected. 4DCT was used for each patient to determine the internal target volume. Abdominal compression was applied to minimize respiratory motion for SBRT patients. For treatment planning, a 5 mm margin was given to the ITV to generate a planning target volume. The prescription dose was 48 Gy in 4 fractions and normalized to 95% of the PTV. Organs at risk (OAR) included spinal cord, esophagus, heart, trachea, bilateral lung, and great vessels. Optimization constraints were set to meet the criteria of the RTOG-0915 protocol. All VMAT plans were optimized with the RapidArc technique using two full arcs in Eclipse treatment planning system. The RapidArc SBRT plans with flattened 6MV beam and 6MV FFF beam were generated and dosimetric results were compared with the previous treated 3D non-coplanar plans. RapidArc plans demonstrated better conformity to target, sharper dose fall-off in normal tissues and lower dose to normal lung and other OARs than the 3D conformai plans. RapidArc SBRT for FFF beam showed comparable target conformity, adequate tumor dose, and clinically acceptable DVHs of OARs to flattened beams and significantly reduced treatment delivery time

  12. Robust 3-D Algorithm for Flare Planning and Guidance for Impaired Aircraft Project

    National Aeronautics and Space Administration — Development of a robust nonlinear guidance law for planning and executing the flare-touchdown maneuver for impaired aircraft under adverse wind conditions is...

  13. Accuracy of 3D Virtual Planning of Corrective Osteotomies of the Distal Radius

    Stockmans, Filip; Dezillie, Marleen; Vanhaecke, Jeroen

    2013-01-01

    Corrective osteotomies of the distal radius for symptomatic malunion are time-tested procedures that rely on accurate corrections. Patients with combined intra- and extra-articular malunions present a challenging deformity. Virtual planning and patient-specific instruments (PSIs) to transfer the planning into the operating room have been used both to simplify the surgery and to make it more accurate. This report focuses on the clinically achieved accuracy in four patients treated between 2008...

  14. Ultrasound and 3D Skin Imaging: Methods to Evaluate Efficacy of Striae Distensae Treatment

    Mariella Bleve

    2012-01-01

    Full Text Available Background. Over time, the striae rubra develop into striae alba that appear white, flat, and depressed. It is very important to determine the optimum striae management. In order to evaluate the effectiveness of these therapies, objective measurement tools are necessary. Objective. The aim of this study is to evaluate if ultrasonography and PRIMOS can be used to obtain an objective assessment of stretch marks type and stage; furthermore, we aim to apply these techniques to evaluate the efficacy of a topical treatment. Methods. 20 volunteers were enrolled with a two-month study. A marketed cosmetic product was used as the active over one body area. The controlateral area with stretch marks was treated with a “placebo” formulation without active, as a control. The instrumental evaluation was carried out at the beginning of the trial (baseline values or 0, after 1 month (1, and at the end of the study (2. Results. PRIMOS was able to measure and document striae distensae maturation; furthermore, ultrasound imaging permitted to visualize and diagnose the striae. Statistical analysis of skin roughness demonstrated a statistically significant reduction of Rp value only in a treated group. In fact, the Rp value represented a maximum peak height in the area selected. These results demonstrated that after two months of treatment only the striae rubra can be treated successfully. Conclusions. This work demonstrated that the 22MHz ultrasound can diagnose stretch marks; PRIMOS device can detect and measure striae distensae type and maturation. Furthermore, the high-frequency ultrasound and the 3D image device, described in this work, can be successfully employed in order to evaluate the efficacy of a topical treatment.

  15. Impact of geometrical uncertainties on 3D CRT and IMRT dose distributions for lung cancer treatment

    Purpose: To quantify the effect of set-up errors and respiratory motion on dose distributions for non-small cell lung cancer (NSCLC) treatment. Methods and Materials: Irradiations of 5 NSCLC patients were planned with 3 techniques, two (conformal radiation therapy (CRT) and intensity modulated radiation therapy (IMRT1)) with a homogeneous dose in the planning target volume (PTV) and a third (IMRT2) with dose heterogeneity. Set-up errors were simulated for gross target volume (GTV) and organs at risk (OARs). For the GTV, the respiration was also simulated with a periodical motion around a varying average. Two configurations were studied for the breathing motion, to describe the situations of free-breathing (FB) and respiration-correlated (RC) CT scans, each with 2 amplitudes (5 and 10 mm), thus resulting in 4 scenarios (FB5, FB10, RC5 and RC10). Five thousand treatment courses were simulated, producing probability distributions for the dosimetric parameters. Results: For CRT and IMRT1, RC5, RC10 and FB5 were associated with a small degradation of the GTV coverage. IMRT2 with FB10 showed the largest deterioration of the GTV dosimetric indices, reaching 7% for Dmin at the 95% probability level. Removing the systematic error due to the periodic breathing motion was advantageous for a 10 mm respiration amplitude. The estimated probability of radiation pneumonitis and acute complication for the esophagus showed limited sensitivity to geometrical uncertainties. Dmax in the spinal cord and the parameters predicting the risk of late esophageal toxicity were associated to a probability up to 50% of violating the dose tolerances. Conclusions: Simulating the effect of geometrical uncertainties on the individual patient plan should become part of the standard pre-treatment verification procedure

  16. Physical and methodological aspects of the multimodality imaging and principles of the treatment planning for the conformal 3-D radiation therapy; Aspects physiques et methodologiques de l'imagerie multimodalites et principes de planification dosimetrique pour la radiotherapie conformationnelle tridimensionnelle

    Lefkopoulos, D.; Foulquier, J.N.; Petegnief, Y. [Hopital Tenon, Unite de Physique Medicale, 75 - Paris (France); Touboul, E. [Hopital Tenon, Service d' Oncologie-Radiotherapie, 75 - Paris (France); Petegnief, Y. [Hopital Tenon, Service de Medecine Nucleaire, 75 - Paris (France)

    2001-10-01

    The recent evolutions of the imaging modalities, the dose calculation models, the linear accelerators and the portal imaging permit to improve the quality of the conformal radiation therapy treatment planning. With DICOM protocols, the acquired imaging data coming from different modalities are treated by efficient image fusion algorithms and yield more precise target volumes and organs at risk. The transformation of the clinical target volumes (CTV) to planning target volumes (PTV) can be realised using advanced probabilistic techniques based on clinical experience. The treatment plans evaluation is based on the dose volume histograms. Their precision and clinical relevance are improved by the multimodality imaging and the advanced dose calculation models. The introduction of the inverse planning systems permitting to realize modulated intensity radiation therapy generates highly conformal dose distributions. All the previously cited complex techniques require the application of rigorous quality assurance programs. (author)

  17. Automatic 3D segmentation of the prostate on magnetic resonance images for radiotherapy planning

    Alvarez Jiménez, Charlems

    2015-01-01

    Abstract. Accurate segmentation of the prostate, the seminal vesicles, the bladder and the rectum is a crucial step for planning radiotherapy (RT) procedures. Modern radiotherapy protocols have included the delineation of the pelvic organs in magnetic resonance images (MRI), as the guide to the therapeutic beam irradiation over the target organ. However, this task is highly inter and intra-expert variable and may take about 20 minutes per patient, even for trained experts, constituting an imp...

  18. SU-F-BRE-13: Replacing Pre-Treatment Phantom QA with 3D In-Vivo Portal Dosimetry for IMRT Breast Cancer

    Purpose: Pre-treatment QA of individual treatment plans requires costly linac time and physics effort. Starting with IMRT breast treatments, we aim to replace pre-treatment QA with in-vivo portal dosimetry. Methods: Our IMRT breast cancer plans are routinely measured using the ArcCheck device (SunNuclear). 2D-Gamma analysis is performed with 3%/3mm criteria and the percentage of points with gamma<1 (nG1) is calculated within the 50% isodose surface. Following AAPM recommendations, plans with nG1<90% are approved; others need further inspection and might be rejected. For this study, we used invivo portal dosimetry (IPD) to measure the 3D back-projected dose of the first three fractions for IMRT breast plans. Patient setup was online corrected before for all measured fractions. To reduce patient related uncertainties, the three IPD results were averaged and 3D-gamma analysis was applied with abovementioned criteria . For a subset of patients, phantom portal dosimetry (PPD) was also performed on a slab phantom. Results: Forty consecutive breast patients with plans that fitted the EPID were analysed. The average difference between planned and IPD dose in the reference point was −0.7+/−1.6% (1SD). Variation in nG1 between the 3 invivo fractions was about 6% (1SD). The average nG1 for IPD was 89+/−6%, worse than ArcCheck (95+/−3%). This can be explained by patient related factors such as changes in anatomy and/or model deficiencies due to e.g. inhomogeneities. For the 20 cases with PPD, mean nG1 was equal to ArcCheck values, which indicates that the two systems are equally accurate. These data therefore suggest that proper criteria for 3D invivo verification of breast treatments should be nG1>80% instead of nG1>90%, which, for our breast cases, would result in 5% (2/40) further inspections. Conclusion: First-fraction in-vivo portal dosimetry using new gamma-evaluation criteria will replace phantom measurements in our institution, saving resources and yielding 3D

  19. Atlas and feature based 3D pathway visualization enhancement for skull base pre-operative fast planning from head CT

    Aghdasi, Nava; Li, Yangming; Berens, Angelique; Moe, Kris S.; Bly, Randall A.; Hannaford, Blake

    2015-03-01

    Minimally invasive neuroendoscopic surgery provides an alternative to open craniotomy for many skull base lesions. These techniques provides a great benefit to the patient through shorter ICU stays, decreased post-operative pain and quicker return to baseline function. However, density of critical neurovascular structures at the skull base makes planning for these procedures highly complex. Furthermore, additional surgical portals are often used to improve visualization and instrument access, which adds to the complexity of pre-operative planning. Surgical approach planning is currently limited and typically involves review of 2D axial, coronal, and sagittal CT and MRI images. In addition, skull base surgeons manually change the visualization effect to review all possible approaches to the target lesion and achieve an optimal surgical plan. This cumbersome process relies heavily on surgeon experience and it does not allow for 3D visualization. In this paper, we describe a rapid pre-operative planning system for skull base surgery using the following two novel concepts: importance-based highlight and mobile portal. With this innovation, critical areas in the 3D CT model are highlighted based on segmentation results. Mobile portals allow surgeons to review multiple potential entry portals in real-time with improved visualization of critical structures located inside the pathway. To achieve this we used the following methods: (1) novel bone-only atlases were manually generated, (2) orbits and the center of the skull serve as features to quickly pre-align the patient's scan with the atlas, (3) deformable registration technique was used for fine alignment, (4) surgical importance was assigned to each voxel according to a surgical dictionary, and (5) pre-defined transfer function was applied to the processed data to highlight important structures. The proposed idea was fully implemented as independent planning software and additional data are used for verification and

  20. Building Analysis for Urban Energy Planning Using Key Indicators on Virtual 3d City Models - the Energy Atlas of Berlin

    Krüger, A.; Kolbe, T. H.

    2012-07-01

    In the context of increasing greenhouse gas emission and global demographic change with the simultaneous trend to urbanization, it is a big challenge for cities around the world to perform modifications in energy supply chain and building characteristics resulting in reduced energy consumption and carbon dioxide mitigation. Sound knowledge of energy resource demand and supply including its spatial distribution within urban areas is of great importance for planning strategies addressing greater energy efficiency. The understanding of the city as a complex energy system affects several areas of the urban living, e.g. energy supply, urban texture, human lifestyle, and climate protection. With the growing availability of 3D city models around the world based on the standard language and format CityGML, energy system modelling, analysis and simulation can be incorporated into these models. Both domains will profit from that interaction by bringing together official and accurate building models including building geometries, semantics and locations forming a realistic image of the urban structure with systemic energy simulation models. A holistic view on the impacts of energy planning scenarios can be modelled and analyzed including side effects on urban texture and human lifestyle. This paper focuses on the identification, classification, and integration of energy-related key indicators of buildings and neighbourhoods within 3D building models. Consequent application of 3D city models conforming to CityGML serves the purpose of deriving indicators for this topic. These will be set into the context of urban energy planning within the Energy Atlas Berlin. The generation of indicator objects covering the indicator values and related processing information will be presented on the sample scenario estimation of heating energy consumption in buildings and neighbourhoods. In their entirety the key indicators will form an adequate image of the local energy situation for

  1. 3D soft tissue predictions with a tetrahedral mass tensor model for a maxillofacial planning system: a quantitative validation study

    Mollemans, W.; Schutyser, F.; Nadjmi, N.; Maes, F.; Suetens, P.

    2006-03-01

    In this paper we present an extensive quantitative validation on 3D facial soft tissue simulation for maxillofacial surgery planning. The study group contained 10 patients. In previous work we presented a new Mass Tensor Model to simulate the new facial appearance after maxillofacial surgery in a fast way. 10 patients were preoperatively CT-scanned and the surgical intervention was planned. 4 months after surgery, a post-operative control CT was acquired. In this study, the simulated facial outlook is compared with post-operative image data. After defining corresponding points between the predicted and actual post-operative facial skin surface, using a variant of the non-rigid TPS-RPM algorithm, distances between these correspondences are quantified and visualized in 3D. As shown, the average median distance measures only 0.60 mm and the average 90% percentile stays below 1.5 mm. We can conclude that our model clearly provides an accurate prediction of the real post-operative outcome and is therefore suitable for use in clinical practice.

  2. 中上段食管癌3D-CRT与IMRT肺损伤剂量学的对比研究%Dosimetric Comparison of Intensity-modulated Radiotherapy Versus 3D Conformal Radiotherapy in Treatment of Cancer of Upper/Mid Esophagus

    张莉; 罗辉

    2011-01-01

    Objective To compared 3D-conformal radiotherapy (3D-CRT)-induced and intensity-modulated radiotherapy (IMRT)-induced pulmonary injury by using 3D treatment planning system,and to explore the optimum treatment strategy for upper/mid esophageal carcinoma.Methods Eight patients with upper/mid esophageal carcinoma were selected in this study. Four different radiotherapy plans were developed for each patient,including 5-field 3D-CRT(CRT5),7-field 3D-CRT(CRT7), 5-field IMRT (IMRT5) and 7-field IMRT (IMRT7). The planning target volume (PTV) received at least 95% of the prescription dose. The mean lung dose (MLD),V5,V10,V20 and V30 were evaluated using dose volume histogram(DVH). All statistics were analyzed using the SPSS version 11.5 software. Results CRT5 plan reduced lung V10 compared with CRT7 (P=0. 006), but V5, V20, V30 and MLD were not different between the two plans(P>0. 008 3). There were no significant differences in lung parameters between IMRT5 and IMRT7.Compared with IMRT plans, V20, V30 and MLD were increased by 3D-CRT, while V5 was decreased by 3D-CRT(P<0. 0083). Conclusion Compared with 3D-CRT, IMRT can reduce the MLD,V20 and V30 to achieve lung sparing in treatment of upper/mid esophageal carcinoma.There were no significant differences in the protection of lung tissues between 5-field and 7-field techniques for both 3D-CRT and IMRT plans.%目的 应用三维适形放疗(3D-CRT)计划比较中上段食管鳞癌3D-CRT和调强放疗(IMRT)的放射性肺损伤情况从而探讨理想的治疗计划模式.方法 8例患者每例分别设计4个放疗计划(CRT-5 、CRT-7、IMRT-5及 IMRT-7),规定PTV至少达到95%处方剂量前提下用DVH评价每个计划的V5 、V10 、V20 、V30及肺 MLD.采用SPSS 11.5软件包进行数据统计与分析.结果 采用3D-CRT技术时,5野的V10优于7野(P=0.006);5野与7野的肺Mean、肺V5、V20、V30(P>0.0083)之间无统计学意义;采用IMRT技术时,5野与7野之间各参数的对

  3. 3D-CTA、DSA对颅内动脉瘤诊疗价值的对比%Comparative study of 3D-CTA and DSA in the diagnosis and treatment of intracranial aneurysms

    李祥; 于如同; 范月超; 郭克勤

    2009-01-01

    Objective To compare the clinical value of three-dimensional digital subtraction angiography(3D-DSA), three-dimensional computed tomographic angiography (3D-CTA) and conventional DSA(2D-DSA) in the diagnosis and treatment of Intracranial aneurysms. Methods The data of 3D-DSA, 3D-CTA, 2D-DSA and operation of 32 patients with Intracranial aneurysms were reviewed, retrospectively. Results 35 aneurysms were detected by 3D-DSA and correlated well with microsurgical findings. The shape of the aneurysms, their neck size and their relationships to the parent vessels and other branches were depicted clearly, especially compared with images obtained by 3D-CTA and 2D-DSA. 33 aneurysms were detected by 3D-CTA. 32 aneurysms were detected by 2D-DSA. Aneurysms' body, neck, parent artery and the relationship between the aneurysms and surrounding structures (bone) were clearly and surely displayed by 3D-CTA. Conclusion 3D-CTA is a sensitivity and rapid and noninvasive method for detecting aneurysms. 3D-CTA can be the first choice for diagnosing Intracranial aneurysms without performing 2D-DSA. During CT for ruptured aneurysms, a negative 3D-CTA should be investigated further by 3D-DSA. 3D-DSA should be performed in cases of multiple intracranial aneurysms with complex shapes or very small size. 3D-DSA should be the "gold standard" for detecting intracranial aneurysms.%目的 评价3D-DSA、3D-CTA、2D-DSA在颅内动脉瘤诊疗中的作用.方法 回顾性分析32例动脉瘤患者3D-DSA、3D-CTA、2D-DSA和手术资料.结果 32例患者共35个动脉瘤(有3例患者为多发动脉瘤).3D-DSA能清楚显示所有动脉瘤的形态,准确判断3例多发动脉瘤中破裂的动脉瘤且手术顺利夹闭;3D-CTA检出33个,遗漏1个前交通动脉瘤及1个颈内动脉瘤;2D-DSA检出32个,遗漏2个前交通动脉瘤和1个大脑中动脉瘤.3D-DSA及3D-CTA在显示瘤颈上明显优于2D-DSA,3D-CTA可准确显示动脉瘤与相邻骨质结构关系.结论 3D~CTA是检查颅

  4. 4D analysis of influence of patient movement and anatomy alteration on the quality of 3D U/S-based prostate HDR brachytherapy treatment delivery

    Purpose: Modern HDR brachytherapy treatment for prostate cancer based on the 3D ultrasound (U/S) plays increasingly important role. The purpose of this study is to investigate possible patient movement and anatomy alteration between the clinical image set acquisition, made after the needle implantation, and the patient irradiation and their influence on the quality of treatment. Methods: The authors used 3D U/S image sets and the corresponding treatment plans based on a 4D-treatment planning procedure: plans of 25 patients are obtained right after the needle implantation (clinical plan is based on this 3D image set) and just before and after the treatment delivery. The authors notice the slight decrease of treatment quality with increase of time gap between the clinical image set acquisition and the patient irradiation. 4D analysis of dose-volume-histograms (DVHs) for prostate: CTV1 = PTV, and urethra, rectum, and bladder as organs at risk (OARs) and conformity index (COIN) is presented, demonstrating the effect of prostate, OARs, and needles displacement. Results: The authors show that in the case that the patient body movement/anatomy alteration takes place, this results in modification of DVHs and radiobiological parameters, hence the plan quality. The observed average displacement of needles (1 mm) and of prostate (0.57 mm) is quite small as compared with the average displacement noted in several other reports [A. A. Martinez et al., Int. J. Radiat. Oncol., Biol., Phys. 49(1), 61-69 (2001); S. J. Damore et al., Int. J. Radiat. Oncol., Biol., Phys. 46(5), 1205-1211 (2000); P. J. Hoskin et al., Radiotherm. Oncol. 68(3), 285-288 (2003); E. Mullokandov et al., Int. J. Radiat. Oncol., Biol., Phys. 58(4), 1063-1071 (2004)] in the literature. Conclusions: Although the decrease of quality of dosimetric and radiobiological parameters occurs, this does not cause clinically unacceptable changes to the 3D dose distribution, according to our clinical protocol.

  5. 3D dose distribution in gamma knife treatment near tissue inhomogeneities

    The treatment planning system, GammaPlan, uses CT, MR or angiographic images to calculate and simulate the dose distribution in a matrix volume of interest assuming that tissues in human head are homogeneous and water equivalent. The absence of electronic equilibrium in the vicinity of air-tissue inhomogeneity in the head will misrepresent the deposited dose under the above assumption. Polymer gel dosimetry has already been used in different scenarios of radiotherapy dosimetry; however, little work has been reported for polymer gel phantoms with air cavities irradiated in Gamma Knife surgery. Increasing dose levels are reflected into lower MR relaxation time constants T1 and T2, in the neighbouring water protons. The MAGIC Gel was manufactured under normal atmospheric conditions using the formulation proposed by Fong, et al.: 8% Gelatine Type A from porcine skin Sigma Bloom 300; 10mmol/l Hydroquinone, 99%; 2 mmol/l Ascorbic Acid, 99%; 0,02 mmol/l CuSO4*5 H2O; 9% Methacrylic acid, and 83% distilled water. For the paranosal sinuses cavity experiment (a lesion in the head near the paranosal sinuses is simulated), two spherical glass balloons with a volume of 2 liter each were the phantom containers. Both glass balloons were filled with the MAGIC gel. The inhomogeneous phantom was prepared by placing a cylindrical cork to represent the air cavity: the diameter was 2,5 cm and the length 8 cm (3). The homogeneous phantom simulates the physical structure considered in the GammaPlan. Seven plastic vials of 100 ml were filled with the gel and were irradiated with doses of 0, 3, 5, 10, 15, 20 and 25 Gy with the Cobalt-60 TeleTherapy machine to obtain the calibration curve in order to derive the equivalent dose values from GammaPLan. The simulated tumour was given one shot with a dose of 20 Gray in the Gamma Knife using the 18 mm Helmet. A week following the irradiation, the phantoms and vials were scanned in a clinical Siemens 1.5 Tesla MR unit. For calculating the dose

  6. Virtual 3-D operational planning in the maintenance of main mine equipment; Virtuelle 3D-Ablaufplanung in der Instandhaltung von Tagebaugrossgeraeten

    Suchodoll, Dirk; Eberlein, Mark [RWE Power AG, Frechen (Germany). Technikzentrum Tagebaue/HW; Stock, Wilhelm [RWE Power AG, Koeln (Germany)

    2012-09-15

    To optimise the sequence of operations for replacing the ball race of a bucket-wheel excavator during an outage of several weeks using a virtual 3-D model of this ball race, an interdisciplinary project team consisting of employees of the Fraunhofer Institute of Factory Operation and Automation (IFF) in Magdeburg, mechanical engineers specialised in maintenance and main mine equipment and employees of RWE Power AG specialised in technical further education developed, optimised and applied such a model. Owing to the fact that a process of this complexity has never been examined, documented and assessed at this level of detail before, immense knowledge present only in experts' minds so far could be recorded and transferred to the model. This constitutes a significant added value to RWE Power AG's maintenance core competency. Following a modification of its data set, this model can be used further for subsequent projects in connection with other bucket-wheel excavators. This model combines engineering, maintenance and occupational safety and can be equally applied for process optimisation, trainings on the construction site and technical further education. This is promoted by the fact that the virtual model is intuitive to use and has no special hardware requirements. The results have shown that virtualising processes and plants also opens up new ways in knowledge retention and transfer to respond more effectively, promptly and in a more demand-oriented manner to the further-education requirements of a modern company. The use of this virtual 3-D model cannot be assessed reliably in terms of costs and benefits because of its manifold and complex application fields on the one hand and due to the difficulty of evaluating the process improvements achieved on the other hand. In addition, it must be taken into account that those process improvements could only be made in the first place because of the development of this model, allowing the &apos

  7. Integral multidisciplinary rehabilitation treatment planning

    Braaksma, A.; Kortbeek, Nikky; Post, Gerhard; Nollet, Frans

    2012-01-01

    This paper presents a methodology to plan treatments for rehabilitation outpatients. These patients require a series of treatments by therapists from various disciplines. In current practice, when treatments are planned, a lack of coordination between the different disciplines, along with a failure to plan the entire treatment plan at once, often occurs. This situation jeopardizes both the quality of care and the logistical performance. The multidisciplinary nature of the rehabilitation proce...

  8. Comparative study of software techniques for 3D mapping of perforators in deep inferior epigastric artery perforator flap planning

    Hunter-Smith, David J.; Rozen, Warren Matthew

    2016-01-01

    Background Computed tomographic (CT) angiography (CTA) is widely considered the gold standard imaging modality for preoperative planning autologous breast reconstruction with deep inferior epigastric artery (DIEA) perforator (DIEP) flap. Improved anatomical understanding from CTA has translated to enhanced clinical outcomes. To achieve this, the use of appropriate CT hardware and software is vital. Various CT scanners and contrast materials have been demonstrated to consistently produce adequate scan data. However, the availability of affordable and easily accessible imaging software capable of generating 3D volume-rendered perforator images to clinically useful quality has been lacking. Osirix (Pixmeo, Geneva, Switzerland) is a free, readily available medical image processing software that shows promise. We have previously demonstrated in a case report the usefulness of Osirix in localizing perforators and their course. Methods In the current case series of 50 consecutive CTA scans, we compare the accuracy of Osirix to a commonly used proprietary 3D imaging software, Siemens Syngo InSpace 4D (Siemens, Erlangen, Germany), in identifying perforator number and location. Moreover, we compared both programs to intraoperative findings. Results We report a high rate of concordance with Osirix and Siemens Syngo InSpace 4D (99.6%). Both programs correlated closely with operative findings (92.2%). Most of the discrepancies were found in the lateral row perforators (90%). Conclusions In the current study, we report the accuracy of Osirix that is comparable to Siemens Syngo InSpace 4D, a proprietary software, in mapping perforators. However, it provides an added advantage of being free, easy-to-use, portable, and potentially a superior quality of 3D reconstructed image. PMID:27047778

  9. A Bayesian approach to real-time 3D tumor localization via monoscopic x-ray imaging during treatment delivery

    Purpose: Monoscopic x-ray imaging with on-board kV devices is an attractive approach for real-time image guidance in modern radiation therapy such as VMAT or IMRT, but it falls short in providing reliable information along the direction of imaging x-ray. By effectively taking consideration of projection data at prior times and/or angles through a Bayesian formalism, the authors develop an algorithm for real-time and full 3D tumor localization with a single x-ray imager during treatment delivery. Methods: First, a prior probability density function is constructed using the 2D tumor locations on the projection images acquired during patient setup. Whenever an x-ray image is acquired during the treatment delivery, the corresponding 2D tumor location on the imager is used to update the likelihood function. The unresolved third dimension is obtained by maximizing the posterior probability distribution. The algorithm can also be used in a retrospective fashion when all the projection images during the treatment delivery are used for 3D localization purposes. The algorithm does not involve complex optimization of any model parameter and therefore can be used in a ''plug-and-play'' fashion. The authors validated the algorithm using (1) simulated 3D linear and elliptic motion and (2) 3D tumor motion trajectories of a lung and a pancreas patient reproduced by a physical phantom. Continuous kV images were acquired over a full gantry rotation with the Varian TrueBeam on-board imaging system. Three scenarios were considered: fluoroscopic setup, cone beam CT setup, and retrospective analysis. Results: For the simulation study, the RMS 3D localization error is 1.2 and 2.4 mm for the linear and elliptic motions, respectively. For the phantom experiments, the 3D localization error is < 1 mm on average and < 1.5 mm at 95th percentile in the lung and pancreas cases for all three scenarios. The difference in 3D localization error for different scenarios is small and is not

  10. 3D Preoperative Planning in the ER with OsiriX®: When There is No Time for Neuronavigation

    Almir Ferreira de Andrade

    2013-05-01

    Full Text Available The evaluation of patients in the emergency room department (ER through more accurate imaging methods such as computed tomography (CT has revolutionized their assistance in the early 80s. However, despite technical improvements seen during the last decade, surgical planning in the ER has not followed the development of image acquisition methods. The authors present their experience with DICOM image processing as a navigation method in the ER. The authors present 18 patients treated in the Emergency Department of the Hospital das Clínicas of the University of Sao Paulo. All patients were submitted to volumetric CT. We present patients with epidural hematomas, acute/subacute subdural hematomas and contusional hematomas. Using a specific program to analyze images in DICOM format (OsiriX®, the authors performed the appropriate surgical planning. The use of 3D surgical planning made it possible to perform procedures more accurately and less invasively, enabling better postoperative outcomes. All sorts of neurosurgical emergency pathologies can be treated appropriately with no waste of time. The three-dimensional processing of images in the preoperative evaluation is easy and possible even within the emergency care. It should be used as a tool to reduce the surgical trauma and it may dispense methods of navigation in many cases.

  11. Individualized margins in 3D conformal radiotherapy planning for lung cancer: analysis of physiological movements and their dosimetric impacts.

    Germain, François; Beaulieu, Luc; Fortin, André

    2008-01-01

    In conformal radiotherapy planning for lung cancer, respiratory movements are not taken into account when a single computed tomography (CT) scan is performed. This study examines tumor movements to design individualized margins to account for these movements and evaluates their dosimetric impacts on planning volume. Fifteen patients undergoing CT-based planning for radical radiotherapy for localized lung cancer formed the study cohort. A reference plan was constructed based on reference gross, clinical, and planning target volumes (rGTV, rCTV, and rPTV, respectively). The reference plans were compared with individualized plans using individualized margins obtained by using 5 serial CT scans to generate individualized target volumes (iGTV, iCTV, and iPTV). Three-dimensional conformal radiation therapy was used for plan generation using 6- and 23-MV photon beams. Ten plans for each patient were generated and dose-volume histograms (DVHs) were calculated. Comparisons of volumetric and dosimetric parameters were performed using paired Student t-tests. Relative to the rGTV, the total volume occupied by the superimposed GTVs increased progressively with each additional CT scans. With the use of all 5 scans, the average increase in GTV was 52.1%. For the plans with closest dosimetric coverage, target volume was smaller (iPTV/rPTV ratio 0.808) but lung irradiation was only slightly decreased. Reduction in the proportion of lung tissue that received 20 Gy or more outside the PTV (V20) was observed both for 6-MV plans (-0.73%) and 23-MV plans (-0.65%), with p = 0.02 and p = 0.04, respectively. In conformal RT planning for the treatment of lung cancer, the use of serial CT scans to evaluate respiratory motion and to generate individualized margins to account for these motions produced only a limited lung sparing advantage. PMID:18262123

  12. Individualized Margins in 3D Conformal Radiotherapy Planning for Lung Cancer: Analysis of Physiological Movements and Their Dosimetric Impacts

    In conformal radiotherapy planning for lung cancer, respiratory movements are not taken into account when a single computed tomography (CT) scan is performed. This study examines tumor movements to design individualized margins to account for these movements and evaluates their dosimetric impacts on planning volume. Fifteen patients undergoing CT-based planning for radical radiotherapy for localized lung cancer formed the study cohort. A reference plan was constructed based on reference gross, clinical, and planning target volumes (rGTV, rCTV, and rPTV, respectively). The reference plans were compared with individualized plans using individualized margins obtained by using 5 serial CT scans to generate individualized target volumes (iGTV, iCTV, and iPTV). Three-dimensional conformal radiation therapy was used for plan generation using 6- and 23-MV photon beams. Ten plans for each patient were generated and dose-volume histograms (DVHs) were calculated. Comparisons of volumetric and dosimetric parameters were performed using paired Student t-tests. Relative to the rGTV, the total volume occupied by the superimposed GTVs increased progressively with each additional CT scans. With the use of all 5 scans, the average increase in GTV was 52.1%. For the plans with closest dosimetric coverage, target volume was smaller (iPTV/rPTV ratio 0.808) but lung irradiation was only slightly decreased. Reduction in the proportion of lung tissue that received 20 Gy or more outside the PTV (V20) was observed both for 6-MV plans (-0.73%) and 23-MV plans (-0.65%), with p = 0.02 and p = 0.04, respectively. In conformal RT planning for the treatment of lung cancer, the use of serial CT scans to evaluate respiratory motion and to generate individualized margins to account for these motions produced only a limited lung sparing advantage

  13. Different effects of bladder distention on point A-based and 3D-conformal intracavitary brachytherapy planning for cervical cancer

    This study sought to evaluate the differential effects of bladder distention on point A-based (AICBT) and three-dimensional conformal intracavitary brachytherapy (3D-ICBT) planning for cervical cancer. Two sets of CT scans were obtained for ten patients to evaluate the effect of bladder distention. After the first CT scan, with an empty bladder, a second set of CT scans was obtained with the bladder filled. The clinical target volume (CTV), bladder, rectum, and small bowel were delineated on each image set. The AICBT and 3D-ICBT plans were generated, and we compared the different planning techniques with respect to the dose characteristics of CTV and organs at risk. As a result of bladder distention, the mean dose (D50) was decreased significantly and geometrical variations were observed in the bladder and small bowel, with acceptable minor changes in the CTV and rectum. The average D2cm3 and D1cm3 showed a significant change in the bladder and small bowel with AICBT; however, no change was detected with the 3D-ICBT planning. No significant dose change in the CTV or rectum was observed with either the AICBT or the 3D-ICBT plan. The effect of bladder distention on dosimetrical change in 3D-ICBT planning appears to be minimal, in comparison with AICBT planning. (author)

  14. SU-E-T-04: 3D Printed Patient-Specific Surface Mould Applicators for Brachytherapy Treatment of Superficial Lesions

    Cumming, I; Lasso, A; Rankin, A; Fichtinger, G [Laboratory for Percutaneous Surgery, School of Computing, Queen' s University, Kingston, Ontario (Canada); Joshi, C P; Falkson, C; Schreiner, L John [CCSEO, Kingston General Hospital and Department of Oncology, Queen' s University, Kingston, Ontario (Canada)

    2014-06-01

    Purpose: Evaluate the feasibility of constructing 3D-printed patient-specific surface mould applicators for HDR brachytherapy treatment of superficial lesions. Methods: We propose using computer-aided design software to create 3D printed surface mould applicators for brachytherapy. A mould generation module was developed in the open-source 3D Slicer ( http://www.slicer.org ) medical image analysis platform. The system extracts the skin surface from CT images, and generates smooth catheter paths over the region of interest based on user-defined start and end points at a specified stand-off distance from the skin surface. The catheter paths are radially extended to create catheter channels that are sufficiently wide to ensure smooth insertion of catheters for a safe source travel. An outer mould surface is generated to encompass the channels. The mould is also equipped with fiducial markers to ensure its reproducible placement. A surface mould applicator with eight parallel catheter channels of 4mm diameters was fabricated for the nose region of a head phantom; flexible plastic catheters of 2mm diameter were threaded through these channels maintaining 10mm catheter separations and a 5mm stand-off distance from the skin surface. The apparatus yielded 3mm thickness of mould material between channels and the skin. The mould design was exported as a stereolithography file to a Dimension SST1200es 3D printer and printed using ABS Plus plastic material. Results: The applicator closely matched its design and was found to be sufficiently rigid without deformation during repeated application on the head phantom. Catheters were easily threaded into channels carved along catheter paths. Further tests are required to evaluate feasibility of channel diameters smaller than 4mm. Conclusion: Construction of 3D-printed mould applicators show promise for use in patient specific brachytherapy of superficial lesions. Further evaluation of 3D printing techniques and materials is required

  15. SU-E-T-04: 3D Printed Patient-Specific Surface Mould Applicators for Brachytherapy Treatment of Superficial Lesions

    Purpose: Evaluate the feasibility of constructing 3D-printed patient-specific surface mould applicators for HDR brachytherapy treatment of superficial lesions. Methods: We propose using computer-aided design software to create 3D printed surface mould applicators for brachytherapy. A mould generation module was developed in the open-source 3D Slicer ( http://www.slicer.org ) medical image analysis platform. The system extracts the skin surface from CT images, and generates smooth catheter paths over the region of interest based on user-defined start and end points at a specified stand-off distance from the skin surface. The catheter paths are radially extended to create catheter channels that are sufficiently wide to ensure smooth insertion of catheters for a safe source travel. An outer mould surface is generated to encompass the channels. The mould is also equipped with fiducial markers to ensure its reproducible placement. A surface mould applicator with eight parallel catheter channels of 4mm diameters was fabricated for the nose region of a head phantom; flexible plastic catheters of 2mm diameter were threaded through these channels maintaining 10mm catheter separations and a 5mm stand-off distance from the skin surface. The apparatus yielded 3mm thickness of mould material between channels and the skin. The mould design was exported as a stereolithography file to a Dimension SST1200es 3D printer and printed using ABS Plus plastic material. Results: The applicator closely matched its design and was found to be sufficiently rigid without deformation during repeated application on the head phantom. Catheters were easily threaded into channels carved along catheter paths. Further tests are required to evaluate feasibility of channel diameters smaller than 4mm. Conclusion: Construction of 3D-printed mould applicators show promise for use in patient specific brachytherapy of superficial lesions. Further evaluation of 3D printing techniques and materials is required

  16. Inverse planning and class solutions for brachytherapy treatment planning

    Brachytherapy or interventional radiooncology is a method of radiation therapy. It is a method, where a small encapsulated radioactive source is placed near to / in the tumour and therefore delivers high doses directly to the target volume. Organs at risk (OARs) are spared due to the inverse square dose fall-off. In the past years there was a slight stagnation in the development of techniques for brachytherapy treatment. While external beam radiotherapy became more and more sophisticated, in brachytherapy traditional methods have been still used. Recently, 3D imaging was considered also as the modality for brachytherapy and more precise brachytherapy could expand. Nowadays, an image guided brachytherapy is state-of-art in many centres. Integration of imaging methods lead to the dose distribution individually tailored for each patient. Treatment plan optimization is mostly performed manually as an adaptation of a standard loading pattern. Recently, inverse planning approaches have been introduced into brachytherapy. The aim of this doctoral thesis was to analyze inverse planning and to develop concepts how to integrate inverse planning into cervical cancer brachytherapy. First part of the thesis analyzes the Hybrid Inverse treatment Planning and Optimization (HIPO) algorithm and proposes a workflow how to safely work with this algorithm. The problem of inverse planning generally is that only the dose and volume parameters are taken into account and spatial dose distribution is neglected. This fact can lead to unwanted high dose regions in a normal tissue. A unique implementation of HIPO into the treatment planning system using additional features enabled to create treatment plans similar to the plans resulting from manual optimization and to shape the high dose regions inside the CTV. In the second part the HIPO algorithm is compared to the Inverse Planning Simulated Annealing (IPSA) algorithm. IPSA is implemented into the commercial treatment planning system. It

  17. Integral multidisciplinary rehabilitation treatment planning

    Braaksma, A.; Kortbeek, Nikky; Post, Gerhard; Nollet, Frans

    2012-01-01

    This paper presents a methodology to plan treatments for rehabilitation outpatients. These patients require a series of treatments by therapists from various disciplines. In current practice, when treatments are planned, a lack of coordination between the different disciplines, along with a failure

  18. Integral multidisciplinary rehabilitation treatment planning

    Braaksma, A.; Kortbeek, N.; Post, G.F.; Nollet, F.

    2014-01-01

    This paper presents a methodology to plan treatments for rehabilitation outpatients. These patients require a series of treatments by therapists from various disciplines. In current practice, when treatments are planned, a lack of coordination between the different disciplines, along with a failure

  19. Class solution to decrease rectal dose in prostate radiotherapy treatments 3D-CRT; Solucion de clase para disminuir dosis en recto en tratamientos de prostata con radioterapia 3D-CRT

    Andres Rodriguez, C.; Tortosa Oliver, R.; Alonso Hernandez, D.; Mari Palacios, A.; Castillo Belmonte, A. del

    2011-07-01

    This paper contains a method developed in our center with conventional 3D radiotherapy techniques to increase the dose conformation around the target volume in prostate cancer treatments significantly reduced the doses to the rectum. To evaluate the goodness of the method, the results are compared with two classical techniques of treatment.

  20. A Novel Bio-carrier Fabricated Using 3D Printing Technique for Wastewater Treatment

    Dong, Yang; Fan, Shu-Qian; Shen, Yu; Yang, Ji-Xiang; Yan, Peng; Chen, You-Peng; Li, Jing; Guo, Jin-Song; Duan, Xuan-Ming; Fang, Fang; Liu, Shao-Yang

    2015-07-01

    The structure of bio-carriers is one of the key operational characteristics of a biofilm reactor. The goal of this study is to develop a series of novel fullerene-type bio-carriers using the three-dimensional printing (3DP) technique. 3DP can fabricate bio-carriers with more specialized structures compared with traditional fabrication processes. In this research, three types of fullerene-type bio-carriers were fabricated using the 3DP technique and then compared with bio-carrier K3 (from AnoxKaldnes) in the areas of physicochemical properties and biofilm growth. Images acquired by 3D profiling and SEM indicated that the surface roughness of the 3DP bio-carrier was greater than that of K3. Furthermore, contact angle data indicated that the 3DP bio-carriers were more hydrophilic than K3. The biofilm on the 3DP bio-carriers exhibited higher microbial activity and stronger adhesion ability. These findings were attributed to excellent mass transfer of the substrate (and oxygen) between the vapour-liquid-solid tri-phase system and to the surface characteristics. It is concluded that the novel 3DP fullerene-type bio-carriers are ideal carriers for biofilm adherence and growth.

  1. Temporomandibular Joint Prosthesis - 3D-CT Reconstruction before and after Treatment

    Feltlová, E.; Dostálová, T.; Kašparová, M.; Daněk, J.; Hliňáková, P.; Hubáček, M.; Nedoma, Jiří

    2010-01-01

    Roč. 6, č. 1 (2010), s. 15-19. ISSN 1801-5603 Institutional research plan: CEZ:AV0Z10300504 Keywords : dentistry * maxillofacial surgery * partial TMJ prosthesis * three-dimensional computed tomography * magnetic resonance imaging * temporomandibular joint Subject RIV: BA - General Mathematics http://www.ejbi.cz/articles/201012/50/1.html

  2. Verification of Rapid Arc™ planning with AAA algorithm using an inhomogeneous 3D phantom; Verificacao de planejamentos de RapidArc™ com algoritmo AAA usando um fantoma heterogeneo 3D

    Trindade, Cassia; Silva, Leonardo P.; Souza, Roberto S.; Batista, Delano V.L.; Martins, Lais P.; Santos, Maira R.; Garcia, Paulo L., E-mail: cassiatr@gmail.com [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil)

    2013-12-15

    New technologies have been developed to improve the quality assurance of the planning with modulated beams. One way to deal with the high costs of the dosimetry equipment was to develop a 3D phantom, using TLDs and radiochromic film, designed by the Radiotherapy Quality Program of INCa. The calculus was done using the AAA algorithm with heterogeneity correction, making the phantom rather heterogeneous. Five measurements related to the Rapid Arc™ planning were taken, once there was the phantom CT for optimization. The purpose of this work is a 3D verification of the dose distribution in the heterogeneous phantom. The mean deviation in planning target volumes was lower than ±5%. On the other side, the results dispersion for the others heterogeneities was higher, the maximum mean deviation obtained, for example, for the heterogeneity related to the bladder, was 7.41%. The maximum standard deviation found for both cases was around 9% for the target heterogeneity and 11% for the other heterogeneities. The phantom might be an interesting tool in order to verify the Rapid Arc™ planning, however, more statistical data is necessary as to achieve better results for the analysis of dose distribution. (author)heterogeneous phantom. The mean deviation in planning target volumes was lower than ±5%. On the other side, the results dispersion for the others heterogeneities was higher, the maximum mean deviation obtained, for example, for the heterogeneity related to the bladder, was 7.41%. The maximum standard deviation found for both cases was around 9% for the target heterogeneity and 11% for the other heterogeneities. The phantom might be an interesting tool in order to verify the Rapid Arc™ planning, however, more statistical data is necessary as to achieve better results for the analysis of dose distribution. (author)

  3. Real-time interactive treatment planning

    The goal of this work is to develop an interactive treatment planning platform that permits real-time manipulation of dose distributions including DVHs and other dose metrics. The hypothesis underlying the approach proposed here is that the process of evaluating potential dose distribution options and deciding on the best clinical trade-offs may be separated from the derivation of the actual delivery parameters used for the patient’s treatment. For this purpose a novel algorithm for deriving an Achievable Dose Estimate (ADE) was developed. The ADE algorithm is computationally efficient so as to update dose distributions in effectively real-time while accurately incorporating the limits of what can be achieved in practice. The resulting system is a software environment for interactive real-time manipulation of dose that permits the clinician to rapidly develop a fully customized 3D dose distribution. Graphical navigation of dose distributions is achieved by a sophisticated method of identifying contributing fluence elements, modifying those elements and re-computing the entire dose distribution. 3D dose distributions are calculated in ∼2–20 ms. Including graphics processing overhead, clinicians may visually interact with the dose distribution (e.g. ‘drag’ a DVH) and display updates of the dose distribution at a rate of more than 20 times per second. Preliminary testing on various sites shows that interactive planning may be completed in ∼1–5 min, depending on the complexity of the case (number of targets and OARs). Final DVHs are derived through a separate plan optimization step using a conventional VMAT planning system and were shown to be achievable within 2% and 4% in high and low dose regions respectively. With real-time interactive planning trade-offs between Target(s) and OARs may be evaluated efficiently providing a better understanding of the dosimetric options available to each patient in static or adaptive RT. (paper)

  4. The Effect of Flattening Filter Free on Three-dimensional Conformal Radiation Therapy (3D-CRT), Intensity-Modulated Radiation Therapy (IMRT), and Volumetric Modulated Arc Therapy (VMAT) Plans for Metastatic Brain Tumors from Non-small Cell Lung Cancer.

    Shi, Li-Wan; Lai, You-Qun; Lin, Qin; Ha, Hui-Ming; Fu, Li-Rong

    2015-07-01

    Flattening filter free (FFF) may affect outcome measures of radiotherapy. The objective of this study is to compare the dosimetric parameters in three types of radiotherapy plans, three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT), with or without the flattening filter (FF), developed for the treatment of metastatic brain tumors from non-small cell lung cancer (NSCLC). From July 2013 to October 2013, 3D-CRT, IMRT, and VMAT treatment plans were designed using 6 MV and 10 MV, with and without FF, for 10 patients with brain metastasis from NSCLC. The evaluation of the treatment plans included homogeneity index (HI), conformity index (CI), monitor units (MU), mean dose (Dmean), treatment time, and the influence of FFF on volumes. There was no difference in CI or HI between FFF and FF models with 3D-CRT, IMRT, and VMAT plans. At 6 MV, a lower Dmean was seen in the FFF model of 3D-CRT and in the VMAT plan at 10 MV. In the IMRT 6 MV, IMRT 10 MV, and VMAT 10 MV plans, higher MUs were seen in the FFF models. FFF treatments are similar in quality to FF plans, generally lead to more monitor units, and are associated with shorter treatment times. FFF plans ranked by the order of superiority in terms of a time advantage are VMAT, 3D-CRT, and IMRT. PMID:26011493

  5. Implementation of three dimensional treatment planning system for external radiotherapy

    A three dimensional (3D) treatment planning system was installed at Apollo Cancer Hospital, Chennai, India in 1995. This paper gives a short description of the system including hardware components, calculation algorithm, measured data requirements and specific three dimensional features. The concept and the structure of the system are shortly described. The first impressions along with critical opinions and the experiences are gained during the data acquisition are mentioned. Some improvements in the user interface are suggested. It is emphasized that although a 3D system offers more detailed and accurate dose distributions compared to a 2D system, it also introduces a greatly increased workload for the planning staff. (author)

  6. Mechanism and Microstructure Transformation of 3D-Si/LG5 Composites by High Temperature Diffusion Treatment

    Xiu, Ziyang; Deng, Zongquan; Wang, Xiaofeng; Wu, Gaohui

    A dense and uniform Sip/LG5 composite were fabricated by squeeze casting technology, and high temperature diffusion treatment was adapted to the composite. Microstructure observation indicated that Si transformed from irregular particles to 3D-structure. Fine dispersive precipitates Si were also observed on Si-Al interface and within Al matrix, smoothing and improving the interface. Based on the microstructure observation, three transformation stages were designated: melting, dissolution and precipitation, solidification. Thermodynamics and kinetics of the transformation can be explained by Gibbs-Thomson effect.

  7. Particle sedimentation in curved tubes: A 3D simulation and optimization for treatment of vestibular vertigo

    White, Brian; Squires, Todd M.; Hain, Timothy C.; Stone, Howard A.

    2003-11-01

    Benign paroxysmal positional vertigo (BPPV) is a mechanical disorder of the vestibular system where micron-size crystals abnormally drift into the semicircular canals of the inner ear that sense angular motion of the head. Sedimentation of these crystals causes sensation of motion after true head motion has stopped: vertigo results. The usual clinical treatment is through a series of head maneuvers designed to move the particles into a less sensitive region of the canal system. We present a three-dimensional model to simulate treatment of BPPV by determining the complete hydrodynamic motion of the particles through the course of a therapeutic maneuver while using a realistic representation of the actual geometry. Analyses of clinical maneuvers show the parameter range for which they are effective, and indicate inefficiencies in current practice. In addition, an optimization process determines the most effective head maneuver, which significantly differs from those currently in practice.

  8. Determining DVH parameters for combined external beam and brachytherapy treatment: 3D biological dose adding for patients with cervical cancer

    J.B. van de Kamer; A.A.C. de Leeuw; M.A. Moerland; I.M. Jürgenliemk-Schulz

    2010-01-01

    Purpose: To compare two methods of DVH parameter determination for combined external beam and brachytherapy treatment of cervical cancer. Materials and methods: Clinical treatment plans from five patients were used in this study. We simulated two applications given with PDR (32 x 60 cGy per applicat

  9. 3D numerical modeling of coupled phenomena in induced processes of heat treatment with malice

    Triwong Peeteenut

    2008-01-01

    Full Text Available This paper describes a multi-method Malice package for three dimension coupled phenomena in induced processes of heat treatment by an algorithm weakly coupled with the Migen package integral method defining the electromagnetic model and the Flux-Expert package finite element method defining the thermal model. The integral method is well suited to inductive systems undergoing sinusoidal excitation at midrange or high frequency. The unknowns of both models are current density, scalar potential and temperature. Joule power in the electromagnetic model is generated by Eddy currents. It becomes the heat source in the thermal model.

  10. 3D EPID based dosimetry for pre-treatment verification of VMAT – methods and challenges

    This article presents an overview of pre-treatment verification of volumetric modulated arc therapy (VMAT) with electronic portal imaging devices (EPIDs). Challenges to VMAT verification with EPIDs are discussed including EPID sag/flex during rotation, acquisition using cine-mode imaging, image artefacts during VMAT and determining the gantry angle for each image. The major methods that have been proposed to verify VMAT with EPIDs are introduced including those using or adapting commercial software systems and non-commercial implementations. Both two-dimensional and three-dimensional methods are reviewed.

  11. Reconstruction of 3D lung models from 2D planning data sets for Hodgkin's lymphoma patients using combined deformable image registration and navigator channels

    Ng, Angela; Nguyen, Thao-Nguyen; Moseley, Joanne L.; Hodgson, David C.; Sharpe, Michael B.; Brock, Kristy K. [Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario M5G 2M9 (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario M5G 2M9 (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9 (Canada) and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9 (Canada)

    2010-03-15

    Purpose: Late complications (cardiac toxicities, secondary lung, and breast cancer) remain a significant concern in the radiation treatment of Hodgkin's lymphoma (HL). To address this issue, predictive dose-risk models could potentially be used to estimate radiotherapy-related late toxicities. This study investigates the use of deformable image registration (DIR) and navigator channels (NCs) to reconstruct 3D lung models from 2D radiographic planning images, in order to retrospectively calculate the treatment dose exposure to HL patients treated with 2D planning, which are now experiencing late effects. Methods: Three-dimensional planning CT images of 52 current HL patients were acquired. 12 image sets were used to construct a male and a female population lung model. 23 ''Reference'' images were used to generate lung deformation adaptation templates, constructed by deforming the population model into each patient-specific lung geometry using a biomechanical-based DIR algorithm, MORFEUS. 17 ''Test'' patients were used to test the accuracy of the reconstruction technique by adapting existing templates using 2D digitally reconstructed radiographs. The adaptation process included three steps. First, a Reference patient was matched to a Test patient by thorax measurements. Second, four NCs (small regions of interest) were placed on the lung boundary to calculate 1D differences in lung edges. Third, the Reference lung model was adapted to the Test patient's lung using the 1D edge differences. The Reference-adapted Test model was then compared to the 3D lung contours of the actual Test patient by computing their percentage volume overlap (POL) and Dice coefficient. Results: The average percentage overlapping volumes and Dice coefficient expressed as a percentage between the adapted and actual Test models were found to be 89.2{+-}3.9% (Right lung=88.8%; Left lung=89.6%) and 89.3{+-}2.7% (Right=88.5%; Left=90

  12. Reconstruction of 3D lung models from 2D planning data sets for Hodgkin's lymphoma patients using combined deformable image registration and navigator channels

    Purpose: Late complications (cardiac toxicities, secondary lung, and breast cancer) remain a significant concern in the radiation treatment of Hodgkin's lymphoma (HL). To address this issue, predictive dose-risk models could potentially be used to estimate radiotherapy-related late toxicities. This study investigates the use of deformable image registration (DIR) and navigator channels (NCs) to reconstruct 3D lung models from 2D radiographic planning images, in order to retrospectively calculate the treatment dose exposure to HL patients treated with 2D planning, which are now experiencing late effects. Methods: Three-dimensional planning CT images of 52 current HL patients were acquired. 12 image sets were used to construct a male and a female population lung model. 23 ''Reference'' images were used to generate lung deformation adaptation templates, constructed by deforming the population model into each patient-specific lung geometry using a biomechanical-based DIR algorithm, MORFEUS. 17 ''Test'' patients were used to test the accuracy of the reconstruction technique by adapting existing templates using 2D digitally reconstructed radiographs. The adaptation process included three steps. First, a Reference patient was matched to a Test patient by thorax measurements. Second, four NCs (small regions of interest) were placed on the lung boundary to calculate 1D differences in lung edges. Third, the Reference lung model was adapted to the Test patient's lung using the 1D edge differences. The Reference-adapted Test model was then compared to the 3D lung contours of the actual Test patient by computing their percentage volume overlap (POL) and Dice coefficient. Results: The average percentage overlapping volumes and Dice coefficient expressed as a percentage between the adapted and actual Test models were found to be 89.2±3.9% (Right lung=88.8%; Left lung=89.6%) and 89.3±2.7% (Right=88.5%; Left=90.2%), respectively. Paired T-tests demonstrated that the volumetric

  13. Selection of candidate wells and optimization of conformance treatment design in the Barrancas Field using a 3D conformance simulator

    Crosta, Dante; Elitseche, Luis [Repsol YPF (Argentina); Gutierrez, Mauricio; Ansah, Joe; Everett, Don [Halliburton Argentina S.A., Buenos Aires (Argentina)

    2004-07-01

    Minimizing the amount of unwanted water production is an important goal at the Barrancas field. This paper describes a selection process for candidate injection wells that is part of a pilot conformance project aimed at improving vertical injection profiles, reducing water cut in producing wells, and improving ultimate oil recovery from this field. The well selection process is based on a review of limited reservoir information available for this field to determine inter-well communications. The methodology focuses on the best use of available information, such as production and injection history, well intervention files, open hole logs and injectivity surveys. After the candidate wells were selected and potential water injection channels were identified, conformance treatment design and future performance of wells in the selected pilot area were evaluated using a new 3 -D conformance simulator, developed specifically for optimization of the design and placement of unwanted fluid shut-off treatments. Thus, when acceptable history match ing of the pilot area production was obtained, the 3 -D simulator was used to: evaluate the required volume of selected conformance treatment fluid; review expected pressures and rates during placement;. model temperature behavior; evaluate placement techniques, and forecast water cut reduction and incremental oil recovery from the producers in this simulated section of the pilot area. This paper outlines a methodology for selecting candidate wells for conformance treatments. The method involves application of several engineering tools, an integral component of which is a user-friendly conformance simulator. The use of the simulator has minimized data preparation time and allows the running of sensitivity cases quickly to explore different possible scenarios that best represent the reservoir. The proposed methodology provides an efficient means of identifying conformance problems and designing optimized solutions for these individual

  14. Treatment planning system for carbon ion radiotherapy

    This paper describes the treatment planning (TP) and its peripheral system for carbon ion therapy that has been developed and in clinical use in recent two years at our institution. A new treatment planning system which is FOCUS customized to our irradiation system will be launched in clinical use soon. A new DICOM based PACS has been developed and in use. Now MRI, PET images are ready to be utilized for patient definition with image fusion functionality of radiotherapy TP. We implemented the exchange functionality of TP data specified by RTOG 3D QA Center in FOCUS, Pinnacle3 and heavy ion TP. Target volume and normal structure contours and dose distributions are exchangeable. A database system of carbon ion therapy dedicated to analysis of therapy data has been designed and implemented. All accessible planning data and treatment records of more than 1000 patients treated for seven and half years have been archived. The system has a DICOM RT sever and a database for miscellaneous text data. Limited numbers of private attributes were introduced for ion therapy specific objects. On-line as well as manual registration along with edit functionalities is prepared. Standard web browser is used to search and retrieve information. A DICOM RT viewer has been developed to view and retrieve RT images, dose distributions and structure set. These system described above are all designed to conform to the up-to-date standards of radiation therapy so as to be bases of the future development of the therapy at our institution. (author)

  15. Comparison between 3D conventional techniques, field-in-field and electronic tissue compensation for mantle fields planning; Comparacao entre tecnica 3D convencional, field-in-field e compensacao eletronica para planejamento de manto

    Martins, Lais P.; Silva, Leonardo P.; Trindade, Cassia; Garcia, Paulo L.; Santos, Maira R.; Batista, Delano V.S., E-mail: pm.lais@gmail.com [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil)

    2012-12-15

    External radiotherapy treatment for Hodgkin's lymphoma over diaphragm region requires large radiation fields with protections applied to larynx, humerus head and lungs. The size and shape of the field, which covers different depths, make it difficult to distribute a homogeneous dose. Techniques such as field-in-field and electronic tissue compensation may be used to make dose homogeneous and compensate the obliquity from the tissue. Three types of planning were performed for diagnose of nodular sclerosis Hodgkin's lymphoma: one plan with two fields, AP-PA (AP plan), another with four fields field-in- field (FF plan), and a third one with two fields and electronic tissue compensation (ETC plan). Results showed better gradient, cover of PTV and dose distribution for the ETC plan, besides the advantage from this technique of does not require protection blocks. In the meanwhile, AP and FF plans require simpler dosimetry and fewer MU. Related to the uniformity of dose distribution, AP plan showed hot areas in the neck region, FF plan showed hot areas in the shoulder region and ETC plan showed most uniform distribution without hot areas. The electronic tissue compensation is a useful tool for large and shaped fields as the mantle field, however higher MU and complex dosimetry should be taken in account. (author)

  16. Treatment planning in conservative dentistry

    Andamuthu Sivakumar; Vinod Thangaswamy; Vaiyapuri Ravi

    2012-01-01

    A patient attending for treatment of a restorative nature may present for a variety of reasons. The success is built upon careful history taking coupled with a logical progression to diagnosis of the problem that has been presented. Each stage follows on from the preceding one. A fitting treatment plan should be formulated and should involve a holistic approach to what is required.

  17. Correlation of Point B and Lymph Node Dose in 3D-Planned High-Dose-Rate Cervical Cancer Brachytherapy

    Purpose: To compare high dose rate (HDR) point B to pelvic lymph node dose using three-dimensional-planned brachytherapy for cervical cancer. Methods and Materials: Patients with FIGO Stage IB-IIIB cervical cancer received 70 tandem HDR applications using CT-based treatment planning. The obturator, external, and internal iliac lymph nodes (LN) were contoured. Per fraction (PF) and combined fraction (CF) right (R), left (L), and bilateral (Bil) nodal doses were analyzed. Point B dose was compared with LN dose-volume histogram (DVH) parameters by paired t test and Pearson correlation coefficients. Results: Mean PF and CF doses to point B were R 1.40 Gy ± 0.14 (CF: 7 Gy), L 1.43 ± 0.15 (CF: 7.15 Gy), and Bil 1.41 ± 0.15 (CF: 7.05 Gy). The correlation coefficients between point B and the D100, D90, D50, D2cc, D1cc, and D0.1cc LN were all less than 0.7. Only the D2cc to the obturator and the D0.1cc to the external iliac nodes were not significantly different from the point B dose. Significant differences between R and L nodal DVHs were seen, likely related to tandem deviation from irregular tumor anatomy. Conclusions: With HDR brachytherapy for cervical cancer, per fraction nodal dose approximates a dose equivalent to teletherapy. Point B is a poor surrogate for dose to specific nodal groups. Three-dimensional defined nodal contours during brachytherapy provide a more accurate reflection of delivered dose and should be part of comprehensive planning of the total dose to the pelvic nodes, particularly when there is evidence of pathologic involvement.

  18. Peripheral CT angiography for interventional treatment planning

    Lower extremity CT angiography (CTA) has evolved into a very effective, widely available and robust imaging modality for patients with peripheral arterial occlusive disease (PAOD). In this article we briefly review the acquisition and contrast administration techniques for 4- through 64-channel peripheral CTA. Visualization of atherosclerotic disease with CTA in general requires 'angiography-like' 3D images (such as volume rendered or maximum intensity projection images), but-notably in the presence of vessel wall calcifications and stents-cross-sectional views (such as curved planar reformations, CPR) are also required to accurately assess the flow lumen of the aorta down to the pedal arteries. Adequate visualization and mapping of atherosclerotic lesions in patients with PAOD is not only a prerequisite for generating a dictated report, but more importantly, standardized postprocessed images are the key to communicating the findings to the treating physician, and they also serve as a treatment planning tool. Treatment decisions (surgical versus transluminal revascularization, or conservative treatment), and percutaneous treatment planning (access site, antegrade versus retrograde puncture) can be made in the majority of patients with PAOD based on lower extremity CT angiograms. (orig.)

  19. 3D virtual planning in orthognathic surgery and CAD/CAM surgical splints generation in one patient with craniofacial microsomia: a case report

    Francisco Vale

    2016-02-01

    Full Text Available Objective: In this case report, the feasibility and precision of tridimensional (3D virtual planning in one patient with craniofacial microsomia is tested using Nemoceph 3D-OS software (Software Nemotec SL, Madrid, Spain to predict postoperative outcomes on hard tissue and produce CAD/CAM (Computer Aided Design/Computer Aided Manufacturing surgical splints. Methods: The clinical protocol consists of 3D data acquisition of the craniofacial complex by cone-beam computed tomography (CBCT and surface scanning of the plaster dental casts. The ''virtual patient'' created underwent virtual surgery and a simulation of postoperative results on hard tissues. Surgical splints were manufactured using CAD/CAM technology in order to transfer the virtual surgical plan to the operating room. Intraoperatively, both CAD/CAM and conventional surgical splints are comparable. A second set of 3D images was obtained after surgery to acquire linear measurements and compare them with measurements obtained when predicting postoperative results virtually. Results: It was found a high similarity between both types of surgical splints with equal fitting on the dental arches. The linear measurements presented some discrepancies between the actual surgical outcomes and the predicted results from the 3D virtual simulation, but caution must be taken in the analysis of these results due to several variables. Conclusions: The reported case confirms the clinical feasibility of the described computer-assisted orthognathic surgical protocol. Further progress in the development of technologies for 3D image acquisition and improvements on software programs to simulate postoperative changes on soft tissue are required.

  20. 3D game environments create professional 3D game worlds

    Ahearn, Luke

    2008-01-01

    The ultimate resource to help you create triple-A quality art for a variety of game worlds; 3D Game Environments offers detailed tutorials on creating 3D models, applying 2D art to 3D models, and clear concise advice on issues of efficiency and optimization for a 3D game engine. Using Photoshop and 3ds Max as his primary tools, Luke Ahearn explains how to create realistic textures from photo source and uses a variety of techniques to portray dynamic and believable game worlds.From a modern city to a steamy jungle, learn about the planning and technological considerations for 3D modelin

  1. Integrated 3D Reservoir/Fault Property Modelling Aided Well Planning and Improved Hydrocarbon Recovery in a Niger Delta Field

    The large and varied portfolio of assets managed by oil companies requires quick decision-making and the deployment of best in class technologies in asset management. Timely decision making and the application of the best technologies in reservoir management are however sometimes in conflict due to large time requirements of the latter.Optimizing the location of development wells is critical to account for variable fluid contact movements and pressure interference effects between wells, which can be significant because of the high permeability (Darcy range) of Niger Delta reservoirs. With relatively high drilling costs, the optimization of well locations necessitates a good realistic static and dynamic 3D reservoir description, especially in the recovery of remaining oil and oil rim type of reservoirs.A detailed 3D reservoir model with fault properties was constructed for a Niger delta producing field. This involved the integration of high quality 3D seismic, core, petrophysics, reservoir engineering, production and structural geology data to construct a realistic 3D reservoir/fault property model for the field. The key parameters considered during the construction of the internal architecture of the model were the vertical and horizontal reservoir heterogeneities-this controls the fluid flow within the reservoir. In the production realm, the fault thickness and fault permeabilities are factors that control the impedance of fluid flow across the fault-fault transmissibility. These key internal and external reservoir/structural variables were explicitly modeled in a 3D modeling software to produce different realizations and manage the uncertainties.The resulting 3D reservoir/fault property model was upscaled for simulation purpose such that grid blocks along the fault planes have realistic transmissibility multipliers of 0 to 1 attached to them. The model was also used in the well planner to optimize the positioning of a high angle deviated well that penetrated

  2. 3D Projection Installations

    Halskov, Kim; Johansen, Stine Liv; Bach Mikkelsen, Michelle

    2014-01-01

    Three-dimensional projection installations are particular kinds of augmented spaces in which a digital 3-D model is projected onto a physical three-dimensional object, thereby fusing the digital content and the physical object. Based on interaction design research and media studies, this article...... contributes to the understanding of the distinctive characteristics of such a new medium, and identifies three strategies for designing 3-D projection installations: establishing space; interplay between the digital and the physical; and transformation of materiality. The principal empirical case, From...... Fingerplan to Loop City, is a 3-D projection installation presenting the history and future of city planning for the Copenhagen area in Denmark. The installation was presented as part of the 12th Architecture Biennale in Venice in 2010....

  3. Validation of a method for in vivo 3D dose reconstruction for IMRT and VMAT treatments using on-treatment EPID images and a model-based forward-calculation algorithm

    Van Uytven, Eric, E-mail: eric.vanuytven@cancercare.mb.ca; Van Beek, Timothy [Medical Physics Department, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); McCowan, Peter M. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada and Medical Physics Department, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Chytyk-Praznik, Krista [Medical Physics Department, Nova Scotia Cancer Centre, 5820 University Avenue, Halifax, Nova Scotia B3H 1V7 (Canada); Greer, Peter B. [School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, NSW 2308 (Australia); Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Newcastle, NSW 2298 (Australia); McCurdy, Boyd M. C. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Medical Physics Department, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Department of Radiology, University of Manitoba, 820 Sherbrook Street, Winnipeg, Manitoba R3A 1R9 (Canada)

    2015-12-15

    Purpose: Radiation treatments are trending toward delivering higher doses per fraction under stereotactic radiosurgery and hypofractionated treatment regimens. There is a need for accurate 3D in vivo patient dose verification using electronic portal imaging device (EPID) measurements. This work presents a model-based technique to compute full three-dimensional patient dose reconstructed from on-treatment EPID portal images (i.e., transmission images). Methods: EPID dose is converted to incident fluence entering the patient using a series of steps which include converting measured EPID dose to fluence at the detector plane and then back-projecting the primary source component of the EPID fluence upstream of the patient. Incident fluence is then recombined with predicted extra-focal fluence and used to calculate 3D patient dose via a collapsed-cone convolution method. This method is implemented in an iterative manner, although in practice it provides accurate results in a single iteration. The robustness of the dose reconstruction technique is demonstrated with several simple slab phantom and nine anthropomorphic phantom cases. Prostate, head and neck, and lung treatments are all included as well as a range of delivery techniques including VMAT and dynamic intensity modulated radiation therapy (IMRT). Results: Results indicate that the patient dose reconstruction algorithm compares well with treatment planning system computed doses for controlled test situations. For simple phantom and square field tests, agreement was excellent with a 2%/2 mm 3D chi pass rate ≥98.9%. On anthropomorphic phantoms, the 2%/2 mm 3D chi pass rates ranged from 79.9% to 99.9% in the planning target volume (PTV) region and 96.5% to 100% in the low dose region (>20% of prescription, excluding PTV and skin build-up region). Conclusions: An algorithm to reconstruct delivered patient 3D doses from EPID exit dosimetry measurements was presented. The method was applied to phantom and patient

  4. Validation of a method for in vivo 3D dose reconstruction for IMRT and VMAT treatments using on-treatment EPID images and a model-based forward-calculation algorithm

    Purpose: Radiation treatments are trending toward delivering higher doses per fraction under stereotactic radiosurgery and hypofractionated treatment regimens. There is a need for accurate 3D in vivo patient dose verification using electronic portal imaging device (EPID) measurements. This work presents a model-based technique to compute full three-dimensional patient dose reconstructed from on-treatment EPID portal images (i.e., transmission images). Methods: EPID dose is converted to incident fluence entering the patient using a series of steps which include converting measured EPID dose to fluence at the detector plane and then back-projecting the primary source component of the EPID fluence upstream of the patient. Incident fluence is then recombined with predicted extra-focal fluence and used to calculate 3D patient dose via a collapsed-cone convolution method. This method is implemented in an iterative manner, although in practice it provides accurate results in a single iteration. The robustness of the dose reconstruction technique is demonstrated with several simple slab phantom and nine anthropomorphic phantom cases. Prostate, head and neck, and lung treatments are all included as well as a range of delivery techniques including VMAT and dynamic intensity modulated radiation therapy (IMRT). Results: Results indicate that the patient dose reconstruction algorithm compares well with treatment planning system computed doses for controlled test situations. For simple phantom and square field tests, agreement was excellent with a 2%/2 mm 3D chi pass rate ≥98.9%. On anthropomorphic phantoms, the 2%/2 mm 3D chi pass rates ranged from 79.9% to 99.9% in the planning target volume (PTV) region and 96.5% to 100% in the low dose region (>20% of prescription, excluding PTV and skin build-up region). Conclusions: An algorithm to reconstruct delivered patient 3D doses from EPID exit dosimetry measurements was presented. The method was applied to phantom and patient

  5. Radiation treatment planning system verification

    Optimum radiotherapy requires accurate and consistent radiation doses. To fulfil this requirement, it is necessary to make quality checks of the equipment and software included in the planning process. Treatment planning system is used to calculate monitor units required to deliver prescribed dose to a designated volume with acceptable distribution of radiation dose. The aim of this study was to verify the Theraplan Plus treatment program used in our Department to calculate treatment times for radiation therapy with 60Co unit. To run a Theraplan Plus system, it is necessary to input data describing mechanical and radiation aspects of treatment unit. One of the checks included a comparison of the measured depth doses and off-axis ratios with those calculated using the treatment program. The second step included the measurement of the dose using ionisation chamber and thermoluminescent dosimeters (TLD), which was then compared with calculated values for several treatment scenarios (central axis dose on specified depth of square fields, elongated fields, under the block and wedges etc.). The third step involved the comparison between the dose calculated for a specific treatment plan with the doses measured with TLD dosimeters in the Alderson phantom.(author)

  6. Dosimetric prospective study comparing 2D and 3D planning for irradiation of supraclavicular and infraclavicular regions in breast cancer patients

    Purpose: The purpose of this study is to compare 2D plan and 3D plan regarding coverage of the target (supraclavicular and infraclavicular regions) and dose reaching the risk organs (using mean DVH). Depending on the results of this study, modifications can be made to the 2D conventional planning of supraclavicular and infraclavicular regions in order to achieve better coverage of the target tissues. Materials and methods: This is a dosimetric study carried out at the radiation oncology department in NCI-Cairo University in the period from January 2012 to October 2012, on 15 patients with breast cancer who are eligible for supraclavicular and infraclavicular irradiation. For All patients, a 2D and a 3D plan were done. Results: We found that the coverage of the supraclavicular and infraclavicular regions and the chest wall or breast together with levels I and II axilla (PTV) were significantly better with the 3D technique with less over dose than the 2D technique. That difference was highly significant and was most evident in MRM cases. Also we found that organs at risk received a dose in the 3D technique that was more than that received in the 2D technique, again that difference was highly significant and was also most evident in MRM cases but all doses were still within tolerance. Conclusions: From the present study we concluded that the coverage of the supraclavicular and infraclavicular PTV is significantly worse with the 2D technique using a single oblique field at a fixed depth of 3 cm for all patients despite their different builts.

  7. Different effects of bladder distention on point A-based and 3D-conformal intracavitary brachytherapy planning for cervical cancer

    Ju, Sang Gyu; Huh, Seung Jae; Shin, Jung Suk; Park, Won; Nam, Heerim; Bae, Sunhyun; Oh, Dongryul; Hong, Chae-Seon; Kim, Jin Sung; Han, Youngyih; Choi, Doo Ho

    2012-01-01

    This study sought to evaluate the differential effects of bladder distention on point A-based (AICBT) and three-dimensional conformal intracavitary brachytherapy (3D-ICBT) planning for cervical cancer. Two sets of CT scans were obtained for ten patients to evaluate the effect of bladder distention. After the first CT scan, with an empty bladder, a second set of CT scans was obtained with the bladder filled. The clinical target volume (CTV), bladder, rectum, and small bowel were delineated on ...

  8. Implant restoration of edentulous jaws with 3D software planning, guided surgery, immediate loading, and CAD-CAM full arch frameworks

    Silvio Mario Meloni; Giacomo De Riu; Milena Pisano; Francesco Maria Lolli; Alessandro Deledda; Guglielmo Campus; Antonio Tullio

    2013-01-01

    Purpose. The aim of this study was to analyze the clinical and radiographic outcomes of 23 edentulous jaws treated with 3D software planning, guided surgery, and immediate loading and restored with CAD-CAM full arch frameworks. Materials and Methods. This work was designed as a prospective case series clinical study. Twenty patients have been consecutively rehabilitated with an immediately loaded implant supported fixed full prosthesis. A total of 120 fixtures supporting 23 bridges were place...

  9. Automatic liver contouring for radiotherapy treatment planning.

    Li, Dengwang; Liu, Li; Kapp, Daniel S; Xing, Lei

    2015-10-01

    To develop automatic and efficient liver contouring software for planning 3D-CT and four-dimensional computed tomography (4D-CT) for application in clinical radiation therapy treatment planning systems.The algorithm comprises three steps for overcoming the challenge of similar intensities between the liver region and its surrounding tissues. First, the total variation model with the L1 norm (TV-L1), which has the characteristic of multi-scale decomposition and an edge-preserving property, is used for removing the surrounding muscles and tissues. Second, an improved level set model that contains both global and local energy functions is utilized to extract liver contour information sequentially. In the global energy function, the local correlation coefficient (LCC) is constructed based on the gray level co-occurrence matrix both of the initial liver region and the background region. The LCC can calculate the correlation of a pixel with the foreground and background regions, respectively. The LCC is combined with intensity distribution models to classify pixels during the evolutionary process of the level set based method. The obtained liver contour is used as the candidate liver region for the following step. In the third step, voxel-based texture characterization is employed for refining the liver region and obtaining the final liver contours.The proposed method was validated based on the planning CT images of a group of 25 patients undergoing radiation therapy treatment planning. These included ten lung cancer patients with normal appearing livers and ten patients with hepatocellular carcinoma or liver metastases. The method was also tested on abdominal 4D-CT images of a group of five patients with hepatocellular carcinoma or liver metastases. The false positive volume percentage, the false negative volume percentage, and the dice similarity coefficient between liver contours obtained by a developed algorithm and a current standard delineated by the expert group

  10. Automatic liver contouring for radiotherapy treatment planning

    Li, Dengwang; Liu, Li; Kapp, Daniel S.; Xing, Lei

    2015-09-01

    To develop automatic and efficient liver contouring software for planning 3D-CT and four-dimensional computed tomography (4D-CT) for application in clinical radiation therapy treatment planning systems. The algorithm comprises three steps for overcoming the challenge of similar intensities between the liver region and its surrounding tissues. First, the total variation model with the L1 norm (TV-L1), which has the characteristic of multi-scale decomposition and an edge-preserving property, is used for removing the surrounding muscles and tissues. Second, an improved level set model that contains both global and local energy functions is utilized to extract liver contour information sequentially. In the global energy function, the local correlation coefficient (LCC) is constructed based on the gray level co-occurrence matrix both of the initial liver region and the background region. The LCC can calculate the correlation of a pixel with the foreground and background regions, respectively. The LCC is combined with intensity distribution models to classify pixels during the evolutionary process of the level set based method. The obtained liver contour is used as the candidate liver region for the following step. In the third step, voxel-based texture characterization is employed for refining the liver region and obtaining the final liver contours. The proposed method was validated based on the planning CT images of a group of 25 patients undergoing radiation therapy treatment planning. These included ten lung cancer patients with normal appearing livers and ten patients with hepatocellular carcinoma or liver metastases. The method was also tested on abdominal 4D-CT images of a group of five patients with hepatocellular carcinoma or liver metastases. The false positive volume percentage, the false negative volume percentage, and the dice similarity coefficient between liver contours obtained by a developed algorithm and a current standard delineated by the expert group

  11. A New Total Digital Smile Planning Technique (3D-DSP) to Fabricate CAD-CAM Mockups for Esthetic Crowns and Veneers

    Mastrangelo, F.; Gherlone, E. F.; Gastaldi, G.

    2016-01-01

    Purpose. Recently, the request of patients is changed in terms of not only esthetic but also previsualization therapy planning. The aim of this study is to evaluate a new 3D-CAD-CAM digital planning technique that uses a total digital smile process. Materials and Methods. Study participants included 28 adult dental patients, aged 19 to 53 years, with no oral, periodontal, or systemic diseases. For each patient, 3 intra- and extraoral pictures and intraoral digital impressions were taken. The digital images improved from the 2D Digital Smile System software and the scanner stereolithographic (STL) file was matched into the 3D-Digital Smile System to obtain a virtual previsualization of teeth and smile design. Then, the mockups were milled using a CAM system. Minimally invasive preparation was carried out on the enamel surface with the mockups as position guides. Results. The patients found both the digital smile design previsualization (64.3%) and the milling mockup test (85.7%) very effective. Conclusions. The new total 3D digital planning technique is a predictably and minimally invasive technique, allows easy diagnosis, and improves the communication with the patient and helps to reduce the working time and the errors usually associated with the classical prosthodontic manual step. PMID:27478442

  12. Phantom investigation of 3D motion-dependent volume aliasing during CT simulation for radiation therapy planning

    To quantify volumetric and positional aliasing during non-gated fast- and slow-scan acquisition CT in the presence of 3D target motion. Single-slice fast, single-slice slow, and multi-slice fast scan helical CTs were acquired of dynamic spherical targets (1 and 3.15 cm in diameter), embedded in an anthropomorphic phantom. 3D target motions typical of clinically observed tumor motion parameters were investigated. Motion excursions included ± 5, ± 10, and ± 15 mm displacements in the S-I direction synchronized with constant displacements of ± 5 and ± 2 mm in the A-P and lateral directions, respectively. For each target, scan technique, and motion excursion, eight different initial motion-to-scan phase relationships were investigated. An anticipated general trend of target volume overestimation was observed. The mean percentage overestimation of the true physical target volume typically increased with target motion amplitude and decreasing target diameter. Slow-scan percentage overestimations were larger, and better approximated the time-averaged motion envelope, as opposed to fast-scans. Motion induced centroid misrepresentation was greater in the S-I direction for fast-scan techniques, and transaxial direction for the slow-scan technique. Overestimation is fairly uniform for slice widths < 5 mm, beyond which there is gross overestimation. Non-gated CT imaging of targets describing clinically relevant, 3D motion results in aliased overestimation of the target volume and misrepresentation of centroid location, with little or no correlation between the physical target geometry and the CT-generated target geometry. Slow-scan techniques are a practical method for characterizing time-averaged target position. Fast-scan techniques provide a more reliable, albeit still distorted, target margin

  13. SU-D-201-07: Exploring the Utility of 4D FDG-PET/CT Scans in Design of Radiation Therapy Planning Compared with 3D PET/CT: A Prospective Study

    Ma, C; Yin, Y [Shandong Tumor Hospital, Jinan, Shandong Provice (China)

    2015-06-15

    Purpose: A method using four-dimensional(4D) PET/CT in design of radiation treatment planning was proposed and the target volume and radiation dose distribution changes relative to standard three-dimensional (3D) PET/CT were examined. Methods: A target deformable registration method was used by which the whole patient’s respiration process was considered and the effect of respiration motion was minimized when designing radiotherapy planning. The gross tumor volume of a non-small-cell lung cancer was contoured on the 4D FDG-PET/CT and 3D PET/CT scans by use of two different techniques: manual contouring by an experienced radiation oncologist using a predetermined protocol; another technique using a constant threshold of standardized uptake value (SUV) greater than 2.5. The target volume and radiotherapy dose distribution between VOL3D and VOL4D were analyzed. Results: For all phases, the average automatic and manually GTV volume was 18.61 cm3 (range, 16.39–22.03 cm3) and 31.29 cm3 (range, 30.11–35.55 cm3), respectively. The automatic and manually volume of merged IGTV were 27.82 cm3 and 49.37 cm3, respectively. For the manual contour, compared to 3D plan the mean dose for the left, right, and total lung of 4D plan have an average decrease 21.55%, 15.17% and 15.86%, respectively. The maximum dose of spinal cord has an average decrease 2.35%. For the automatic contour, the mean dose for the left, right, and total lung have an average decrease 23.48%, 16.84% and 17.44%, respectively. The maximum dose of spinal cord has an average decrease 1.68%. Conclusion: In comparison to 3D PET/CT, 4D PET/CT may better define the extent of moving tumors and reduce the contouring tumor volume thereby optimize radiation treatment planning for lung tumors.

  14. SU-D-201-07: Exploring the Utility of 4D FDG-PET/CT Scans in Design of Radiation Therapy Planning Compared with 3D PET/CT: A Prospective Study

    Purpose: A method using four-dimensional(4D) PET/CT in design of radiation treatment planning was proposed and the target volume and radiation dose distribution changes relative to standard three-dimensional (3D) PET/CT were examined. Methods: A target deformable registration method was used by which the whole patient’s respiration process was considered and the effect of respiration motion was minimized when designing radiotherapy planning. The gross tumor volume of a non-small-cell lung cancer was contoured on the 4D FDG-PET/CT and 3D PET/CT scans by use of two different techniques: manual contouring by an experienced radiation oncologist using a predetermined protocol; another technique using a constant threshold of standardized uptake value (SUV) greater than 2.5. The target volume and radiotherapy dose distribution between VOL3D and VOL4D were analyzed. Results: For all phases, the average automatic and manually GTV volume was 18.61 cm3 (range, 16.39–22.03 cm3) and 31.29 cm3 (range, 30.11–35.55 cm3), respectively. The automatic and manually volume of merged IGTV were 27.82 cm3 and 49.37 cm3, respectively. For the manual contour, compared to 3D plan the mean dose for the left, right, and total lung of 4D plan have an average decrease 21.55%, 15.17% and 15.86%, respectively. The maximum dose of spinal cord has an average decrease 2.35%. For the automatic contour, the mean dose for the left, right, and total lung have an average decrease 23.48%, 16.84% and 17.44%, respectively. The maximum dose of spinal cord has an average decrease 1.68%. Conclusion: In comparison to 3D PET/CT, 4D PET/CT may better define the extent of moving tumors and reduce the contouring tumor volume thereby optimize radiation treatment planning for lung tumors

  15. 3-D VARIABLE PARAMETER NUMERICAL MODEL FOR EVALUATION OF THE PLANNED EXPLOITABLE GROUNDWATER RESOURCE IN REGIONAL UNCONSOLIDATED SEDIMENTS

    LUO Zu-jiang; WANG Yan

    2012-01-01

    In order to correctly evaluate the exploitable groundwater resource in regional complex,thick Quaternary unconsolidated sediments,the whole Quaternary unconsolidated sediments are considered as a unified hydrogeological unit and a 3-D unsteady groundwater flow numerical model is adopted.Meanwhile,with the consideration of the dynamic changes of the porosity,the hydraulic conductivity and the specific storage with the groundwater level dropping during the exploitation process,an improved composite element seepage matrix adjustment method is applied to solve the unsteady flow problem of free surface.In order to evaluate the exploitable groundwater resource in Cangzhou,Hebei Province,the hydrogeological conceptual model of Cangzhou is generalized to establish,a 3-D variable parameter numerical model of Cangzhou.Based on the prediction of the present groundwater exploitation,and by adjusting the groundwater exploitation layout,the exploitable groundwater resource is predicted.The model enjoys features like good convergence,good stability and high precision.

  16. Standard and fenestrated endograft sizing in EVAR planning: Description and validation of a semi-automated 3D software.

    Macía, Iván; de Blas, Mariano; Legarreta, Jon Haitz; Kabongo, Luis; Hernández, Óscar; Egaña, José María; Emparanza, José Ignacio; García-Familiar, Ainhoa; Graña, Manuel

    2016-06-01

    An abdominal aortic aneurysm (AAA) is a pathological dilation of the abdominal aorta that may lead to a rupture with fatal consequences. Endovascular aneurysm repair (EVAR) is a minimally invasive surgical procedure consisting of the deployment and fixation of a stent-graft that isolates the damaged vessel wall from blood circulation. The technique requires adequate endovascular device sizing, which may be performed by vascular analysis and quantification on Computerized Tomography Angiography (CTA) scans. This paper presents a novel 3D CTA image-based software for AAA inspection and EVAR sizing, eVida Vascular, which allows fast and accurate 3D endograft sizing for standard and fenestrated endografts. We provide a description of the system and its innovations, including the underlying vascular image analysis and visualization technology, functional modules and user interaction. Furthermore, an experimental validation of the tool is described, assessing the degree of agreement with a commercial, clinically validated software, when comparing measurements obtained for standard endograft sizing in a group of 14 patients. PMID:25747803

  17. A dosimetric comparison of four treatment planning methods for high grade glioma

    Miller Robert W

    2009-10-01

    Full Text Available Abstract Background High grade gliomas (HGG are typically treated with a combination of surgery, radiotherapy and chemotherapy. Three dimensional (3D conformal radiotherapy treatment planning is still the main stay of treatment for these patients. New treatment planning methods suggest better dose distributions and organ sparing but their clinical benefit is unclear. The purpose of the current study was to compare normal tissue sparing and tumor coverage using four different radiotherapy planning methods in patients with high grade glioma. Methods Three dimensional conformal (3D, sequential boost IMRT, integrated boost (IB IMRT and Tomotherapy (TOMO treatment plans were generated for 20 high grade glioma patients. T1 and T2 MRI abnormalities were used to define GTV and CTV with 2 and 2.5 cm margins to define PTV1 and PTV2 respectively. Results The mean dose to PTV2 but not to PTV1 was less then 95% of the prescribed dose with IB and IMRT plans. The mean doses to the optic chiasm and the ipsilateral globe were highest with 3D plans and least with IB plans. The mean dose to the contralateral globe was highest with TOMO plans. The mean of the integral dose (ID to the brain was least with the IB plan and was lower with IMRT compared to 3D plans. The TOMO plans had the least mean D10 to the normal brain but higher mean D50 and D90 compared to IB and IMRT plans. The mean D10 and D50 but not D90 were significantly lower with the IMRT plans compared to the 3D plans. Conclusion No single treatment planning method was found to be superior to all others and a personalized approach is advised for planning and treating high-grade glioma patients with radiotherapy. Integral dose did not reflect accurately the dose volume histogram (DVH of the normal brain and may not be a good indicator of delayed radiation toxicity.

  18. Design and implementation of a rotational radiotherapy technique for breast cancer treatment and their comparison with 3-D-Crt irradiation technique

    Breast cancer is one of oncological diseases worldwide, as well in Mexico, which causes even more deaths than cervical cancer; this condition is the second death cause in women aged 30-54 years and threatens all socio-economic groups. The treatment is highly dependent on the stage which is detected and based on protocols that include a combination of surgery, chemotherapy and radiotherapy. This paper studies the main irradiation technique for patients with mastectomy, breast full cycle (irradiation of the chest well and supraclavicular nodes) in their mode Three Dimensional - Conformal Radiation Therapy (3-D-Crt), and compared with the Volumetric Modulated Arc Therapy (VMAT) technique proposed in this paper. In both techniques the prescription was 50 Gy divided into 25 fractions. The techniques were applied in three female patients (being an initial study) with disease of the left side, the target volume and organs at risk were delineated by the medical treating radiation oncologist, the planning system used was Eclipse version 10; for quantitative comparison of both plans indexes of homogeneity were used, con formality, the target volume coverage and normal tissue, sub factors and overdosing, the conformation number and coverage quality. They were evaluated and compared the media, maximum and minimum dose of the organs at risk, based on the fact that the coverage of the target volume, dose gradient and dose at risk organs are acceptable (prescription dose greater that 90% coverage, gradient less that 20% and organs at risk in accordance with the Quantec limitations for both versions). (Author)

  19. Three-dimensional (3D) palladium-zinc oxide nanowire nanofiber as photo-catalyst for water treatment.

    Choi, Jungsu; Chan, Sophia; Joo, Hyunjong; Yang, Heejae; Ko, Frank K

    2016-09-15

    Zinc Oxide Nano Wires (ZNWs) has been considered as a promising material for purification and disinfection of water and remediation of hazardous waste owing to its high activity and lower cost. In this study, three-dimensional (3D) structured palladium (Pd)/ZNWs were synthesized on the fabricated electrospun nanofibers and explored for enhancement of organic matter (OM) removal efficiency in water by suppressing electron-hole recombination during photocatalytic activity and increased surface area. The densely populated ZNWs were fabricated on the electrospun nanofiber by electroless plating (EP) and hydrothermal synthesis. In order to improve photocatalytic efficiency, a thin layer of Pd was coated prior to ZNWs growth to induce suppression of electron hole recombination produced during catalyst activity. The creation of a highly porous network of nanofibers decorated with ZNWs resulted in an increase of specific removal rate (SRR) of OM from 0.0249 to 0.0377 mg CODCr removed/mg ZNWs-hr when ZNW were grown on a Pd layer. It is believed that the demonstration of OM removal in the water through Pd/ZNWs membrane and enhanced photocatalytic activity under UV irradiation from layered structure can broaden potential applicability of Pd/ZNWs membranes for various photo catalytic water treatment. PMID:27286471

  20. Comparison of 2D and 3D algorithms for adding a margin to the gross tumor volume in the conformal radiotherapy planning of prostate cancer

    Purpose: To evaluate the adequacy of tumor volume coverage using a three dimensional (3D) margin growing algorithm compared to a two dimensional (2D) margin growing algorithm in the conformal radiotherapy planning of prostate cancer. Methods and Materials: Two gross tumor volumes (GTV) were segmented in each of ten patients with localized prostate cancer: prostate gland only (PO) and prostate with seminal vesicles (PSV). A margin of 10 mm was applied to these two groups (PO and PSV) using both the 2D and 3D margin growing algorithms. The true planning target volume (PTV) was defined as the region delineated by the 3D algorithm. Adequacy of geometric coverage of the GTV with the two algorithms was examined throughout the target volume. Discrepancies between the two margin methods were measured in the transaxial plane. Results: The 2D algorithm underestimated the PTV by 17% (range 12-20) in the PO group and by 20% (range 13-28) for the PSV group when compared to the 3D algorithm. For both the PO and PSV groups, the inferior coverage of the PTV was consistently underestimated by the 2D margin algorithm when compared to the 3D margins with a mean radial distance of 4.8 mm (range 0-10). In the central region of the prostate gland, the anterior, posterior, and lateral PTV borders were underestimated with the 2D margin in both the PO and PSV groups by a mean of 3.6 mm (range 0-9), 2.1 mm (range 0-8), and 1.8 (range 0-9) respectively. The PTV coverage of the PO group superiorly was radially underestimated by 4.5mm (range 0-14) when comparing the 2D margins to the 3D margins. For the PSV group, the junction region between the prostate and the seminal vesicles was underestimated by the 2D margin by a mean transaxial distance of 18.1 mm in the anterior PTV border (range 4-30), 7.2 mm posteriorly (range 0-20), and 3.7 mm laterally (range 0-14). The superior region of the seminal vesicles in the PSV group was also consistently underestimated with a radial discrepancy of 3.3 mm

  1. Comparison of 2D and 3D algorithms for adding a margin to the gross tumor volume in the conformal radiotherapy planning of prostate cancer

    Purpose: To evaluate the adequacy of tumor volume coverage using a three-dimensional (3D) margin-growing algorithm compared to a two-dimensional (2D) margin-growing algorithm in the conformal radiotherapy planning of prostate cancer. Methods and Materials: Two gross tumor volumes (GTV) were segmented in each of 10 patients with localized prostate cancer; prostate gland only (PO) and prostate with seminal vesicles (PSV). A predetermined margin of 10 mm was applied to these two groups (PO and PSV) using both 2D and 3D margin-growing algorithms. The 2D algorithm added a transaxial margin to each GTV slice, whereas the 3D algorithm added a volumetric margin all around the GTV. The true planning target volume (PTV) was defined as the region delineated by the 3D algorithm. The adequacy of geometric coverage of the GTV by the two algorithms was examined in a series of transaxial planes throughout the target volume. Results: The 2D margin-growing algorithm underestimated the PTV by 17% (range 12-20) in the PO group and by 20% (range 13-28) for the PSV group when compared to the 3D-margin algorithm. For the PO group, the mean transaxial difference between the 2D and 3D algorithm was 3.8 mm inferiorly (range 0-20), 1.8 mm centrally (range 0-9), and 4.4 mm superiorly (range 0-22). Considering all of these regions, the mean discrepancy anteriorly was 5.1 mm (range 0-22), posteriorly 2.2 (range 0-20), right border 2.8 mm (range 0-14), and left border 3.1 mm (range 0-12). For the PSV group, the mean discrepancy in the inferior region was 3.8 mm (range 0-20), central region of the prostate was 1.8 mm ( range 0-9), the junction region of the prostate and the seminal vesicles was 5.5 mm (range 0-30), and the superior region of the seminal vesicles was 4.2 mm (range 0-55). When the different borders were considered in the PSV group, the mean discrepancies for the anterior, posterior, right, and left borders were 6.4 mm (range 0-55), 2.5 mm (range 0-20), 2.6 mm (range 0-14), and 3

  2. Concepts of radiotherapy treatment planning

    Full text: Radiotherapy treatment planning (RTP) relies heavily on medical imaging. Until recently, the most important planning tool was the treatment simulator. The kilovoltage radiographic capabilities in a treatment simulator enabled the boundaries of treatment fields to be visualized with respect to bony anatomic landmarks. Perhaps the most important advance in treatment planning in recent years is the ability to visualize the passage of the beams with respect to a more accurate geometrical representation of the tumor and other soft tissue structures. This 'virtual simulation' uses a computer-based representation of a patient to determine the extent of the disease and the location of radiation sensitive normal tissue. Computer tomographic (CT) imaging produces a high-resolution three-dimensional representation of anatomy that can be correlated with other image sets such as magnetic resonance images (MRI) of function. Positron emission tomographic (PET) imaging is beginning to be used to determine tumor proliferation and the presence of distant disease. It is likely that accurate RTP in conjunction with CT simulators will eliminate traditional treatment simulators in the future. Traditionally, patient dose calculation algorithms have been based on correcting measured dose in water phantoms to take into account beam modifiers, patient surface contours and internal tissue inhomogeneities. Recently, model-based algorithms have been computing the dose directly in the patient representation using the CT to obtain a voxel-by-voxel density map. The convolution/superposition method, which uses a Monte Carlo-derived transport kernel, is the current state-of-the-art algorithm for dose computation. Soon direct Monte Carlo simulation will be used in model-based dose computation. Model-based dose computations enable a simpler monitor unit calculation formulation. The other major breakthrough in RTP is computer-based optimization. The goals of the treatment are specified as

  3. Application of a 3D printed customized implant for canine cruciate ligament treatment by tibial tuberosity advancement

    Fabrication of customized implants based on patient bone defect characteristics is required for successful clinical application of bone tissue engineering. Recently a new surgical procedure, tibial tuberosity advancement (TTA), has been used to treat cranial cruciate ligament (CrCL) deficient stifle joints in dogs, which involves an osteotomy and the use of substitutes to restore the bone. However, limitations in the use of non-biodegradable implants have been reported. To overcome these limitations, this study presents the development of a bioceramic customized cage to treat a large domestic dog assigned for TTA treatment. A cage was designed using a suitable topology optimization methodology in order to maximize its permeability whilst maintaining the structural integrity, and was manufactured using low temperature 3D printing and implanted in a dog. The cage material and structure was adequately characterized prior to implantation and the in vivo response was carefully monitored regarding the biological response and patient limb function. The manufacturing process resulted in a cage composed of brushite, monetite and tricalcium phosphate, and a highly permeable porous morphology. An overall porosity of 59.2% was achieved by the combination of a microporosity of approximately 40% and a designed interconnected macropore network with pore sizes of 845 μm. The mechanical properties were in the range of the trabecular bone although limitations in the cage's reliability and capacity to absorb energy were identified. The dog's limb function was completely restored without patient lameness or any adverse complications and also the local biocompatibility and osteoconductivity were improved. Based on these observations it was possible to conclude that the successful design, fabrication and application of a customized cage for a dog CrCL treatment using a modified TTA technique is a promising method for the future fabrication of patient-specific bone implants

  4. Three-dimensional radiation treatment planning system based on STARDENT super graphic workstation

    In this paper we have demonstrated our 3D treatment planning system developed on a commercial workstation. The system has been in routine use for planning stereotactic brain implants for the last 2 years. Also we have demonstrated a few cases of the application of our 3D planning system for external beams. In future, several patient with specific clinical indication will be designated for planning, using this system. However, in its current state, the system is not ready to replace 2D planning with 3D planning. This is partly due to the inadequacy of the system, but mostly related to the lack of manpower, commitment and inadequacy of proper technology in the treatment machines in our department. (author). 6 refs., 14 figs

  5. Real time 3D scanner: investigations and results

    Nouri, Taoufik; Pflug, Leopold

    1993-12-01

    This article presents a concept of reconstruction of 3-D objects using non-invasive and touch loss techniques. The principle of this method is to display parallel interference optical fringes on an object and then to record the object under two angles of view. According to an appropriated treatment one reconstructs the 3-D object even when the object has no symmetrical plan. The 3-D surface data is available immediately in digital form for computer- visualization and for analysis software tools. The optical set-up for recording the 3-D object, the 3-D data extraction and treatment, as well as the reconstruction of the 3-D object are reported and commented on. This application is dedicated for reconstructive/cosmetic surgery, CAD, animation and research purposes.

  6. Chest wall desmoid tumours treated with definitive radiotherapy: a plan comparison of 3D conformal radiotherapy, intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy

    Liu, Jia; Ng, Diana; Lee, James; Stalley, Paul; Hong, Angela

    2016-01-01

    Purpose Definitive radiotherapy is often used for chest wall desmoid tumours due to size or anatomical location. The delivery of radiotherapy is challenging due to the large size and constraints of normal surrounding structures. We compared the dosimetry of 3D conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) to evaluate the best treatment option. Methods and materials Ten consecutive patients with inoperable chest wall de...

  7. An analysing of heat treatment process planning

    B. Smoljan

    2007-01-01

    Purpose: Process planning of heat treatment has been investigated. The established approach of heat treatingprocess planning is suitable for effective integration of heat treatment in computer added manufacturing.Design/methodology/approach: Process plan of heat treating process has been established based on fundamentalprocess planning principals. The heat treatment was treated in the same as other manufacture processes.Findings: The general approach for process planning of heat treatment pro...

  8. Volume definition system for treatment planning

    Purpose: Volume definition is a difficult and time consuming task in 3D treatment planning. We have studied a systems approach for constructing an efficient and reliable set of tools for volume definition. Our intent is to automate body outline, air cavities and bone volume definition and accelerate definition of other anatomical structures. An additional focus is on assisting in definition of CTV and PTV. The primary goals of this work are to cut down the time used in contouring and to improve the accuracy of volume definition. Methods: We used the following tool categories: manual, semi-automatic, automatic, structure management, target volume definition, and visualization tools. The manual tools include mouse contouring tools with contour editing possibilities and painting tools with a scaleable circular brush and an intelligent brush. The intelligent brush adapts its shape to CT value boundaries. The semi-automatic tools consist of edge point chaining, classical 3D region growing of single segment and competitive volume growing of multiple segments. We tuned the volume growing function to take into account both local and global region image values, local volume homogeneity, and distance. Heuristic seeding followed with competitive volume growing finds the body outline, couch and air automatically. The structure management tool stores ICD-O coded structures in a database. The codes have predefined volume growing parameters and thus are able to accommodate the volume growing dissimilarity function for different volume types. The target definition tools include elliptical 3D automargin for CTV to PTV transformation and target volume interpolation and extrapolation by distance transform. Both the CTV and the PTV can overlap with anatomical structures. Visualization tools show the volumes as contours or color wash overlaid on an image and displays voxel rendering or translucent triangle mesh rendering in 3D. Results: The competitive volume growing speeds up the

  9. Intensity modulated radiotherapy and 3D conformal radiotherapy for whole breast irradiation: a comparative dosimetric study and introduction of a novel qualitative index for plan evaluation, the normal tissue index

    Yim, Jackie; Suttie, Clare; Bromley, Regina; Morgia, Marita; Lamoury, Gillian [Department of Radiation Oncology, Royal North Shore Hospital, St Leonards, New South Wales (Australia)

    2015-09-15

    We report on a retrospective dosimetric study, comparing 3D conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (hIMRT). We evaluated plans based on their planning target volume coverage, dose homogeneity, dose to organs at risk (OARs) and exposure of normal tissue to radiation. The Homogeneity Index (HI) was used to assess the dose homogeneity in the target region, and we describe a new index, the normal tissue index (NTI), to assess the dose in the normal tissue inside the tangent treatment portal. Plans were generated for 25 early-stage breast cancer patients, using a hIMRT technique. These were compared with the 3DCRT plans of the treatment previously received by the patients. Plan quality was evaluated using the HI, NTI and dose to OARs. The hIMRT technique was significantly more homogenous than the 3DCRT technique, while maintaining target coverage. The hIMRT technique was also superior at minimising the amount of tissue receiving D{sub 105%} and above (P < 0.0001). The ipsilateral lung and contralateral breast maximum were significantly lower in the hIMRT plans (P < 0.05 and P < 0.005), but the 3DCRT technique achieved a lower mean heart dose in left-sided breast cancer patients (P < 0.05). Hybrid intensity modulated radiotherapy plans achieved improved dose homogeneity compared to the 3DCRT plans and superior outcome with regard to dose to normal tissues. We propose that the addition of both HI and NTI in evaluating the quality of intensity modulated radiotherapy (IMRT) breast plans provides clinically relevant comparators which more accurately reflect the new paradigm of treatment goals and outcomes in the era of breast IMRT.

  10. Intensity modulated radiotherapy and 3D conformal radiotherapy for whole breast irradiation: a comparative dosimetric study and introduction of a novel qualitative index for plan evaluation, the normal tissue index

    We report on a retrospective dosimetric study, comparing 3D conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (hIMRT). We evaluated plans based on their planning target volume coverage, dose homogeneity, dose to organs at risk (OARs) and exposure of normal tissue to radiation. The Homogeneity Index (HI) was used to assess the dose homogeneity in the target region, and we describe a new index, the normal tissue index (NTI), to assess the dose in the normal tissue inside the tangent treatment portal. Plans were generated for 25 early-stage breast cancer patients, using a hIMRT technique. These were compared with the 3DCRT plans of the treatment previously received by the patients. Plan quality was evaluated using the HI, NTI and dose to OARs. The hIMRT technique was significantly more homogenous than the 3DCRT technique, while maintaining target coverage. The hIMRT technique was also superior at minimising the amount of tissue receiving D105% and above (P < 0.0001). The ipsilateral lung and contralateral breast maximum were significantly lower in the hIMRT plans (P < 0.05 and P < 0.005), but the 3DCRT technique achieved a lower mean heart dose in left-sided breast cancer patients (P < 0.05). Hybrid intensity modulated radiotherapy plans achieved improved dose homogeneity compared to the 3DCRT plans and superior outcome with regard to dose to normal tissues. We propose that the addition of both HI and NTI in evaluating the quality of intensity modulated radiotherapy (IMRT) breast plans provides clinically relevant comparators which more accurately reflect the new paradigm of treatment goals and outcomes in the era of breast IMRT

  11. Accuracy and consequences of 3D-fluoroscopy in upper and lower extremity fracture treatment: A systematic review

    Beerekamp, M.S.H., E-mail: m.s.beerekamp@amc.nl [Trauma Unit, Department of Surgery, Academic Medical Center, Amsterdam (Netherlands); Sulkers, George S.I., E-mail: georgesulkers@gmail.com [Trauma Unit, Department of Surgery, Academic Medical Center, Amsterdam (Netherlands); Ubbink, Dirk T., E-mail: D.Ubbink@amc.nl [Department of Quality and Process Innovation, Academic Medical Center, Amsterdam (Netherlands); Maas, Mario, E-mail: M.Maas@amc.nl [Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Schep, Niels W.L., E-mail: N.W.Schep@amc.nl [Trauma Unit, Department of Surgery, Academic Medical Center, Amsterdam (Netherlands); Goslings, J. Carel, E-mail: J.C.Goslings@amc.nl [Trauma Unit, Department of Surgery, Academic Medical Center, Amsterdam (Netherlands)

    2012-12-15

    Objectives: The aim of this systematic review was to compare the diagnostic accuracy, subjective image quality and clinical consequences of 3D-fluoroscopy with standard imaging modalities (2D-fluoroscopy, X-ray or CT) during reduction and fixation of intra-articular upper and lower extremity fractures. Methods: A systematic literature search was performed in MEDLINE, EMBASE and the Cochrane library. In total 673 articles were identified (up to March 2012). The 19 included studies described patients/cadavers with intra-articular upper/lower extremity fractures and compared 3D-fluoroscopy to standard imaging. The study was performed in accordance with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) guidelines. Diagnostic accuracy was defined by the quality of fracture reduction or implant position and, if possible, expressed as sensitivity and specificity; subjective image quality was determined by the quality of depiction of bone or implants; clinical consequences were defined as corrections in reduction or implant position following 3D-fluoroscopy. Results: Ten cadaver- and nine clinical studies were included. A meta-analysis was not possible, because studies used different scoring protocols to express diagnostic accuracy and reported incomplete data. Based on the individual studies, diagnostic accuracy of 3D-fluoroscopy was better than 2D-fluoroscopy and X-ray, but similar to CT-scanning. Subjective image quality of 3D-fluoroscopy was inferior compared to all other imaging modalities. In 11–40% of the operations additional corrections were performed after 3D-fluoroscopy, while the necessity for these corrections were not recognized based on 2D-fluoroscopic images. Conclusions: Although subjective image quality is rated inferior compared to other imaging modalities, intra-operative use of 3D-fluoroscopy is a helpful diagnostic tool for improving the quality of reduction and implant position in intra-articular fractures.

  12. Accuracy and consequences of 3D-fluoroscopy in upper and lower extremity fracture treatment: A systematic review

    Objectives: The aim of this systematic review was to compare the diagnostic accuracy, subjective image quality and clinical consequences of 3D-fluoroscopy with standard imaging modalities (2D-fluoroscopy, X-ray or CT) during reduction and fixation of intra-articular upper and lower extremity fractures. Methods: A systematic literature search was performed in MEDLINE, EMBASE and the Cochrane library. In total 673 articles were identified (up to March 2012). The 19 included studies described patients/cadavers with intra-articular upper/lower extremity fractures and compared 3D-fluoroscopy to standard imaging. The study was performed in accordance with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) guidelines. Diagnostic accuracy was defined by the quality of fracture reduction or implant position and, if possible, expressed as sensitivity and specificity; subjective image quality was determined by the quality of depiction of bone or implants; clinical consequences were defined as corrections in reduction or implant position following 3D-fluoroscopy. Results: Ten cadaver- and nine clinical studies were included. A meta-analysis was not possible, because studies used different scoring protocols to express diagnostic accuracy and reported incomplete data. Based on the individual studies, diagnostic accuracy of 3D-fluoroscopy was better than 2D-fluoroscopy and X-ray, but similar to CT-scanning. Subjective image quality of 3D-fluoroscopy was inferior compared to all other imaging modalities. In 11–40% of the operations additional corrections were performed after 3D-fluoroscopy, while the necessity for these corrections were not recognized based on 2D-fluoroscopic images. Conclusions: Although subjective image quality is rated inferior compared to other imaging modalities, intra-operative use of 3D-fluoroscopy is a helpful diagnostic tool for improving the quality of reduction and implant position in intra-articular fractures.

  13. Treatment planning optimization for linear accelerator radiosurgery

    Purpose: Linear accelerator radiosurgery uses multiple arcs delivered through circular collimators to produce a nominally spherical dose distribution. Production of dose distributions that conform to irregular lesions or conformally avoid critical neural structures requires a detailed understanding of the available treatment planning parameters. Methods and Materials: Treatment planning parameters that may be manipulated within a single isocenter to provide conformal avoidance and dose conformation to ellipsoidal lesions include differential arc weighting and gantry start/stop angles. More irregular lesions require the use of multiple isocenters. Iterative manipulation of treatment planning variables can be difficult and computationally expensive, especially if the effects of these manipulations are not well defined. Effects of treatment parameter manipulation are explained and illustrated. This is followed by description of the University of Florida Stereotactic Radiosurgery Treatment Planning Algorithm. This algorithm organizes the manipulations into a practical approach for radiosurgery treatment planning. Results: Iterative treatment planning parameters may be efficiently manipulated to achieve optimal treatment plans by following the University of Florida Treatment Planning Algorithm. The ability to produce conformal stereotactic treatment plans using the algorithm is demonstrated for a variety of clinical presentations. Conclusion: The standard dose distribution produced in linear accelerator radiosurgery is spherical, but manipulation of available treatment planning parameters may result in optimal dose conformation. The University of Florida Treatment Planning Algorithm organizes available treatment parameters to efficiently produce conformal radiosurgery treatment plans

  14. Automatic planning of head and neck treatment plans

    Hazell, Irene; Bzdusek, Karl; Kumar, Prashant;

    2016-01-01

    overall treatment qual-ity since consistent, high-quality plans are generated which even can be further optimized, if necessary. This makes it possible for the dosimetrist to focus more time on difficult dose planning goals and to spend less time on the more tedious parts of the planning process.......Treatment planning is time-consuming and the outcome depends on the person performing the optimization. A system that automates treatment planning could potentially reduce the manual time required for optimization and could also pro-vide a method to reduce the variation between persons performing...... radiation dose planning (dosimetrist) and potentially improve the overall plan quality. This study evaluates the performance of the Auto-Planning module that has recently become clinically available in the Pinnacle3 radiation therapy treatment planning system. Twenty-six clinically delivered head and neck...

  15. Treatment with tibolone partially protects 3-D microarchitecture of lumbar Vertebral Bone Tissues and Prevents Ovariectomy-induced Reduction in Mechanical Properties

    Ding, Ming

    Treatment with Tibolone partially Protects 3-D Microarchitecture of Lumbar Vertebral Bone Tissues and Prevents Ovariectomy-induced Reduction in Mechanical Properties Tibolone (Org OD14) is a tissue selective steroid with estrogenic effects on the brain, bone and vagina, without stimulating...

  16. Dynamic MLC tracking of moving targets with a single kV imager for 3D conformal and IMRT treatments

    Background. Tumor motion during radiotherapy is a major challenge for accurate dose delivery, in particular for hypofractionation and dose painting. The motion may be compensated by dynamic multileaf collimator (DMLC) tracking. Previous work has demonstrated that a single kV imager can accurately localize moving targets for DMLC tracking during rotational delivery, however this method has not been investigated for the static gantry geometry used for conformal and IMRT treatments. In this study we investigate the accuracy of single kV-imager based DMLC tracking for static-gantry delivery. Material and methods. A 5-field treatment plan with circular field shape and 200 MU per field was delivered in 20 s per field to a moving phantom with an embedded gold marker. Fluoroscopic kV images were acquired at 5 Hz perpendicular to the treatment beam axis during a 120 deg pre-treatment gantry rotation, during treatment delivery, and during inter-field gantry rotations. The three-dimensional marker position was estimated from the kV images and used for MLC adaptation. Experiments included 12 thoracic/abdominal tumor trajectories and five prostate trajectories selected from databases with 160 and 548 trajectories, respectively. The tracking error was determined as the mismatch between the marker position and the MLC aperture center in portal images. Simulations extended the study to all trajectories in the databases and to treatments with prolonged duration of 60 s per field. Results. In the experiments, the mean root-mean-square (rms) tracking error was 0.9 mm (perpendicular to MLC) and 1.1 mm (parallel to MLC) for thoracic/abdominal tumor trajectories and 0.6 mm (perpendicular) and 0.5 mm (parallel) for prostate trajectories. Simulations of these experiments agreed to within 0.1 mm. Simulations of all trajectories in the databases resulted in mean rms tracking errors of 0.6 mm (perpendicular) and 0.9 mm (parallel) for thorax/abdomen tumors and 0.4 mm (perpendicular) and 0

  17. Discretized mesh tools and related treatment for hybrid transport application with 3d discrete ordinates and Monte Carlo

    Hybrid methods of neutron transport have increased greatly in use, for example, in applications of using both Monte Carlo and deterministic transport methods to calculate quantities of interest, such as the flux and eigenvalue in a nuclear reactor. Many 3d parallel Sn codes apply a Cartesian mesh, and thus for nuclear reactors the representation of curved fuels (cylinder, sphere, etc.) are impacted in the representation of proper fuel inventory, resulting in both a deviation of mass and exact geometry in the computer model representation. In addition, we discuss auto-conversion techniques with our 3d Cartesian mesh generation tools to allow for full generation of MCNP5 inputs (Cartesian mesh and Multigroup XS) from a basis PENTRAN Sn model. For a PWR assembly eigenvalue problem, we explore the errors associated with this Cartesian discrete mesh representation, and perform an analysis to calculate a slope parameter that relates the pcm to the percent areal/volumetric deviation (areal → 2d problems, volumetric → 3d problems). This paper analysis demonstrates a linear relationship between pcm change and areal/volumetric deviation using Multigroup MCNP on a PWR assembly compared to a reference exact combinatorial MCNP geometry calculation. For the same MCNP multigroup problems, we also characterize this linear relationship in discrete ordinates (3d PENTRAN). Finally, for 3D Sn models, we show an application of corner fractioning, a volume-weighted recovery of underrepresented target fuel mass that reduced pcm error to < 100, compared to reference Monte Carlo, in the application to a PWR assembly. (author)

  18. Design and fabrication of 3D-printed anatomically shaped lumbar cage for intervertebral disc (IVD) degeneration treatment.

    Serra, T; Capelli, C; Toumpaniari, R; Orriss, I R; Leong, J J H; Dalgarno, K; Kalaskar, D M

    2016-01-01

    Spinal fusion is the gold standard surgical procedure for degenerative spinal conditions when conservative therapies have been unsuccessful in rehabilitation of patients. Novel strategies are required to improve biocompatibility and osseointegration of traditionally used materials for lumbar cages. Furthermore, new design and technologies are needed to bridge the gap due to the shortage of optimal implant sizes to fill the intervertebral disc defect. Within this context, additive manufacturing technology presents an excellent opportunity to fabricate ergonomic shape medical implants. The goal of this study is to design and manufacture a 3D-printed lumbar cage for lumbar interbody fusion. Optimisations of the proposed implant design and its printing parameters were achieved via in silico analysis. The final construct was characterised via scanning electron microscopy, contact angle, x-ray micro computed tomography (μCT), atomic force microscopy, and compressive test. Preliminary in vitro cell culture tests such as morphological assessment and metabolic activities were performed to access biocompatibility of 3D-printed constructs. Results of in silico analysis provided a useful platform to test preliminary cage design and to find an optimal value of filling density for 3D printing process. Surface characterisation confirmed a uniform coating of nHAp with nanoscale topography. Mechanical evaluation showed mechanical properties of final cage design similar to that of trabecular bone. Preliminary cell culture results showed promising results in terms of cell growth and activity confirming biocompatibility of constructs. Thus for the first time, design optimisation based on computational and experimental analysis combined with the 3D-printing technique for intervertebral fusion cage has been reported in a single study. 3D-printing is a promising technique for medical applications and this study paves the way for future development of customised implants in spinal

  19. Intensity modulated radiotherapy as neoadjuvant chemoradiation for the treatment of patients with locally advanced pancreatic cancer. Outcome analysis and comparison with a 3D-treated patient cohort

    Combs, S.E.; Habermehl, D.; Kessel, K.; Brecht, I. [Univ. Hospital of Heidelberg (Germany). Dept. of Radiation Oncology; Bergmann, F.; Schirmacher, P. [Univ. Hospital of Heidelberg (Germany). Dept. of Pathology; Werner, J.; Buechler, M.W. [Univ. Hospital of Heidelberg (Germany). Dept. of Surgery; Jaeger, D. [National Center for Tumor Diseases (NCT), Heidelberg (Germany); Debus, J. [Univ. Hospital of Heidelberg (Germany). Dept. of Radiation Oncology; Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Clinical Cooperation Unit Radiation Oncology

    2013-09-15

    Background: To evaluate outcome after intensity modulated radiotherapy (IMRT) compared to 3D conformal radiotherapy (3D-RT) as neoadjuvant treatment in patients with locally advanced pancreatic cancer (LAPC). Materials and methods: In total, 57 patients with LAPC were treated with IMRT and chemotherapy. A median total dose of 45 Gy to the PTV {sub baseplan} and 54 Gy to the PTV {sub boost} in single doses of 1.8 Gy for the PTV {sub baseplan} and median single doses of 2.2 Gy in the PTV {sub boost} were applied. Outcomes were evaluated and compared to a large cohort of patients treated with 3D-RT. Results: Overall treatment was well tolerated in all patients and IMRT could be completed without interruptions. Median overall survival was 11 months (range 5-37.5 months). Actuarial overall survival at 12 and 24 months was 36 % and 8 %, respectively. A significant impact on overall survival could only be observed for a decrease in CA 19-9 during treatment, patients with less pre-treatment CA 19-9 than the median, as well as weight loss during treatment. Local progression-free survival was 79 % after 6 months, 39 % after 12 months, and 13 % after 24 months. No factors significantly influencing local progression-free survival could be identified. There was no difference in overall and progression-free survival between 3D-RT and IMRT. Secondary resectability was similar in both groups (26 % vs. 28 %). Toxicity was comparable and consisted mainly of hematological toxicity due to chemotherapy. Conclusion: IMRT leads to a comparable outcome compared to 3D-RT in patients with LAPC. In the future, the improved dose distribution, as well as advances in image-guided radiotherapy (IGRT) techniques, may improve the use of IMRT in local dose escalation strategies to potentially improve outcome. (orig.)

  20. Three-dimensional treatment planning and conformal radiation therapy: preliminary evaluation

    Preliminary clinical results are presented for 209 patients with cancer who had treatment planned on our three-dimensional radiation treatment planning (3-D RTP) system and were treated with external beam conformal radiation therapy. Average times (min) for CT volumetric simulation were: 74 without or 84 with contrast material; 36 for contouring of tumor/target volume and 44 for normal anatomy; 78 for treatment planning; 53 for plan evaluation/optimization; and 58 for verification simulation. Average time of daily treatment sessions with 3-D conformal therapy or standard techniques was comparable for brain, head and neck, thoracic, and hepatobiliary tumors (11.8-14 min and 11.5-12.1, respectively). For prostate cancer patients treated with 3-D conformal technique and Cerrobend blocks, mean treatment time was 19 min; with multileaf collimation it was 14 min and with bilateral arc rotation, 9.8 min. Acute toxicity was comparable to or lower than with standard techniques. Sophisticated 3-D RTP and conformal irradiation can be performed in a significant number of patients at a reasonable cost. Further efforts, including dose-escalation studies, are necessary to develop more versatile and efficient 3-D RTP systems and to enhance the cost benefit of this technology in treatment of patients with cancer

  1. SU-E-T-596: Axillary Nodes Radiotherapy Boost Field Dosimetric Impact Study: Oblique Field and Field Optimization in 3D Conventional Breast Cancer Radiation Treatment

    Purpose: To evaluate dosimetric impact of two axillary nodes (AX) boost techniques: (1) posterior-oblique optimized field boost (POB), (2) traditional posterior-anterior boost (PAB) with field optimization (O-PAB), for a postmastectomy breast patient with positive axillary lymph nodes. Methods: Five patients, 3 left and 2 right chest walls, were included in this study. All patients were simulated in 5mm CT slice thickness. Supraclavicular (SC) and level I/II/III AX were contoured based on the RTOG atlas guideline. Five treatment plans, (1) tangential chest wall, (2) oblique SC including AX, (3) PAB, O-PAB and POB, were created for each patient. Three plan sums (PS) were generated by sum one of (3) plan with plan (1) and (2). The field optimization was done through PS dose distribution, which included a field adjustment, a fractional dose, a calculation location and a gantry angle selection for POB. A dosimetric impact was evaluated by comparing a SC and AX coverage, a PS maximum dose, an irradiated area percentage volume received dose over 105% prescription dose (V105), an ipsi-laterial mean lung dose (MLD), an ipsi-laterial mean humeral head dose (MHHD), a mean heart dose (MHD) (for left case only) and their DVH amount these three technique. Results: O-PAB, POB and PAB dosimetric results showed that there was no significant different on SC and AX coverage (p>0.43) and MHD (p>0.16). The benefit of sparing lung irradiation from PAB to O-PAB to POB was significant (p<0.004). PAB showed a highest PS maximum dose (p<0.005), V105 (p<0.023) and MLD (compared with OPAB, p=0.055). MHHD showed very sensitive to the patient arm positioning and anatomy. O-PAB convinced a lower MHHD than PAB (p=0.03). Conclusion: 3D CT contouring plays main role in accuracy radiotherapy. Dosimetric advantage of POB and O-PAB was observed for a better normal tissue irradiation sparing

  2. SU-E-T-596: Axillary Nodes Radiotherapy Boost Field Dosimetric Impact Study: Oblique Field and Field Optimization in 3D Conventional Breast Cancer Radiation Treatment

    Su, M [Mount Sinai School of Medicine, Elmhurst, NY (United States); Sura, S

    2014-06-01

    Purpose: To evaluate dosimetric impact of two axillary nodes (AX) boost techniques: (1) posterior-oblique optimized field boost (POB), (2) traditional posterior-anterior boost (PAB) with field optimization (O-PAB), for a postmastectomy breast patient with positive axillary lymph nodes. Methods: Five patients, 3 left and 2 right chest walls, were included in this study. All patients were simulated in 5mm CT slice thickness. Supraclavicular (SC) and level I/II/III AX were contoured based on the RTOG atlas guideline. Five treatment plans, (1) tangential chest wall, (2) oblique SC including AX, (3) PAB, O-PAB and POB, were created for each patient. Three plan sums (PS) were generated by sum one of (3) plan with plan (1) and (2). The field optimization was done through PS dose distribution, which included a field adjustment, a fractional dose, a calculation location and a gantry angle selection for POB. A dosimetric impact was evaluated by comparing a SC and AX coverage, a PS maximum dose, an irradiated area percentage volume received dose over 105% prescription dose (V105), an ipsi-laterial mean lung dose (MLD), an ipsi-laterial mean humeral head dose (MHHD), a mean heart dose (MHD) (for left case only) and their DVH amount these three technique. Results: O-PAB, POB and PAB dosimetric results showed that there was no significant different on SC and AX coverage (p>0.43) and MHD (p>0.16). The benefit of sparing lung irradiation from PAB to O-PAB to POB was significant (p<0.004). PAB showed a highest PS maximum dose (p<0.005), V105 (p<0.023) and MLD (compared with OPAB, p=0.055). MHHD showed very sensitive to the patient arm positioning and anatomy. O-PAB convinced a lower MHHD than PAB (p=0.03). Conclusion: 3D CT contouring plays main role in accuracy radiotherapy. Dosimetric advantage of POB and O-PAB was observed for a better normal tissue irradiation sparing.

  3. Optimizing global liver function in radiation therapy treatment planning

    Wu, Victor W.; Epelman, Marina A.; Wang, Hesheng; Romeijn, H. Edwin; Feng, Mary; Cao, Yue; Ten Haken, Randall K.; Matuszak, Martha M.

    2016-09-01

    Liver stereotactic body radiation therapy (SBRT) patients differ in both pre-treatment liver function (e.g. due to degree of cirrhosis and/or prior treatment) and radiosensitivity, leading to high variability in potential liver toxicity with similar doses. This work investigates three treatment planning optimization models that minimize risk of toxicity: two consider both voxel-based pre-treatment liver function and local-function-based radiosensitivity with dose; one considers only dose. Each model optimizes different objective functions (varying in complexity of capturing the influence of dose on liver function) subject to the same dose constraints and are tested on 2D synthesized and 3D clinical cases. The normal-liver-based objective functions are the linearized equivalent uniform dose (\\ell \\text{EUD} ) (conventional ‘\\ell \\text{EUD} model’), the so-called perfusion-weighted \\ell \\text{EUD} (\\text{fEUD} ) (proposed ‘fEUD model’), and post-treatment global liver function (GLF) (proposed ‘GLF model’), predicted by a new liver-perfusion-based dose-response model. The resulting \\ell \\text{EUD} , fEUD, and GLF plans delivering the same target \\ell \\text{EUD} are compared with respect to their post-treatment function and various dose-based metrics. Voxel-based portal venous liver perfusion, used as a measure of local function, is computed using DCE-MRI. In cases used in our experiments, the GLF plan preserves up to 4.6 % ≤ft(7.5 % \\right) more liver function than the fEUD (\\ell \\text{EUD} ) plan does in 2D cases, and up to 4.5 % ≤ft(5.6 % \\right) in 3D cases. The GLF and fEUD plans worsen in \\ell \\text{EUD} of functional liver on average by 1.0 Gy and 0.5 Gy in 2D and 3D cases, respectively. Liver perfusion information can be used during treatment planning to minimize the risk of toxicity by improving expected GLF; the degree of benefit varies with perfusion pattern. Although fEUD model optimization is computationally inexpensive and

  4. 3D video

    Lucas, Laurent; Loscos, Céline

    2013-01-01

    While 3D vision has existed for many years, the use of 3D cameras and video-based modeling by the film industry has induced an explosion of interest for 3D acquisition technology, 3D content and 3D displays. As such, 3D video has become one of the new technology trends of this century.The chapters in this book cover a large spectrum of areas connected to 3D video, which are presented both theoretically and technologically, while taking into account both physiological and perceptual aspects. Stepping away from traditional 3D vision, the authors, all currently involved in these areas, provide th

  5. 3D Animation Essentials

    Beane, Andy

    2012-01-01

    The essential fundamentals of 3D animation for aspiring 3D artists 3D is everywhere--video games, movie and television special effects, mobile devices, etc. Many aspiring artists and animators have grown up with 3D and computers, and naturally gravitate to this field as their area of interest. Bringing a blend of studio and classroom experience to offer you thorough coverage of the 3D animation industry, this must-have book shows you what it takes to create compelling and realistic 3D imagery. Serves as the first step to understanding the language of 3D and computer graphics (CG)Covers 3D anim

  6. Computerized treatment planning systems for external photon beam radiotherapy

    Computerized treatment planning systems (TPSs) are used in external beam radiotherapy to generate beam shapes and dose distributions with the intent to maximize tumour control and minimize normal tissue complications. Patient anatomy and tumour targets can be represented as 3-D models. The entire process of treatment planning involves many steps and the medical physicist is responsible for the overall integrity of the computerized TPS to accurately and reliably produce dose distributions and associated calculations for external beam radiotherapy. The planning itself is most commonly carried out by a dosimetrist, and the plan must be approved by a radiation oncologist before implementation in actual patient treatments. Treatment planning prior to the 1970s was generally carried out through the manual manipulation of standard isodose charts on to patient body contours that were generated by direct tracing or lead wire representation, and relied heavily on the judicious choice of beam weight and wedging by an experienced dosimetrist. The simultaneous development of computed tomography (CT), along with the advent of readily accessible computing power from the 1970s on, led to the development of CT based computerized treatment planning, providing the ability to view dose distributions directly superimposed upon a patient's axial anatomy. The entire treatment planning process involves many steps, beginning from beam data acquisition and entry into the computerized TPS, through patient data acquisition, to treatment plan generation and the final transfer of data to the treatment machine. Successive improvements in treatment planning hardware and software have been most notable in the graphics, calculation and optimization aspects of current systems. Systems encompassing the 'Virtual Patient' are able to display beam's eye views (BEVs) of radiation beams and digitally reconstructed radiographs (DRRs) for arbitrary dose distributions. Dose calculations have evolved from

  7. Quality assurance of treatment planning systems

    In Finland the inspections (site visits) of the Finnish Centre for Radiation and Nuclear Safety (STUK) represent quality audit procedures for the treatment machines and simulators, but at present do not cover treatment planning and CT imaging. The centre has now planned to extend the quality audit program to include the whole treatment chain. The preliminary step of this program was the intercomparison of radiotherapy treatment planning system. As the next step, a special phantom has been designed in order to check the whole treatment chain from treatment planning to dose delivery. (author). 2 figs, 1 tab

  8. [The 3D-printed dental splint: a valuable tool in the surgical treatment of malocclusion after polytrauma].

    van de Velde, W L; Schepers, R H; van Minnen, B

    2016-01-01

    A 22-year old male was referred to the Department of Oral and Maxillofacial Surgery of a university clinic 2 months after he had sustained multiple traumatic injuries abroad because of an anterior malocclusion. The malocclusion was the sequel of an unrecognised, untreated, already consolidated paramedian mandibular fracture on the right and a fracture of the contralateral mandibular angle on the left. Preoperatively, a cobalt-chrome 3D-printed dental splint was prepared. Surgical correction of the malocclusion was carried out by segmental osteotomies of the mandible at the original fracture sites. This involved a vertical paramedian osteotomy on the right side and a unilateral sagittal split osteotomy on the left mandibular angle side. The mandibular segment was mobilised in the correct occlusion with the aid of the 3D-printed dental splint. The splint was fixed to the teeth with dental composite. The custom made 3D-printed dental splint is considered a promising procedural innovation in oral and maxillofacial surgery. PMID:26780333

  9. Treatment Planning Systems for BNCT Requirements and Peculiarities

    Daquino, G G

    2003-01-01

    The main requirements and peculiarities expected from the BNCT-oriented treatment planning system (TPS) are summarized in this paper. The TPS is a software, which can be integrated or composed by several auxiliary programs. It plays important roles inside the whole treatment planning of the patient's organ in BNCT. However, the main goal is the simulation of the irradiation, in order to obtain the optimal configuration, in terms of neutron spectrum, patient positioning and dose distribution in the tumour and healthy tissues. The presence of neutrons increases the level of complexity, because much more nuclear reactions need to be monitored and properly calculated during the simulation of the patient's treatment. To this purposes several 3D geometry reconstruction techniques, generally based on the CT scanning data, are implemented and Monte Carlo codes are normally used. The TPSs are expected to show also the results (basically doses and fluences) in a proper format, such as isocurves (or isosurfaces) along t...

  10. 基于ArcGIS的林业规划3D分析与制图%3D Analysis and Mapping in Forestry Planning by ArcGIS

    涂琼

    2012-01-01

    以浙江凤阳山自然保护区为例,对GIS在林业规划中的应用进行了深入分析.详细介绍了在ArcGIS软件环境下进行DEM创建、地表分析(包括坡度、坡向、剖面等)、地图设计和三维可视化的方法.%Taking Zhejiang provinces' Fengyangshan nature reserve as an example, the application of GIS in forestry planning has been analyzed deeply. On the base of ArcGIS, this study introduced some methods in detail, such as surface analysis, DEM creating, slope, aspect and profile analysis, mapping designing and 3D visualization.

  11. Advances in conformal radiotherapy 3-D CRT and IMRT

    It tries on IMRT and 3-D conformal radiotherapy. Advanced imaging, planning and delivery tools such as 3D TPS, ITP and IMRT, allow the creation of highly conformal dose distributions. The treatment is only as good as the ability to know where the target and the sensitive structures are at all times. Margins to the target volume should account for uncertainties in localization, for patient repositioning and immobilization, and for organ motion

  12. Diagnostic reasoning and treatment planning: II. Treatment.

    Nurcombe, B

    1987-12-01

    The concepts of therapy-oriented and problem-oriented plans are discussed and their advantages and disadvantages considered. Goal-directed planning is proposed as an alternative to intuitive decision making. Goal-directed planning involves the abstraction of pivotal problems from a diagnostic formulation, the restatement of problems as goals, the selection of appropriate therapy, the designation of a target date, the stipulation of objectives, the selection of methods of evaluation and the monitoring of progress. Systematic goal-directed planning fosters teamwork, promotes accountability, obviates therapeutic drift and enhances outcome evaluation. Its chief disadvantage is its unfamiliarity. PMID:3502386

  13. Four-dimensional IMRT treatment planning using a DMLC motion-tracking algorithm

    Suh, Yelin; Sawant, Amit; Venkat, Raghu; Keall, Paul J.

    2009-06-01

    The purpose of this study is to develop a four-dimensional (4D) intensity-modulated radiation therapy (IMRT) treatment-planning method by modifying and applying a dynamic multileaf collimator (DMLC) motion-tracking algorithm. The 4D radiotherapy treatment scenario investigated is to obtain a 4D treatment plan based on a 4D computed tomography (CT) planning scan and to have the delivery flexible enough to account for changes in tumor position during treatment delivery. For each of 4D CT planning scans from 12 lung cancer patients, a reference phase plan was created; with its MLC leaf positions and three-dimensional (3D) tumor motion, the DMLC motion-tracking algorithm generated MLC leaf sequences for the plans of other respiratory phases. Then, a deformable dose-summed 4D plan was created by merging the leaf sequences of individual phase plans. Individual phase plans, as well as the deformable dose-summed 4D plan, are similar for each patient, indicating that this method is dosimetrically robust to the variations of fractional time spent in respiratory phases on a given 4D CT planning scan. The 4D IMRT treatment-planning method utilizing the DMLC motion-tracking algorithm explicitly accounts for 3D tumor motion and thus hysteresis and nonlinear motion, and is deliverable on a linear accelerator.

  14. 3-Dimentional radiotherapy versus conventional treatment plans for gastric cancer

    Aghili M

    2010-11-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: The current standard of adjuvant management for gastric cancer after curative resection based on the results of intergroup 0116 is concurrent chemoradiation. Current guidelines for designing these challenging fields still include two-dimensional simulation with simple AP-PA parallel opposed design. However, the implementation of radiotherapy (RT remains a concern. Our objective was to compare three-dimensional (3D techniques to the more commonly used AP-PA technique."n"nMethods: A total of 24 patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiation with simple AP-PA technique, using Cobalt-60. Total radiation dose was 50.4Gy. Landmark-based fields were simulated to assess PTV coverage. For each patient, three additional radiotherapy treatment plans were generated using three-dimensional (3D technique. The four treatment plans were then compared for target volume coverage and dose to normal tissues (liver, spinal cord, kidneys using dose volume histogram (DVH analysis."n"nResults: The three-dimensional planning techniques provided 10% superior PTV coverage compared to conventional AP-PA fields (p<0.001. Comparative DVHs for the right kidney, left kidney

  15. EUROPEANA AND 3D

    D. Pletinckx

    2012-09-01

    Full Text Available The current 3D hype creates a lot of interest in 3D. People go to 3D movies, but are we ready to use 3D in our homes, in our offices, in our communication? Are we ready to deliver real 3D to a general public and use interactive 3D in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real 3D of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering 3D content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create 3D learning objects, 3D tourist information or 3D scholarly communication. We are still in a prototype phase when it comes to integrate 3D objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, 3D has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable 3D objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.

  16. WE-F-16A-04: Micro-Irradiator Treatment Verification with High-Resolution 3D-Printed Rodent-Morphic Dosimeters

    Bache, S; Belley, M [Duke University Medical Physics Graduate Program, Durham, NC (United States); Benning, R; Adamovics, J [Rider University, Lawrenceville, NJ (United States); Stanton, I; Therien, M [Department of Chemistry, Duke University, Durham, NC (United States); Yoshizumi, T [Department of Radiology, Duke University Medical Center, Durham, NC (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Oldham, M [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)

    2014-06-15

    Purpose: Pre-clinical micro-radiation therapy studies often utilize very small beams (∼0.5-5mm), and require accurate dose delivery in order to effectively investigate treatment efficacy. Here we present a novel high-resolution absolute 3D dosimetry procedure, capable of ∼100-micron isotopic dosimetry in anatomically accurate rodent-morphic phantoms Methods: Anatomically accurate rat-shaped 3D dosimeters were made using 3D printing techniques from outer body contours and spinal contours outlined on CT. The dosimeters were made from a radiochromic plastic material PRESAGE, and incorporated high-Z PRESASGE inserts mimicking the spine. A simulated 180-degree spinal arc treatment was delivered through a 2 step process: (i) cone-beam-CT image-guided positioning was performed to precisely position the rat-dosimeter for treatment on the XRad225 small animal irradiator, then (ii) treatment was delivered with a simulated spine-treatment with a 180-degree arc with 20mm x 10mm cone at 225 kVp. Dose distribution was determined from the optical density change using a high-resolution in-house optical-CT system. Absolute dosimetry was enabled through calibration against a novel nano-particle scintillation detector positioned in a channel in the center of the distribution. Results: Sufficient contrast between regular PRESAGE (tissue equivalent) and high-Z PRESAGE (spinal insert) was observed to enable highly accurate image-guided alignment and targeting. The PRESAGE was found to have linear optical density (OD) change sensitivity with respect to dose (R{sup 2} = 0.9993). Absolute dose for 360-second irradiation at isocenter was found to be 9.21Gy when measured with OD change, and 9.4Gy with nano-particle detector- an agreement within 2%. The 3D dose distribution was measured at 500-micron resolution Conclusion: This work demonstrates for the first time, the feasibility of accurate absolute 3D dose measurement in anatomically accurate rat phantoms containing variable density

  17. WE-F-16A-04: Micro-Irradiator Treatment Verification with High-Resolution 3D-Printed Rodent-Morphic Dosimeters

    Purpose: Pre-clinical micro-radiation therapy studies often utilize very small beams (∼0.5-5mm), and require accurate dose delivery in order to effectively investigate treatment efficacy. Here we present a novel high-resolution absolute 3D dosimetry procedure, capable of ∼100-micron isotopic dosimetry in anatomically accurate rodent-morphic phantoms Methods: Anatomically accurate rat-shaped 3D dosimeters were made using 3D printing techniques from outer body contours and spinal contours outlined on CT. The dosimeters were made from a radiochromic plastic material PRESAGE, and incorporated high-Z PRESASGE inserts mimicking the spine. A simulated 180-degree spinal arc treatment was delivered through a 2 step process: (i) cone-beam-CT image-guided positioning was performed to precisely position the rat-dosimeter for treatment on the XRad225 small animal irradiator, then (ii) treatment was delivered with a simulated spine-treatment with a 180-degree arc with 20mm x 10mm cone at 225 kVp. Dose distribution was determined from the optical density change using a high-resolution in-house optical-CT system. Absolute dosimetry was enabled through calibration against a novel nano-particle scintillation detector positioned in a channel in the center of the distribution. Results: Sufficient contrast between regular PRESAGE (tissue equivalent) and high-Z PRESAGE (spinal insert) was observed to enable highly accurate image-guided alignment and targeting. The PRESAGE was found to have linear optical density (OD) change sensitivity with respect to dose (R2 = 0.9993). Absolute dose for 360-second irradiation at isocenter was found to be 9.21Gy when measured with OD change, and 9.4Gy with nano-particle detector- an agreement within 2%. The 3D dose distribution was measured at 500-micron resolution Conclusion: This work demonstrates for the first time, the feasibility of accurate absolute 3D dose measurement in anatomically accurate rat phantoms containing variable density PRESAGE

  18. Utilizing 3-D and 4-D ultrasound systems to improve radiation treatment of cervix and prostate cancer patients

    Baker, Mariwan

    megavoltage (MV) image guided radiotherapy (IGRT) methods are developed. However, these ionization systems provide poor visualization of soft tissue, and therefore the bone matching is frequently applied as a daily tumor alignment method in cervical radiotherapy. In this project, the Clarity 3D ultrasound...... conventional probe (C-probe) has limitations, while applying transabdominal US (TAUS) scan, when it came to capturing the entire uterus owing to the difficulty in probe handling. Contrarily, the novel autoscan-probe (A-probe) was shown to be capable of capturing the entire uterus in almost all of the scans...... images, which has limitations in addressing real-time prostate motion, and includes inter-observer variations while matching image to image. In this project, the recently developed transperineal ultrasound 4D autoscan probe is used to investigate the real-time prostate monitoring. The purpose of this...

  19. TU-F-17A-04: Respiratory Phase-Resolved 3D MRI with Isotropic High Spatial Resolution: Determination of the Average Breathing Motion Pattern for Abdominal Radiotherapy Planning

    Purpose: To develop a retrospective 4D-MRI technique (respiratory phase-resolved 3D-MRI) for providing an accurate assessment of tumor motion secondary to respiration. Methods: A 3D projection reconstruction (PR) sequence with self-gating (SG) was developed for 4D-MRI on a 3.0T MRI scanner. The respiration-induced shift of the imaging target was recorded by SG signals acquired in the superior-inferior direction every 15 radial projections (i.e. temporal resolution 98 ms). A total of 73000 radial projections obtained in 8-min were retrospectively sorted into 10 time-domain evenly distributed respiratory phases based on the SG information. Ten 3D image sets were then reconstructed offline. The technique was validated on a motion phantom (gadolinium-doped water-filled box, frequency of 10 and 18 cycles/min) and humans (4 healthy and 2 patients with liver tumors). Imaging protocol included 8-min 4D-MRI followed by 1-min 2D-realtime (498 ms/frame) MRI as a reference. Results: The multiphase 3D image sets with isotropic high spatial resolution (1.56 mm) permits flexible image reformatting and visualization. No intra-phase motion-induced blurring was observed. Comparing to 2D-realtime, 4D-MRI yielded similar motion range (phantom: 10.46 vs. 11.27 mm; healthy subject: 25.20 vs. 17.9 mm; patient: 11.38 vs. 9.30 mm), reasonable displacement difference averaged over the 10 phases (0.74mm; 3.63mm; 1.65mm), and excellent cross-correlation (0.98; 0.96; 0.94) between the two displacement series. Conclusion: Our preliminary study has demonstrated that the 4D-MRI technique can provide high-quality respiratory phase-resolved 3D images that feature: a) isotropic high spatial resolution, b) a fixed scan time of 8 minutes, c) an accurate estimate of average motion pattern, and d) minimal intra-phase motion artifact. This approach has the potential to become a viable alternative solution to assess the impact of breathing on tumor motion and determine appropriate treatment margins

  20. TU-F-17A-04: Respiratory Phase-Resolved 3D MRI with Isotropic High Spatial Resolution: Determination of the Average Breathing Motion Pattern for Abdominal Radiotherapy Planning

    Deng, Z; Pang, J; Yang, W; Yue, Y; Tuli, R; Fraass, B; Li, D; Fan, Z [Cedars-Sinai Medical Center, Los Angeles, CA (United States)

    2014-06-15

    Purpose: To develop a retrospective 4D-MRI technique (respiratory phase-resolved 3D-MRI) for providing an accurate assessment of tumor motion secondary to respiration. Methods: A 3D projection reconstruction (PR) sequence with self-gating (SG) was developed for 4D-MRI on a 3.0T MRI scanner. The respiration-induced shift of the imaging target was recorded by SG signals acquired in the superior-inferior direction every 15 radial projections (i.e. temporal resolution 98 ms). A total of 73000 radial projections obtained in 8-min were retrospectively sorted into 10 time-domain evenly distributed respiratory phases based on the SG information. Ten 3D image sets were then reconstructed offline. The technique was validated on a motion phantom (gadolinium-doped water-filled box, frequency of 10 and 18 cycles/min) and humans (4 healthy and 2 patients with liver tumors). Imaging protocol included 8-min 4D-MRI followed by 1-min 2D-realtime (498 ms/frame) MRI as a reference. Results: The multiphase 3D image sets with isotropic high spatial resolution (1.56 mm) permits flexible image reformatting and visualization. No intra-phase motion-induced blurring was observed. Comparing to 2D-realtime, 4D-MRI yielded similar motion range (phantom: 10.46 vs. 11.27 mm; healthy subject: 25.20 vs. 17.9 mm; patient: 11.38 vs. 9.30 mm), reasonable displacement difference averaged over the 10 phases (0.74mm; 3.63mm; 1.65mm), and excellent cross-correlation (0.98; 0.96; 0.94) between the two displacement series. Conclusion: Our preliminary study has demonstrated that the 4D-MRI technique can provide high-quality respiratory phase-resolved 3D images that feature: a) isotropic high spatial resolution, b) a fixed scan time of 8 minutes, c) an accurate estimate of average motion pattern, and d) minimal intra-phase motion artifact. This approach has the potential to become a viable alternative solution to assess the impact of breathing on tumor motion and determine appropriate treatment margins

  1. Does the IMRT technique allow improvement of treatment plans (e.g. lung sparing) for lung cancer patients with small lung volume: a planning study

    Aim: We evaluated whether intensity-modulated radiation therapy (IMRT) may offer any advantages in comparison with three-dimensional conformal radiotherapy (3D-CRT) for patients with small lung volume (SLV). Methods: Treatment planning was performed for 10 NSCLC patients with the smallest lung volume (mean: 2241 cc) among 200 patients from our database. For each patient 3D-CRT and IMRT plans were prepared. The goal was to deliver 66 Gy/33 fractions, with dose constraints: mean lung dose (MLD) < 20 Gy, V20 < 35%; spinal cord - Dmax < 45 Gy. When the plan could not meet these criteria, total dose was reduced. The 3D-CRT and IMRT plans were compared. We investigated: prescribed dose, coverage and conformity indices, MLD, V5-V65 in the lung. Results: In 4 out of 10 plans, 3D-CRT did not allow 66 Gy to be delivered, because of predicted pulmonary toxicity. These 4 cases included 3 for which we did not reach 66 Gy with IMRT; still, for these 3 plans the total dose was increased by an average of 9 Gy with IMRT in comparison with 3D-CRT. Coverage indices were similar for both techniques. Conformity indices were better for IMRT plans. MLD was lower in five IMRT and two 3D-CRT plans if equal doses were delivered. The decrease in MLD was seen for cases with large PTV and high PTV/lung volume ratio. Lung V5 was lower for all 3D-CRT plans, 47% vs. 57% for IMRT; V15 and above were larger for 3D-CRT Conclusion: In the planning study, IMRT seems to be a promising technique for cases with SLV, especially when associated with large PT V. (authors)

  2. 颅内动脉瘤不同影像技术诊疗效果比较%Comparative Study of 3D-DSA, 3D-CTA and MRA Techniques in the Diagnosis and Treatment of Intracranial Aneurysms

    毛崇梅; 衣玲; 李胜

    2012-01-01

    目的 探讨CTA、MRA、DSA三维重建技术在诊断颅内动脉瘤的差异,为颅内动脉瘤患者的诊断及治疗方案的制订提供有价值的依据.方法 选择急性蛛网膜下腔出血和/或疑似颅内动脉瘤的患者29例,行脑血管造影术(DSA)及三维重建(3D-DSA).之前全部病例行3D-CTA、21例病例行MRA检查并行三维重建,以3D-DSA及脑外科术中检查为标准,比较3D-DSA与3D-CTA、MRA之间显示动脉瘤立体形态、载瘤动脉与毗邻血管的关系、瘤颈及其与载瘤血管关系及穿支情况等方面信息的区别.结果 SAH患者资料共29例,其中28例共患有动脉瘤38个,阴性1个.CTA和DSA/3D-DSA各检出27例37个动脉瘤,二者检出动脉瘤的数目及诊断符合率比较差异无统计学意义(P>0.05).MRA检查18例动脉瘤,漏诊3例.结论 CTA/3D-CTA和DSA/3D-DSA二者检出动脉瘤的数目及诊断符合率比较差异无统计学意义,与MRA比较差异有统计学意义.DSA/3D -DSA在与载瘤动脉关系、动脉瘤上有无穿支方面优于CTA/3D-CTA及MRA.

  3. Open 3D Projects

    Felician ALECU

    2010-01-01

    Full Text Available Many professionals and 3D artists consider Blender as being the best open source solution for 3D computer graphics. The main features are related to modeling, rendering, shading, imaging, compositing, animation, physics and particles and realtime 3D/game creation.

  4. Automated planning of ablation targets in atrial fibrillation treatment

    Keustermans, Johannes; De Buck, Stijn; Heidbüchel, Hein; Suetens, Paul

    2011-03-01

    Catheter based radio-frequency ablation is used as an invasive treatment of atrial fibrillation. This procedure is often guided by the use of 3D anatomical models obtained from CT, MRI or rotational angiography. During the intervention the operator accurately guides the catheter to prespecified target ablation lines. The planning stage, however, can be time consuming and operator dependent which is suboptimal both from a cost and health perspective. Therefore, we present a novel statistical model-based algorithm for locating ablation targets from 3D rotational angiography images. Based on a training data set of 20 patients, consisting of 3D rotational angiography images with 30 manually indicated ablation points, a statistical local appearance and shape model is built. The local appearance model is based on local image descriptors to capture the intensity patterns around each ablation point. The local shape model is constructed by embedding the ablation points in an undirected graph and imposing that each ablation point only interacts with its neighbors. Identifying the ablation points on a new 3D rotational angiography image is performed by proposing a set of possible candidate locations for each ablation point, as such, converting the problem into a labeling problem. The algorithm is validated using a leave-one-out-approach on the training data set, by computing the distance between the ablation lines obtained by the algorithm and the manually identified ablation points. The distance error is equal to 3.8+/-2.9 mm. As ablation lesion size is around 5-7 mm, automated planning of ablation targets by the presented approach is sufficiently accurate.

  5. Three-dimensional (3D) real-time conformal brachytherapy - a novel solution for prostate cancer treatment. Part II. A feasibility clinical pilot study

    The pilot feasibility clinical study was designed to test the tolerance and early efficacy of the 3D-real time conformal brachytherapy combined with external irradiation of patients with prostate cancer. Seventy six consecutive patients with prostate cancer in stage T1-2N0M0 entered the study. Median pretreatment PSA level was 13.6 ng/ml and Gleason score was 8 or lower. All patients received conformal external irradiation of 54 Gy in 27 fractions followed by a 10 Gy boost given using 3D-real time CBRT. All patients tolerated the CBRT implant procedure and prior external irradiation very well, with no discomfort, and no protocol violation was noted. Acute urinary bladder toxicity grade III was noted in 1% of patients. There were no grade III gastrointestinal acute toxicity. Mild, grade I or II toxicity, was observed in 62% of patients and it did not significantly influence patient comfort. Early actuarial 1-year BNED was 97.3%. Dosimetric analysis has shown that the mean value of D100 PTV was 91.7%, D90 was 97.6% and D10 for the urethra was 126.3%. All dosimetric parameters were within the limits recommended by the American Brachytherapy Society (ABS). 3D-real time conformal brachytherapy using a single boost dose of 10 Gy combined with 54 Gy in 27 fractions of conformal irradiation is a safe and well tolerated treatment in case of patients with T1-2N0M0 prostate cancer. From the radiobiological point of view there is still room to intensify treatment towards fractionated 3D-real time CBRT interdigited with external irradiation. ((author)

  6. Volume-Rendering-Based Interactive 3D Measurement for Quantitative Analysis of 3D Medical Images

    Yakang Dai; Jian Zheng; Yuetao Yang; Duojie Kuai; Xiaodong Yang

    2013-01-01

    3D medical images are widely used to assist diagnosis and surgical planning in clinical applications, where quantitative measurement of interesting objects in the image is of great importance. Volume rendering is widely used for qualitative visualization of 3D medical images. In this paper, we introduce a volume-rendering-based interactive 3D measurement framework for quantitative analysis of 3D medical images. In the framework, 3D widgets and volume clipping are integrated with volume render...

  7. 3d-3d correspondence revisited

    Chung, Hee-Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr

    2016-04-01

    In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d {N}=2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. We also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.

  8. 3D scanning and printing as conversation tools: an innovative treatment of a vandalized bronze statue, The Thinker by Rodin

    T. Beentjes; R. van der Molen

    2011-01-01

    This contribution discusses the innovative treatment of a severely vandalized bronze sculpture, The Thinker by Auguste Rodin, from the Singer Museum in Laren, The Netherlands. Additional aspects of this controversial treatment such as decision making and documentation are also discussed. In 2007 the

  9. Monte Carlo Treatment Planning for Advanced Radiotherapy

    Cronholm, Rickard

    validation of a Monte Carlo model of a medical linear accelerator (i), converting a CT scan of a patient to a Monte Carlo compliant phantom (ii) and translating the treatment plan parameters (including beam energy, angles of incidence, collimator settings etc) to a Monte Carlo input file (iii). A protocol...... more sophisticated than previous algorithms since it uses delineations of structures in order to include and/or exclude certain media in various anatomical regions. This method has the potential to reduce anatomically irrelevant media assignment. In house MATLAB scripts translating the treatment plan...... presented. Comparison between dose distribution for clinical treatment plans generated by a commercial Treatment Planning System and by the implemented Monte Carlo Treatment Planning workflow were conducted. Good agreement was generally found, but for regions involving large density gradients differences of...

  10. IZDELAVA TISKALNIKA 3D

    Brdnik, Lovro

    2015-01-01

    Diplomsko delo analizira trenutno stanje 3D tiskalnikov na trgu. Prikazan je razvoj in principi delovanja 3D tiskalnikov. Predstavljeni so tipi 3D tiskalnikov, njihove prednosti in slabosti. Podrobneje je predstavljena zgradba in delovanje koračnih motorjev. Opravljene so meritve koračnih motorjev. Opisana je programska oprema za rokovanje s 3D tiskalniki in komponente, ki jih potrebujemo za izdelavo. Diploma se oklepa vprašanja, ali je izdelava 3D tiskalnika bolj ekonomična kot pa naložba v ...

  11. Dosimetric tests for treatment planning commissioning in 3DCRT

    The radiotherapy evolution from 2D treatments to 3D conformal treatments was possible after the advent the treatment planning systems commercially available and tridimensional images techniques like computed tomography. These systems have tools that allow delineate anatomical structures from tomographic images. Calculations dose tools allow the planner evaluate the dose received in the anatomical structures. When these systems are acquired or an upgrade is made many dosimetric and non-dosimetric tests need to be performed to know the system limitations and correct functioning and to verify the correct dosimetric data insertion. This study was based in International Atomic Energy Agency protocols, Task Groups documents from American Association of Physics in Medicine, and other papers. A dosimetric test set was done to commissioning the Eclipse 10.0.28 (Varian Medical Systems) treatments planning system This version has two photon calculation algorithm (Pencil Beam Convolution and Analytical Anisotropic Algorithm – AAA) and Gaussian Pencil Beam algorithm for electron beams. However, tests for AAA it was not performed. In this study was possible to conclude that the dosimetric data was correctly added in the treatment planning system. Some results allowed to understand the algorithm limitations to calculate dose distributions in specifics situations, that was not clinically relevant in our routine. (author)

  12. Assessment tool for planning fallback Tomotherapy treatment plans

    Interruption of radiotherapy treatments in an increase the total time of the same to the detriment of tumour control. In centers that have a unique special unit as the TomoTherapy, is emphasized the difficulty to resume treatment at another unit, since the technique of helical TomoTherapy is not portable to conventional accelerators and therefore requires the planning of new dosimetry distributions emulating the initially obtained and accepted. This work evaluates the ability of an automatic planning tool to mimic TomoTherapy plans. (Author)

  13. Implant Restoration of Edentulous Jaws with 3D Software Planning, Guided Surgery, Immediate Loading, and CAD-CAM Full Arch Frameworks

    De Riu, Giacomo; Pisano, Milena; Campus, Guglielmo; Tullio, Antonio

    2013-01-01

    Purpose. The aim of this study was to analyze the clinical and radiographic outcomes of 23 edentulous jaws treated with 3D software planning, guided surgery, and immediate loading and restored with CAD-CAM full arch frameworks. Materials and Methods. This work was designed as a prospective case series clinical study. Twenty patients have been consecutively rehabilitated with an immediately loaded implant supported fixed full prosthesis. A total of 120 fixtures supporting 23 bridges were placed. 117 out of 120 implants were immediately loaded. Outcome measures were implants survival, radiographic marginal bone levels and remodeling, soft tissue parameters, and complications. Results. 114 of 117 implants reached a 30 months follow-up, and no patients dropped out from the study. The cumulative survival rate was 97.7%; after 30 months, mean marginal bone level was 1.25 ± 0.31 mm, mean marginal bone remodeling value was 1.08 ± 0.34, mean PPD value was 2.84 ± 0.55 mm, and mean BOP value was 4% ± 2.8%. Only minor prosthetic complications were recorded. Conclusion. Within the limitations of this study, it can be concluded that computer-guided surgery and immediate loading seem to represent a viable option for the immediate rehabilitations of completely edentulous jaws with fixed implant supported restorations. This trial is registered with Clinicaltrials.gov NCT01866696. PMID:23983690

  14. Implant Restoration of Edentulous Jaws with 3D Software Planning, Guided Surgery, Immediate Loading, and CAD-CAM Full Arch Frameworks

    Silvio Mario Meloni

    2013-01-01

    Full Text Available Purpose. The aim of this study was to analyze the clinical and radiographic outcomes of 23 edentulous jaws treated with 3D software planning, guided surgery, and immediate loading and restored with CAD-CAM full arch frameworks. Materials and Methods. This work was designed as a prospective case series clinical study. Twenty patients have been consecutively rehabilitated with an immediately loaded implant supported fixed full prosthesis. A total of 120 fixtures supporting 23 bridges were placed. 117 out of 120 implants were immediately loaded. Outcome measures were implants survival, radiographic marginal bone levels and remodeling, soft tissue parameters, and complications. Results. 114 of 117 implants reached a 30 months follow-up, and no patients dropped out from the study. The cumulative survival rate was 97.7%; after 30 months, mean marginal bone level was  mm, mean marginal bone remodeling value was , mean PPD value was  mm, and mean BOP value was 4% ± 2.8%. Only minor prosthetic complications were recorded. Conclusion. Within the limitations of this study, it can be concluded that computer-guided surgery and immediate loading seem to represent a viable option for the immediate rehabilitations of completely edentulous jaws with fixed implant supported restorations. This trial is registered with Clinicaltrials.gov NCT01866696.

  15. Dosimetric influence of hyaluronic acid in patients with prostate cancer treated with RT3D

    This study aims to assess the influence on dosimetry by the introduction of hyaluronic acid and assess the need for the realization of a second CT scan and consequent re-planning of RT3D treatment. (Author)

  16. Comparison of 2D and 3D gamma analyses

    Pulliam, Kiley B.; Huang, Jessie Y.; Howell, Rebecca M.; Followill, David; Kry, Stephen F., E-mail: sfkry@mdanderson.org [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States); Bosca, Ryan [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States); O’Daniel, Jennifer [Department of Radiation Oncology, Duke University, Durham, North Carolina 27705 (United States)

    2014-02-15

    Purpose: As clinics begin to use 3D metrics for intensity-modulated radiation therapy (IMRT) quality assurance, it must be noted that these metrics will often produce results different from those produced by their 2D counterparts. 3D and 2D gamma analyses would be expected to produce different values, in part because of the different search space available. In the present investigation, the authors compared the results of 2D and 3D gamma analysis (where both datasets were generated in the same manner) for clinical treatment plans. Methods: Fifty IMRT plans were selected from the authors’ clinical database, and recalculated using Monte Carlo. Treatment planning system-calculated (“evaluated dose distributions”) and Monte Carlo-recalculated (“reference dose distributions”) dose distributions were compared using 2D and 3D gamma analysis. This analysis was performed using a variety of dose-difference (5%, 3%, 2%, and 1%) and distance-to-agreement (5, 3, 2, and 1 mm) acceptance criteria, low-dose thresholds (5%, 10%, and 15% of the prescription dose), and data grid sizes (1.0, 1.5, and 3.0 mm). Each comparison was evaluated to determine the average 2D and 3D gamma, lower 95th percentile gamma value, and percentage of pixels passing gamma. Results: The average gamma, lower 95th percentile gamma value, and percentage of passing pixels for each acceptance criterion demonstrated better agreement for 3D than for 2D analysis for every plan comparison. The average difference in the percentage of passing pixels between the 2D and 3D analyses with no low-dose threshold ranged from 0.9% to 2.1%. Similarly, using a low-dose threshold resulted in a difference between the mean 2D and 3D results, ranging from 0.8% to 1.5%. The authors observed no appreciable differences in gamma with changes in the data density (constant difference: 0.8% for 2D vs 3D). Conclusions: The authors found that 3D gamma analysis resulted in up to 2.9% more pixels passing than 2D analysis. It must

  17. Three-Dimensional Treatment Planning In Radiotherapy: Experience with Prostate Irradiation At Hashed Hospital

    Six years ago, we implemented in our department three-dimensional conformal radiotherapy treatment planning (RTP) and dose delivery. This technique has been designed to deliver prescribed radiation doses to localized tumors with high precision, while effectively excluding the surrounding normal tissues, thus allowing tumor dose escalation. The 3D treatment planning process is significantly different from the 2D, and is much more than a multi-planar 2D planning technique. Four major functions need to be carried out by any 3D treatment planning system: - anatomic display - beam design - dose calculation and display - plan analysis Since prostate cancer is a very common cancer, and since it has been demonstrated that there is a strong. statistically significant relationship between total dose and local recurrence (improvement in tumor control depends on the ability to deliver precision high dose radiation without increasing treatment related toxicity), we implemented in our clinic a conformal six field technique for prostate treatment, allowing an increase in dose delivered to prostate from 70.2 Gy to 75.6 Gy, and later to 81.0 Gy. The planning process consists of several steps: - immobilization of the patient - performance of a CT scan - in the RTP system: transfer of the CT images into the system outlining of the structures positioning of the beams and block/MLC design dose calculation and display * plan evaluation with DVH plot The implementation of 3D treatment techniques requires a close connection between physicists and technicians, and increased quality assurance physics checks of the machines. Even after the learning period, 3D treatment of the prostate require more physician, physicist and technician time than 2D, but from the dosimetric perspective of sparing normal tissues, it is clearly superior to traditional techniques

  18. Value of 64-slice 3D-CTA in diagnosis and surgical treatment of intracranial aneurysm%64层3D-CTA对颅内动脉瘤诊断及临床评估的应用价值

    江涌; 孙晓川; 朱继; 何朝晖; 阮建; 张晓冬; 唐文渊

    2007-01-01

    目的 通过比较64层3D-CTA与DSA在临床诊断颅内动脉瘤及其评估外科治疗的优缺点,评价64层3D-CTA在颅内动脉瘤诊断及治疗中的临床应用价值.方法 回顾性分析2005年9月至2006年12月期间,重庆医科大学附属第一医院神经外科99例自发性蛛网膜下腔出血患者的临床资料,患者均行3D-CTA检查,分析CTA检查结果并与DSA检查结果比较.结果 99例SAH患者经3D-CTA检查发现动脉瘤70例,其中41例同时接受DSA检查,除1例外,全部证实DSA的发现,DSA所漏诊的1例经手术证实为微小动脉瘤.结论 64层螺旋CTA对颅内动脉瘤的诊断敏感性及特异性高,且能够清楚显示解剖结构,有助于治疗方法的选择和难度的评估.

  19. 3D and Education

    Meulien Ohlmann, Odile

    2013-02-01

    Today the industry offers a chain of 3D products. Learning to "read" and to "create in 3D" becomes an issue of education of primary importance. 25 years professional experience in France, the United States and Germany, Odile Meulien set up a personal method of initiation to 3D creation that entails the spatial/temporal experience of the holographic visual. She will present some different tools and techniques used for this learning, their advantages and disadvantages, programs and issues of educational policies, constraints and expectations related to the development of new techniques for 3D imaging. Although the creation of display holograms is very much reduced compared to the creation of the 90ies, the holographic concept is spreading in all scientific, social, and artistic activities of our present time. She will also raise many questions: What means 3D? Is it communication? Is it perception? How the seeing and none seeing is interferes? What else has to be taken in consideration to communicate in 3D? How to handle the non visible relations of moving objects with subjects? Does this transform our model of exchange with others? What kind of interaction this has with our everyday life? Then come more practical questions: How to learn creating 3D visualization, to learn 3D grammar, 3D language, 3D thinking? What for? At what level? In which matter? for whom?

  20. Optical laser scanning of a leucodye micelle gel: preliminary results of a 3D dose verification of an IMRT treatment for a brain tumor

    Vandecasteele, J.; De Deene, Y.

    2013-06-01

    In the present study an in-house developed leucodye micelle gel was used in combination with an in-house developed optical laser scanner for the 3D dose verification of an IMRT treatment of a pituitary adenoma. In an initial prospective study, a gel measured depth dose distribution of a square 6 MV photon beam was compared with an ion chamber measurement. In a second experiment, the gel and scanner were used to verify a clinical dose distribution on a recently installed linear accelerator. The calibration procedure is identified as the major source of dose deviations.

  1. Clinical evaluation of 3D/3D MRI-CBCT automatching on brain tumors for online patient setup verification - A step towards MRI-based treatment planning

    Buhl, S.K.; Duun-Christensen, Anne Katrine; Kristensen, B.H.;

    2010-01-01

    undergoing postoperative radiotherapy for malignant brain tumors received a weekly CBCT. In total 18 scans was matched with both CT and MRI as reference. The CBCT scans were acquired using a Clinac iX 2300 linear accelerator (Varian Medical Systems) with an On-Board Imager (OBI). Results. For the phantom...

  2. 3-D conformal treatment of prostate cancer to 74 Gy vs. high-dose-rate brachytherapy boost: A cross-sectional quality-of-life survey

    Vordermark, Dirk [Univ. of Wuerzburg (DE). Dept. of Radiation Oncology] (and others)

    2006-09-15

    The effects of two modalities of dose-escalated radiotherapy on health-related quality of life (HRQOL) were compared. Forty-one consecutive patients were treated with a 3-D conformal (3-DC) boost to 74 Gy, and 43 with high-dose rate (HDR) brachytherapy boost (2x9 Gy), following 3-D conformal treatment to 46 Gy. Median age was 70 years in both groups, median initial PSA was 7.9 {mu}g/l in 3-DC boost patients and 8.1 {mu}g/l in HDR boost patients. Stage was 7 in 52% and 47%, respectively. HRQOL was assessed cross-sectionally using EORTC QLQ-C30 and organ-specific PR25 modules 3-32 (median 19) and 4-25 (median 14) months after treatment, respectively. Questionnaires were completed by 93% and 97% of patients, respectively. Diarrhea and insomnia scores were significantly increased in both groups. In the PR25 module, scores of 3-DC boost and HDR boost patients for urinary, bowel and treatment-related symptoms were similar. Among responders, 34% of 3-DC boost patients and 86% of HDR boost patients had severe erectile problems. Dose escalation in prostate cancer by either 3-DC boost to 74 Gy or HDR brachytherapy boost appears to result in similar HRQOL profiles.

  3. 3-D conformal treatment of prostate cancer to 74 Gy vs. high-dose-rate brachytherapy boost: A cross-sectional quality-of-life survey

    The effects of two modalities of dose-escalated radiotherapy on health-related quality of life (HRQOL) were compared. Forty-one consecutive patients were treated with a 3-D conformal (3-DC) boost to 74 Gy, and 43 with high-dose rate (HDR) brachytherapy boost (2x9 Gy), following 3-D conformal treatment to 46 Gy. Median age was 70 years in both groups, median initial PSA was 7.9 μg/l in 3-DC boost patients and 8.1 μg/l in HDR boost patients. Stage was 7 in 52% and 47%, respectively. HRQOL was assessed cross-sectionally using EORTC QLQ-C30 and organ-specific PR25 modules 3-32 (median 19) and 4-25 (median 14) months after treatment, respectively. Questionnaires were completed by 93% and 97% of patients, respectively. Diarrhea and insomnia scores were significantly increased in both groups. In the PR25 module, scores of 3-DC boost and HDR boost patients for urinary, bowel and treatment-related symptoms were similar. Among responders, 34% of 3-DC boost patients and 86% of HDR boost patients had severe erectile problems. Dose escalation in prostate cancer by either 3-DC boost to 74 Gy or HDR brachytherapy boost appears to result in similar HRQOL profiles

  4. An analysing of heat treatment process planning

    B. Smoljan

    2007-01-01

    Full Text Available Purpose: Process planning of heat treatment has been investigated. The established approach of heat treatingprocess planning is suitable for effective integration of heat treatment in computer added manufacturing.Design/methodology/approach: Process plan of heat treating process has been established based on fundamentalprocess planning principals. The heat treatment was treated in the same as other manufacture processes.Findings: The general approach for process planning of heat treatment processes has been established. Heattreatment processes have to be designed into operations and sub-operations with the same principles that are alsovalid for other manufacturing processes.Research limitations/implications: The further research should be focused on development of methods for thebetter application of achieved results.Practical implications: This way of heat treatment process planning is more appropriate for integral trends ofmanufacturing, i.e., with the trend of introducing the modern systems in all parts of industrial manufacturing.Originality/value: The global approach of process planning of heat treatment processes was established andbetter unification with other manufacturing processes was achieved.

  5. 3D Modelling and monitoring of denervated muscle under Functional Electrical Stimulation treatment and associated bone structural changes

    Paolo Gargiulo

    2011-03-01

    Full Text Available A novel clinical rehabilitation method for patients who have permanent and non recoverable muscle denervation in the legs was developed in the frame of the European Project RISE. The technique is based on FES and the project results shows, in these severely disabled patients, restoration of muscle tissue and function. This study propose novel methods based on image processing technique and medical modelling to monitor growth in denervated muscle treated with FES. Geometrical and structural changes in muscle and bone are studied and modelled. Secondary effects on the bone mineral density produced by the stimulation treatment and due the elicited muscle contraction are also investigated. The restoration process in DDM is an important object of discussion since there isn’t yet a complete understanding of the mechanisms regulating growth in denervated muscle. This study approaches the problem from a macroscopic point of view, developing 3-dimensional models of the whole stimulated muscles and following changes in volume, geometry and density very accurately. The method is based on the acquisition of high resolution Spiral CT scans from patients who have long-term flaccid paraplegia and the use of special image processing tools allowing tissue discriminations and muscle segmentation. Three patients were measured at different points of time during 4 years of electrical stimulation treatment. In this study is quantitatively demonstrated the influences of FES treatment on the different quadriceps bellies. The rectus femoris muscle is positioned in the middle of the quadriceps and responds (in general better to stimulation. In a patient with abundant adipose tissue surrounding the quadriceps, rectus femoris almost doubled the volume during the FES treatment while in the other bellies the changes measured were minimal. The analysis of the density shows clearly a restoration of the muscular structure in the growing muscle. The remarkable increase of

  6. KPG Index versus OPG Measurements: A Comparison between 3D and 2D Methods in Predicting Treatment Duration and Difficulty Level for Patients with Impacted Maxillary Canines

    Domenico Dalessandri

    2014-01-01

    Full Text Available Aim. The aim of this study was to test the agreement between orthopantomography (OPG based 2D measurements and the KPG index, a new index based on 3D Cone Beam Computed Tomography (CBCT images, in predicting orthodontic treatment duration and difficulty level of impacted maxillary canines. Materials and Methods. OPG and CBCT images of 105 impacted canines were independently scored by three orthodontists at t0 and after 1 month (t1, using the KPG index and the following 2D methods: distance from cusp tip and occlusal plane, cusp tip position in relation to the lateral incisor, and canine inclination. Pearson’s coefficients were used to evaluate the degree of agreement and the χ2 with Yates correction test was used to assess the independence between them. Results. Inter- and intrarater reliability were higher with KPG compared to 2D methods. Pearson’s coefficients showed a statistically significant association between all the indexes, while the χ2 with Yates correction test resulted in a statistically significant rejection of independency only for one 2D index. Conclusions. 2D indexes for predicting impacted maxillary canines treatment duration and difficulty sometimes are discordant; a 3D index like the KPG index could be useful in solving these conflicts.

  7. Assessment of the Efficiency of Consolidation Treatment through Injections of Expanding Resins by Geotechnical Tests and 3D Electrical Resistivity Tomography

    Apuani, T.; Giani, G. P.; d'Attoli, M.; Fischanger, F.; Morelli, G.; Ranieri, G.; Santarato, G.

    2015-01-01

    The design and execution of consolidation treatment of settled foundations by means of injection of polyurethane expanding resins require a proper investigation of the state of the foundation soil, in order to better identify anomalies responsible for the instability. To monitor the injection process, a procedure has been developed, which involves, in combination with traditional geotechnical tests, the application of a noninvasive, geophysical technique based on the electrical resistivity, which is strongly sensitive to presence of water or voids. Three-dimensional electrical resistivity tomography is a useful tool to produce effective 3D images of the foundation soils before, during, and after the injections. The achieved information allows designing the consolidation scheme and monitoring its effects on the treated volumes in real time. To better understand the complex processes induced by the treatment and to learn how variations of resistivity accompany increase of stiffness, an experiment was carried out in a full-scale test site. Injections of polyurethane expanding resin were performed as in real worksite conditions. Results confirm that the experimented approach by means of 3D resistivity imaging allows a reliable procedure of consolidation, and geotechnical tests demonstrate the increase of mechanical stiffness. PMID:26167521

  8. Training Psychotherapists in Hierarchical Treatment Planning

    MAKOVER, RICHARD B.

    1992-01-01

    Treatment planning is a central and persistent challenge in psychotherapy. This paper outlines a four-level planning hierarchy that encourages the therapist to conceptualize a desired overall outcome (the "aim") that can be realized through subsidiary objectives (the "goals"). The "strategies" by which goals are pursued and the "tactics" that carry out those strategies are subordinate and instrumental elements of the treatment process. Greater emphasis on this type of ...

  9. Evaluation of effect of 3D video glasses on perceived pain and unpleasantness induced by restorative dental treatment

    Bentsen, Bo; Svensson, Peter; Wenzel, Ann

    2001-01-01

    whether distraction induced by video glasses also had an effect on the perceived intensity of pain and unpleasantness during dental treatment. Pain and unpleasantness was evoked by the preparation (drilling) of a minor dental cavity (class I). Twenty-three patients (17 female and six male, age range 20...... and control situation were tested by Student's t-test. There was no statistically significant effect on the perceived pain (p = 0.90) or unpleasantness (p = 0.39), but the majority (74%) of the patients would still prefer to wear video glasses if they were to have another dental filling, and 73% had expected...... a positive effect of the video glasses. These findings suggest that perceived intensity of dental pain is resistant to a simple distraction technique. (C) 2001 European Federation of Chapters of the International Association for the Study of Pain....

  10. Design and implementation of a rotational radiotherapy technique for breast cancer treatment and their comparison with 3-D-Crt irradiation technique; Diseno e implementacion de una tecnica de radioterapia rotacional para tratamiento de cancer de mama y su comparacion contra la tecnica 3D-CRT de irradiacion

    Gutierrez M, J. G.; Lopez V, A.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Velazquez T, J. J.; Adame G, C. S. [Centro Medico Nacional Siglo XXI, Hospital de Oncologia, Departamento de Fisica Medica, Av. Cuauhtemoc No. 330, Col. Doctores, 06720 Mexico D. F. (Mexico); Rubio N, O.; Chagoya G, A.; Hernandez G, J. C., E-mail: jggm25@yahoo.com.mx [Centro Medico Nacional Siglo XXI, Hospital de Oncologia, Departamento de Radioterapia, Av. Cuauhtemoc No. 330, Col. Doctores, 06720 Mexico D. F. (Mexico)

    2015-10-15

    Breast cancer is one of oncological diseases worldwide, as well in Mexico, which causes even more deaths than cervical cancer; this condition is the second death cause in women aged 30-54 years and threatens all socio-economic groups. The treatment is highly dependent on the stage which is detected and based on protocols that include a combination of surgery, chemotherapy and radiotherapy. This paper studies the main irradiation technique for patients with mastectomy, breast full cycle (irradiation of the chest well and supraclavicular nodes) in their mode Three Dimensional - Conformal Radiation Therapy (3-D-Crt), and compared with the Volumetric Modulated Arc Therapy (VMAT) technique proposed in this paper. In both techniques the prescription was 50 Gy divided into 25 fractions. The techniques were applied in three female patients (being an initial study) with disease of the left side, the target volume and organs at risk were delineated by the medical treating radiation oncologist, the planning system used was Eclipse version 10; for quantitative comparison of both plans indexes of homogeneity were used, con formality, the target volume coverage and normal tissue, sub factors and overdosing, the conformation number and coverage quality. They were evaluated and compared the media, maximum and minimum dose of the organs at risk, based on the fact that the coverage of the target volume, dose gradient and dose at risk organs are acceptable (prescription dose greater that 90% coverage, gradient less that 20% and organs at risk in accordance with the Quantec limitations for both versions). (Author)

  11. 3D virtuel udstilling

    Tournay, Bruno; Rüdiger, Bjarne

    2006-01-01

    3d digital model af Arkitektskolens gård med virtuel udstilling af afgangsprojekter fra afgangen sommer 2006. 10 s.......3d digital model af Arkitektskolens gård med virtuel udstilling af afgangsprojekter fra afgangen sommer 2006. 10 s....

  12. Normalisation: ROI optimal treatment planning - SNDH pattern

    Dose precision maximally to the target / ROI (Region of Interest), taking care of tolerance dose of normal tissue is the aim of ideal treatment planning. This goal is achieved with advanced modalities such as, micro MLC, simulator and 3-dimensional treatment planning system. But SNDH PATTERN uses minimum available resources as, ALCYON II Telecobalt unit, CT Scan, MULTIDATA 2-dimensional treatment planning system to their maximum utility and reaches to the required precision, same as that with advance modalities. Among the number of parameters used, 'NORMALISATION TO THE ROI' will achieve the aim of the treatment planning effectively. This is dealing with an example of canal of esophagus modified treatment planning based on SNDH pattern. Results are attractive and self explanatory. By implementing SNDH pattern, the QUALITY INDEX of treatment plan will reach to greater than 90%, with substantial reduction in dose to the vital organs. Aim is to utilize the minimum available resources efficiently to achieve highest possible precision for delivering homogenous dose to ROI while taking care of tolerance dose to vital organs

  13. Underwater 3D filming

    Roberto Rinaldi

    2014-12-01

    Full Text Available After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie’s box offices due to the overall quality of its products. Special environments such as space (“Gravity” and the underwater realm look perfect to be reproduced in 3D. “Filming in space” was possible in “Gravity” using special effects and computer graphic. The underwater realm is still difficult to be handled. Underwater filming in 3D was not that easy and effective as filming in 2D, since not long ago. After almost 3 years of research, a French, Austrian and Italian team realized a perfect tool to film underwater, in 3D, without any constrains. This allows filmmakers to bring the audience deep inside an environment where they most probably will never have the chance to be.

  14. 4D Proton treatment planning strategy for mobile lung tumors

    Purpose: To investigate strategies for designing compensator-based 3D proton treatment plans for mobile lung tumors using four-dimensional computed tomography (4DCT) images. Methods and Materials: Four-dimensional CT sets for 10 lung cancer patients were used in this study. The internal gross tumor volume (IGTV) was obtained by combining the tumor volumes at different phases of the respiratory cycle. For each patient, we evaluated four planning strategies based on the following dose calculations: (1) the average (AVE) CT; (2) the free-breathing (FB) CT; (3) the maximum intensity projection (MIP) CT; and (4) the AVE CT in which the CT voxel values inside the IGTV were replaced by a constant density (AVERIGTV). For each strategy, the resulting cumulative dose distribution in a respiratory cycle was determined using a deformable image registration method. Results: There were dosimetric differences between the apparent dose distribution, calculated on a single CT dataset, and the motion-corrected 4D dose distribution, calculated by combining dose distributions delivered to each phase of the 4DCT. The AVERIGTV plan using a 1-cm smearing parameter had the best overall target coverage and critical structure sparing. The MIP plan approach resulted in an unnecessarily large treatment volume. The AVE and FB plans using 1-cm smearing did not provide adequate 4D target coverage in all patients. By using a larger smearing value, adequate 4D target coverage could be achieved; however, critical organ doses were increased. Conclusion: The AVERIGTV approach is an effective strategy for designing proton treatment plans for mobile lung tumors

  15. Intensity modulated radiotherapy and 3D conformal radiotherapy for whole breast irradiation: a comparative dosimetric study and introduction of a novel qualitative index for plan evaluation, the normal tissue index

    Yim, Jackie; Suttie, Clare; Bromley, Regina; Morgia, Marita; Lamoury, Gillian

    2015-01-01

    Introduction We report on a retrospective dosimetric study, comparing 3D conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (hIMRT). We evaluated plans based on their planning target volume coverage, dose homogeneity, dose to organs at risk (OARs) and exposure of normal tissue to radiation. The Homogeneity Index (HI) was used to assess the dose homogeneity in the target region, and we describe a new index, the normal tissue index (NTI), to assess the dose in the normal...

  16. Emergency Planning for Municipal Wastewater Treatment Facilities.

    Lemon, R. A.; And Others

    This manual for the development of emergency operating plans for municipal wastewater treatment systems was compiled using information provided by over two hundred municipal treatment systems. It covers emergencies caused by natural disasters, civil disorders and strikes, faulty maintenance, negligent operation, and accidents. The effects of such…

  17. The impact of 18F-fluorodeoxyglucose positron emission tomography on the 3D conformal radiotherapy planning in patients with non-small cell lung cancer

    Traditional radiation treatment planning relies on density imaging such as Computed Tomography for anatomic information of various structures of interest including target and normal tissues. However, the difficulties to distinguish malignant from normal tissue on CT slides often leads to inaccurate outlining of the GTV and/or to geographic misses. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) has shown an increase in both sensitivity and specificity over CT in locoregional staging of patients with non-small cell lung cancer (NSCLC). The co registration of FDG-PET images to the data of the CT planning offers the radiation oncologist the possibility to include functional information into the target outlining. For the treatment of patients with NSCLC, it has been shown that the use of FDG-PET images: 1) modified the shape and volume of radiation fields in 22-62% of cases, mainly due to a better nodal staging and distinction of atelectasis from tumor and; 2) significantly reduced the interobserver and intra-observer variability. This paper reviews the results reported in the literature. Challenges and proposed solutions are discussed. (author)

  18. 3D laptop for defense applications

    Edmondson, Richard; Chenault, David

    2012-06-01

    Polaris Sensor Technologies has developed numerous 3D display systems using a US Army patented approach. These displays have been developed as prototypes for handheld controllers for robotic systems and closed hatch driving, and as part of a TALON robot upgrade for 3D vision, providing depth perception for the operator for improved manipulation and hazard avoidance. In this paper we discuss the prototype rugged 3D laptop computer and its applications to defense missions. The prototype 3D laptop combines full temporal and spatial resolution display with the rugged Amrel laptop computer. The display is viewed through protective passive polarized eyewear, and allows combined 2D and 3D content. Uses include robot tele-operation with live 3D video or synthetically rendered scenery, mission planning and rehearsal, enhanced 3D data interpretation, and simulation.

  19. Blender 3D cookbook

    Valenza, Enrico

    2015-01-01

    This book is aimed at the professionals that already have good 3D CGI experience with commercial packages and have now decided to try the open source Blender and want to experiment with something more complex than the average tutorials on the web. However, it's also aimed at the intermediate Blender users who simply want to go some steps further.It's taken for granted that you already know how to move inside the Blender interface, that you already have 3D modeling knowledge, and also that of basic 3D modeling and rendering concepts, for example, edge-loops, n-gons, or samples. In any case, it'

  20. Implementation of BNCT treatment planning procedures

    Estimation of radiation doses delivered during boron neutron capture therapy (BNCT) requires combining data on spatial distribution of both the thermal neutron fluence and the 10B concentration, as well as the relative biological effectiveness of various radiation dose components in the tumor and normal tissues. Using the treatment planning system created at Idaho National Engineering and Environmental Laboratory and the procedures we had developed for clinical trials, we were able to optimize the treatment position, safely deliver the prescribed BNCT doses, and carry out retrospective analyses and reviews. In this paper we describe the BNCT treatment planning process and its implementation in the ongoing dose escalation trials at Brookhaven National Laboratory. (author)

  1. SU-E-T-575: Isocenter Shifts in Treatment Planning and Its Clinical Implications

    Ahmed, Y; Damiani, S; Cao, Y; Jamshidi, A [Long Island Jewish Medical Center, New Hyde Park, NY (United States)

    2014-06-01

    Purpose: To investigate causes of isocenter shifts in treatment planning and its clinical impact on patient treatment efficiency and safety. Methods/Materials: Treatment planning data of 340 patients under treatment over 8 weeks period were gathered to identify isocenter shifts according to site of the treatment, types of treatment plan or types of the machine used. Treatment plans included inversed and forward IMRT, as well as 3D plans. Treatment sites included pelvis, chest, abdomen, breasts, head and necks and extremities. Re-planning were performed without the isocenter shift for pelvis and chest plans, the dosimetric parameters such as PTV coverage, and dose sparing of OARs of these plans were analyzed and compared. Results/Discussions: Results showed that the isocenter shift was always necessary for some of sites such as breasts, two or more distinctive PTVs, or special cases such as large PTV treated with enhanced dynamic wedge. Many other cases, the re-planning results indicated 53% of the plans that the same quality of the plan can be achieved without the shift of the isocenter. Repositioning patients on a daily basis demanded unambiguous instructions for therapists for patient setups, and additional time to perform the shifts before treatment. Opportunities for error propagation exist during the communication and hand-over of such plans. Conclusion: Isocenter shifts demanded unambiguous instructions and times for therapists for daily patient setups, therefore it impacted both safety and efficiency of the patient treatment. Based on the analysis, the isocenter shifts were unavoidable for cases such as treatment of multiple sites, overcoming limitations of treatment machines, and/or sometime better dosimetry. However, we found many initially proposed shifts may have been eliminated either by careful planning or by improved CT simulation process such as detailed review of the images and localization of the PTV during simulation.

  2. 3D Digital Modelling

    Hundebøl, Jesper

    wave of new building information modelling tools demands further investigation, not least because of industry representatives' somewhat coarse parlance: Now the word is spreading -3D digital modelling is nothing less than a revolution, a shift of paradigm, a new alphabet... Research qeustions. Based...... on empirical probes (interviews, observations, written inscriptions) within the Danish construction industry this paper explores the organizational and managerial dynamics of 3D Digital Modelling. The paper intends to - Illustrate how the network of (non-)human actors engaged in the promotion (and arrest) of 3......D Modelling (in Denmark) stabilizes - Examine how 3D Modelling manifests itself in the early design phases of a construction project with a view to discuss the effects hereof for i.a. the management of the building process. Structure. The paper introduces a few, basic methodological concepts...

  3. Professional Papervision3D

    Lively, Michael

    2010-01-01

    Professional Papervision3D describes how Papervision3D works and how real world applications are built, with a clear look at essential topics such as building websites and games, creating virtual tours, and Adobe's Flash 10. Readers learn important techniques through hands-on applications, and build on those skills as the book progresses. The companion website contains all code examples, video step-by-step explanations, and a collada repository.

  4. On the quality of treatment planning systems in radiation therapy

    Purpose: To assist in the design of quality assurance activities of 3D treatment planning systems (TPSs), a postal survey has been carried out, addressing TPS users on quality characteristics and their relative importance in clinical routine planning. Material and methods: The approach as described in ISO/IEC 9126 has been used to analyze TPS quality. Both TPS quality characteristics and how these may be used to establish a quality model are included. A questionnaire on ranking of these TPS quality characteristics has been sent out to the German DEGRO members in February 1997. Results: By the end of July 1997, 90 individual assessments (of 45 physicists, 35 physicians, and 10 radiographers) had been collected. On an importance scale from 1 (very important) to 6 (unimportant), weight factors of 1.71 (portability), 2.84 (maintainability), 3.18 (efficiency), 3.85 (usability), 4.52 (functionality) and 4.90 (reliability) have been determined from the data. From user satisfaction data also obtained from the questionnaire responses, baseline quality indices could be established from the quality model for the RTPs Cadplan, TMS Helax, and Voxelplan. Conclusion: The responses highlight the need for TPS quality assurance at the same time along the lines of safety-related, research-oriented, and interactive end-user software systems in radiotherapy treatment planning. Quality assurance activities must take this into account. Their effect can be monitored by using quality indices as derivable from the established quality model. (orig.)

  5. A novel implementation of mARC treatment for non-dedicated planning systems using converted IMRT plans

    The modulated arc (mARC) technique has recently been introduced by Siemens as an analogue to VMAT treatment. However, up to now only one certified treatment planning system supports mARC planning. We therefore present a conversion algorithm capable of converting IMRT plans created by any treatment planning system into mARC plans, with the hope of expanding the availability of mARC to a larger range of clinical users and researchers. As additional advantages, our implementation offers improved functionality for planning hybrid arcs and provides an equivalent step-and-shoot plan for each mARC plan, which can be used as a back-up concept in institutions where only one linac is equipped with mARC. We present a feasibility study to outline a practical implementation of mARC plan conversion using Philips Pinnacle and Prowess Panther. We present examples for three different kinds of prostate and head-and-neck plans, for 6 MV and flattening-filter-free (FFF) 7 MV photon energies, which are dosimetrically verified. It is generally more difficult to create good quality IMRT plans in Pinnacle using a large number of beams and few segments. We present different ways of optimization as examples. By careful choosing the beam and segment arrangement and inversion objectives, we achieve plan qualities similar to our usual IMRT plans. The conversion of the plans to mARC format yields functional plans, which can be irradiated without incidences. Absolute dosimetric verification of both the step-and-shoot and mARC plans by point dose measurements showed deviations below 5% local dose, mARC plans deviated from step-and-shoot plans by no more than 1%. The agreement between GafChromic film measurements of planar dose before and after mARC conversion is excellent. The comparison of the 3D dose distribution measured by PTW Octavius 729 2D-Array with the step-and-shoot plans and with the TPS is well above the pass criteria of 90% of the points falling within 5% local dose and 3 mm distance

  6. 3 D打印技术在肾肿瘤治疗的应用%The Application of 3 D Printing Technology in Renal Tumor Treatment

    王锋; 赵淼; 马静

    2016-01-01

    Objective To analysis the application of 3 D printing in renal tumor treatment.Methods Selected 48 patients with renal tumors, according to the random distribution divided into research group (24 cases) and control group (24 cases) and control group received MRI and CT reconstruction image analysis, the study group received 3 D printing technology reconstruction image analysis, compared two groups ofoperation indicators. Results Through the analysis, the team estimated blood loss, blocking blood lfow to the time, operation time, blood creatinine levels and the incidence of adverse reactions were lower than those of the control group obviously (P<0.05). Conclusion In the treatment for kidney cancer, 3 D printing technology in the preoperative simulation and resection of guidance, can reduce the risk of surgery, reduce the rate of renal injury.%目的:分析3 D打印技术在肾肿瘤治疗中的应用效果。方法选取我院48例肾肿瘤患者,按照随机分配,分为研究组(24例)和对照组(24例),对照组通过MRI和CT重建图像分析,研究组通过3 D打印技术重建图像分析,对比两组手术指标。结果经分析,研究组估计出血量、血流阻断时间、手术时间、血肌酐水平和不良反应发生率比对照组更低,两组对比差异存在统计学意义(P<0.05)。结论对于肾肿瘤治疗,3 D打印技术在术前模拟和切除术指导,可减少手术风险,降低肾功能损伤率。

  7. Automatic Treatment Planning with Convex Imputing

    Current inverse optimization-based treatment planning for radiotherapy requires a set of complex DVH objectives to be simultaneously minimized. This process, known as multi-objective optimization, is challenging due to non-convexity in individual objectives and insufficient knowledge in the tradeoffs among the objective set. As such, clinical practice involves numerous iterations of human intervention that is costly and often inconsistent. In this work, we propose to address treatment planning with convex imputing, a new-data mining technique that explores the existence of a latent convex objective whose optimizer reflects the DVH and dose-shaping properties of previously optimized cases. Using ten clinical prostate cases as the basis for comparison, we imputed a simple least-squares problem from the optimized solutions of the prostate cases, and show that the imputed plans are more consistent than their clinical counterparts in achieving planning goals.

  8. The evolution of brachytherapy treatment planning

    Brachytherapy is a mature treatment modality that has benefited from technological advances. Treatment planning has advanced from simple lookup tables to complex, computer-based dose-calculation algorithms. The current approach is based on the AAPM TG-43 formalism with recent advances in acquiring single-source dose distributions. However, this formalism has clinically relevant limitations for calculating patient dose. Dose-calculation algorithms are being developed based on Monte Carlo methods, collapsed cone, and solving the linear Boltzmann transport equation. In addition to improved dose-calculation tools, planning systems and brachytherapy treatment planning will account for material heterogeneities, scatter conditions, radiobiology, and image guidance. The AAPM, ESTRO, and other professional societies are working to coordinate clinical integration of these advancements. This Vision 20/20 article provides insight into these endeavors.

  9. The evolution of brachytherapy treatment planning

    Rivard, Mark J.; Venselaar, Jack L. M.; Beaulieu, Luc [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Department of Medical Physics, Instituut Verbeeten, P.O. Box 90120, 5000 LA Tilburg (Netherlands); Departement de Radio-Oncologie et Centre de Recherche en Cancerologie de l' Universite Laval, Centre Hospitalier Universitaire de Quebec, 11 Cote du Palais, Quebec, Quebec G1R 2J6 (Canada) and Departement de Physique, de Genie Physique et d' Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada)

    2009-06-15

    Brachytherapy is a mature treatment modality that has benefited from technological advances. Treatment planning has advanced from simple lookup tables to complex, computer-based dose-calculation algorithms. The current approach is based on the AAPM TG-43 formalism with recent advances in acquiring single-source dose distributions. However, this formalism has clinically relevant limitations for calculating patient dose. Dose-calculation algorithms are being developed based on Monte Carlo methods, collapsed cone, and solving the linear Boltzmann transport equation. In addition to improved dose-calculation tools, planning systems and brachytherapy treatment planning will account for material heterogeneities, scatter conditions, radiobiology, and image guidance. The AAPM, ESTRO, and other professional societies are working to coordinate clinical integration of these advancements. This Vision 20/20 article provides insight into these endeavors.

  10. A Monte Carlo dose calculation tool for radiotherapy treatment planning

    Ma, C.-M.; Li, J. S.; Pawlicki, T.; Jiang, S. B.; Deng, J.; Lee, M. C.; Koumrian, T.; Luxton, M.; Brain, S.

    2002-05-01

    A Monte Carlo user code, MCDOSE, has been developed for radiotherapy treatment planning (RTP) dose calculations. MCDOSE is designed as a dose calculation module suitable for adaptation to host RTP systems. MCDOSE can be used for both conventional photon/electron beam calculation and intensity modulated radiotherapy (IMRT) treatment planning. MCDOSE uses a multiple-source model to reconstruct the treatment beam phase space. Based on Monte Carlo simulated or measured beam data acquired during commissioning, source-model parameters are adjusted through an automated procedure. Beam modifiers such as jaws, physical and dynamic wedges, compensators, blocks, electron cut-outs and bolus are simulated by MCDOSE together with a 3D rectilinear patient geometry model built from CT data. Dose distributions calculated using MCDOSE agreed well with those calculated by the EGS4/DOSXYZ code using different beam set-ups and beam modifiers. Heterogeneity correction factors for layered-lung or layered-bone phantoms as calculated by both codes were consistent with measured data to within 1%. The effect of energy cut-offs for particle transport was investigated. Variance reduction techniques were implemented in MCDOSE to achieve a speedup factor of 10-30 compared to DOSXYZ.

  11. Three-dimensional teletherapy treatment planning

    This thesis deals with physical/mathematical backgrounds of computerized teletherapy treatment planning. The subjects discussed in this thesis can be subdivided into three main categories: a) Three-dimensional treatment planning. A method is evaluated which can be used for the purpose of simulation and optimization of dose distributions in three dimensions. b) The use of Computed Tomography. The use of patient information obtained from Computed Tomography for the purpose of dose computations is evaluated. c) Dose computational models for photon- and electron beams. Models are evaluated which provide information regarding the way in which the radiation dose is distributed in the patient (viz. is absorbed and/or dispersed). (Auth.)

  12. A software tool for 3D dose verification and analysis

    Sa'd, M. Al; Graham, J.; Liney, G. P.

    2013-06-01

    The main recent developments in radiotherapy have focused on improved treatment techniques in order to generate further significant improvements in patient prognosis. There is now an internationally recognised need to improve 3D verification of highly conformal radiotherapy treatments. This is because of the very high dose gradients used in modern treatment techniques, which can result in a small error in the spatial dose distribution leading to a serious complication. In order to gain the full benefits of using 3D dosimetric technologies (such as gel dosimetry), it is vital to use 3D evaluation methods and algorithms. We present in this paper a software solution that provides a comprehensive 3D dose evaluation and analysis. The software is applied to gel dosimetry, which is based on magnetic resonance imaging (MRI) as a read-out method. The software can also be used to compare any two dose distributions, such as two distributions planned using different methods of treatment planning systems, or different dose calculation algorithms.

  13. A software tool for 3D dose verification and analysis

    The main recent developments in radiotherapy have focused on improved treatment techniques in order to generate further significant improvements in patient prognosis. There is now an internationally recognised need to improve 3D verification of highly conformal radiotherapy treatments. This is because of the very high dose gradients used in modern treatment techniques, which can result in a small error in the spatial dose distribution leading to a serious complication. In order to gain the full benefits of using 3D dosimetric technologies (such as gel dosimetry), it is vital to use 3D evaluation methods and algorithms. We present in this paper a software solution that provides a comprehensive 3D dose evaluation and analysis. The software is applied to gel dosimetry, which is based on magnetic resonance imaging (MRI) as a read-out method. The software can also be used to compare any two dose distributions, such as two distributions planned using different methods of treatment planning systems, or different dose calculation algorithms.

  14. Use of 3D printers to create a patient-specific 3D bolus for external beam therapy.

    Burleson, Sarah; Baker, Jamie; Hsia, An Ting; Xu, Zhigang

    2015-01-01

    The purpose of this paper is to demonstrate that an inexpensive 3D printer can be used to manufacture patient-specific bolus for external beam therapy, and to show we can accurately model this printed bolus in our treatment planning system for accurate treatment delivery. Percent depth-dose measurements and tissue maximum ratios were used to determine the characteristics of the printing materials, acrylonitrile butadiene styrene and polylactic acid, as bolus material with physical density of 1.04 and 1.2 g/cm3, and electron density of 3.38 × 10²³ electrons/cm3 and 3.80 × 10²³ electrons/ cm3, respectively. Dose plane comparisons using Gafchromic EBT2 film and the RANDO phantom were used to verify accurate treatment planning. We accurately modeled a printing material in Eclipse treatment planning system, assigning it a Hounsfield unit of 260. We were also able to verify accurate treatment planning using gamma analysis for dose plane comparisons. With gamma criteria of 5% dose difference and 2 mm DTA, we were able to have 86.5% points passing, and with gamma criteria of 5% dose difference and 3 mm DTA, we were able to have 95% points passing. We were able to create a patient-specific bolus using an inexpensive 3D printer and model it in our treatment planning system for accurate treatment delivery. PMID:26103485

  15. Orthodontics: computer-aided diagnosis and treatment planning

    Yi, Yaxing; Li, Zhongke; Wei, Suyuan; Deng, Fanglin; Yao, Sen

    2000-10-01

    The purpose of this article is to introduce the outline of our newly developed computer-aided 3D dental cast analyzing system with laser scanning, and its preliminary clinical applications. The system is composed of a scanning device and a personal computer as a scanning controller and post processor. The scanning device is composed of a laser beam emitter, two sets of linear CCD cameras and a table which is rotatable by two-degree-of-freedom. The rotating is controlled precisely by a personal computer. The dental cast is projected and scanned with a laser beam. Triangulation is applied to determine the location of each point. Generation of 3D graphics of the dental cast takes approximately 40 minutes. About 170,000 sets of X,Y,Z coordinates are store for one dental cast. Besides the conventional linear and angular measurements of the dental cast, we are also able to demonstrate the size of the top surface area of each molar. The advantage of this system is that it facilitates the otherwise complicated and time- consuming mock surgery necessary for treatment planning in orthognathic surgery.

  16. Computer aided diagnosis and treatment planning for developmental dysplasia of the hip

    Li, Bin; Lu, Hongbing; Cai, Wenli; Li, Xiang; Meng, Jie; Liang, Zhengrong

    2005-04-01

    The developmental dysplasia of the hip (DDH) is a congenital malformation affecting the proximal femurs and acetabulum that are subluxatable, dislocatable, and dislocated. Early diagnosis and treatment is important because failure to diagnose and improper treatment can result in significant morbidity. In this paper, we designed and implemented a computer aided system for the diagnosis and treatment planning of this disease. With the design, the patient received CT (computed tomography) or MRI (magnetic resonance imaging) scan first. A mixture-based PV partial-volume algorithm was applied to perform bone segmentation on CT image, followed by three-dimensional (3D) reconstruction and display of the segmented image, demonstrating the special relationship between the acetabulum and femurs for visual judgment. Several standard procedures, such as Salter procedure, Pemberton procedure and Femoral Shortening osteotomy, were simulated on the screen to rehearse a virtual treatment plan. Quantitative measurement of Acetabular Index (AI) and Femoral Neck Anteversion (FNA) were performed on the 3D image for evaluation of DDH and treatment plans. PC graphics-card GPU architecture was exploited to accelerate the 3D rendering and geometric manipulation. The prototype system was implemented on PC/Windows environment and is currently under clinical trial on patient datasets.

  17. The Transition from 2-D Brachytherapy to 3-D High Dose Rate Brachytherapy

    Brachytherapy is a major treatment modality in the treatment of common cancers including cervical cancer. This publication addresses the recent technological change in brachytherapy treatment planning with better access to 3-D volumetric patient imaging modalities including computed tomography (CT) and magnetic resonance (MR) as opposed to traditional 2-D planar images. In the context of 2-D and 3-D brachytherapy, the publication provides definitions, clinical indications, transitioning milestones, commissioning steps, quality assurance measures, and a related questionnaire. Staff training and resourcing are also addressed. The publication will serve as a guide to radiotherapy departments in Member States who wish to make the transition from 2-D to 3-D brachytherapy

  18. 3D Spectroscopic Instrumentation

    Bershady, Matthew A

    2009-01-01

    In this Chapter we review the challenges of, and opportunities for, 3D spectroscopy, and how these have lead to new and different approaches to sampling astronomical information. We describe and categorize existing instruments on 4m and 10m telescopes. Our primary focus is on grating-dispersed spectrographs. We discuss how to optimize dispersive elements, such as VPH gratings, to achieve adequate spectral resolution, high throughput, and efficient data packing to maximize spatial sampling for 3D spectroscopy. We review and compare the various coupling methods that make these spectrographs ``3D,'' including fibers, lenslets, slicers, and filtered multi-slits. We also describe Fabry-Perot and spatial-heterodyne interferometers, pointing out their advantages as field-widened systems relative to conventional, grating-dispersed spectrographs. We explore the parameter space all these instruments sample, highlighting regimes open for exploitation. Present instruments provide a foil for future development. We give an...

  19. Development of a computational system for radiotherapic planning with the IMRT technique applied to the MCNP computer code with 3D graphic interface for voxel models

    The Intensity Modulated Radiation Therapy - IMRT is an advanced treatment technique used worldwide in oncology medicine branch. On this master proposal was developed a software package for simulating the IMRT protocol, namely SOFT-RT which attachment the research group 'Nucleo de Radiacoes Ionizantes' - NRI at UFMG. The computational system SOFT-RT allows producing the absorbed dose simulation of the radiotherapic treatment through a three-dimensional voxel model of the patient. The SISCODES code, from NRI, research group, helps in producing the voxel model of the interest region from a set of CT or MRI digitalized images. The SOFT-RT allows also the rotation and translation of the model about the coordinate system axis for better visualization of the model and the beam. The SOFT-RT collects and exports the necessary parameters to MCNP code which will carry out the nuclear radiation transport towards the tumor and adjacent healthy tissues for each orientation and position of the beam planning. Through three-dimensional visualization of voxel model of a patient, it is possible to focus on a tumoral region preserving the whole tissues around them. It takes in account where exactly the radiation beam passes through, which tissues are affected and how much dose is applied in both tissues. The Out-module from SOFT-RT imports the results and express the dose response superimposing dose and voxel model in gray scale in a three-dimensional graphic representation. The present master thesis presents the new computational system of radiotherapic treatment - SOFT-RT code which has been developed using the robust and multi-platform C++ programming language with the OpenGL graphics packages. The Linux operational system was adopted with the goal of running it in an open source platform and free access. Preliminary simulation results for a cerebral tumor case will be reported as well as some dosimetric evaluations. (author)

  20. Radiotherapy treatment planning linear-quadratic radiobiology

    Chapman, J Donald

    2015-01-01

    Understand Quantitative Radiobiology from a Radiation Biophysics PerspectiveIn the field of radiobiology, the linear-quadratic (LQ) equation has become the standard for defining radiation-induced cell killing. Radiotherapy Treatment Planning: Linear-Quadratic Radiobiology describes tumor cell inactivation from a radiation physics perspective and offers appropriate LQ parameters for modeling tumor and normal tissue responses.Explore the Latest Cell Killing Numbers for Defining Iso-Effective Cancer TreatmentsThe book compil

  1. Herramientas SIG 3D

    Francisco R. Feito Higueruela

    2010-04-01

    Full Text Available Applications of Geographical Information Systems on several Archeology fields have been increasing during the last years. Recent avances in these technologies make possible to work with more realistic 3D models. In this paper we introduce a new paradigm for this system, the GIS Thetrahedron, in which we define the fundamental elements of GIS, in order to provide a better understanding of their capabilities. At the same time the basic 3D characteristics of some comercial and open source software are described, as well as the application to some samples on archeological researchs

  2. Bootstrapping 3D fermions

    Iliesiu, Luca; Kos, Filip; Poland, David; Pufu, Silviu S.; Simmons-Duffin, David; Yacoby, Ran

    2016-03-01

    We study the conformal bootstrap for a 4-point function of fermions in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ × ψ OPE, and also on the central charge C T . We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N . We also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.

  3. Interaktiv 3D design

    Villaume, René Domine; Ørstrup, Finn Rude

    2002-01-01

    Projektet undersøger potentialet for interaktiv 3D design via Internettet. Arkitekt Jørn Utzons projekt til Espansiva blev udviklet som et byggesystem med det mål, at kunne skabe mangfoldige planmuligheder og mangfoldige facade- og rumudformninger. Systemets bygningskomponenter er digitaliseret som...... 3D elementer og gjort tilgængelige. Via Internettet er det nu muligt at sammenstille og afprøve en uendelig  række bygningstyper som  systemet blev tænkt og udviklet til....

  4. 3D Dental Scanner

    Kotek, L.

    2015-01-01

    This paper is about 3D scan of plaster dental casts. The main aim of the work is a hardware and software proposition of 3D scan system for scanning of dental casts. There were used camera, projector and rotate table for this scanning system. Surface triangulation was used, taking benefits of projections of structured light on object, which is being scanned. The rotate table is controlled by PC. The camera, projector and rotate table are synchronized by PC. Controlling of stepper motor is prov...

  5. TOWARDS: 3D INTERNET

    Ms. Swapnali R. Ghadge

    2013-01-01

    In today’s ever-shifting media landscape, it can be a complex task to find effective ways to reach your desired audience. As traditional media such as television continue to lose audience share, one venue in particular stands out for its ability to attract highly motivated audiences and for its tremendous growth potential the 3D Internet. The concept of '3D Internet' has recently come into the spotlight in the R&D arena, catching the attention of many people, and leading to a lot o...

  6. Dosimetric verification of a commercial inverse treatment planning system

    Xing, Lei; Curran, Bruce; Hill, Robert; Holmes, Tim; Ma, Lijun; Forster, Kenneth M.; Boyer, Arthur L.

    1999-02-01

    A commercial three-dimensional (3D) inverse treatment planning system, Corvusimages/0031-9155/44/2/013/img10.gif" ALIGN="TOP"/> (Nomos Corporation, Sewickley, PA), was recently made available. This paper reports our preliminary results and experience with commissioning this system for clinical implementation. This system uses a simulated annealing inverse planning algorithm to calculate intensity-modulated fields. The intensity-modulated fields are divided into beam profiles that can be delivered by means of a sequence of leaf settings by a multileaf collimator (MLC). The treatments are delivered using a computer-controlled MLC. To test the dose calculation algorithm used by the Corvus software, the dose distributions for single rectangularly shaped fields were compared with water phantom scan data. The dose distributions predicted to be delivered by multiple fields were measured using an ion chamber that could be positioned in a rotatable cylindrical water phantom. Integrated charge collected by the ion chamber was used to check the absolute dose of single- and multifield intensity modulated treatments at various spatial points. The measured and predicted doses were found to agree to within 4% at all measurement points. Another set of measurements used a cubic polystyrene phantom with radiographic film to record the radiation dose distribution. The films were calibrated and scanned to yield two-dimensional isodose distributions. Finally, a beam imaging system (BIS) was used to measure the intensity-modulated x-ray beam patterns in the beam's-eye view. The BIS-measured images were then compared with a theoretical calculation based on the MLC leaf sequence files to verify that the treatment would be executed accurately and without machine faults. Excellent correlation (correlation coefficients images/0031-9155/44/2/013/img11.gif" ALIGN="TOP"/>) was found for all cases. Treatment plans generated using intensity-modulated beams appear to be suitable for treatment of

  7. NOTE: MMCTP: a radiotherapy research environment for Monte Carlo and patient-specific treatment planning

    Alexander, A.; DeBlois, F.; Stroian, G.; Al-Yahya, K.; Heath, E.; Seuntjens, J.

    2007-07-01

    Radiotherapy research lacks a flexible computational research environment for Monte Carlo (MC) and patient-specific treatment planning. The purpose of this study was to develop a flexible software package on low-cost hardware with the aim of integrating new patient-specific treatment planning with MC dose calculations suitable for large-scale prospective and retrospective treatment planning studies. We designed the software package 'McGill Monte Carlo treatment planning' (MMCTP) for the research development of MC and patient-specific treatment planning. The MMCTP design consists of a graphical user interface (GUI), which runs on a simple workstation connected through standard secure-shell protocol to a cluster for lengthy MC calculations. Treatment planning information (e.g., images, structures, beam geometry properties and dose distributions) is converted into a convenient MMCTP local file storage format designated, the McGill RT format. MMCTP features include (a) DICOM_RT, RTOG and CADPlan CART format imports; (b) 2D and 3D visualization views for images, structure contours, and dose distributions; (c) contouring tools; (d) DVH analysis, and dose matrix comparison tools; (e) external beam editing; (f) MC transport calculation from beam source to patient geometry for photon and electron beams. The MC input files, which are prepared from the beam geometry properties and patient information (e.g., images and structure contours), are uploaded and run on a cluster using shell commands controlled from the MMCTP GUI. The visualization, dose matrix operation and DVH tools offer extensive options for plan analysis and comparison between MC plans and plans imported from commercial treatment planning systems. The MMCTP GUI provides a flexible research platform for the development of patient-specific MC treatment planning for photon and electron external beam radiation therapy. The impact of this tool lies in the fact that it allows for systematic, platform

  8. MMCTP: a radiotherapy research environment for Monte Carlo and patient-specific treatment planning

    Radiotherapy research lacks a flexible computational research environment for Monte Carlo (MC) and patient-specific treatment planning. The purpose of this study was to develop a flexible software package on low-cost hardware with the aim of integrating new patient-specific treatment planning with MC dose calculations suitable for large-scale prospective and retrospective treatment planning studies. We designed the software package 'McGill Monte Carlo treatment planning' (MMCTP) for the research development of MC and patient-specific treatment planning. The MMCTP design consists of a graphical user interface (GUI), which runs on a simple workstation connected through standard secure-shell protocol to a cluster for lengthy MC calculations. Treatment planning information (e.g., images, structures, beam geometry properties and dose distributions) is converted into a convenient MMCTP local file storage format designated, the McGill RT format. MMCTP features include (a) DICOMRT, RTOG and CADPlan CART format imports; (b) 2D and 3D visualization views for images, structure contours, and dose distributions; (c) contouring tools; (d) DVH analysis, and dose matrix comparison tools; (e) external beam editing; (f) MC transport calculation from beam source to patient geometry for photon and electron beams. The MC input files, which are prepared from the beam geometry properties and patient information (e.g., images and structure contours), are uploaded and run on a cluster using shell commands controlled from the MMCTP GUI. The visualization, dose matrix operation and DVH tools offer extensive options for plan analysis and comparison between MC plans and plans imported from commercial treatment planning systems. The MMCTP GUI provides a flexible research platform for the development of patient-specific MC treatment planning for photon and electron external beam radiation therapy. The impact of this tool lies in the fact that it allows for systematic, platform-independent, large

  9. Effects of surface treatment on the bonding quality of wafer-level Cu-to-Cu thermo-compression bonding for 3D integration

    Various surface treatments are applied for surface oxide removal prior to wafer-level Cu-to-Cu thermo-compression bonding and the bonding quality is systematically analyzed in this work. Three methods are investigated: self-assembled monolayer (SAM) passivation, forming gas annealing and acetic acid wet cleaning. The surface conditions are carefully examined including roughness, contact angle and x-ray photoelectron spectroscopy (XPS) scan. The wafer pairs are bonded at 250 °C under a bonding force of 5500 N for a duration of 1 h in a vacuum environment. The bonding medium consists of a Cu (300 nm) bonding layer and a Ti (50 nm) barrier layer. The bonding quality investigation consists of two parts: hermeticity based on helium leak test and mechanical strength using four-point bending method. Although all samples under test with different surface treatment methods present an excellent hermetic seal and a robust mechanical support, the measurement results show that samples bonded after SAM passivation exhibit the best hermeticity and bonding strength for 3D integration application. (paper)

  10. Modelling of linear accelerator table for use in the design of 3D and VMAT radiotherapy treatments; Modelizacion de mesa de acelerador lineal para aplicacion en los disenos de tratamientos radioterapicos 3D y VMAT

    Velazquez Miranda, S.; Jimenez Domingiuez, M.; Mateos Perez, J. C.; Herrador Cordoba, M.

    2011-07-01

    The new design of carbon treatment tables for rotational IMRT application is being submitted in multiple publications, all dosimetric test to determine their influence on treatment. In most publications can be concluded that their influence is not negligible, especially in near-horizontal angles. In the case of IMRT its influence becomes non-intuitive and therefore difficult to estimate. These publications can not consider all the possibilities of clinical practice, so that its applicability is limited. We propose, therefore, a role-table with the exact geometry of the treatment and density adjusted to the experimental data, to resolve the estimation of their influence in each clinical case.

  11. Dosimetric influence of hyaluronic acid in patients with prostate cancer treated with RT3D; Influencia dosimetrica del acido hialuronico en pacientes cancer de prostata tratados con RT3D externa+HDR braquiterapia

    Sanchez, J.; Vazquez, J. A.; Garcia Blanco, A. S.; Gomez, F.; Montejo, A.; Raba, J. I.; Pacheco, M. T.; Cardenal Carro, J.; Mendigueren, M. A.

    2013-07-01

    This study aims to assess the influence on dosimetry by the introduction of hyaluronic acid and assess the need for the realization of a second CT scan and consequent re-planning of RT3D treatment. (Author)

  12. Improvements in patient treatment planning systems

    The Boron Neutron Capture Therapy, Radiation treatment planning environment (BNCT-Rtpe) software system is used to develop treatment planning information. In typical use BNCT-Rtpe consists of three main components: (1) Semi-automated geometric modeling of objects (brain, target, eyes, sinus) derived from MRI, CT, and other medical imaging modalities, (2) Dose computations for these geometric models with rtt-MC, the INEL Monte Carlo radiation transport computer code, and (3) Dose contouring overlaid on medical images as well as generation of other dose displays. We continue to develop a planning system based on three-dimensional image-based reconstructions using Bspline surfaces. Even though this software is in an experimental state, it has been applied for large animal research and for an isolated case of treatment for a human glioma. Radiation transport is based on Monte Carlo, however there will be implementations of faster methods (e.g. diffusion theory) in the future. The important thing for treatment planning is the output which must convey, to the radiologist, the deposition of dose to healthy and target tissue. Many edits are available such that one can obtain contours registered to medical image, dose/volume histograms and most information required for treatment planning and response assessment. Recent work has been to make the process more automatic and easier to use. The interface, now implemented for contouring and reconstruction, utilizes the Xwindowing system and the MOTIF graphical users interface for effective interaction with the planner. Much work still remains before the tool can be applied in a routine clinical setting

  13. Tangible 3D Modelling

    Hejlesen, Aske K.; Ovesen, Nis

    2012-01-01

    This paper presents an experimental approach to teaching 3D modelling techniques in an Industrial Design programme. The approach includes the use of tangible free form models as tools for improving the overall learning. The paper is based on lecturer and student experiences obtained through...

  14. Shaping 3-D boxes

    Stenholt, Rasmus; Madsen, Claus B.

    2011-01-01

    Enabling users to shape 3-D boxes in immersive virtual environments is a non-trivial problem. In this paper, a new family of techniques for creating rectangular boxes of arbitrary position, orientation, and size is presented and evaluated. These new techniques are based solely on position data...

  15. 3D Harmonic Echocardiography:

    M.M. Voormolen

    2007-01-01

    textabstractThree dimensional (3D) echocardiography has recently developed from an experimental technique in the ’90 towards an imaging modality for the daily clinical practice. This dissertation describes the considerations, implementation, validation and clinical application of a unique

  16. Cost-Effective Fuel Treatment Planning

    Kreitler, J.; Thompson, M.; Vaillant, N.

    2014-12-01

    The cost of fighting large wildland fires in the western United States has grown dramatically over the past decade. This trend will likely continue with growth of the WUI into fire prone ecosystems, dangerous fuel conditions from decades of fire suppression, and a potentially increasing effect from prolonged drought and climate change. Fuel treatments are often considered the primary pre-fire mechanism to reduce the exposure of values at risk to wildland fire, and a growing suite of fire models and tools are employed to prioritize where treatments could mitigate wildland fire damages. Assessments using the likelihood and consequence of fire are critical because funds are insufficient to reduce risk on all lands needing treatment, therefore prioritization is required to maximize the effectiveness of fuel treatment budgets. Cost-effectiveness, doing the most good per dollar, would seem to be an important fuel treatment metric, yet studies or plans that prioritize fuel treatments using costs or cost-effectiveness measures are absent from the literature. Therefore, to explore the effect of using costs in fuel treatment planning we test four prioritization algorithms designed to reduce risk in a case study examining fuel treatments on the Sisters Ranger District of central Oregon. For benefits we model sediment retention and standing biomass, and measure the effectiveness of each algorithm by comparing the differences among treatment and no treat alternative scenarios. Our objective is to maximize the averted loss of net benefits subject to a representative fuel treatment budget. We model costs across the study landscape using the My Fuel Treatment Planner software, tree list data, local mill prices, and GIS-measured site characteristics. We use fire simulations to generate burn probabilities, and estimate fire intensity as conditional flame length at each pixel. Two prioritization algorithms target treatments based on cost-effectiveness and show improvements over those

  17. Registration and planning of radiotherapy and proton therapy treatment

    Within the frame of an update and renewal project, the Orsay Proton Therapy Centre of the Curie Institute (IPCO) renews its software used for the treatment of patients by proton therapy, a radiotherapy technique which uses proton beams. High energies used in these treatments and the precision provided by proton particle characteristics require a more precise patient positioning than conventional radiotherapy: proton therapy requires a precision of about a millimetre. Thus, markers are placed on the skull which are generally well accepted by patients, but are a problem in the case of paediatric treatment, notably for the youngest children whose skull is still growing. The first objective of this research is thus to use only intrinsic information from X-ray images used when positioning the patient. A second objective is to make the new software (TPS Isogray) perfectly compatible with IPCO requirements by maintaining the strengths of the previous TPS (Treatment Planning System) and being prepared to the implementation of a new installation. After a presentation of the context and state of the art in radiotherapy and patient positioning, the author proposes an overview of 2D registration methods, presents a new method for 2x2D registration, and addresses the problem of 3D registration. Then, after a presentation of proton therapy, the author addresses different specific issues and aspects: the compensator (simulation, calculation, and tests), dose calculation, the 'Pencil-Beam' algorithm, tests, and introduced improvements

  18. Status of quality assurance of treatment planning systems in Europe

    Quality assurance, QA, of treatment planning systems, TPS, is generally performed by individual physicists directed to the specific needs of their own institution. In the past a number of tests has been performed by national societies mainly of the accuracy of dose calculation algorithms. Little information is available on national recommendations in the field of QA of TPS. A questionnaire was therefore distributed amongst European countries to review national activities in this field. From the 19 responding countries 7 indicated that only limited efforts are underway, 8 answered that a working group is evaluating their specific national requirements while in 4 countries a document is drafted or tested in various clinics. The main part of these reports concerns detailed descriptions of acceptance tests and constancy checks, including action levels and frequency tests. Additional information concerns recommendations for documentation and short descriptions of dose calculation algorithms. In some countries, having a large number of TPS of the same type, regular users meetings and/or close co-operation with the manufacturer are employed to exchange information concerning QA of their systems. Some of the working groups mentioned separate checks of 2-D and 3-D features of a TPS. Special attention should also be paid to monitor unit computation programs. The survey showed that currently not many countries in Europe have national recommendations on the QA of treatment planning systems. ESTRO and other international organizations, in co-operation with national societies and manufacturers, might therefore play an important role in stimulating the drafting of guidelines for QA of treatment planning systems

  19. Inverse treatment planning for targeted radionuclide therapy

    Full text: A method for inverse treatment planning was developed for targeted radionuclide therapy. Taking into account the fact that the efficacy of targeting radionuclide therapy is affected by nonuniformity dose and dose rate distributions in tumors, we introduce the equivalent uniform biologically effective dose (EUBED) concept on treatment planning for targeting radionuclide therapy. The EUBED model converts the spatial biologically effective dose (BED) distribution into an equivalent uniform biologically effective dose value that would produce a biological response similar to that expected from de original BED distribution. According to this, the treatment planning must quantify the relationship between administered activity and the absorbed dose distribution that expressed in terms of biological effect maximizing the EUBED in tumor while the mean dose in dose-limiting normal organs is maintained within accepted values. The method is based on calculation of the absorbed dose distribution using patient-specific imaging data, incorporating radiobiologic modeling to account for effects of dose rate distribution for better prediction of tumor response. For BED calculation, we use a BED model based on cell repair and proliferation during the internal irradiation at low dose rate with beta emitters. The inverse planning process consists in the estimation of activity to be administered from treatment prescription in terms of tumor control probability (TCP), assuming that each amount of administered activity produces the same biological effect, for treatment schemes that uses multiple activity administrations equally time-spaced. From SPECT images of absorbed dose distribution at voxel level in Gy/GBq, the differential dose volume histogram is obtained and used together with the mean absorbed dose of the dose-limiting organ as input parameters. From prescribed TCP, the corresponding EUBED is calculated and divided by the number of activity administrations to

  20. 3D-Conformal Versus Intensity-Modulated Postoperative Radiotherapy of Vaginal Vault: A Dosimetric Comparison

    We evaluated a step-and-shoot IMRT plan in the postoperative irradiation of the vaginal vault compared with equispaced beam arrangements (3-5) 3D-radiotherapy (RT) optimized plans. Twelve patients were included in this analysis. Four plans for each patient were compared in terms of dose-volume histograms, homogeneity index (HI), and conformity index (CI): (1) 3 equispaced beam arrangement 3D-RT; (2) 4 equispaced beam arrangement 3D-RT; (3) 5 equispaced beam arrangement 3D-RT; (4) step-and-shoot IMRT technique. CI showed a good discrimination between the four plans. The mean scores of CI were 0.58 (range: 0.38-0.67) for the 3F-CRT plan, 0.58 (range: 0.41-0.66) for 4F-CRT, 0.62 (range: 0.43-0.68) for 5F-CRT and 0.69 (range: 0.58-0.78) for the IMRT plan. A significant improvement of the conformity was reached by the IMRT plan (p mean, V90%, V95%, V100% was recorded for rectal and bladder irradiation with the IMRT plan. Surprisingly, IMRT supplied a significant dose reduction also for rectum and bladder V30% and V50%. A significant dosimetric advantage of IMRT over 3D-RT in the adjuvant treatment of vaginal vault alone in terms of treatment conformity and rectum and bladder sparing is shown.

  1. 3D-CT imaging processing for qualitative and quantitative analysis of maxillofacial cysts and tumors

    The objective of this study was to evaluate spiral-computed tomography (3D-CT) images of 20 patients presenting with cysts and tumors in the maxillofacial complex, in order to compare the surface and volume techniques of image rendering. The qualitative and quantitative appraisal indicated that the volume technique allowed a more precise and accurate observation than the surface method. On the average, the measurements obtained by means of the 3D volume-rendering technique were 6.28% higher than those obtained by means of the surface method. The sensitivity of the 3D surface technique was lower than that of the 3D volume technique for all conditions stipulated in the diagnosis and evaluation of lesions. We concluded that the 3D-CT volume rendering technique was more reproducible and sensitive than the 3D-CT surface method, in the diagnosis, treatment planning and evaluation of maxillofacial lesions, especially those with intra-osseous involvement. (author)

  2. The effects of Δ9-Tetrahydrocannabinole treatment on gonadal micro-vascularization and affected fertility examined by SEM and 3D-morphometry

    Erlbacher, K. M. T.; Minnich, B.

    2015-10-01

    The present study focuses on the effects of Δ9-tetrahydrocannabinol (THC) on the reproductive system in nude rats with special emphasis on how Δ9-THC impacts the vascularization of testes which in turn indirectly influences fertility. Basically, Δ9-tetrahydrocannabinol (THC) causes not only negative (psychoactive) effects in the human body as cannabinole administration in medical use (dose-dependent) offers multiple new treatment opportunities such as pain relief or containment of various cancers. Concerning the reproductive system it strongly influences CB-receptors along the hypothalamic-pituitary-gonadal axis resulting in reduced plasma testosterone levels. There is also altered sperm quality parameters reported such as sperm motility or sperm count. On the other hand Δ9-THC effects endothelial growth factors (VEGF, Ang-1 etc.) respectively acts on their specific receptors which in turn modify angiogenesis and vascularization of tissues and organs (e.g. tumorous tissues). This leads to new therapeutical strategies in the suppression of various cancers by inhibiting (neo-)vascularization and in turn famishment of tumorous tissues (lack of nutrition supply). Here we studied the micro-vascularization of gonads in a long-term THC-treated nude rat model by vascular corrosion casting, SEM and 3D-morphometry.

  3. Effect of cold plasma pre-treatment on photocatalytic activity of 3D fabric loaded with nano-photocatalysts: Response surface methodology

    Ghoreishian, Seyed Majid; Badii, Khashayar; Norouzi, Mohammad; Malek, Kaveh

    2016-03-01

    In this study, the physico-chemical effects occasioned by the cold plasma discharge (CPD) on the photo-decolorization of Reactive Orange 16 (RO16) by 3D fabrics (spacer fabrics) loaded with ZnO:TiO2 nano-photocatalysts (nphs) were optimized via response surface methodology (RSM). CPD was employed to improve the surface characteristics of the spacer fabrics for nphs loading. Surface morphology and color variation were studied utilizing scanning electron microscopy (SEM) and CIE-Lab system, respectively. The effect of CPD on the wetting ability of the spacer fabrics was examined using dynamic adsorption measurement (DAM). Also, X-ray fluorescence (XRF) was utilized to investigate the durability of the nphs on the spacer fabrics. All the experiments were implemented in a Box-Behnken design (BBD) with three independent variables (CPD treatment time, dye concentration and irradiation time) in order to optimize the decolorization of RO16. The anticipated values of the decolorization efficiency were found to be in excellent agreement with the experimental values (R2 = 0.9996, Adjusted R2 = 0.9992). The kinetic analysis demonstrated that the photocatalytic decolorization followed the Langmuir-Hinshelwood kinetic model. In conclusion, this heterogeneous photocatalytic process is capable of decolorizing and mineralizing azoic reactive dye in textile wastewater. Moreover, the results confirmed that RSM based on the BBD was a suitable method to optimize the operating conditions of RO16 degradation.

  4. 3D animace

    Klusoň, Jindřich

    2010-01-01

    Computer animation has a growing importance and application in the world. With expansion of technologies increases quality of the final animation as well as number of 3D animation software. This thesis is currently mapped animation software for creating animation in film, television industry and video games which are advisable users requirements. Of them were selected according to criteria the best - Autodesk Maya 2011. This animation software is unique with tools for creating special effects...

  5. A semiautomatic tool for prostate segmentation in radiotherapy treatment planning

    Delineation of the target volume is a time-consuming task in radiotherapy treatment planning, yet essential for a successful treatment of cancers such as prostate cancer. To facilitate the delineation procedure, the paper proposes an intuitive approach for 3D modeling of the prostate by slice-wise best fitting ellipses. The proposed estimate is initialized by the definition of a few control points in a new patient. The method is not restricted to particular image modalities but assumes a smooth shape with elliptic cross sections of the object. A training data set of 23 patients was used to calculate a prior shape model. The mean shape model was evaluated based on the manual contour of 10 test patients. The patient records of training and test data are based on axial T1-weighted 3D fast-field echo (FFE) sequences. The manual contours were considered as the reference model. Volume overlap (Vo), accuracy (Ac) (both ratio, range 0-1, optimal value 1) and Hausdorff distance (HD) (mm, optimal value 0) were calculated as evaluation parameters. The median and median absolute deviation (MAD) between manual delineation and deformed mean best fitting ellipses (MBFE) was Vo (0.9 ± 0.02), Ac (0.81 ± 0.03) and HD (4.05 ± 1.3)mm and between manual delineation and best fitting ellipses (BFE) was Vo (0.96 ± 0.01), Ac (0.92 ± 0.01) and HD (1.6 ± 0.27)mm. Additional results show a moderate improvement of the MBFE results after Monte Carlo Markov Chain (MCMC) method. The results emphasize the potential of the proposed method of modeling the prostate by best fitting ellipses. It shows the robustness and reproducibility of the model. A small sample test on 8 patients suggest possible time saving using the model

  6. Tridimensional Treatment Planning and Rapid Prototyping for Maxillofacial Prosthesis

    ZHANGWen-qiang; YUANJian-bing; YEMing; HUANGXue-mei; WANGCheng-tao

    2004-01-01

    The currert stmulation planing systmes for maxillofacial prosthesis surgery were used to extrapolate 3D surgical movements and outcomes based on the 2D radiographs,which were inadequate for complex surgical movements A 3D treatmenl planning system based on the computerized tomography(CT)data was presented A 3D data field was costructed out of the sectional image stack through linear interpolation after objectire tissue segmentation and using the marching cubes algorithm method,the triangular mesh model and 3D geometric model of diseased facial skeleton were reconstructed then the model was cut,the segments were moved or totated to their predicted positions,and angles and distances were measured after triangular mesh model was decimaled a RP model was manufactured for surgical simulation and prosthesis design The system was used in clinic with more than fifty cases and technically wilidated with success.

  7. Electron Density Calibration for Radiotherapy Treatment Planning

    Herrera-Martínez, F.; Rodríguez-Villafuerte, M.; Martínez-Dávalos, A.; Ruiz-Trejo, C.; Celis-López, M. A.; Lárraga-Gutiérrez, J. M.; García-Garduño, A.

    2006-09-01

    Computed tomography (CT) images are used as basic input data for most modern radiosurgery treatment planning systems (TPS). CT data not only provide anatomic information to delineate target volumes, but also allow the introduction of corrections for tissue inhomogeneities into dose calculations during the treatment planning procedure. These corrections involve the determination of a relationship between tissue electron density (ρe) and their corresponding Hounsfield Units (HU). In this work, an elemental analysis of different commercial tissue equivalent materials using Scanning Electron Microscopy was carried out to characterize their chemical composition. The tissue equivalent materials were chosen to ensure a large range of ρe to be included in the CT scanner calibration. A phantom was designed and constructed with these materials to simulate the size of a human head.

  8. Heavy charged-particle treatment planning

    An essential element of the heavy-ion radiotherapy program is the development of a computerized treatment planning system. A computerized tomographic (CT) based system is currently in operation, where sequential scans are first displayed on a dedicated raster graphics display unit. Target contours in appropriate slices are then entered via cursor by the radiotherapist. After the entry angle and ion type are chosen, the treatment planning program uses CT data on a pixel-by-pixel basis to (1) design appropriate compensators to contour the stopping region of the therapy beams, (2) select an appropriate spread Bragg peak for the irradiation, (3) design a collimator aperture for each entry portal, and (4) generate isoeffect and physical dose distributions overlayed on the CT image. In this section, we review progress in the area of clinical physics, and outline future lines of investigation

  9. Simple Case Treatment Planning: Diastema Closure.

    Calamia, Vincent; Pantzis, Alexandria

    2015-07-01

    This article demonstrates the use of a smile evaluation form as an adjunct in arriving at diagnosis and developing a treatment plan for a patient desiring Diastema closure. It also shows the importance of the diagnostic wax-up for temporization and visualization of case outcome. The case also demonstrates the use of soft tissue lasers to create a gingival harmony that enhanced the resulting esthetics. Feldspathic porcelain was used for the final restorations because they provide optimal esthetics and translucency. PMID:26140972

  10. Dosimetric comparison of intensity modulated radiotherapy isocentric field plans and field in field (FIF) forward plans in the treatment of breast cancer

    Al-Rahbi, Zakiya Salem; Al Mandhari, Zahid; Ravichandran, Ramamoorthy; Al-Kindi, Fatma; Davis, Cheriyathmanjiyil Anthony; Bhasi, Saju; Satyapal, Namrata; Rajan, Balakrishnan

    2013-01-01

    The present study is aimed at comparing the planning and delivery efficiency between three-dimensional conformal radiotherapy (3D-CRT), field-in-field, forward planned, intensity modulated radiotherapy (FIF-FP-IMRT), and inverse planned intensity modulated radiotherapy (IP-IMRT). Treatment plans of 20 patients with left-sided breast cancer, 10 post-mastectomy treated to a prescribed dose of 45 Gy to the chest wall in 20 fractions, and 10 post-breast-conserving surgery to a prescribed dose of ...

  11. Radiobiological aspects of radiotherapy treatment planning

    The aim of an oncological treatment is to eradicate the tumor without inducing unacceptable side effects. The optimization of a dose distribution with external beams requires the selection of the radiation type and energy, the number of fields, their sizes and incidence angles of the beams and then the possible use of wedges or compensating filters. The goal of optimal treatment planning is to provide maximum tumor killing while sparing normal tissues as much as possible. New, more sophisticated planning systems, based on three dimensional dose distribution calculations, require simplified data interpretation techniques. Dose volume histograms represent a convenient and useful tool to summarize dose distribution information through the entire volume of a given anatomic structure and to quickly highlight characteristics such as dose uniformity and hot and cold spots. It is difficult however to choose among competing histograms concerning different organs when they cross one another. This paper discusses the development of a computerized treatment planning system in which dose volume histograms are used to estimate tumor control and normal tissue complication probabilities

  12. VMAT to arclet plan conversion in a treatment planning system. Feasibility and dosimetric relationship between VMAT, arclet, and stationary fields

    Dzierma, Yvonne; Licht, Norbert; Nuesken, Frank; Ruebe, Christian; Fleckenstein, Jochen [Saarland University Medical Center, Department of Radiotherapy, Homburg/Saar (Germany); Norton, Ian [Philips Radiation Oncology Systems, Fitchburg, WI (United States)

    2015-12-15

    The aim of this study was to make dynamic rotation treatment with mARC available for the non-dedicated Philips Pinnacle treatment planning system by converting SmartArc plans, offering insight into the relationship between SmartArc, mARC, and stationary field irradiation. A scripting solution is presented that can be run in the Pinnacle system. This allows for the conversion of SmartArc plans into mARC format. The dose distribution of the converted mARC plan can be evaluated both in the form of a ''real'' mARC plan with arclets and - as is generally done in treatment planning systems certified for mARC planning - by approximating the arclets as stationary fields. We present the proof of principle and dosimetric comparisons. The converted plans were irradiated without problems. For the measured 3D dose distributions, on average over 90 % points agreed with the calculated dose distributions (mARC and stationary field plans) within the gamma criteria of 3 % deviation in the local dose, 3-mm distance to agreement, for all dose values above 10 % of the maximum. The agreement between the three calculated dose distributions (SmartArc with both converted plans) was above 87 % (above 92 % when comparing mARC with stationary fields). Our solution offers the possibility of mARC planning in Pinnacle. The dose comparisons furthermore prove that the dosimetric differences between SmartArc and mARC, when appropriately translated, are minor. (orig.) [German] Diese Studie praesentiert die Konversion von SmartArc-Plaenen in mARC-Format innerhalb des Philips Pinnacle Bestrahlungsplanungssystems und vergleicht SmartArc, mARC und Stehfeldbestrahlungstechniken. Innerhalb des Pinnacle-Systems wird die Konversion von SmartArc- zu mARC-Plaenen skriptbasiert durchgefuehrt. Die resultierenden Dosisverteilungen werden sowohl mit einem Plan mit Arclet-Abstrahlung als auch mit angenaeherten Stehfelder-Plaenen verglichen. Die konvertierten Plaene koennen problemlos

  13. Full scale 3D-modelling of the coupled gas migration and heat dissipation in a planned repository for radioactive waste in the Callovo-Oxfordian clay

    An important question related to the long-term safety performance of a repository for long-lived medium and high-level radioactive waste in the Callovo-Oxfordian clay unit is the impact of heat and gas generated in the waste emplacement areas on the gas and water pressure and on the water saturation in the backfilled repository and in the host rock. The current design of such a repository consists of a multitude of different underground structures, such as emplacement drifts for waste canisters and other types of waste packages, access and ventilation drifts, and access shafts in the central part of the repository. The individual underground structures exhibit different thermo-hydraulic and geometrical properties yielding a large and complex system for the flow and transport of gas, water and heat. A detailed 3D modelling of the entire repository would require a tremendous computational effort, even when using high performance simulator codes. A newly developed method (Poller et al., 2011) allows for the 3D modelling of the two-phase gas-water flow and thermal evolution in the entire repository/host-rock system in a simplified manner. Besides accounting for both the detailed structures at local scale and the global geometry of the drift network, it also allows for an assessment of the gas phase pressure as well as the hydrogen and heat fluxes developing over the complete lifetime of the repository system. In this paper, the results of a reference scenario are presented. The assessment focuses on the two dominant processes, i.e. the dissolution. and. diffusion of the generated hydrogen, and the advective migration of the forming hydrogen gas phase in space and time (up to 1 million years). Further, the main findings of a sensitivity analysis on different features, physical processes and parameter uncertainty are presented. (authors)

  14. Side-to-side 3D coverage path planning approach for agricultural robots to minimize skip/overlap areas between swaths

    Hameed, Ibrahim; la Cour-Harbo, Anders; Osen, O. L.

    2016-01-01

    Automated path planning is important for the automation and optimization of field operations. It can provide the waypoints required for guidance, navigation and control of agricultural robots and autonomous tractors throughout the execution of these field operations. In agriculture, field...

  15. Massive 3D Supergravity

    Andringa, Roel; de Roo, Mees; Hohm, Olaf; Sezgin, Ergin; Townsend, Paul K

    2009-01-01

    We construct the N=1 three-dimensional supergravity theory with cosmological, Einstein-Hilbert, Lorentz Chern-Simons, and general curvature squared terms. We determine the general supersymmetric configuration, and find a family of supersymmetric adS vacua with the supersymmetric Minkowski vacuum as a limiting case. Linearizing about the Minkowski vacuum, we find three classes of unitary theories; one is the supersymmetric extension of the recently discovered `massive 3D gravity'. Another is a `new topologically massive supergravity' (with no Einstein-Hilbert term) that propagates a single (2,3/2) helicity supermultiplet.

  16. Massive 3D supergravity

    Andringa, Roel; Bergshoeff, Eric A; De Roo, Mees; Hohm, Olaf [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Sezgin, Ergin [George and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Townsend, Paul K, E-mail: E.A.Bergshoeff@rug.n, E-mail: O.Hohm@rug.n, E-mail: sezgin@tamu.ed, E-mail: P.K.Townsend@damtp.cam.ac.u [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)

    2010-01-21

    We construct the N=1 three-dimensional supergravity theory with cosmological, Einstein-Hilbert, Lorentz Chern-Simons, and general curvature squared terms. We determine the general supersymmetric configuration, and find a family of supersymmetric adS vacua with the supersymmetric Minkowski vacuum as a limiting case. Linearizing about the Minkowski vacuum, we find three classes of unitary theories; one is the supersymmetric extension of the recently discovered 'massive 3D gravity'. Another is a 'new topologically massive supergravity' (with no Einstein-Hilbert term) that propagates a single (2,3/2) helicity supermultiplet.

  17. A new method for commissioning Monte Carlo treatment planning systems

    Aljarrah, Khaled Mohammed

    2005-11-01

    The Monte Carlo method is an accurate method for solving numerical problems in different fields. It has been used for accurate radiation dose calculation for radiation treatment of cancer. However, the modeling of an individual radiation beam produced by a medical linear accelerator for Monte Carlo dose calculation, i.e., the commissioning of a Monte Carlo treatment planning system, has been the bottleneck for the clinical implementation of Monte Carlo treatment planning. In this study a new method has been developed to determine the parameters of the initial electron beam incident on the target for a clinical linear accelerator. The interaction of the initial electron beam with the accelerator target produces x-ray and secondary charge particles. After successive interactions in the linac head components, the x-ray photons and the secondary charge particles interact with the patient's anatomy and deliver dose to the region of interest. The determination of the initial electron beam parameters is important for estimating the delivered dose to the patients. These parameters, such as beam energy and radial intensity distribution, are usually estimated through a trial and error process. In this work an easy and efficient method was developed to determine these parameters. This was accomplished by comparing calculated 3D dose distributions for a grid of assumed beam energies and radii in a water phantom with measurements data. Different cost functions were studied to choose the appropriate function for the data comparison. The beam parameters were determined on the light of this method. Due to the assumption that same type of linacs are exactly the same in their geometries and only differ by the initial phase space parameters, the results of this method were considered as a source data to commission other machines of the same type.

  18. WE-F-16A-05: Use of 3D-Printers to Create a Tissue Equivalent 3D-Bolus for External Beam Therapy

    Burleson, S; Baker, J; Hsia, A; Xu, Z [Stony Brook Medicine, Stony Brook, NY (United States)

    2014-06-15

    Purpose: The purpose of this project is to demonstrate that a non-expensive 3D-printer can be used to manufacture a 3D-bolus for external beam therapy. The printed bolus then can be modeled in our treatment planning system to ensure accurate dose delivery to the patient. Methods: We developed a simple method to manufacture a patient-specific custom 3Dbolus. The bolus is designed using Eclipse Treatment Planning System, contoured onto the patients CT images. The bolus file is exported from Eclipse to 3D-printer software, and then printed using a 3D printer. Various tests were completed to determine the properties of the printing material. Percent depth dose curves in this material were measured with electron and photon beams for comparison to other materials. In order to test the validity of the 3D printed bolus for treatment planning, a custom bolus was printed and tested on the Rando phantom using film for a dose plane comparison. We compared the dose plane measured on the film to the same dose plane exported from our treatment planning system using Film QA software. The gamma-dose distribution tool was used in our film analysis. Results: We compared point measurements throughout the dose plane and were able to achieve greater than 95% passing rate at 3% dose difference and 3 mm distance to agreement, which is our departments acceptable gamma pixel parameters. Conclusion: The printed 3D bolus has proven to be accurately modeled in our treatment planning system, it is more conformal to the patient surface and more durable than other bolus currently used (wax, superflab etc.). It is also more convenient and less costly than comparable bolus from milling machine companies.

  19. WE-F-16A-05: Use of 3D-Printers to Create a Tissue Equivalent 3D-Bolus for External Beam Therapy

    Purpose: The purpose of this project is to demonstrate that a non-expensive 3D-printer can be used to manufacture a 3D-bolus for external beam therapy. The printed bolus then can be modeled in our treatment planning system to ensure accurate dose delivery to the patient. Methods: We developed a simple method to manufacture a patient-specific custom 3Dbolus. The bolus is designed using Eclipse Treatment Planning System, contoured onto the patients CT images. The bolus file is exported from Eclipse to 3D-printer software, and then printed using a 3D printer. Various tests were completed to determine the properties of the printing material. Percent depth dose curves in this material were measured with electron and photon beams for comparison to other materials. In order to test the validity of the 3D printed bolus for treatment planning, a custom bolus was printed and tested on the Rando phantom using film for a dose plane comparison. We compared the dose plane measured on the film to the same dose plane exported from our treatment planning system using Film QA software. The gamma-dose distribution tool was used in our film analysis. Results: We compared point measurements throughout the dose plane and were able to achieve greater than 95% passing rate at 3% dose difference and 3 mm distance to agreement, which is our departments acceptable gamma pixel parameters. Conclusion: The printed 3D bolus has proven to be accurately modeled in our treatment planning system, it is more conformal to the patient surface and more durable than other bolus currently used (wax, superflab etc.). It is also more convenient and less costly than comparable bolus from milling machine companies

  20. Clinical Utility of 4D FDG-PET/CT Scans in Radiation Treatment Planning

    Aristophanous, Michalis, E-mail: maristophanous@lroc.harvard.edu [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center and Harvard Medical School, Boston, MA (United States); Berbeco, Ross I.; Killoran, Joseph H. [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center and Harvard Medical School, Boston, MA (United States); Yap, Jeffrey T. [Department of Radiology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA (United States); Sher, David J.; Allen, Aaron M.; Larson, Elysia; Chen, Aileen B. [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center and Harvard Medical School, Boston, MA (United States)

    2012-01-01

    Purpose: The potential role of four-dimensional (4D) positron emission tomography (PET)/computed tomography (CT) in radiation treatment planning, relative to standard three-dimensional (3D) PET/CT, was examined. Methods and Materials: Ten patients with non-small-cell lung cancer had sequential 3D and 4D [{sup 18}F]fluorodeoxyglucose PET/CT scans in the treatment position prior to radiation therapy. The gross tumor volume and involved lymph nodes were contoured on the PET scan by use of three different techniques: manual contouring by an experienced radiation oncologist using a predetermined protocol; a technique with a constant threshold of standardized uptake value (SUV) greater than 2.5; and an automatic segmentation technique. For each technique, the tumor volume was defined on the 3D scan (VOL3D) and on the 4D scan (VOL4D) by combining the volume defined on each of the five breathing phases individually. The range of tumor motion and the location of each lesion were also recorded, and their influence on the differences observed between VOL3D and VOL4D was investigated. Results: We identified and analyzed 22 distinct lesions, including 9 primary tumors and 13 mediastinal lymph nodes. Mean VOL4D was larger than mean VOL3D with all three techniques, and the difference was statistically significant (p < 0.01). The range of tumor motion and the location of the tumor affected the magnitude of the difference. For one case, all three tumor definition techniques identified volume of moderate uptake of approximately 1 mL in the hilar region on the 4D scan (SUV maximum, 3.3) but not on the 3D scan (SUV maximum, 2.3). Conclusions: In comparison to 3D PET, 4D PET may better define the full physiologic extent of moving tumors and improve radiation treatment planning for lung tumors. In addition, reduction of blurring from free-breathing images may reveal additional information regarding regional disease.

  1. TOWARDS: 3D INTERNET

    Ms. Swapnali R. Ghadge

    2013-08-01

    Full Text Available In today’s ever-shifting media landscape, it can be a complex task to find effective ways to reach your desired audience. As traditional media such as television continue to lose audience share, one venue in particular stands out for its ability to attract highly motivated audiences and for its tremendous growth potential the 3D Internet. The concept of '3D Internet' has recently come into the spotlight in the R&D arena, catching the attention of many people, and leading to a lot of discussions. Basically, one can look into this matter from a few different perspectives: visualization and representation of information, and creation and transportation of information, among others. All of them still constitute research challenges, as no products or services are yet available or foreseen for the near future. Nevertheless, one can try to envisage the directions that can be taken towards achieving this goal. People who take part in virtual worlds stay online longer with a heightened level of interest. To take advantage of that interest, diverse businesses and organizations have claimed an early stake in this fast-growing market. They include technology leaders such as IBM, Microsoft, and Cisco, companies such as BMW, Toyota, Circuit City, Coca Cola, and Calvin Klein, and scores of universities, including Harvard, Stanford and Penn State.

  2. The adaptation of megavoltage cone beam CT for use in standard radiotherapy treatment planning

    Thomas, T. Hannah Mary; Devakumar, D.; Purnima, S.; Ravindran, B. Paul

    2009-04-01

    Potential areas where megavoltage computed tomography (MVCT) could be used are second- and third-phase treatment planning in 3D conformal radiotherapy and IMRT, adaptive radiation therapy, single fraction palliative treatment and for the treatment of patients with metal prostheses. A feasibility study was done on using MV cone beam CT (CBCT) images generated by proprietary 3D reconstruction software based on the FDK algorithm for megavoltage treatment planning. The reconstructed images were converted to a DICOM file set. The pixel values of megavoltage cone beam computed tomography (MV CBCT) were rescaled to those of kV CT for use with a treatment planning system. A calibration phantom was designed and developed for verification of geometric accuracy and CT number calibration. The distance measured between two marker points on the CBCT image and the physical dimension on the phantom were in good agreement. Point dose verification for a 10 cm × 10 cm beam at a gantry angle of 0° and SAD of 100 cm were performed for a 6 MV beam for both kV and MV CBCT images. The point doses were found to vary between ±6.1% of the dose calculated from the kV CT image. The isodose curves for 6 MV for both kV CT and MV CBCT images were within 2% and 3 mm distance-to-agreement. A plan with three beams was performed on MV CBCT, simulating a treatment plan for cancer of the pituitary. The distribution obtained was compared with those corresponding to that obtained using the kV CT. This study has shown that treatment planning with MV cone beam CT images is feasible.

  3. The adaptation of megavoltage cone beam CT for use in standard radiotherapy treatment planning

    Thomas, T Hannah Mary; Purnima, S; Ravindran, B Paul [Department of Radiotherapy, Christian Medical College, Vellore (India); Devakumar, D [Department of Nuclear Medicine, Christian Medical College, Vellore (India)], E-mail: paul@cmcvellore.ac.in

    2009-04-07

    Potential areas where megavoltage computed tomography (MVCT) could be used are second- and third-phase treatment planning in 3D conformal radiotherapy and IMRT, adaptive radiation therapy, single fraction palliative treatment and for the treatment of patients with metal prostheses. A feasibility study was done on using MV cone beam CT (CBCT) images generated by proprietary 3D reconstruction software based on the FDK algorithm for megavoltage treatment planning. The reconstructed images were converted to a DICOM file set. The pixel values of megavoltage cone beam computed tomography (MV CBCT) were rescaled to those of kV CT for use with a treatment planning system. A calibration phantom was designed and developed for verification of geometric accuracy and CT number calibration. The distance measured between two marker points on the CBCT image and the physical dimension on the phantom were in good agreement. Point dose verification for a 10 cm x 10 cm beam at a gantry angle of 0{sup 0} and SAD of 100 cm were performed for a 6 MV beam for both kV and MV CBCT images. The point doses were found to vary between {+-}6.1% of the dose calculated from the kV CT image. The isodose curves for 6 MV for both kV CT and MV CBCT images were within 2% and 3 mm distance-to-agreement. A plan with three beams was performed on MV CBCT, simulating a treatment plan for cancer of the pituitary. The distribution obtained was compared with those corresponding to that obtained using the kV CT. This study has shown that treatment planning with MV cone beam CT images is feasible.

  4. 3D printing: technology and processing

    Kurinov, Ilya

    2016-01-01

    The objective of the research was to improve the process of 3D printing on the laboratory machine. In the study processes of designing, printing and post-print-ing treatment were improved. The study was commissioned by Mikko Ruotsalainen, head of the laboratory. The data was collected during the test work. All the basic information about 3D printing was taken from the Internet or library. As the results of the project higher model accuracy, solutions for post-printing treatment, printin...

  5. Virtual 3D planning and patient specific surgical guides for osteotomies around the knee: a feasibility and proof-of-concept study.

    Victor, J; Premanathan, A

    2013-11-01

    We have investigated the benefits of patient specific instrument guides, applied to osteotomies around the knee. Single, dual and triple planar osteotomies were performed on tibias or femurs in 14 subjects. In all patients, a detailed pre-operative plan was prepared based upon full leg standing radiographic and CT scan information. The planned level of the osteotomy and open wedge resection was relayed to the surgery by virtue of a patient specific guide developed from the images. The mean deviation between the planned wedge angle and the executed wedge angle was 0° (-1 to 1, sd 0.71) in the coronal plane and 0.3° (-0.9 to 3, sd 1.14) in the sagittal plane. The mean deviation between the planned hip, knee, ankle angle (HKA) on full leg standing radiograph and the post-operative HKA was 0.3° (-1 to 2, sd 0.75). It is concluded that this is a feasible and valuable concept from the standpoint of pre-operative software based planning, surgical application and geometrical accuracy of outcome. PMID:24187376

  6. mTOR-inhibitor treatment of metastatic renal cell carcinoma: contribution of Choi and modified Choi criteria assessed in 2D or 3D to evaluate tumor response

    Lamuraglia, M. [Laboratoire d' Imagerie Biomedicale, Sorbonne Universites, UPMC Univ Paris 06, INSERM, CNRS, Paris (France); Raslan, S.; Penna, R.R.; Wagner, M. [Groupe Hospitalier Pitie-Salpetriere, APHP UPMC, Service de Radiologie Polyvalente et Oncologique, Paris Cedex 13 (France); Elaidi, R.; Oudard, S. [APHP, Oncology Unit, Georges-Pompidou Hospital, Paris (France); Escudier, B. [Gustave-Roussy Institute, Medical Oncology Department, Villejuif (France); Slimane, K. [Novartis Pharma, Rueil-Malmaison (France); Lucidarme, O. [Groupe Hospitalier Pitie-Salpetriere, APHP UPMC, Service de Radiologie Polyvalente et Oncologique, Paris Cedex 13 (France); Laboratoire d' Imagerie Biomedicale, Sorbonne Universites, UPMC Univ Paris 06, INSERM, CNRS, Paris (France)

    2016-01-15

    To determine whether 2D or 3D Choi and modified Choi (mChoi) criteria could assess the efficacy of everolimus against metastatic renal cell carcinoma (mRCC). RECIST-1.1, Choi, and mChoi criteria were applied retrospectively to analyse baseline and 2-month contrast-enhanced computed tomography (CECT) images in 48 patients with mRCC enrolled in the everolimus arm of the French randomized double-blind multicentre phase III trial comparing everolimus versus placebo (RECORD-1). The primary endpoint was centrally reviewed progression-free survival (PFS) calculated from the initial RECORD-1 analysis. Mean attenuation was determined for 2D target lesion regions of interest drawn on CECT sections whose largest diameters had been measured, and for the 3D whole target lesion. The median PFS was 5.5 months. The median PFS for everolimus responders defined using 3D mChoi criteria was significantly longer than for non-responders (7.6 versus 5.4 months, respectively), corresponding to a hazard ratio for progression of 0.45 (95 % CI: 0.22-0.92), with respective 1-year survival rates of 31 % and 9 %. No other 2D or 3D imaging criteria at 2 months identified patients who would benefit from everolimus. At 2 months, only 3D mChoi criteria were able to identify mRCC patients with a PFS benefit from everolimus. (orig.)

  7. mTOR-inhibitor treatment of metastatic renal cell carcinoma: contribution of Choi and modified Choi criteria assessed in 2D or 3D to evaluate tumor response

    To determine whether 2D or 3D Choi and modified Choi (mChoi) criteria could assess the efficacy of everolimus against metastatic renal cell carcinoma (mRCC). RECIST-1.1, Choi, and mChoi criteria were applied retrospectively to analyse baseline and 2-month contrast-enhanced computed tomography (CECT) images in 48 patients with mRCC enrolled in the everolimus arm of the French randomized double-blind multicentre phase III trial comparing everolimus versus placebo (RECORD-1). The primary endpoint was centrally reviewed progression-free survival (PFS) calculated from the initial RECORD-1 analysis. Mean attenuation was determined for 2D target lesion regions of interest drawn on CECT sections whose largest diameters had been measured, and for the 3D whole target lesion. The median PFS was 5.5 months. The median PFS for everolimus responders defined using 3D mChoi criteria was significantly longer than for non-responders (7.6 versus 5.4 months, respectively), corresponding to a hazard ratio for progression of 0.45 (95 % CI: 0.22-0.92), with respective 1-year survival rates of 31 % and 9 %. No other 2D or 3D imaging criteria at 2 months identified patients who would benefit from everolimus. At 2 months, only 3D mChoi criteria were able to identify mRCC patients with a PFS benefit from everolimus. (orig.)

  8. A graphical user interface for automatic image registration software designed for radiotherapy treatment planning

    Medical imaging forms a vital component of radiotherapy treatment planning and its evaluation. The integration of the useful data obtained from multiple imaging modalities for radiotherapy planning is achieved by image registration softwares. In radiotherapy planning systems, normally the computed tomography (CT) slices are kept as a standard upon which other modality images (magnetic resonance imaging [MRI], single photon emission computed tomography [SPECT], positron emission tomography [PET], etc.) are aligned-automatically or interactively. Following validation of successful registration, they are resampled and reformatted, as per the requirements. This paper defines the minimum requirements of automatic image registration software for 3-dimensional (3D) radiotherapy planning and describes the implementation of a suitable graphical user interface developed in Visual Basic (version 5). The automatic image registration (AIR) routines freely available from Dr. Roger P. Woods, UCLA, (USA) were used in this software. This software could be easily implemented and was easy to use for image processing suitable for radiotherapy planning systems

  9. 2D mapping of the MV photon fluence and 3D dose reconstruction in real time for quality assurance during radiotherapy treatment

    Summary: the photon irradiation response of a 2D solid state transmission detector array mounted in a linac block tray is used to reconstruct the projected 2D dose map in a homogenous phantom along rays that diverge from the X-ray source and pass through each of the 121 detector elements. A unique diode response-to-dose scaling factor, applied to all detectors, is utilised in the reconstruction to demonstrate that real time QA during radiotherapy treatment is feasible. Purpose: to quantitatively demonstrate reconstruction of the real time radiation dose from the irradiation response of the 11×11 silicon Magic Plate (MP) detector array operated in Transmission Mode (MPTM). Methods and Materials: in transmission mode the MP is positioned in the block tray of a linac so that the central detector of the array lies on the central axis of the radiation beam. This central detector is used to determine the conversion factor from measured irradiation response to reconstructed dose at any point on the central axis within a homogenous solid water phantom. The same unique conversion factor is used for all MP detector elements lying within the irradiation field. Using the two sets of data, the 2D or 3D dose map is able to be reconstructed in the homogenous phantom. The technique we have developed is illustrated here for different depths and irradiation field sizes, (5 × 5 cm2 to 40 × 40 cm2) as well as a highly non uniform irradiation field.Results: we find that the MPTM response is proportional to the projected 2D dose map measured at a specific phantom depth, the 'sweet depth'. A single factor, for several irradiation field sizes and depths, is derived to reconstruct the dose in the phantom along rays projected from the photon source through each MPTM detector element. We demonstrate that for all field sizes using the above method, the 2D reconstructed and measured doses agree to within ± 2.48% (2 standard deviation) for all in-field MP detector elements

  10. 2D mapping of the MV photon fluence and 3D dose reconstruction in real time for quality assurance during radiotherapy treatment

    Alrowaili, Z. A.; Lerch, M. L. F.; Carolan, M.; Fuduli, I.; Porumb, C.; Petasecca, M.; Metcalfe, P.; Rosenfeld, A. B.

    2015-09-01

    Summary: the photon irradiation response of a 2D solid state transmission detector array mounted in a linac block tray is used to reconstruct the projected 2D dose map in a homogenous phantom along rays that diverge from the X-ray source and pass through each of the 121 detector elements. A unique diode response-to-dose scaling factor, applied to all detectors, is utilised in the reconstruction to demonstrate that real time QA during radiotherapy treatment is feasible. Purpose: to quantitatively demonstrate reconstruction of the real time radiation dose from the irradiation response of the 11×11 silicon Magic Plate (MP) detector array operated in Transmission Mode (MPTM). Methods and Materials: in transmission mode the MP is positioned in the block tray of a linac so that the central detector of the array lies on the central axis of the radiation beam. This central detector is used to determine the conversion factor from measured irradiation response to reconstructed dose at any point on the central axis within a homogenous solid water phantom. The same unique conversion factor is used for all MP detector elements lying within the irradiation field. Using the two sets of data, the 2D or 3D dose map is able to be reconstructed in the homogenous phantom. The technique we have developed is illustrated here for different depths and irradiation field sizes, (5 × 5 cm2 to 40 × 40 cm2) as well as a highly non uniform irradiation field. Results: we find that the MPTM response is proportional to the projected 2D dose map measured at a specific phantom depth, the "sweet depth". A single factor, for several irradiation field sizes and depths, is derived to reconstruct the dose in the phantom along rays projected from the photon source through each MPTM detector element. We demonstrate that for all field sizes using the above method, the 2D reconstructed and measured doses agree to within ± 2.48% (2 standard deviation) for all in-field MP detector elements. Conclusions: a

  11. Patient specific optimization-based treatment planning for catheter-based ultrasound hyperthermia and thermal ablation

    Prakash, Punit; Chen, Xin; Wootton, Jeffery; Pouliot, Jean; Hsu, I.-Chow; Diederich, Chris J.

    2009-02-01

    A 3D optimization-based thermal treatment planning platform has been developed for the application of catheter-based ultrasound hyperthermia in conjunction with high dose rate (HDR) brachytherapy for treating advanced pelvic tumors. Optimal selection of applied power levels to each independently controlled transducer segment can be used to conform and maximize therapeutic heating and thermal dose coverage to the target region, providing significant advantages over current hyperthermia technology and improving treatment response. Critical anatomic structures, clinical target outlines, and implant/applicator geometries were acquired from sequential multi-slice 2D images obtained from HDR treatment planning and used to reconstruct patient specific 3D biothermal models. A constrained optimization algorithm was devised and integrated within a finite element thermal solver to determine a priori the optimal applied power levels and the resulting 3D temperature distributions such that therapeutic heating is maximized within the target, while placing constraints on maximum tissue temperature and thermal exposure of surrounding non-targeted tissue. This optimizationbased treatment planning and modeling system was applied on representative cases of clinical implants for HDR treatment of cervix and prostate to evaluate the utility of this planning approach. The planning provided significant improvement in achievable temperature distributions for all cases, with substantial increase in T90 and thermal dose (CEM43T90) coverage to the hyperthermia target volume while decreasing maximum treatment temperature and reducing thermal dose exposure to surrounding non-targeted tissues and thermally sensitive rectum and bladder. This optimization based treatment planning platform with catheter-based ultrasound applicators is a useful tool that has potential to significantly improve the delivery of hyperthermia in conjunction with HDR brachytherapy. The planning platform has been extended

  12. Wireless 3D Chocolate Printer

    FROILAN G. DESTREZA

    2014-02-01

    Full Text Available This study is for the BSHRM Students of Batangas State University (BatStateU ARASOF for the researchers believe that the Wireless 3D Chocolate Printer would be helpful in their degree program especially on making creative, artistic, personalized and decorative chocolate designs. The researchers used the Prototyping model as procedural method for the successful development and implementation of the hardware and software. This method has five phases which are the following: quick plan, quick design, prototype construction, delivery and feedback and communication. This study was evaluated by the BSHRM Students and the assessment of the respondents regarding the software and hardware application are all excellent in terms of Accuracy, Effecitveness, Efficiency, Maintainability, Reliability and User-friendliness. Also, the overall level of acceptability of the design project as evaluated by the respondents is excellent. With regard to the observation about the best raw material to use in 3D printing, the chocolate is good to use as the printed material is slightly distorted,durable and very easy to prepare; the icing is also good to use as the printed material is not distorted and is very durable but consumes time to prepare; the flour is not good as the printed material is distorted, not durable but it is easy to prepare. The computation of the economic viability level of 3d printer with reference to ROI is 37.14%. The recommendation of the researchers in the design project are as follows: adding a cooling system so that the raw material will be more durable, development of a more simplified version and improving the extrusion process wherein the user do not need to stop the printing process just to replace the empty syringe with a new one.

  13. Multiple two-dimensional versus three-dimensional PTV definition in treatment planning for conformal radiotherapy

    Purpose: To demonstrate the need for a fully three-dimensional (3D) computerized expansion of the gross tumour volume (GTV) or clinical target volume (CTV), as delineated by the radiation oncologist on CT slices, to obtain the proper planning target volume (PTV) for treatment planning according to the ICRU-50 recommendations. Materials and methods: For 10 prostate cancer patients two PTVs have been determined by expansion of the GTV with a 1.5 cm margin, i.e. a 3D PTV and a multiple 2D PTV. The former was obtained by automatically adding the margin while accounting in 3D for GTV contour differences in neighbouring slices. The latter was generated by automatically adding the 1.5 cm margin to the GTV in each CT slice separately; the resulting PTV is a computer simulation of the PTV that a radiation oncologist would obtain with (the still common) manual contouring in CT slices. For each patient the two PTVs were compared to assess the deviations of the multiple 2D PTV from the 3D PTV. For both PTVs conformal plans were designed using a three-field technique with fixed block margins. For each patient dose-volume histograms and tumour control probabilities (TCPs) of the (correct) 3D PTV were calculated, both for the plan designed for this PTV and for the treatment plan based on the (deviating) 2D PTV.Results: Depending on the shape of the GTV, multiple 2D PTV generation could locally result in a 1 cm underestimation of the GTV-to-PTV margin. The deviations occurred predominantly in the cranio-caudal direction at locations where the GTV contour shape varies significantly from slice to slice. This could lead to serious underdosage and to a TCP decrease of up to 15%. Conclusions: A full 3D GTV-to-PTV expansion should be applied in conformal radiotherapy to avoid underdosage. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. Dentofacial Asymmetries: Challenging Diagnosis and Treatment Planning.

    Agrawal, Manish; Agrawal, Jiwan Asha; Nanjannawar, Lalita; Fulari, Sangamesh; Kagi, Vishwal

    2015-07-01

    Dentofacial asymmetry is quite common and when sufficiently severe can require surgical orthodontic intervention. Asymmetries can be classified according to the structures involved into skeletal, dental and functional. In diagnosing asymmetries, a thorough clinical examination and radiographic survey are essential to determine the extent of soft tissue, skeletal, dental and functional involvement. Dental asymmetries, as well as a variety of functional deviations, can be managed orthodontically, whereas significant structural facial asymmetries require a comprehensive orthodontic and orthognathic management. With less severe dental, skeletal and soft tissue deviations the advisability of treatment should be carefully considered. The following article also contains a case report highlighting the importance of proper diagnosis in treatment plan for management of dentofacial asymmetry. PMID:26229387

  15. Verification of ophthalmic brachytherapy treatment planning

    Ophthalmic brachytherapy dose calculations were performed as an independent verification of commercial dosimetry software (BEBIG Plaque Simulator). Excel spreadsheets were constructed to follow the formalism of the AAPM Task Group No. 43. As a software commissioning tool, TG43 seed-based coordinates were reformatted to be compatible with plaque-based BEBIG dose tables for centrally positioned seeds. Plaque central axis doses were also calculated for rings of seeds. Close agreement with BEBIG doses was obtained in both cases. Tailored spreadsheet versions were subsequently created to verify patient treatment plans. Treatment time and dose to a specified central-axis point are calculated for ROPES plaques fully loaded with I-125 model 6702 seeds. Copyright (2001) Australasian College of Physical Scientists and Engineers in Medicine

  16. Prostate seed implantation using 3D-computer assisted intraoperative planning vs. a standard look-up nomogram: Improved target conformality with reduction in urethral and rectal wall dose

    Purpose: To compare dosimetric outcomes between two real-time prostate seed implantation (PSI) techniques to evaluate the impact of three-dimensional (3D) intraoperative computer planning on target coverage, conformality, and preset urethral and rectal dose constraints. Methods and materials: One hundred and fourteen patients with clinically localized prostate cancer underwent ultrasound-guided transperineal PSI of the prostate with 125I sources as monotherapy. From 1999 to 2001, 69 patients were implanted in real-time using a standard look-up nomogram (Group 1: NG-PSI). All patients were implanted with a modified peripheral loading technique in which 75-80% of the calculated total activity was delivered to the gland periphery, with the remaining 20-25% activity placed in the gland interior, to achieve a prescribed dose (PD) of 144 Gy to cover the gland with acceptable homogeneity. No preoperative or intraoperative planning was performed to set dose constraints to the urethra or anterior rectal wall. Dosimetric outcome from this group was compared with 45 patients subsequently implanted after 2001 using an intraoperative 3D computer planning system (Group 2: 3D-PSI). A similar modified peripheral loading technique was used as an option in the planning system. Preoperative dose constraints were placed on the urethra (V150 95% of PD; D90: 140-180 Gy), and rectal wall (V110 125I sources to adhere to urethral and rectal constraints and target coverage goals. Both groups underwent postimplant CT analysis to determine dosimetric outcome with regard toV100prostate, D90prostate, V150urethra, and V110rectum. Univariate and multivariate analysis was performed to determine variables impacting on dosimetric outcome. Results: Analysis of preimplant and postimplant variables demonstrated no difference in the median preimplant gland volume (33 cc vs. 35 cc; p = 0.31), median mCi/seed strengths (0.4 vs. 0.45 mCi; p = 0.23), median V100 (94% vs. 94%), or median D90 at postimplant

  17. Semi-automatic registration of 3D orthodontics models from photographs

    Destrez, Raphaël; Treuillet, Sylvie; Lucas, Yves; Albouy-Kissi, Benjamin

    2013-01-01

    In orthodontics, a common practice used to diagnose and plan the treatment is the dental cast. After digitization by a CT-scan or a laser scanner, the obtained 3D surface models can feed orthodontics numerical tools for computer-aided diagnosis and treatment planning. One of the pre-processing critical steps is the 3D registration of dental arches to obtain the occlusion of these numerical models. For this task, we propose a vision based method to automatically compute the registration based ...

  18. Recovery post treatment: plans, barriers and motivators

    Duffy Paul

    2013-01-01

    Full Text Available Abstract Background The increasing focus on achieving a sustained recovery from substance use brings with it a need to better understand the factors (recovery capital that contribute to recovery following treatment. This work examined the factors those in recovery perceive to be barriers to (lack of capital or facilitators of (presence of capital sustained recovery post treatment. Methods A purposive sample of 45 participants was recruited from 11 drug treatment services in northern England. Semi-structured qualitative interviews lasting between 30 and 90 minutes were conducted one to three months after participants completed treatment. Interviews examined key themes identified through previous literature but focused on allowing participants to explore their unique recovery journey. Interviews were transcribed and analysed thematically using a combination of deductive and inductive approaches. Results Participants generally reported high levels of confidence in maintaining their recovery with most planning to remain abstinent. There were indications of high levels of recovery capital. Aftercare engagement was high, often through self referral, with non substance use related activity felt to be particularly positive. Supported housing was critical and concerns were raised about the ability to afford to live independently with financial stability and welfare availability a key concern in general. Employment, often in the substance use treatment field, was a desire. However, it was a long term goal, with substantial risks associated with pursuing this too early. Positive social support was almost exclusively from within the recovery community although the re-building of relationships with family (children in particular was a key motivator post treatment. Conclusions Addressing internal factors and underlying issues i.e. ‘human capital’, provided confidence for continued recovery whilst motivators focused on external factors such as family and

  19. Intensity-modulated radiotherapy of nasopharyngeal carcinoma: a comparative treatment planning study of photons and protons

    Taheri-Kadkhoda Zahra

    2008-01-01

    Full Text Available Abstract Background The aim of this treatment planning study was to investigate the potential advantages of intensity-modulated (IM proton therapy (IMPT compared with IM photon therapy (IMRT in nasopharyngeal carcinoma (NPC. Methods Eight NPC patients were chosen. The dose prescriptions in cobalt Gray equivalent (GyE for gross tumor volumes of the primary tumor (GTV-T, planning target volumes of GTV-T and metastatic (PTV-TN and elective (PTV-N lymph node stations were 72.6 GyE, 66 GyE, and 52.8 GyE, respectively. For each patient, nine coplanar fields IMRT with step-and-shoot technique and 3D spot-scanned three coplanar fields IMPT plans were prepared. Both modalities were planned in 33 fractions to be delivered with a simultaneous integrated boost technique. All plans were prepared and optimized by using the research version of the inverse treatment planning system KonRad (DKFZ, Heidelberg. Results Both treatment techniques were equal in terms of averaged mean dose to target volumes. IMPT plans significantly improved the tumor coverage and conformation (P E were more than doubled by IMRT plans. Conclusion In radiotherapy of NPC patients, three-field IMPT has greater potential than nine-field IMRT with respect to tumor coverage and reduction of the integral dose to OARs and non-specific normal tissues. The practicality of IMPT in NPC deserves further exploration when this technique becomes available on wider clinical scale.

  20. Bologna 3D: la pianificazione partecipata del Piano Strutturale Comunale

    Andrea Deiana; Andrea Minghetti; Luca Lorenzini; Paola Africani

    2008-01-01

    Bologna 3D: the Municipal Structural Plan partecipated planningThe Bologna Municipality used 3D GIS solutions by Skyline for opening to citizens the decision process which leaded to its new urban plan (PSC): 3D prospective is enhancing understanding of territory strategical planning, even to nontechnical and common people. A Skyline 3D terrain, produced in TerraBuilder environment from 10 meters DTM and from 50 centimeters per pixel colour imagery, is served online by TerraGate streaming serv...

  1. Visualization of liver in 3-D

    Chen, Chin-Tu; Chou, Jin-Shin; Giger, Maryellen L.; Kahn, Charles E., Jr.; Bae, Kyongtae T.; Lin, Wei-Chung

    1991-05-01

    Visualization of the liver in three dimensions (3-D) can improve the accuracy of volumetric estimation and also aid in surgical planning. We have developed a method for 3-D visualization of the liver using x-ray computed tomography (CT) or magnetic resonance (MR) images. This method includes four major components: (1) segmentation algorithms for extracting liver data from tomographic images; (2) interpolation techniques for both shape and intensity; (3) schemes for volume rendering and display, and (4) routines for electronic surgery and image analysis. This method has been applied to cases from a living-donor liver transplant project and appears to be useful for surgical planning.

  2. Initial evaluation of automated treatment planning software.

    Gintz, Dawn; Latifi, Kujtim; Caudell, Jimmy; Nelms, Benjamin; Zhang, Geoffrey; Moros, Eduardo; Feygelman, Vladimir

    2016-01-01

    Even with advanced inverse-planning techniques, radiation treatment plan opti-mization remains a very time-consuming task with great output variability, which prompted the development of more automated approaches. One commercially available technique mimics the actions of experienced human operators to pro-gressively guide the traditional optimization process with automatically created regions of interest and associated dose-volume objectives. We report on the initial evaluation of this algorithm on 10 challenging cases of locoreginally advanced head and neck cancer. All patients were treated with VMAT to 70 Gy to the gross disease and 56 Gy to the elective bilateral nodes. The results of post-treatment autoplanning (AP) were compared to the original human-driven plans (HDP). We used an objective scoring system based on defining a collection of specific dosimetric metrics and corresponding numeric score functions for each. Five AP techniques with different input dose goals were applied to all patients. The best of them averaged the composite score 8% lower than the HDP, across the patient population. The difference in median values was statistically significant at the 95% confidence level (Wilcoxon paired signed-rank test p = 0.027). This result reflects the premium the institution places on dose homogeneity, which was consistently higher with the HDPs. The OAR sparing was consistently better with the APs, the differences reaching statistical significance for the mean doses to the parotid glands (p < 0.001) and the inferior pharyngeal constrictor (p = 0.016), as well as for the maximum doses to the spinal cord (p = 0.018) and brainstem (p = 0.040). If one is prepared to accept less stringent dose homogeneity criteria from the RTOG 1016 protocol, nine APs would comply with the protocol, while providing lower OAR doses than the HDPs. Overall, AP is a promising clinical tool, but it could benefit from a better process for shifting the balance between the target dose

  3. Assessment of dose-volume histograms in brachytherapy 3D high-rate; Evaluacion de los histogramas dosis volumen en braquiterapia de alta tasa 3D

    Gomez Barrado, A.; Tripero Oter, J.; Sanchez Jimenez, E.; Sanchez-Reyes, A.

    2013-07-01

    The use of systems of treatment planning using 3D reconstruction algorithms are becoming more frequent in brachytherapy treatments. The implementation of these systems entails great qualitative and quantitative procedural changes in the way to evaluate the clinical dosimetry about the 2D classical systems. This paper describes the experience of our Centre in employment and prescription dose using histograms dose-volume in the treatment of brachytherapy of high rate. (Author)

  4. 3D interfractional patient position verification using 2D-3D registration of orthogonal images

    Reproducible positioning of the patient during fractionated external beam radiation therapy is imperative to ensure that the delivered dose distribution matches the planned one. In this paper, we expand on a 2D-3D image registration method to verify a patient's setup in three dimensions (rotations and translations) using orthogonal portal images and megavoltage digitally reconstructed radiographs (MDRRs) derived from CT data. The accuracy of 2D-3D registration was improved by employing additional image preprocessing steps and a parabolic fit to interpolate the parameter space of the cost function utilized for registration. Using a humanoid phantom, precision for registration of three-dimensional translations was found to be better than 0.5 mm (1 s.d.) for any axis when no rotations were present. Three-dimensional rotations about any axis were registered with a precision of better than 0.2 deg. (1 s.d.) when no translations were present. Combined rotations and translations of up to 4 deg. and 15 mm were registered with 0.4 deg. and 0.7 mm accuracy for each axis. The influence of setup translations on registration of rotations and vice versa was also investigated and mostly agrees with a simple geometric model. Additionally, the dependence of registration accuracy on three cost functions, angular spacing between MDRRs, pixel size, and field-of-view, was examined. Best results were achieved by mutual information using 0.5 deg. angular spacing and a 10x10 cm2 field-of-view with 140x140 pixels. Approximating patient motion as rigid transformation, the registration method is applied to two treatment plans and the patients' setup errors are determined. Their magnitude was found to be ≤6.1 mm and ≤2.7 deg. for any axis in all of the six fractions measured for each treatment plan

  5. 3D printing for dummies

    Hausman, Kalani Kirk

    2014-01-01

    Get started printing out 3D objects quickly and inexpensively! 3D printing is no longer just a figment of your imagination. This remarkable technology is coming to the masses with the growing availability of 3D printers. 3D printers create 3-dimensional layered models and they allow users to create prototypes that use multiple materials and colors.  This friendly-but-straightforward guide examines each type of 3D printing technology available today and gives artists, entrepreneurs, engineers, and hobbyists insight into the amazing things 3D printing has to offer. You'll discover methods for

  6. Specific CT 3D rendering of the treatment zone after Irreversible Electroporation (IRE) in a pig liver model: the “Chebyshev Center Concept” to define the maximum treatable tumor size

    Size and shape of the treatment zone after Irreversible electroporation (IRE) can be difficult to depict due to the use of multiple applicators with complex spatial configuration. Exact geometrical definition of the treatment zone, however, is mandatory for acute treatment control since incomplete tumor coverage results in limited oncological outcome. In this study, the “Chebyshev Center Concept” was introduced for CT 3d rendering to assess size and position of the maximum treatable tumor at a specific safety margin. In seven pig livers, three different IRE protocols were applied to create treatment zones of different size and shape: Protocol 1 (n = 5 IREs), Protocol 2 (n = 5 IREs), and Protocol 3 (n = 5 IREs). Contrast-enhanced CT was used to assess the treatment zones. Technique A consisted of a semi-automated software prototype for CT 3d rendering with the “Chebyshev Center Concept” implemented (the “Chebyshev Center” is the center of the largest inscribed sphere within the treatment zone) with automated definition of parameters for size, shape and position. Technique B consisted of standard CT 3d analysis with manual definition of the same parameters but position. For Protocol 1 and 2, short diameter of the treatment zone and diameter of the largest inscribed sphere within the treatment zone were not significantly different between Technique A and B. For Protocol 3, short diameter of the treatment zone and diameter of the largest inscribed sphere within the treatment zone were significantly smaller for Technique A compared with Technique B (41.1 ± 13.1 mm versus 53.8 ± 1.1 mm and 39.0 ± 8.4 mm versus 53.8 ± 1.1 mm; p < 0.05 and p < 0.01). For Protocol 1, 2 and 3, sphericity of the treatment zone was significantly larger for Technique A compared with B. Regarding size and shape of the treatment zone after IRE, CT 3d rendering with the “Chebyshev Center Concept” implemented provides significantly different results compared with standard CT 3d

  7. 3D monitor

    Szkandera, Jan

    2009-01-01

    Tato bakalářská práce se zabývá návrhem a realizací systému, který umožní obraz scény zobrazovaný na ploše vnímat prostorově. Prostorové vnímání 2D obrazové informace je umožněno jednak stereopromítáním a jednak tím, že se obraz mění v závislosti na poloze pozorovatele. Tato práce se zabývá hlavně druhým z těchto problémů. This Bachelor's thesis goal is to design and realize system, which allows user to perceive 2D visual information as three-dimensional. 3D visual preception of 2D image i...

  8. Mobile 3D tomograph

    Mobile tomographs often have the problem that high spatial resolution is impossible owing to the position or setup of the tomograph. While the tree tomograph developed by Messrs. Isotopenforschung Dr. Sauerwein GmbH worked well in practice, it is no longer used as the spatial resolution and measuring time are insufficient for many modern applications. The paper shows that the mechanical base of the method is sufficient for 3D CT measurements with modern detectors and X-ray tubes. CT measurements with very good statistics take less than 10 min. This means that mobile systems can be used, e.g. in examinations of non-transportable cultural objects or monuments. Enhancement of the spatial resolution of mobile tomographs capable of measuring in any position is made difficult by the fact that the tomograph has moving parts and will therefore have weight shifts. With the aid of tomographies whose spatial resolution is far higher than the mechanical accuracy, a correction method is presented for direct integration of the Feldkamp algorithm

  9. X3D: Extensible 3D Graphics Standard

    Daly, Leonard; Brutzman, Don

    2007-01-01

    The article of record as published may be located at http://dx.doi.org/10.1109/MSP.2007.905889 Extensible 3D (X3D) is the open standard for Web-delivered three-dimensional (3D) graphics. It specifies a declarative geometry definition language, a run-time engine, and an application program interface (API) that provide an interactive, animated, real-time environment for 3D graphics. The X3D specification documents are freely available, the standard can be used without paying any royalties,...

  10. Noncoplanar VMAT for nasopharyngeal tumors: Plan quality versus treatment time

    Purpose: The authors investigated the potential of optimized noncoplanar irradiation trajectories for volumetric modulated arc therapy (VMAT) treatments of nasopharyngeal patients and studied the trade-off between treatment plan quality and delivery time in radiation therapy. Methods: For three nasopharyngeal patients, the authors generated treatment plans for nine different delivery scenarios using dedicated optimization methods. They compared these scenarios according to dose characteristics, number of beam directions, and estimated delivery times. In particular, the authors generated the following treatment plans: (1) a 4π plan, which is a not sequenced, fluence optimized plan that uses beam directions from approximately 1400 noncoplanar directions and marks a theoretical upper limit of the treatment plan quality, (2) a coplanar 2π plan with 72 coplanar beam directions as pendant to the noncoplanar 4π plan, (3) a coplanar VMAT plan, (4) a coplanar step and shoot (SnS) plan, (5) a beam angle optimized (BAO) coplanar SnS IMRT plan, (6) a noncoplanar BAO SnS plan, (7) a VMAT plan with rotated treatment couch, (8) a noncoplanar VMAT plan with an optimized great circle around the patient, and (9) a noncoplanar BAO VMAT plan with an arbitrary trajectory around the patient. Results: VMAT using optimized noncoplanar irradiation trajectories reduced the mean and maximum doses in organs at risk compared to coplanar VMAT plans by 19% on average while the target coverage remains constant. A coplanar BAO SnS plan was superior to coplanar SnS or VMAT; however, noncoplanar plans like a noncoplanar BAO SnS plan or noncoplanar VMAT yielded a better plan quality than the best coplanar 2π plan. The treatment plan quality of VMAT plans depended on the length of the trajectory. The delivery times of noncoplanar VMAT plans were estimated to be 6.5 min in average; 1.6 min longer than a coplanar plan but on average 2.8 min faster than a noncoplanar SnS plan with comparable

  11. Noncoplanar VMAT for nasopharyngeal tumors: Plan quality versus treatment time

    Wild, Esther, E-mail: e.wild@dkfz.de; Bangert, Mark [Department of Medical Physics in Radiation Oncology, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg (Germany); Nill, Simeon [Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London SM2 5NG (United Kingdom); Oelfke, Uwe [Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London SM2 5NG, United Kingdom and Department of Medical Physics in Radiation Oncology, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg (Germany)

    2015-05-15

    Purpose: The authors investigated the potential of optimized noncoplanar irradiation trajectories for volumetric modulated arc therapy (VMAT) treatments of nasopharyngeal patients and studied the trade-off between treatment plan quality and delivery time in radiation therapy. Methods: For three nasopharyngeal patients, the authors generated treatment plans for nine different delivery scenarios using dedicated optimization methods. They compared these scenarios according to dose characteristics, number of beam directions, and estimated delivery times. In particular, the authors generated the following treatment plans: (1) a 4π plan, which is a not sequenced, fluence optimized plan that uses beam directions from approximately 1400 noncoplanar directions and marks a theoretical upper limit of the treatment plan quality, (2) a coplanar 2π plan with 72 coplanar beam directions as pendant to the noncoplanar 4π plan, (3) a coplanar VMAT plan, (4) a coplanar step and shoot (SnS) plan, (5) a beam angle optimized (BAO) coplanar SnS IMRT plan, (6) a noncoplanar BAO SnS plan, (7) a VMAT plan with rotated treatment couch, (8) a noncoplanar VMAT plan with an optimized great circle around the patient, and (9) a noncoplanar BAO VMAT plan with an arbitrary trajectory around the patient. Results: VMAT using optimized noncoplanar irradiation trajectories reduced the mean and maximum doses in organs at risk compared to coplanar VMAT plans by 19% on average while the target coverage remains constant. A coplanar BAO SnS plan was superior to coplanar SnS or VMAT; however, noncoplanar plans like a noncoplanar BAO SnS plan or noncoplanar VMAT yielded a better plan quality than the best coplanar 2π plan. The treatment plan quality of VMAT plans depended on the length of the trajectory. The delivery times of noncoplanar VMAT plans were estimated to be 6.5 min in average; 1.6 min longer than a coplanar plan but on average 2.8 min faster than a noncoplanar SnS plan with comparable

  12. 3D Printing an Octohedron

    Aboufadel, Edward F.

    2014-01-01

    The purpose of this short paper is to describe a project to manufacture a regular octohedron on a 3D printer. We assume that the reader is familiar with the basics of 3D printing. In the project, we use fundamental ideas to calculate the vertices and faces of an octohedron. Then, we utilize the OPENSCAD program to create a virtual 3D model and an STereoLithography (.stl) file that can be used by a 3D printer.

  13. Interactive dose shaping part 1: a new paradigm for IMRT treatment planning

    Ziegenhein, Peter; Kamerling, Cornelis Ph; Oelfke, Uwe

    2016-03-01

    In this work we present a novel treatment planning technique called interactive dose shaping (IDS) to be employed for the optimization of intensity modulated radiation therapy (IMRT). IDS does not rely on a Newton-based optimization algorithm which is driven by an objective function formed of dose volume constraints on pre-segmented volumes of interest (VOIs). Our new planning technique allows for direct, interactive adaptation of localized planning features. This is realized by a dose modification and recovery (DMR) planning engine which implements a two-step approach: firstly, the desired localized plan adaptation is imposed on the current plan (modification) while secondly inevitable, undesired disturbances of the dose pattern elsewhere are compensated for automatically by the recovery module. Together with an ultra-fast dose update calculation method the DMR engine has been implemented in a newly designed 3D therapy planning system Dynaplan enabling true real-time interactive therapy planning. Here we present the underlying strategy and algorithms of the DMR based planning concept. The functionality of the IDS planning approach is demonstrated for a phantom geometry of clinical resolution and size.

  14. 3D modelling and recognition

    Rodrigues, Marcos; Robinson, Alan; Alboul, Lyuba; Brink, Willie

    2006-01-01

    3D face recognition is an open field. In this paper we present a method for 3D facial recognition based on Principal Components Analysis. The method uses a relatively large number of facial measurements and ratios and yields reliable recognition. We also highlight our approach to sensor development for fast 3D model acquisition and automatic facial feature extraction.

  15. Alopecia areata: a new treatment plan

    Alsantali A

    2011-07-01

    Full Text Available Adel AlsantaliDepartment of Dermatology, King Fahd Armed Forces Hospital, Jeddah, Saudi ArabiaAbstract: Many therapeutic modalities have been used to treat alopecia areata, with variable efficacy and safety profiles. Unfortunately, none of these agents is curative or preventive. Also, many of these therapeutic agents have not been subjected to randomized, controlled trials, and, except for topical immunotherapy, there are few published studies on long-term outcomes. The treatment plan is designed according to the patient's age and extent of disease. In this paper, the therapeutic agents are organized according to their efficacy and safety profiles into first-line, second-line, and third-line options.Keywords: alopecia areata, corticosteroids, immunotherapy, intralesional, phototherapy, sulfasalazine

  16. Assessing the quality of conformal treatment planning: a new tool for quantitative comparison.

    Menhel, J; Levin, D; Alezra, D; Symon, Z; Pfeffer, R

    2006-10-21

    We develop a novel radiotherapy plan comparison index, critical organ scoring index (COSI), which is a measure of both target coverage and critical organ overdose. COSI is defined as COSI=1-(V(OAR)>tol/TC), where V(OAR)>tol is the fraction of volume of organ at risk receiving more than tolerance dose, and TC is the target coverage, VT,PI/VT, where VT,PI is the target volume receiving at a least prescription dose and VT is the total target volume. COSI approaches unity when the critical structure is completely spared and the target coverage is unity. We propose a two-dimensional, graphical representation of COSI versus conformity index (CI), where CI is a measure of a normal tissue overdose. We show that this 2D representation is a reliable, visual quantitative tool for evaluating competing plans. We generate COSI-CI plots for three sites: head and neck, cavernous sinus, and pancreas, and evaluate competing non-coplanar 3D and IMRT treatment plans. For all three sites this novel 2D representation assisted the physician in choosing the optimal plan, both in terms of target coverage and in terms of critical organ sparing. We verified each choice by analysing individual DVHs and isodose lines. Comparing our results to the widely used conformation number, we found that in all cases where there were discrepancies in the choice of the best treatment plan, the COSI-CI choice was considered the correct one, in several cases indicating that a non-coplanar 3D plan was superior to the IMRT plans. The choice of plan was quick, simple and accurate using the new graphical representation. PMID:17019044

  17. Assessing the quality of conformal treatment planning: a new tool for quantitative comparison

    We develop a novel radiotherapy plan comparison index, critical organ scoring index (COSI), which is a measure of both target coverage and critical organ overdose. COSI is defined as COSI = 1 - (V(OAR)>tol/TC), where V(OAR)>tol is the fraction of volume of organ at risk receiving more than tolerance dose, and TC is the target coverage, VT,PI/VT, where VT,PI is the target volume receiving at a least prescription dose and VT is the total target volume. COSI approaches unity when the critical structure is completely spared and the target coverage is unity. We propose a two-dimensional, graphical representation of COSI versus conformity index (CI), where CI is a measure of a normal tissue overdose. We show that this 2D representation is a reliable, visual quantitative tool for evaluating competing plans. We generate COSI-CI plots for three sites: head and neck, cavernous sinus, and pancreas, and evaluate competing non-coplanar 3D and IMRT treatment plans. For all three sites this novel 2D representation assisted the physician in choosing the optimal plan, both in terms of target coverage and in terms of critical organ sparing. We verified each choice by analysing individual DVHs and isodose lines. Comparing our results to the widely used conformation number, we found that in all cases where there were discrepancies in the choice of the best treatment plan, the COSI-CI choice was considered the correct one, in several cases indicating that a non-coplanar 3D plan was superior to the IMRT plans. The choice of plan was quick, simple and accurate using the new graphical representation

  18. Quantitative MR imaging in planning and assessing novel cancer treatments Radiotherapy

    Baustert, I C

    2001-01-01

    Novel treatments in cancer, like conformal radiotherapy and anticancer drugs, require new MRI techniques to assess their benefits and potential. In conformal radiotherapy, MRI can be used to measure the shape and dose of the conformed radiation field in dose sensitive gel test-objects thus validating the predicted dose computed by complex programs. In antiangiogenic drug treatment, the vascular dysfunction of the tumour can be assessed by MRI prior to treatment. Response to treatment may also be monitored by measuring the changes in vascular function. In this thesis, MRI of polyacrylamide gels is investigated as a 3D dosimeter for conformal radiotherapy treatment planning. Quantitative MRI sequences capable of measuring the wide range of T2 values typically expected in gel dosimetry, are identified. Different T2 measurement methods are compared in terms of accuracy, signal to noise ratio and acquisition time. Examples of a complex dose distribution in 2D and 3D are presented and compared to the planned dose p...

  19. Dosimetric verification of radiotherapy treatment planning systems in Serbia: national audit

    Independent external audits play an important role in quality assurance programme in radiation oncology. The audit supported by the IAEA in Serbia was designed to review the whole chain of activities in 3D conformal radiotherapy (3D-CRT) workflow, from patient data acquisition to treatment planning and dose delivery. The audit was based on the IAEA recommendations and focused on dosimetry part of the treatment planning and delivery processes. The audit was conducted in three radiotherapy departments of Serbia. An anthropomorphic phantom was scanned with a computed tomography unit (CT) and treatment plans for eight different test cases involving various beam configurations suggested by the IAEA were prepared on local treatment planning systems (TPSs). The phantom was irradiated following the treatment plans for these test cases and doses in specific points were measured with an ionization chamber. The differences between the measured and calculated doses were reported. The measurements were conducted for different photon beam energies and TPS calculation algorithms. The deviation between the measured and calculated values for all test cases made with advanced algorithms were within the agreement criteria, while the larger deviations were observed for simpler algorithms. The number of measurements with results outside the agreement criteria increased with the increase of the beam energy and decreased with TPS calculation algorithm sophistication. Also, a few errors in the basic dosimetry data in TPS were detected and corrected. The audit helped the users to better understand the operational features and limitations of their TPSs and resulted in increased confidence in dose calculation accuracy using TPSs. The audit results indicated the shortcomings of simpler algorithms for the test cases performed and, therefore the transition to more advanced algorithms is highly desirable

  20. Dosimetric verification of radiotherapy treatment planning systems in Serbia: national audit

    Rutonjski Laza

    2012-09-01

    Full Text Available Abstract Background Independent external audits play an important role in quality assurance programme in radiation oncology. The audit supported by the IAEA in Serbia was designed to review the whole chain of activities in 3D conformal radiotherapy (3D-CRT workflow, from patient data acquisition to treatment planning and dose delivery. The audit was based on the IAEA recommendations and focused on dosimetry part of the treatment planning and delivery processes. Methods The audit was conducted in three radiotherapy departments of Serbia. An anthropomorphic phantom was scanned with a computed tomography unit (CT and treatment plans for eight different test cases involving various beam configurations suggested by the IAEA were prepared on local treatment planning systems (TPSs. The phantom was irradiated following the treatment plans for these test cases and doses in specific points were measured with an ionization chamber. The differences between the measured and calculated doses were reported. Results The measurements were conducted for different photon beam energies and TPS calculation algorithms. The deviation between the measured and calculated values for all test cases made with advanced algorithms were within the agreement criteria, while the larger deviations were observed for simpler algorithms. The number of measurements with results outside the agreement criteria increased with the increase of the beam energy and decreased with TPS calculation algorithm sophistication. Also, a few errors in the basic dosimetry data in TPS were detected and corrected. Conclusions The audit helped the users to better understand the operational features and limitations of their TPSs and resulted in increased confidence in dose calculation accuracy using TPSs. The audit results indicated the shortcomings of simpler algorithms for the test cases performed and, therefore the transition to more advanced algorithms is highly desirable.

  1. Cornered Quadtrees/Octrees and Multiple Gateways Between Each Two Nodes; A Structure for Path Planning in 2D and 3D Environments

    Namdari, Mohammad Hasan; Hejazi, Seyed Reza; Palhang, Maziar

    2016-06-01

    In this paper, modified versions of quadtree/octree, as structures used in path planning, are proposed which we call them cornered quadtree/octree. Also a new method of creating paths in quadtrees/octrees, once quadrants/octants to be passed are determined, is proposed both to improve traveled distance and path smoothness. In proposed modified versions of quadtree/octree, four corner cells of quadrants and eight corner voxels of octants are also considered as nodes of the graph to be searched for finding the shortest path. This causes better quadrant/octant selection during graph search relative to simple quadtrees and octrees. On the other hand, after that all quadrants/octants are determined, multiple gateways are nominated between each two selected nodes and path is constructed by passing through the gateway which its selection leads in shorter and smoother path. Proposed structures in this paper alongside the utilized path construction approach, creates better paths in terms of path length than those created if simple trees are used, somehow equal to the quality of the achieved paths by framed trees, meanwhile interestingly, consumed time and memory in our proposed method are closer to the used time and memory if simple trees are used.

  2. Grounding-line migration in plan-view marine ice-sheet models: results of the ice2sea MISMIP3d intercomparison

    Pattyn, Frank; Perichon, Laura; Durand, Gaël; Gagliardini, Olivier; Favier, Lionel; Hindmarsh, Richard; Zwinger, Thomas; Participants, Mismip3d

    2013-04-01

    Predictions of marine ice-sheet behaviour require models able to simulate grounding line migration. We present results of an intercomparison experiment for plan-view marine ice-sheet models. Verification is effected by comparison with approximate analytical solutions for flux across the grounding line using simplified geometrical configurations (no lateral variations, no buttressing effects from lateral drag). A unique steady state grounding line position exists for ice sheets on a downward sloping bed under those simplified conditions. Perturbation experiments specifying spatial (lateral) variation in basal sliding parameters permitted the evolution of curved grounding lines, generating buttressing effects. The experiments showed regions of compression and extensional flow across the grounding line, thereby invalidating the boundary layer theory. Models based on the shallow ice approximation, which neither resolve membrane stresses, nor reproduce the approximate analytical results unless appropriate parameterizations for ice flux are imposed at the grounding line, are invalid. Steady-state grounding line positions were found to be dependent on the level of physical model approximation. Models that only include membrane stresses result in ice sheets with a larger span than those that also incorporate vertical shearing at the grounding line, such as higher-order and full-Stokes models. From a numerical perspective, resolving grounding lines requires a sufficiently small grid size (

  3. Federal Facilities Compliance Act, Draft Site Treatment Plan: Compliance Plan Volume. Part 2, Volume 2

    This document presents the details of the implementation of the Site Treatment Plan developed by Ames Laboratory in compliance with the Federal Facilities Compliance Act. Topics discussed in this document include: implementation of the plan; milestones; annual updates to the plan; inclusion of new waste streams; modifications of the plan; funding considerations; low-level mixed waste treatment plan and schedules; and TRU mixed waste streams

  4. Federal Facilities Compliance Act, Draft Site Treatment Plan: Compliance Plan Volume. Part 2, Volume 2

    NONE

    1994-08-31

    This document presents the details of the implementation of the Site Treatment Plan developed by Ames Laboratory in compliance with the Federal Facilities Compliance Act. Topics discussed in this document include: implementation of the plan; milestones; annual updates to the plan; inclusion of new waste streams; modifications of the plan; funding considerations; low-level mixed waste treatment plan and schedules; and TRU mixed waste streams.

  5. 3-D contextual Bayesian classifiers

    Larsen, Rasmus

    distribution for the pixel values as well as a prior distribution for the configuration of class variables within the cross that is made of a pixel and its four nearest neighbours. We will extend these algorithms to 3-D, i.e. we will specify a simultaneous Gaussian distribution for a pixel and its 6 nearest 3......-D neighbours, and generalise the class variable configuration distributions within the 3-D cross given in 2-D algorithms. The new 3-D algorithms are tested on a synthetic 3-D multivariate dataset....

  6. Taming Supersymmetric Defects in 3d-3d Correspondence

    Gang, Dongmin; Romo, Mauricio; Yamazaki, Masahito

    2015-01-01

    We study knots in 3d Chern-Simons theory with complex gauge group $SL(N,\\mathbb{C})$, in the context of its relation with 3d $\\mathcal{N}=2$ theory (the so-called 3d-3d correspondence). The defect has either co-dimension 2 or co-dimension 4 inside the 6d $(2,0)$ theory, which is compactified on a 3-manifold $\\hat{M}$. We identify such defects in various corners of the 3d-3d correspondence, namely in 3d $SL(N,\\mathbb{C})$ Chern-Simons theory, in 3d $\\mathcal{N}=2$ theory, in 5d $\\mathcal{N}=2$ super Yang-Mills theory, and in the M-theory holographic dual. We can make quantitative checks of the 3d-3d correspondence by computing partition functions at each of these theories. This Letter is a companion to a longer paper, which contains more details and more results.

  7. Bologna 3D: la pianificazione partecipata del Piano Strutturale Comunale

    Andrea Deiana

    2008-03-01

    Full Text Available Bologna 3D: the Municipal Structural Plan partecipated planningThe Bologna Municipality used 3D GIS solutions by Skyline for opening to citizens the decision process which leaded to its new urban plan (PSC: 3D prospective is enhancing understanding of territory strategical planning, even to nontechnical and common people. A Skyline 3D terrain, produced in TerraBuilder environment from 10 meters DTM and from 50 centimeters per pixel colour imagery, is served online by TerraGate streaming server as basis layer for the delivering of interactive 3D GIS applications made using TerraExplorer Pro’s authoring environment, integrating all the significant GIS layers and various informations into many 3D projects, now also available online by installing the free plugin TerraExplorer Viewer.

  8. Interpolation of 3D Magnetic Resonance Data

    Mikulka, J.; Gescheidtová, E.; Bartušek, Karel

    2011-01-01

    Roč. 7, č. 1 (2011), s. 31-34. ISSN 1931-7360 R&D Projects: GA ČR GAP102/11/0318 Institutional research plan: CEZ:AV0Z20650511 Keywords : NMR * 3D reconstruction Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  9. 3D Reconstruction in Magnetic Resonance Imaging

    Mikulka, J.; Bartušek, Karel

    Cambridge : The Electromagnetics Academy, 2010, s. 1043-1046. ISBN 978-1-934142-14-1. [PIERS 2010 Cambridge. Cambridge (US), 05.07.2010-08.07.2010] R&D Projects: GA ČR GA102/09/0314 Institutional research plan: CEZ:AV0Z20650511 Keywords : 3D reconstruction * magnetic resonance imaging Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  10. ALARA calculations for removal PESL liner from inner concrete wall of the underground storage reservoirs in the NPP Al by VISIPLAN 3D planning tool

    On the basis of working plan 16/82022/2004 'Removal of PESL from the storage tanks 1, 2, 3/1, 3/2, 4/1, 4/2, 6/1 and 6/2 at the obj. 41' and requirements of UVZ SR it was necessary to establish an optimal sequence of removal of the PESL plastic liner from inner concrete surfaces of the walls of the tanks 6/1 and 6/2. The optimisation concerned the underground tanks 6/1 a 6/2, which have been used for storage and handling the waste water at NPP A-l where the contamination after wet cleaning is still elevated. After the accident at NPP A-l the waters with high activity were also stored in the tanks, leading to significant contamination of their inner walls. The main aim of removal the PESL from the tanks was to examine the state of the tanks construction to determine the potential ways of leakage of liquid waste from the tanks. To make a decision on the tanks future handling it was also necessary to know the level of contamination of the construction and the vicinity of the tanks as well as to collect qualified basic data to perform a boring exploration. The tanks contamination after a draining and surface cleaning were confirmed by dose rate mapping measurements close to the surfaces of the tanks. The evaluation of work program done after finalising the PESL removal from underground reservoirs showed an overestimation of the calculated collective as well as individual doses. The main source of this was fold, however, not in dose rate calculations but in large (≅2-fold) overestimation of the working time duration (it concern to removal (4 h) a swell as to fragmentation duration applied and approved in the work program. (authors)

  11. Radiotherapy Treatment Planning for Testicular Seminoma

    Wilder, Richard B., E-mail: richardbwilder@yahoo.com [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL (United States); Buyyounouski, Mark K. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Efstathiou, Jason A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Beard, Clair J. [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center, Boston, MA (United States)

    2012-07-15

    Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 Multiplication-Sign 1-2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior-posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior-posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

  12. Radiation therapy oncology group: 3-D CRT quality assurance guidelines

    Purpose: Guidelines to conduct multi-institutional three-dimensional conformal radiation therapy (3-D CRT) clinical trials are needed as the modality emerges from a single institution procedure to a research tool in multi-institution clinical group trials. The guidelines are used (1) to ensure that participating institutions have the proper equipment and appropriate techniques to administer 3D CRT; (2) to define a standard data set to be submitted to a review center for each treated patient to assess protocol compliance; and (3) to establish a quality assurance (QA) review process of the submitted data. Materials and Methods: Computer hardware and software components have been implemented which allow the digital data transfer (via either the Internet or magnetic tape), display, manipulation, and storage of a 3D CRT protocol patient treatment planning and image data set for QA review. Each participating institution is required to complete a 3D CRT Facility Questionnaire and submit it to the RTOG 3-D QA Center prior to enrolling patients on a 3-D CRT protocol. In addition, a protocol 'dry run' test has been designed to demonstrate each participating institutions' ability to submit a protocol compliant data set prior to placing patients on a 3D CRT study. This dry run test involves the digital transfer of all protocol required data and the supporting hard copy documentation excepting simulation or portal films/images. Results: The 3D CRT Facility Questionnaire includes descriptions of: (1) linac model, collimation system and energies to be used; (2) isocenter accuracy for gantry, collimator, and couch rotations; (3) type of immobilization repositioning system and patient motion studies if required by protocol (set-up uncertainty, organ movement); and (4) treatment verification system(s). The 3-D RTP system must have the following capabilities: (1) ability to handle at least 40 axial CT slices; (2) beam's-eye-view (BEV) display; (3) calculate 3-D dose matrices; (4

  13. Dosimetric verification of radiotherapy treatment planning systems: Results of IAEA pilot study

    Background and purpose: The methodology developed by IAEA for dosimetric quality control of treatment planning systems has been tested in different hospitals through a pilot study. The aim was to verify the methodology and observe the range of deviations between planned and delivered doses in 3D conformal radiotherapy in situations close to a clinical setting. Material and methods: The methodology was based on an anthropomorphic phantom representing the human thorax, and simulates the whole chain of external beam radiotherapy treatment planning activities. The phantom was scanned using computed tomography and eight test cases were planned on treatment planning systems which imitate different irradiation geometries found in conformal radiotherapy. The doses were measured with ion chambers, and the deviation between measured and treatment planning system calculated doses was reported. This methodology, which employs the same phantom and the same set of test cases, was tested in 17 different hospitals which were using 14 different algorithms/inhomogeneity correction methods implemented in different treatment planning systems. Results: A total of 53 clinical test case datasets for different energies and calculation algorithms were produced. Most of the systems with advanced algorithms complied with predefined agreement criteria. Dose differences more than 20% were discovered for some of the simple algorithms and high energy X-ray beams. The number of deviations outside agreement criteria increases with the beam energy and decreases with advancement of the treatment planning system calculation algorithm. Conclusions: Large deviations exist in some simple dose calculation algorithms, therefore more advanced algorithms would be preferable and therefore should be implemented in clinical practice. The test cases that could be performed in reasonable time would help the users to appreciate the possibilities of their system and understand its limitations

  14. Reducing the sensitivity of IMPT treatment plans to setup errors and range uncertainties via probabilistic treatment planning

    Treatment plans optimized for intensity modulated proton therapy (IMPT) may be very sensitive to setup errors and range uncertainties. If these errors are not accounted for during treatment planning, the dose distribution realized in the patient may by strongly degraded compared to the planned dose distribution. The authors implemented the probabilistic approach to incorporate uncertainties directly into the optimization of an intensity modulated treatment plan. Following this approach, the dose distribution depends on a set of random variables which parameterize the uncertainty, as does the objective function used to optimize the treatment plan. The authors optimize the expected value of the objective function. They investigate IMPT treatment planning regarding range uncertainties and setup errors. They demonstrate that incorporating these uncertainties into the optimization yields qualitatively different treatment plans compared to conventional plans which do not account for uncertainty. The sensitivity of an IMPT plan depends on the dose contributions of individual beam directions. Roughly speaking, steep dose gradients in beam direction make treatment plans sensitive to range errors. Steep lateral dose gradients make plans sensitive to setup errors. More robust treatment plans are obtained by redistributing dose among different beam directions. This can be achieved by the probabilistic approach. In contrast, the safety margin approach as widely applied in photon therapy fails in IMPT and is neither suitable for handling range variations nor setup errors.

  15. Advantage of three-dimensional treatment planning for localized radiotherapy of early stage prostatic cancer

    Conventional two-dimensional (2-d) treatment planning was compared to three-dimensional (3-d) treatment planning for patients with prostatic carcinoma. Both types of treatment planning were performed for all ten patients with five fixed fields. In 3-d planning we used irregular shaped fields. For further evaluation we performed conventional planning in rotation technique in two patients. The target volume included prostate prostate, seminal vesicles and a surrounding security margin of 2 cm. Using the MPR-version of the MEVAPLAN planning system, the three-dimensional dose calculations were performed. For the volumes of interest (VOI's) we discussed quality of the dose distribution concerning homogeneity in the target volume and isodose distribution in the organs at risk, which are the rectum and the urinary bladder. We defined the tumor encompassing reference isodose (ca. 95%) for the calculation of the involved rectum- and bladder volume. Using the five-field technique our results show a reduction of the radiation related rectum- and bladder volume concerning the tumor encompassing reference isodose (ca. 95%) for the rectum inbetween 9.5 and 36.6% (median: 19%, n=10) and for the urinary bladder inbetween 15.7 and 47.8% (median 28%, n=10). Calculated for 80% of the reference isodose the difference for the rectum was 15.7 to 31.3% (median: 23%) and for the urinary bladder 24.5% to 56.7% (median: 42%). A significant reduction of radiation related side-effects concerning rectum and urinary bladder can be expected by a reduction of volume involvement and a consecutive dosage limitation. (orig.)

  16. FoCa: a modular treatment planning system for proton radiotherapy with research and educational purposes

    Sánchez-Parcerisa, D.; Kondrla, M.; Shaindlin, A.; Carabe, A.

    2014-12-01

    FoCa is an in-house modular treatment planning system, developed entirely in MATLAB, which includes forward dose calculation of proton radiotherapy plans in both active and passive modalities as well as a generic optimization suite for inverse treatment planning. The software has a dual education and research purpose. From the educational point of view, it can be an invaluable teaching tool for educating medical physicists, showing the insights of a treatment planning system from a well-known and widely accessible software platform. From the research point of view, its current and potential uses range from the fast calculation of any physical, radiobiological or clinical quantity in a patient CT geometry, to the development of new treatment modalities not yet available in commercial treatment planning systems. The physical models in FoCa were compared with the commissioning data from our institution and show an excellent agreement in depth dose distributions and longitudinal and transversal fluence profiles for both passive scattering and active scanning modalities. 3D dose distributions in phantom and patient geometries were compared with a commercial treatment planning system, yielding a gamma-index pass rate of above 94% (using FoCa’s most accurate algorithm) for all cases considered. Finally, the inverse treatment planning suite was used to produce the first prototype of intensity-modulated, passive-scattered proton therapy, using 13 passive scattering proton fields and multi-leaf modulation to produce a concave dose distribution on a cylindrical solid water phantom without any field-specific compensator.

  17. FoCa: a modular treatment planning system for proton radiotherapy with research and educational purposes

    FoCa is an in-house modular treatment planning system, developed entirely in MATLAB, which includes forward dose calculation of proton radiotherapy plans in both active and passive modalities as well as a generic optimization suite for inverse treatment planning. The software has a dual education and research purpose. From the educational point of view, it can be an invaluable teaching tool for educating medical physicists, showing the insights of a treatment planning system from a well-known and widely accessible software platform. From the research point of view, its current and potential uses range from the fast calculation of any physical, radiobiological or clinical quantity in a patient CT geometry, to the development of new treatment modalities not yet available in commercial treatment planning systems. The physical models in FoCa were compared with the commissioning data from our institution and show an excellent agreement in depth dose distributions and longitudinal and transversal fluence profiles for both passive scattering and active scanning modalities. 3D dose distributions in phantom and patient geometries were compared with a commercial treatment planning system, yielding a gamma-index pass rate of above 94% (using FoCa’s most accurate algorithm) for all cases considered. Finally, the inverse treatment planning suite was used to produce the first prototype of intensity-modulated, passive-scattered proton therapy, using 13 passive scattering proton fields and multi-leaf modulation to produce a concave dose distribution on a cylindrical solid water phantom without any field-specific compensator. (paper)

  18. Combined robotic-aided gait training and 3D gait analysis provide objective treatment and assessment of gait in children and adolescents with Acquired Hemiplegia.

    Molteni, Erika; Beretta, Elena; Altomonte, Daniele; Formica, Francesca; Strazzer, Sandra

    2015-08-01

    To evaluate the feasibility of a fully objective rehabilitative and assessment process of the gait abilities in children suffering from Acquired Hemiplegia (AH), we studied the combined employment of robotic-aided gait training (RAGT) and 3D-Gait Analysis (GA). A group of 12 patients with AH underwent 20 sessions of RAGT in addition to traditional manual physical therapy (PT). All the patients were evaluated before and after the training by using the Gross Motor Function Measures (GMFM), the Functional Assessment Questionnaire (FAQ), and the 6 Minutes Walk Test. They also received GA before and after RAGT+PT. Finally, results were compared with those obtained from a control group of 3 AH children who underwent PT only. After the training, the GMFM and FAQ showed significant improvement in patients receiving RAGT+PT. GA highlighted significant improvement in stance symmetry and step length of the affected limb. Moreover, pelvic tilt increased, and hip kinematics on the sagittal plane revealed statistically significant increase in the range of motion during the hip flex-extension. Our data suggest that the combined program RAGT+PT induces improvements in functional activities and gait pattern in children with AH, and it demonstrates that the combined employment of RAGT and 3D-GA ensures a fully objective rehabilitative program. PMID:26737310

  19. Independent calculation of dose distributions for helical tomotherapy using a conventional treatment planning system

    Purpose: The dosimetric verification of treatment plans in helical tomotherapy usually is carried out via verification measurements. In this study, a method for independent dose calculation of tomotherapy treatment plans is presented, that uses a conventional treatment planning system with a pencil kernel dose calculation algorithm for generation of verification dose distributions based on patient CT data. Methods: A pencil beam algorithm that directly uses measured beam data was configured for dose calculation for a tomotherapy machine. Tomotherapy treatment plans were converted into a format readable by an in-house treatment planning system by assigning each projection to one static treatment field and shifting the calculation isocenter for each field in order to account for the couch movement. The modulation of the fluence for each projection is read out of the delivery sinogram, and with the kernel-based dose calculation, this information can directly be used for dose calculation without the need for decomposition of the sinogram. The sinogram values are only corrected for leaf output and leaf latency. Using the converted treatment plans, dose was recalculated with the independent treatment planning system. Multiple treatment plans ranging from simple static fields to real patient treatment plans were calculated using the new approach and either compared to actual measurements or the 3D dose distribution calculated by the tomotherapy treatment planning system. In addition, dose–volume histograms were calculated for the patient plans. Results: Except for minor deviations at the maximum field size, the pencil beam dose calculation for static beams agreed with measurements in a water tank within 2%/2 mm. A mean deviation to point dose measurements in the cheese phantom of 0.89% ± 0.81% was found for unmodulated helical plans. A mean voxel-based deviation of −0.67% ± 1.11% for all voxels in the respective high dose region (dose values >80%), and a mean local

  20. Independent calculation of dose distributions for helical tomotherapy using a conventional treatment planning system

    Klüter, Sebastian, E-mail: sebastian.klueter@med.uni-heidelberg.de; Schubert, Kai; Lissner, Steffen; Sterzing, Florian; Oetzel, Dieter; Debus, Jürgen [Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany, and Heidelberg Institute for Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120 Heidelberg, Germany, and German Consortium for Translational Cancer Research (DKTK), Im Neuenheimer Feld 400, 69120 Heidelberg (Germany); Schlegel, Wolfgang [German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Oelfke, Uwe [German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany and Jo