LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 337

Search options

  1. Book: Radiolabeled antibody tumor dosimetry

    Wessels, Barry W.

    report of Task Group No. 2 AAPM Nuclear Medicine Committee

    (AAPM report ; 40)

    1993  

    Institution American Association of Physicists in Medicine / Task Group on Dosimetry of Radiolabeled Antibodies
    Author's details Barry W. Wessels, chairman
    Series title AAPM report ; 40
    Collection
    Keywords Neoplasms / radionuclide imaging ; Neoplasms / radiotherapy ; Radioimmunotherapy / methods ; Radiometry
    Language English
    Size S. 499 - 610 : graph. Darst.
    Publisher American Inst. of Physics
    Publishing place New York, NY
    Publishing country United States
    Document type Book
    Note Aus: Medical physics ; 20.1993,2
    HBZ-ID HT007915144
    ISBN 1-56396-233-0 ; 978-1-56396-233-2
    Database Catalogue ZB MED Medicine, Health

    Kategorien

  2. Article ; Online: Development of a Monte Carlo model for treatment planning dose verification of the Leksell Gamma Knife Perfexion radiosurgery system.

    Yuan, Jiankui / Lo, Simon S / Zheng, Yiran / Sohn, Jason W / Sloan, Andrew E / Ellis, Rodney / Machtay, Mitchell / Wessels, Barry

    Journal of applied clinical medical physics

    2016  Volume 17, Issue 4, Page(s) 190–201

    Abstract: Detailed Monte Carlo (MC) modeling of the Leksell Gamma Knife (GK) Perfexion (PFX) collimator system is the only accurate ab initio approach appearing in the literature. As a different approach, in this work, we present a MC model based on film ... ...

    Abstract Detailed Monte Carlo (MC) modeling of the Leksell Gamma Knife (GK) Perfexion (PFX) collimator system is the only accurate ab initio approach appearing in the literature. As a different approach, in this work, we present a MC model based on film measurement. By adjusting the model parameters and fine-tuning the derived fluence map for each individual source to match the manufacturer's ring output factors, we created a reasonable virtual source model for MC simulations to verify treatment planning dose for the GK PFX radiosurgery system. The MC simulation model was commissioned by simple single shots. Dose profiles and both ring and collimator output factors were compared with the treatment planning system (TPS). Good agreement was achieved for dose profiles especially for the region of plateau (< 2%), while larger difference (< 5%) came from the penumbra region. The maximum difference of the calculated output factor was within 0.7%. The model was further validated by a clinical test case. Good agreement was obtained. The DVHs for brainstem and the skull were almost identical and, for the target, the volume covered by the prescription (12.5 Gy to 50% isodose line) was 95.6% from MC calculation versus 100% from the TPS.
    MeSH term(s) Algorithms ; Brain Neoplasms/surgery ; Brain Stem/radiation effects ; Humans ; Models, Theoretical ; Monte Carlo Method ; Phantoms, Imaging ; Radiosurgery/instrumentation ; Radiosurgery/methods ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted/methods ; Radiotherapy, Intensity-Modulated/methods ; Skull/radiation effects
    Language English
    Publishing date 2016--08
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2010347-5
    ISSN 1526-9914 ; 1526-9914
    ISSN (online) 1526-9914
    ISSN 1526-9914
    DOI 10.1120/jacmp.v17i4.6196
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: An automatic method for PET target segmentation using a lookup table based on volume and concentration ratio.

    Zheng, Yiran / Syh, Joseph / Yao, Min / Wessels, Barry W

    Technology in cancer research & treatment

    2010  Volume 9, Issue 3, Page(s) 243–252

    Abstract: Accurate evaluation of functionally significant target volumes in combination with anatomic imaging is of primary importance for effective radiation therapy treatment planning. In this study, a method for rapid and accurate PET image segmentation and ... ...

    Abstract Accurate evaluation of functionally significant target volumes in combination with anatomic imaging is of primary importance for effective radiation therapy treatment planning. In this study, a method for rapid and accurate PET image segmentation and volumetrics based on phantom measurements and independent of scanner calibration was developed. A series of spheres ranging in volume from 0.5 mL to 95 mL were imaged in an anthropomorphic phantom of human thorax using two commercial PET and CT/PET scanners. The target to background radioactivity concentration ratio ranged from 3:1 to 12:1 in 11 separate phantom scanning experiments. The results confirmed that optimal segmentation thresholding depends on target volume and radioactivity concentration ratio. This information can be derived from a generalized pre-determined "lookup table" of volume and contrast dependent threshold values instead of using fitted curves derived from machine specific information. A three-step method based on the PET image intensity information alone was used to delineate volumes of interest. First, a mean intensity segmentation method was used to generate an initial estimate of target volume, and the radioactivity concentration ratio was computed by a family of recovery coefficient curves to compensate for the partial volume effect. Next, the appropriate threshold value was obtained from a phantom-generated threshold lookup table. Lastly, a threshold level set method was performed on the threshold value to further refine the target contour by reducing the limitation of global thresholding. The segmentation results were consistent for spheres greater than 2.5 mL which yielded volume average uncertainty of 11.2% in phantom studies. The results of segmented volumes were comparable to those determined by contrast-oriented method and iterative threshold method (ITM). In addition, the new volume segmentation method was applied clinically to ten patients undergoing PET/CT volume analysis for radiation therapy treatment planning of solitary lung metastases. For these patients, the average PET segmented volumes were within 8.0% of the CT volumes and were highly dependent on the extension of functionally inactive tumor volume. In summary, the current method does not require fitted threshold curves or a priori knowledge of the CT/MRI target volume. This threshold method can be universally applied to radiation therapy treatment planning with comparable accuracy, and may be useful in the rapid identification and assessment of plans containing multiple targets.
    MeSH term(s) Humans ; Image Interpretation, Computer-Assisted/methods ; Phantoms, Imaging ; Positron-Emission Tomography/methods ; Thorax/diagnostic imaging ; Tomography, X-Ray Computed
    Language English
    Publishing date 2010-06
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2146365-7
    ISSN 1533-0338 ; 1533-0346
    ISSN (online) 1533-0338
    ISSN 1533-0346
    DOI 10.1177/153303461000900303
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Development and Validation of a Small Animal Immobilizer and Positioning System for the Study of Delivery of Intracranial and Extracranial Radiotherapy Using the Gamma Knife System.

    Awan, Musaddiq J / Dorth, Jennifer / Mani, Arvind / Kim, Haksoo / Zheng, Yiran / Mislmani, Mazen / Welford, Scott / Yuan, Jiankui / Wessels, Barry W / Lo, Simon S / Letterio, John / Machtay, Mitchell / Sloan, Andrew / Sohn, Jason W

    Technology in cancer research & treatment

    2017  Volume 16, Issue 2, Page(s) 203–210

    Abstract: The purpose of this research is to establish a process of irradiating mice using the Gamma Knife as a versatile system for small animal irradiation and to validate accurate intracranial and extracranial dose delivery using this system. A stereotactic ... ...

    Abstract The purpose of this research is to establish a process of irradiating mice using the Gamma Knife as a versatile system for small animal irradiation and to validate accurate intracranial and extracranial dose delivery using this system. A stereotactic immobilization device was developed for small animals for the Gamma Knife head frame allowing for isocentric dose delivery. Intercranial positional reproducibility of a reference point from a primary reference animal was verified on an additional mouse. Extracranial positional reproducibility of the mouse aorta was verified using 3 mice. Accurate dose delivery was validated using film and thermoluminescent dosimeter measurements with a solid water phantom. Gamma Knife plans were developed to irradiate intracranial and extracranial targets. Mice were irradiated validating successful targeted radiation dose delivery. Intramouse positional variability of the right mandible reference point across 10 micro-computed tomography scans was 0.65 ± 0.48 mm. Intermouse positional reproducibility across 2 mice at the same reference point was 0.76 ± 0.46 mm. The accuracy of dose delivery was 0.67 ± 0.29 mm and 1.01 ± 0.43 mm in the coronal and sagittal planes, respectively. The planned dose delivered to a mouse phantom was 2 Gy at the 50% isodose with a measured thermoluminescent dosimeter dose of 2.9 ± 0.3 Gy. The phosphorylated form of member X of histone family H2A (γH2AX) staining of irradiated mouse brain and mouse aorta demonstrated adjacent tissue sparing. In conclusion, our system for preclinical studies of small animal irradiation using the Gamma Knife is able to accurately deliver intracranial and extracranial targeted focal radiation allowing for preclinical experiments studying focal radiation.
    MeSH term(s) Animals ; Cranial Irradiation/methods ; Disease Models, Animal ; Gamma Rays ; Head Movements ; Humans ; Mice ; Patient Positioning ; Radiometry ; Radiosurgery/methods ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; Radiotherapy, Conformal/methods ; Reproducibility of Results
    Language English
    Publishing date 2017-04
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2146365-7
    ISSN 1533-0338 ; 1533-0346
    ISSN (online) 1533-0338
    ISSN 1533-0346
    DOI 10.1177/1533034616658394
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article: Overview of dosimetry for Systemic Targeted Radionuclide Therapy (STaRT).

    Wessels, Barry W / Syh, Joseph H / Meredith, Ruby F

    International journal of radiation oncology, biology, physics

    2006  Volume 66, Issue 2 Suppl, Page(s) S39–45

    Abstract: The purposes of systemic targeted radionuclide therapy dosimetry include compiling a database of normal organ radiation-absorbed doses that are carrier- and radionuclide-specific, and assuring that the normal organ radiation doses are within a safe range ...

    Abstract The purposes of systemic targeted radionuclide therapy dosimetry include compiling a database of normal organ radiation-absorbed doses that are carrier- and radionuclide-specific, and assuring that the normal organ radiation doses are within a safe range before therapy. Also of importance is quantitation of radiation delivery to tumors vs. normal tissues to correlate absorbed dose with tumor control. For agents with significant and variable excretion, estimates of individual patient distribution/clearance may be needed to optimize the dose-response relationship.
    MeSH term(s) Brain/metabolism ; Dose-Response Relationship, Radiation ; Electrons ; Humans ; Radioimmunotherapy/methods ; Radiometry/methods ; Radiopharmaceuticals/pharmacokinetics ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted/methods ; Relative Biological Effectiveness ; Tissue Distribution
    Chemical Substances Radiopharmaceuticals
    Language English
    Publishing date 2006
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 197614-x
    ISSN 1879-355X ; 0360-3016
    ISSN (online) 1879-355X
    ISSN 0360-3016
    DOI 10.1016/j.ijrobp.2006.05.069
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: MIRD pamphlet No. 24: Guidelines for quantitative 131I SPECT in dosimetry applications.

    Dewaraja, Yuni K / Ljungberg, Michael / Green, Alan J / Zanzonico, Pat B / Frey, Eric C / Bolch, Wesley E / Brill, A Bertrand / Dunphy, Mark / Fisher, Darrell R / Howell, Roger W / Meredith, Ruby F / Sgouros, George / Wessels, Barry W

    Journal of nuclear medicine : official publication, Society of Nuclear Medicine

    2013  Volume 54, Issue 12, Page(s) 2182–2188

    Abstract: The reliability of radiation dose estimates in internal radionuclide therapy is directly related to the accuracy of activity estimates obtained at each imaging time point. The recently published MIRD pamphlet no. 23 provided a general overview of ... ...

    Abstract The reliability of radiation dose estimates in internal radionuclide therapy is directly related to the accuracy of activity estimates obtained at each imaging time point. The recently published MIRD pamphlet no. 23 provided a general overview of quantitative SPECT imaging for dosimetry. The present document is the first in a series of isotope-specific guidelines that will follow MIRD 23 and focuses on one of the most commonly used therapeutic radionuclides, (131)I. The purpose of this document is to provide guidance on the development of protocols for quantitative (131)I SPECT in radionuclide therapy applications that require regional (normal organs, lesions) and 3-dimensional dosimetry.
    MeSH term(s) Antibodies/therapeutic use ; Antibodies, Monoclonal/therapeutic use ; Calibration ; Clinical Trials as Topic ; Humans ; Image Processing, Computer-Assisted ; Iodine Radioisotopes ; Radioimmunotherapy ; Radiometry ; Recombinant Fusion Proteins/pharmacokinetics ; Recombinant Fusion Proteins/therapeutic use ; Time Factors ; Tomography, Emission-Computed, Single-Photon/methods ; Tomography, X-Ray Computed
    Chemical Substances Antibodies ; Antibodies, Monoclonal ; Iodine Radioisotopes ; Recombinant Fusion Proteins ; SIP(L19) fusion protein ; tositumomab I-131 (K1KT5M40JC)
    Language English
    Publishing date 2013-10-15
    Publishing country United States
    Document type Journal Article ; Practice Guideline ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 80272-4
    ISSN 1535-5667 ; 0097-9058 ; 0161-5505 ; 0022-3123
    ISSN (online) 1535-5667
    ISSN 0097-9058 ; 0161-5505 ; 0022-3123
    DOI 10.2967/jnumed.113.122390
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: Establishing a process of irradiating small animal brain using a CyberKnife and a microCT scanner.

    Kim, Haksoo / Fabien, Jeffrey / Zheng, Yiran / Yuan, Jake / Brindle, James / Sloan, Andrew / Yao, Min / Lo, Simon / Wessels, Barry / Machtay, Mitchell / Welford, Scott / Sohn, Jason W

    Medical physics

    2014  Volume 41, Issue 2, Page(s) 21715

    Abstract: Purpose: Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images.: Methods: These ... ...

    Abstract Purpose: Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images.
    Methods: These experiments consisted of four parts: (1) building a mouse phantom for intensity modulated radiotherapy (IMRT) quality assurance (QA), (2) proving usability of a microCT for treatment planning, (3) fabricating a small animal positioning system for use with the CyberKnife's image guided radiotherapy (IGRT) system, and (4)in vivo verification of targeting accuracy. A set of solid water mouse phantoms was designed and fabricated, with radiochromic films (RCF) positioned in selected planes to measure delivered doses. After down-sampling for treatment planning compatibility, a CT image set of a phantom was imported into the CyberKnife treatment planning system--MultiPlan (ver. 3.5.2). A 0.5 cm diameter sphere was contoured within the phantom to represent a hemispherical section of a mouse brain. A nude mouse was scanned in an alpha cradle using a microCT scanner (cone-beam, 157 × 149 pixels slices, 0.2 mm longitudinal slice thickness). Based on the results of our positional accuracy study, a planning treatment volume (PTV) was created. A stereotactic body mold of the mouse was "printed" using a 3D printer laying UV curable acrylic plastic. Printer instructions were based on exported contours of the mouse's skin. Positional reproducibility in the mold was checked by measuring ten CT scans. To verify accurate dose delivery in vivo, six mice were irradiated in the mold with a 4 mm target contour and a 2 mm PTV margin to 3 Gy and sacrificed within 20 min to avoid DNA repair. The brain was sliced and stained for analysis.
    Results: For the IMRT QA using a set of phantoms, the planned dose (6 Gy to the calculation point) was compared to the delivered dose measured via film and analyzed using Gamma analysis (3% and 3 mm). A passing rate of 99% was measured in areas of above 40% of the prescription dose. The final inverse treatment plan was comprised of 43 beams ranging from 5 to 12.5 mm in diameter (2.5 mm size increments are available up to 15 mm in diameter collimation). Using the Xsight Spine Tracking module, the CyberKnife system could not reliably identify and track the tiny mouse spine; however, the CyberKnife system could identify and track the fiducial markers on the 3D mold.In vivo positional accuracy analysis using the 3D mold generated a mean error of 1.41 mm ± 0.73 mm when fiducial markers were used for position tracking. Analysis of the dissected brain confirmed the ability to target the correct brain volume.
    Conclusions: With the use of a stereotactic body mold with fiducial markers, microCT imaging, and resolution down-sampling, the CyberKnife system can successfully perform small-animal radiotherapy studies.
    MeSH term(s) Animals ; Brain/diagnostic imaging ; Brain/radiation effects ; Brain/surgery ; Calibration ; Mice ; Phantoms, Imaging ; Radiosurgery/methods ; Radiotherapy, Intensity-Modulated ; Reproducibility of Results ; X-Ray Microtomography/methods
    Language English
    Publishing date 2014-02
    Publishing country United States
    Document type Journal Article ; Research Support, U.S. Gov't, P.H.S.
    ZDB-ID 188780-4
    ISSN 2473-4209 ; 0094-2405
    ISSN (online) 2473-4209
    ISSN 0094-2405
    DOI 10.1118/1.4861713
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: Renal dosimetry.

    Wessels, Barry W / Dale, Roger G / Cremonesi, Marta / Meredith, Ruby F / Green, Alan J / Brill, Bertrand / Bolch, Wesley E / Sgouros, George / Thomas, Stephen R

    Cancer biotherapy & radiopharmaceuticals

    2010  Volume 25, Issue 5, Page(s) 597–599

    MeSH term(s) Humans ; Kidney/radiation effects ; Models, Theoretical ; Pamphlets ; Predictive Value of Tests ; Radiation Dosage ; Radiometry/methods
    Language English
    Publishing date 2010-10
    Publishing country United States
    Document type Comment ; Letter
    ZDB-ID 1315649-4
    ISSN 1557-8852 ; 1084-9785
    ISSN (online) 1557-8852
    ISSN 1084-9785
    DOI 10.1089/cbr.2010.0867
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Autologous transplant for relapsed follicular lymphoma: impact of pre-transplant rituximab sensitivity.

    Phipps, Colin / Gopal, Ajay K / Storer, Barry E / Cassaday, Ryan D / Press, Oliver W / Till, Brian G / Pagel, John M / Palanca-Wessels, Maria C / Philip, Mary / Bensinger, William I / Holmberg, Leona A / Shustov, Andrei R / Green, Damian J / Chauncey, Thomas / Maloney, David G / Libby, Edward N

    Leukemia & lymphoma

    2014  Volume 56, Issue 1, Page(s) 92–96

    Abstract: Patients with rituximab-refractory follicular lymphoma (FL) have limited options. Before the rituximab era, autologous stem cell transplant (ASCT) was shown to improve outcomes in chemotherapy-sensitive, relapsed FL, but the impact of rituximab- ... ...

    Abstract Patients with rituximab-refractory follicular lymphoma (FL) have limited options. Before the rituximab era, autologous stem cell transplant (ASCT) was shown to improve outcomes in chemotherapy-sensitive, relapsed FL, but the impact of rituximab-sensitivity on these results is unknown. We analyzed 194 consecutive relapsed patients with FL who underwent ASCT at out center and categorized them as rituximab-sensitive (RS, n = 35), rituximab-refractory (RR, n = 65) or no rituximab (NoR, n = 94) if transplanted before rituximab was used. Progression-free survival at 3 years was 85% in RS and 35% in RR patients (p = 0.0004). Only rituximab-sensitivity was significant on multivariate analysis with improved overall survival (OS) (hazard ratio [HR] 0.24, p = 0.01) and progression-free survival (PFS) (HR 0.35, p = 0.006) in RS patients and increased relapse in RR patients (HR 2.11, p = 0.01). Pre-transplant rituximab-sensitivity is a strong independent predictor of post-transplant outcomes in relapsed FL, although one-third of RR patients achieved a PFS of over 3 years with ASCT.
    MeSH term(s) Adolescent ; Adult ; Aged ; Antibodies, Monoclonal, Murine-Derived/therapeutic use ; Antineoplastic Agents/therapeutic use ; Autografts ; Combined Modality Therapy ; Drug Resistance, Neoplasm ; Female ; Hematopoietic Stem Cell Transplantation ; Humans ; Lymphoma, Follicular/mortality ; Lymphoma, Follicular/pathology ; Lymphoma, Follicular/therapy ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Retreatment ; Retrospective Studies ; Rituximab ; Survival Analysis ; Treatment Outcome ; Young Adult
    Chemical Substances Antibodies, Monoclonal, Murine-Derived ; Antineoplastic Agents ; Rituximab (4F4X42SYQ6)
    Language English
    Publishing date 2014-06-17
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 1042374-6
    ISSN 1029-2403 ; 1042-8194
    ISSN (online) 1029-2403
    ISSN 1042-8194
    DOI 10.3109/10428194.2014.911866
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Book: Radiolabeled antibody therapy

    Wessels, Barry W / O'Donoghue, Joe

    dosimetry and radiobiological labeling

    1992  

    Institution Society of Nuclear Medicine (1953- )
    Author's details the Society of Nuclear Medicine
    MeSH term(s) Antibodies, Monoclonal/therapeutic use ; Isotope Labeling ; Neoplasms/radiotherapy ; Radioimmunotherapy
    Language English
    Size 108 slides :, col. with b&w +
    Publisher The Society
    Publishing place New York, NY
    Document type Book
    Note Sound accompaniment for manual and automatic operation. ; Approved for 1.5 credit hr. in category 1 of the Physician's Recognition Award of the AMA.
    Accompanying material 2 sound cassettes (52 min. : analog) + 1 leaflet.
    Database Catalogue of the US National Library of Medicine (NLM)

    More links

    Kategorien

To top