Lijun Ma

Summary

Affiliation: University of California
Country: USA

Publications

  1. ncbi Whole-procedural Radiological Accuracy for Delivering Multi-session Gamma Knife Radiosurgery With a Relocatable Frame System
    L Ma
    Department of Radiation Oncology, University of California, San Francisco, CA 94143
    Technol Cancer Res Treat 13:403-8. 2014
  2. ncbi Impact of millimeter-level margins on peripheral normal brain sparing for gamma knife radiosurgery
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, California Electronic address
    Int J Radiat Oncol Biol Phys 89:206-13. 2014
  3. doi Individual beam sharpening improves composite dose fall-off near a target for non-isocentric cyberknife radiosurgery
    M Wahl
    Department of Radiation Oncology, University of California, San Francisco 505 Parnassus Ave, San Francisco, CA, 94143 0226
    Technol Cancer Res Treat 12:341-8. 2013
  4. doi Assessing small-volume spinal cord dose for repeat spinal stereotactic body radiotherapy treatments
    Lijun Ma
    Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA
    Phys Med Biol 57:7843-51. 2012
  5. doi Reliability of contour-based volume calculation for radiosurgery
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, CA 94143, USA
    J Neurosurg 117:203-10. 2012
  6. doi Shot sequencing based on biological equivalent dose considerations for multiple isocenter Gamma Knife radiosurgery
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, CA 94143, USA
    Phys Med Biol 56:7247-56. 2011
  7. ncbi Whole-procedure clinical accuracy of gamma knife treatments of large lesions
    Lijun Ma
    Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143, USA
    Med Phys 35:5110-4. 2008
  8. doi Effect of composite sector collimation on average dose fall-off for Gamma Knife Perfexion
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, California 94143, USA
    J Neurosurg 109:15-20. 2008
  9. doi A simple and effective method for validation and measurement of collimator output factors for Leksell Gamma Knife Perfexion
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, CA, USA
    Phys Med Biol 54:3897-907. 2009
  10. doi Nonrandom intrafraction target motions and general strategy for correction of spine stereotactic body radiotherapy
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, California 94143, USA
    Int J Radiat Oncol Biol Phys 75:1261-5. 2009

Detail Information

Publications41

  1. ncbi Whole-procedural Radiological Accuracy for Delivering Multi-session Gamma Knife Radiosurgery With a Relocatable Frame System
    L Ma
    Department of Radiation Oncology, University of California, San Francisco, CA 94143
    Technol Cancer Res Treat 13:403-8. 2014
    ....
  2. ncbi Impact of millimeter-level margins on peripheral normal brain sparing for gamma knife radiosurgery
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, California Electronic address
    Int J Radiat Oncol Biol Phys 89:206-13. 2014
    ..To investigate how millimeter-level margins beyond the gross tumor volume (GTV) impact peripheral normal brain tissue sparing for Gamma Knife radiosurgery...
  3. doi Individual beam sharpening improves composite dose fall-off near a target for non-isocentric cyberknife radiosurgery
    M Wahl
    Department of Radiation Oncology, University of California, San Francisco 505 Parnassus Ave, San Francisco, CA, 94143 0226
    Technol Cancer Res Treat 12:341-8. 2013
    ..Therefore, individual beam sharpening provides a straightforward way of improving the composite dose fall-off for non-isocentric Cyberknife SRS. ..
  4. doi Assessing small-volume spinal cord dose for repeat spinal stereotactic body radiotherapy treatments
    Lijun Ma
    Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA
    Phys Med Biol 57:7843-51. 2012
    ....
  5. doi Reliability of contour-based volume calculation for radiosurgery
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, CA 94143, USA
    J Neurosurg 117:203-10. 2012
    ..The aim of this study was to determine the reliability of contour-based volume calculations made by current major SRS platforms...
  6. doi Shot sequencing based on biological equivalent dose considerations for multiple isocenter Gamma Knife radiosurgery
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, CA 94143, USA
    Phys Med Biol 56:7247-56. 2011
    ....
  7. ncbi Whole-procedure clinical accuracy of gamma knife treatments of large lesions
    Lijun Ma
    Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143, USA
    Med Phys 35:5110-4. 2008
    ..In conclusion, Gamma Knife treatments of large lesions can be delivered much more accurately than predicted from the quadrature-sum analysis of major sources of uncertainties from each step of the delivery chain...
  8. doi Effect of composite sector collimation on average dose fall-off for Gamma Knife Perfexion
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, California 94143, USA
    J Neurosurg 109:15-20. 2008
    ..In this study, the authors investigated the effect of composite sector collimation on average dose fall-off compared with the previous Gamma Knife model...
  9. doi A simple and effective method for validation and measurement of collimator output factors for Leksell Gamma Knife Perfexion
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, CA, USA
    Phys Med Biol 54:3897-907. 2009
    ..Given the efficiency of the method, measurement and validation of the collimator output factors can be readily adopted in commissioning and quality assurance of a Leksell Gamma Knife Perfexion system...
  10. doi Nonrandom intrafraction target motions and general strategy for correction of spine stereotactic body radiotherapy
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, California 94143, USA
    Int J Radiat Oncol Biol Phys 75:1261-5. 2009
    ..The dependence of target motions, as well as the effectiveness of the correction strategy for lesions of different locations within the spine, was analyzed...
  11. doi Apparatus dependence of normal brain tissue dose in stereotactic radiosurgery for multiple brain metastases
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, 94143, USA
    J Neurosurg 114:1580-4. 2011
    ..The goal of this study was to investigate whether the dose to normal brain when planning radiosurgery to multiple targets is apparatus dependent...
  12. doi Equivalence in dose fall-off for isocentric and nonisocentric intracranial treatment modalities and its impact on dose fractionation schemes
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, CA 94143, USA
    Int J Radiat Oncol Biol Phys 76:943-8. 2010
    ..To investigate whether dose fall-off characteristics would be significantly different among intracranial radiosurgery modalities and the influence of these characteristics on fractionation schemes in terms of normal tissue sparing...
  13. ncbi Effects of residual target motion for image-tracked spine radiosurgery
    Cynthia Chuang
    Department of Radiation Oncology, University of California San Francisco, California 94143 0226, USA
    Med Phys 34:4484-90. 2007
    ..g., 0.1 cc). In such cases, stringent cord constraints and frequent monitoring of the target position should be implemented...
  14. doi Split-volume treatment planning of multiple consecutive vertebral body metastases for cyberknife image-guided robotic radiosurgery
    Arjun Sahgal
    Department of Radiation Oncology, University of California San Francisco, San Francisco, CA94143, USA
    Med Dosim 33:175-9. 2008
    ..This technique may be of particular importance in clinical situations where stringent spinal cord dose limits are required...
  15. doi Dose gradient near target-normal structure interface for nonisocentric CyberKnife and isocentric intensity-modulated body radiotherapy for prostate cancer
    Sabbir Hossain
    Department of Radiation Oncology, University of California, San Francisco, School of Medicine, San Francisco, CA 94143 1708, USA
    Int J Radiat Oncol Biol Phys 78:58-63. 2010
    ..In particular, the dose gradient across the target and the critical structures such as the rectum and bladder was characterized...
  16. doi Temporal compartmental dosing effects for robotic prostate stereotactic body radiotherapy
    Stephen L Shiao
    Department of Radiation Oncology, University of California, San Francisco, CA, USA
    Phys Med Biol 56:7767-75. 2011
    ..21). We concluded that non-isocentric small-field Cyberknife delivery produced consistent biological dosing that tracked well with the constant-dose-rate, large-field-type delivery for prostate stereotactic body radiotherapy...
  17. doi High-precision volume-staged Gamma Knife surgery and equivalent hypofractionation dose schedules for treating large arteriovenous malformations
    Shannon Fogh
    Department of Radiation Oncology, University of California, San Francisco, California 94143, USA
    J Neurosurg 117:115-9. 2012
    ....
  18. ncbi Concomitant GRID boost for Gamma Knife radiosurgery
    Lijun Ma
    Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21210, USA
    Med Phys 32:3419-23. 2005
    ..e., the near region) were decreased for the GRID boost technique. In conclusion, we demonstrated a new technique for Gamma Knife radiosurgery that can escalate the dose to the target while sparing the adjacent normal brain tissue...
  19. doi Stereotactic body radiotherapy is effective salvage therapy for patients with prior radiation of spinal metastases
    Arjun Sahgal
    Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA
    Int J Radiat Oncol Biol Phys 74:723-31. 2009
    ..To provide actuarial outcomes and dosimetric data for spinal/paraspinal metastases, with and without prior radiation, treated with stereotactic body radiotherapy (SBRT)...
  20. ncbi Boosting central target dose by optimizing embedded dose hot spots for gamma knife radiosurgery
    Lijun Ma
    Department of Radiation Oncology, University of California, San Francisco, CA 94143, USA
    Stereotact Funct Neurosurg 85:259-63. 2007
    ..To develop a boost technique for Gamma Knife radiosurgery by embedding and optimizing dose hot spots inside a conventional Gamma Knife plan...
  21. ncbi Improving a scissor-action couch for conformal arc radiotherapy and radiosurgery
    Kaile Li
    Department of Radiation Oncology, University of Maryland School of Medicine, 22 South Greene Street, Baltimore, Maryland 21201, USA
    J Appl Clin Med Phys 5:62-5. 2004
    ..The couch has been used with over 15 patients and with over 50 modulated conformal arc treatment deliveries at our institution...
  22. doi Prognostic factors for survival in patients treated with stereotactic radiosurgery for recurrent brain metastases after prior whole brain radiotherapy
    Jorge A Caballero
    Stanford University School of Medicine, Stanford, CA, USA
    Int J Radiat Oncol Biol Phys 83:303-9. 2012
    ..To evaluate prognostic factors for survival after stereotactic radiosurgery (SRS) for new, progressive, or recurrent brain metastases (BM) after prior whole brain radiotherapy (WBRT)...
  23. ncbi A constrained tracking algorithm to optimize plug patterns in multiple isocenter gamma knife radiosurgery planning
    Kaile Li
    Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
    Med Phys 32:3132-5. 2005
    ..In summary, we demonstrated a useful source-plugging algorithm for improving complex multi-isocenter Gamma Knife treatment planning cases...
  24. ncbi Apparatus-dependent dosimetric differences in spine stereotactic body radiotherapy
    Lijun Ma
    Department of Radiation Oncology, University of California San Francisco, San Francisco, California, USA
    Technol Cancer Res Treat 9:563-74. 2010
    ....
  25. ncbi Selective source blocking for Gamma Knife radiosurgery of trigeminal neuralgia based on analytical dose modelling
    Kaile Li
    Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD 21210, USA
    Phys Med Biol 49:3455-63. 2004
    ..Considering the small effort involved in using these plugs, we recommend source blocking for all trigeminal neuralgia treatments with Gamma Knife radiosurgery...
  26. ncbi Comparison between prone and supine patient setup for spine stereotactic body radiosurgery
    Martina Descovich
    Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA
    Technol Cancer Res Treat 11:229-36. 2012
    ..In addition, prone plans resulted in a lower number of monitor units compared to supine plans...
  27. ncbi Simulated real time image guided intrafraction tracking-delivery for hypofractionated prostate IMRT
    Sabbir Hossain
    Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143 1708, USA
    Med Phys 35:4041-8. 2008
    ....
  28. doi Stereotactic body radiotherapy as monotherapy or post-external beam radiotherapy boost for prostate cancer: technique, early toxicity, and PSA response
    Siavash Jabbari
    Department of Radiation Oncology, University of California San Francisco, San Francisco, California, USA
    Int J Radiat Oncol Biol Phys 82:228-34. 2012
    ..Here, we report our technique, PSA nadir, and acute and late toxicity with SBRT as monotherapy and post-EBRT boost for PCa using HDR brachytherapy fractionation...
  29. ncbi Dosimetric properties of magnetically collimated electron beams for radiation therapy
    Lijun Ma
    Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
    Med Phys 31:2973-7. 2004
    ..The use of magnetic collimation may lead to improved delivery techniques for breast and head and neck cancer treatments...
  30. ncbi Assessment of variation in Elekta plastic spherical-calibration phantom and its impact on the Leksell Gamma Knife calibration
    Josef Novotny
    Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213, USA
    Med Phys 37:5066-71. 2010
    ..The purpose of this study was to evaluate variations in the Elekta spherical phantom and to assess its impact and use for the LGK calibration...
  31. doi Advances in radiation therapy of brain metastasis
    Simon S Lo
    Department of Radiation Oncology, UH Seidman Cancer Center, Case Western Reserve University, Cleveland, Ohio 44106, USA
    Prog Neurol Surg 25:96-109. 2012
    ..This review provides an overview of advances in the radiotherapeutic management of brain metastases...
  32. ncbi A technique to sharpen the beam penumbra for Gamma Knife radiosurgery
    M Guerrero
    Department of Radiation Oncology, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
    Phys Med Biol 48:1843-53. 2003
    ..In conclusion, the proposed technique is feasible and effective in sharpening the beam penumbra for Gamma Knife beam profiles...
  33. ncbi A quality assurance method for analyzing and verifying intensity modulated fields
    Lijun Ma
    Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
    Med Phys 30:2082-8. 2003
    ..In conclusion, we demonstrated a quantitative method for verifying and analyzing IMRT treatment deliveries...
  34. pmc Intrafractional motion of the prostate during hypofractionated radiotherapy
    Yaoqin Xie
    Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305 5847, USA
    Int J Radiat Oncol Biol Phys 72:236-46. 2008
    ..To report the characteristics of prostate motion as tracked by the stereoscopic X-ray images of the implanted fiducials during hypofractionated radiotherapy with CyberKnife...
  35. ncbi Simultaneous integrated intensity-modulated radiotherapy boost for locally advanced gynecological cancer: radiobiological and dosimetric considerations
    Mariana Guerrero
    Department of Radiation Oncology, University of Maryland, Baltimore, MD, USA
    Int J Radiat Oncol Biol Phys 62:933-9. 2005
    ..Radiobiological modeling is used to design appropriate regimens for the IMRT SIB. To demonstrate feasibility, a dosimetric study is carried out on an example patient...
  36. ncbi Clinical implementation of intensity-modulated arc therapy
    Cedric X Yu
    Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
    Int J Radiat Oncol Biol Phys 53:453-63. 2002
    ..The objectives of this study were to (1) clinically implement the IMAT technique, and (2) evaluate the dosimetry in comparison with conventional three-dimensional (3D) conformal techniques...
  37. ncbi Simultaneous minimizing monitor units and number of segments without leaf end abutment for segmental intensity modulated radiation therapy delivery
    Kaile Li
    Department of Radiation Oncology, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
    Med Phys 31:507-12. 2004
    ..The major strength of our method is its simplicity and high computing speed. This potentially provides a useful means for generating segmental IMRT fields that require high spatial resolution or complex intensity distributions...
  38. ncbi Magnetic collimation and metal foil filtering for electron range and fluence modulation
    N Phaisangittisakul
    Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
    Med Phys 31:17-23. 2004
    ..In conclusion, our study demonstrates new aspects of using magnetic collimation and foil filtration for producing fluence and range modulated electron dose distributions...
  39. ncbi Smoothing intensity-modulated treatment delivery under hardware constraints
    Lijun Ma
    Department of Radiation Oncology, University of Maryland School of Medicine, 22 South Greene Street, Baltimore, Maryland 21201, USA
    Med Phys 29:2937-45. 2002
    ..These results demonstrated the feasibility of maintaining inversely optimized treatment plans under acceptable tolerance levels while smoothing IMRT treatments with hardware constraints...
  40. ncbi An empirical model for independent dose verification of the Gamma Knife treatment planning
    Nakorn Phaisangittisakul
    Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore 21201, USA
    Med Phys 29:1991-7. 2002
    ..Therefore, this method can be served as a useful tool for secondary quality assurance of Gamma Knife treatment plans...
  41. ncbi Concomitant boost of stratified target area with gamma knife radiosurgery: a treatment planning study
    Lijun Ma
    Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore 21201, USA
    Am J Clin Oncol 26:e100-5. 2003
    ..As a result, we conclude that concomitant boost of a stratified target area is feasible for GKSRS...