• Publications
• Experience
• About

Professional Focus

Dr. Ma's research and clinical focus include stereotactic radiosurgery, breast cancer treatments, and imaging guided procedures. Dr. Ma joined UCSF in 2006 and is a member of UCSF CyberKnife and Gamma Knife team. Dr. Ma had led numerous research projects. He implemented and benchmarked multiple clinical procedures and protocols that ranged from initial of dynamic linac-based shaped-beam radiosurgery program to liquid I-125 balloon catheter-based implantation protocols. Dr. Ma has served as grant reviewers for national funding agencies. He is the principal investigator for research awards from US government and non-profit foundations. Dr. Ma is the principal or senior author of over 30 peer-reviewed publications and a US and international patent holder for a beam technology relating to breast cancer treatment. Prior to joining to UCSF, Dr. Ma was an Associate professor in Radiation Oncology Physics at the University of Maryland School of Medicine.

Education

Professional Experience

Awards & Honors

Publications

L. Ma, L. Chin, M. Sarfaraz, D. Shepard, and C. Yu, An investigation of eye lens complication for gamma knife radiosurgery of trigeminal neuralgia Appl. Clin. Med. Phy., Vol 1(4) 116-119, 2000.

C. Ma, T Pawlicki, S B Jiang, J S Li, J Deng, E Mok, A Kapur, L Xing, L Ma, and A L Boyer, Monte Carlo verification of IMRT dose distributions from a commercial treatment planning optimization system, Phys. Med. Biol. 45(9) 2483-2495, 2000.

D. Shepard, M. Ferris, R. Ove, and L. Ma, Inverse treatment planning for gamma knife radiosurgery, Med. Phys. 27(12) 2748-2756, 2000.

L. Xing, Z-X Lin, S.S. Donaldson, Q. T. Le, D Tate, D.R. Goffinet, S. Wolden, L Ma, and A.L. Boyer Dosimetric effects of patient displacement and collimator and gantry angle misalignment on Intensity modulated radiation therapy, Radiother. Oncol. 56: 97-108, 2000.

L. Chin, L, Ma, S. DiBiase, Radiation Necrosis Following Gamma Knife Radiosurgery: A case-controlled comparison of Treatment parameters and long-term clinical follow-up, J. Neurosurgery, 94:899-904, 2001.

L. Ma, Dependence of normal brain integral dose and Normal Tissue Complication Probability on the peripheral g-knife prescription isodose values, Phys Med. Biol. 46(11) 3031-3041, 2001.

X.A Li, L. Ma, S. Naqvi, R. Shih, and C. Yu, Monte Carlo dose verification for intensity modulated arc therapy, Phys. Med. Biol. 46 No 9, 2269-2282. 2001.

L. Ma, C. Yu, M. Earl, T. Holmes, M. Sarfaraz, A. Li, D. Shepard, P. Amin, S. DiBiase, M. Suntharalingam and C. Mansfield Optimized intensity modulated arc therapy for prostate cancer treatments, Int. J. Cancer Vol. 96 (6) 379-384, 2001.

S. DiBiase, L, Chin, and L. Ma, The influence of Gamma Knife radiosurgery on the quality of life in patients with brain metastases, Am. J. Clin. Oncol. 25(2): 131-134, 2002.

M. Earl and L. Ma, Depth dose enhancement of electron beams subject to uniform longitudinal magnetic fields: a Monte Carlo study Med. Phys., 29(4) 484-491, 2002.

C.X. Yu, XA, Li, L. Ma, D, Chen, et al, Clinical implementation of intensity-modulated arc therapy, Int. J. Radiat. Oncol. Biol. Phys., 53(2) 453-463, 2002.

L. Ma, Smoothing intensity-modulated treatment delivery under hardware constraints, Med. Phys. 29(12) 2937-2945, 2002.

N. Phaisangittisakul, and L. Ma, An empirical model for independent dose verification of the Gamma Knife treatment planning, Med. Phys. 29(9) 1991-1997, 2002.

L. Ma, L.Chin, S. DiBiase, R. Gullapalli, A. Kennedy, and J Marc Simard, Concomitant boost of stratified target volume with gamma knife radiosurgery: a treatment planning study, 26(4) 100-105e, Am. J. Clin. Oncol. 2003.

M. Guerrero, XA Li, and L. Ma, A technique to sharpen the beam penumbra for Gamma Knife Radiosurgery, Phys. Med. Biol. 48 1843-1853, 2003.

L. Ma, N. Phaisangittisakul, C. X. Yu and M. Sarfaraz, A quality assurance method for verifying intensity modulated fields, Med. Phys, 30 (8) 2082-2088, 2003.

N. Phaisangittisakul, W. D. D'Souza, and L. Ma, Magnetic collimation and metal foil filtration for electron range and fluence modulation, Med. Phys. 31(1)17-23, 2004.

K. Li, J. Dai, and L. Ma, Simultaneous minimizing monitor units and number of segments without leaf end abutment for segmental intensity modulated radiation therapy delivery, Med. Phys. 31(3)507-512, 2004.

K. Li, and L. Ma, Selective Source Blocking for Treatment of Trigeminal Neuralgia Based on Analytical Gamma Knife Dose Modeling, Phys. Med. Biol. 49(15)3455-3463, 2004.

K. Li, C. Yu and L. Ma Improving a Scissor-Action Couch for Delivering Micro MLC-based Dynamic Arc Radiotherapy and Radiosurgery Appl. Clin. Med. Phy. 5(3) 137-141, 2004.

L. Ma, osimetric properties of magnetically collimated electron beam for radiation therapy, Med. Phys. 31(11), 2973-2977, 2004.

M. Guerrero, X. A. Li, L. Ma, J. Linder, C. Deyoung, B. Erickson, Simultaneous integrated intensity-modulated radiotherapy boost for locally advanced gynecological cancer: Radiobiological and dosimetric considerations Int. J. Rad. Oncol. Biol. Phys. 62, 933-939, 2005.

K. Li and L. Ma, An Efficient Automatic Plugging Algorithm for Multiple Isocenter Gamma Knife Radiosurgery, Med. Phys. 32(10) 3132-3135, 2005.

L. Ma, Y. Kwok, L. Chin, J. Simard, and W.F. Regine, Concomitant GRID boost for Gamma Knife radiosurgery, Med. Phys. 32(11), 3419-3423, 2005.

L. Ma, Y. Kwok, L. Chin, and W. F. Regine, Comparative Analyses of Linac and Gamma Knife Radiosurgery for Trigeminal Neuralgia Treatments, Phys. Med. Biol. 50, 5217-5227, 2005.

L. Ma, D. Larson, P. Petti, C. Chuang and L. Verhey, Boosting Central Target Dose by Optimizing Embedded Dose Hot Spots For Gamma Knife Radiosurgery, Stereotactic and Functional Radiosurgery, Vol 85, No 4, 259-263 2007.

C. Chuang, A. Sahgal,  L. Lee, D. Larson, K. Huang, P. Petti, L. Verhey, and L. Ma, Effects of Residual Target Motion for Image-tracked spine radisurgery,  Med. Phys. Vol 31, No 8, 4484-4490, 2007.

A. Sahgal, D. Chou, C. Ames, L. Ma, K. Lamborn, K. Huang, C. Chuang, P. Petti, P. Weinstein, and D. Larson, Image-Guided Robotic Stereotactic Body Radiotherapy for Benign Spinal Tumors: The University of California San Francisco Preliminary Experience, Tech Cancer Res Treatment, Vol 6, No 6. 595-604, 2007.

A. Sahgal, C. Chuang, K. Huang, P. Petti, P. Weinstein, D. Larson, L. Ma, Split-volume treatment planning of multiple consecutive vertebral body metastases for cyberknife image guided frameless radiosurgery, Med. Dosi. Vol 7, No 7, 175-179. 2007.

L. Ma, C. Chuang, M Descovich, P Petti, V Smith and L Verhey, Whole-procedure accuracy of Gamma Knife treatments of large lesions, Med. Phys. 35(11)2405-2410, 2008.

S. Hossain, P. Xia, C Chuang, A Gottschalk, G Mu, L Verhey and L. Ma, Simulated Real Time Image Guided Intra-Fraction Tracking Delivery for Hypofractionated Prostate IMRT, Med. Phys. 35(9)4041-4048, 2008.

Y. Xie, D. Djajaputra, C. R. King, S Hossain, L. Ma, and L Xing, Intrafractional Motion of the Prostate During Hypofractionated Radiotherapy. Int. J. of Rad. Oncol. Biol. Phys. 72(1): 236-246, 2008.

A Sahgal , L. Ma, Chuang C., Hossain S., Petti P., Larson D., Shrieve D. Comparisons of Novalis and Cyberknife Spinal Stereotactic Body Radiotherapy Treatment Planning Based on Physical and Biologic Modelling Parameters. Radiosurgery. In press 2008.

L. Ma, A Sahgal, Chuang C., Descovich M., Petti P., Smith V., Verhey L., Barbaro N., McDermott M., Huang K., Nakamura J., Sneed P., Larson D., Functional Relationship Between the Volume of a Near-Target Peripheral Isodose Line and its Isodose Value for Gamma Knife Radiosurgery. Radiosurgery. In press 2008.

L. Ma, L Verhey, M McDermott, K Huang, C Chuang, V Smith and P Sneed, Effect of Composite Sector Collimation on Average Dose Fall-off for Gamma Knife Perfexion. J. Neurosurgery, In press, 2008.

Y Zhang, Y Hu, L, Ma and J Dai, Dynamic delivery of IMRT using independent collimator: a model study, Phys Med Biol, tentatively accepted, 2008.

A. Sahgal, C. Ames, D. Chou, L. Ma, K. Huang, W Xu, V. Weinberg, C. Chin, C. Chuang, P. Weinstein, D. Larson, Stereotactic Body Radiosurgery is Effective Salvage Therapy for Patients with Prior Radiation of Spinal Metastases, Int. J. of Rad. Oncol. Biol. Phys. in press, 2008.