**Peer-reviewed journals**

[1] H. Lin, **T. Liu**, C. Shi, S. Petillion, I. Kindts, C. Weltens, T. Depuydt, Y. Song, Z. Saleh, X. G. Xu, and X. Tang, “Individualized optimal positioning selection for left-sided whole breast radiotherapy: DIBH or prone (under review),” *Physics in Medicine and Biology, *(2017).

[2] **T. Liu**, N. Wolfe, C. D. Carothers, W. Ji, and X. G. Xu, “Optimizing the Monte Carlo neutron cross-section construction code, XSBench, for MIC and GPU platforms,” *Nuclear Science and Engineering, 185*(1), pp. 232-242, (2017). [download]

[3] **T. Liu**, X. G. Xu, and C. D. Carothers, “Comparison of two accelerators for Monte Carlo radiation transport calculations, NVIDIA Tesla M2090 GPU and Intel Xeon Phi 5110p coprocessor: a case study for x-ray CT imaging dose calculation,” *Annals of Nuclear Energy, 82*, pp. 230-239, (2014).

[4] L. Su, Y. Yang, B. Bednarz, E. Sterpin, X. Du, **T. Liu**, W. Ji, and X. G. Xu, “ARCHER-RT, A photon-electron coupled Monte Carlo dose computing engine for GPU: software development and application to helical tomotherapy,” *Medical Physics, 41*(7), p. 071709, (2014).

[5] X. G. Xu, **T. Liu**, L. Su, X. Du, M. Riblett, W. Ji, D. Gu, C. D. Carothers, M. S. Shephard, F. B. Brown, M. K. Kalra, and B. Liu, “ARCHER, a new Monte Carlo software tool for emerging heterogeneous computing environments,” *Annals of Nuclear Energy, 82*, pp. 2-9, (2014).

[6] D. Zhang, A. Padole, X. Li, S. Singh, R. D. A. Khawaja, D. Lira, **T. Liu**, J. Q. Shi, A. Otrakji, M. K. Kalra, X. G. Xu, and B. Liu, “In vitro dose measurements in a human cadaver with abdomen/pelvis CT scans,” *Medical Physics, 41*(9), p. 091911, (2014).

[7] A. Ding, M. Mille, **T. Liu**, P. F. Caracappa, and X. G. Xu, “Extension of RPI-adult male and female computational phantoms to obese patients and a Monte Carlo study of the effect on CT imaging dose,” *Physics in Medicine and Biology, 57*(9), pp. 2441-2459, (2012).

**Conference abstracts (oral presentations and posters)**

[1] L. Mao, **T. Liu**, Y. Gao, L. T. Dauer, P. F. Caracappa, and X. G. Xu, “A study of eye lens dose of interventional radiologist wearing protective eye glasses using fast Monte Carlo simulation code — ARCHER (under review),” *Health Physics, *(2017).

[2] L. Yang, **T. Liu**, H. Lin, H. Liu, Z. Wang, X. Pei, Z. Chen, and X. G. Xu, “The dosimetric impact of MRI magnetic field on external-beam therapy using GPU-based rapid Monte Carlo code ARCHER (under review),” in *5th Magnetic Resonance (MR) in Radiation Therapy (RT) symposium 2017*, Sydney, Australia, (2017).

[3] H. Lin, **T. Liu**, C. Shi, S. Petillion, I. Kindts, X. Tang, and X. G. Xu, “Model based classification for optimal position selection for left-sided breast radiotherapy: free breathing, DIBH, or prone,” *Medical Physics, 43*(6), pp. 3629–3630, (2016).

[4] H. Lin, **T. Liu**, L. Su, B. Bednarz, P. Caracappa, and X. G. Xu, “Modeling of radiotherapy Linac source terms using ARCHER Monte Carlo code: performance comparison for GPU and MIC parallel computing devices,” in *13th International Conference on Radiation Shielding & 19th Topical Meeting of the Radiation Protection and Shielding Division (ICRS-13 & RPSD 2016)*, France, Paris, (2016).

[5] **T. Liu**, H. Lin, Y. Gao, P. Caracappa, G. Wang, W. Cong, and X. G. Xu, “Radiation dose simulation for a newly proposed dynamic bowtie filters for CT using fast Monte Carlo methods,” *Medical Physics, 43*(6), p. 3861, (2016).

[6] **T. Liu**, H. Lin, L. Su, C. Shi, X. Tang, B. Bednarz, and X. G. Xu, “Modeling of radiotherapy Linac source terms using ARCHER Monte Carlo code: performance comparison of GPU and MIC computing accelerators,” *Medical Physics, 43*(6), p. 3732, (2016).

[7] **T. Liu**, N. Wolfe, H. Lin, K. Zieb, W. Ji, P. Caracappa, C. D. Carothers, and X. G. Xu, “Performance study of Monte Carlo codes on Xeon Phi coprocessors — testing MCNP 6.1 and profiling ARCHER geometry module on the FS7ONNi problem,” in *13th International Conference on Radiation Shielding & 19th Topical Meeting of the Radiation Protection and Shielding Division (ICRS-13 & RPSD 2016)*, France, Paris, (2016).

[8] Y. Gao, H. Lin, **T. Liu**, X. Li, B. Liu, R. Khawaja, M. Kalra, P. Caracappa, and X. G. Xu, “Simulation study of patient off-centering effect on organ dose in chest CT scan,” *Medical Physics, 42*(6), p. 3544, (2015).

[9] Y. Gao, **T. Liu**, X. Li, B. Liu, M. Kalra, P. Caracappa, and X. G. Xu, “A preliminary method of risk-informed optimization of tube current modulation for dose reduction in CT,” *Medical Physics, 42*(6), p. 3622, (2015).

[10] H. Lin, Y. Gao, **T. Liu**, D. Gelblum, A. Ho, S. Powell, X. Tang, and X. G. Xu, “Towards quantitative clinical decision on Deep Inspiration Breath Hold (DIBH) Or prone for left-sided breast irradiation,” *Medical Physics, 42*(6), p. 3529, (2015).

[11] H. Liu, **T. Liu**, X. G. Xu, J. Wu, and W. Zhuo, “Eye lens dose reduction from CT scan using organ based tube current modulation,” *Medical Physics, 42*(6), p. 3250, (2015).

[12] **T. Liu**, H. Lin, P. F. Caracappa, and X. G. Xu, “Extension of a GPU/MIC based Monte Carlo Code, ARCHER, to internal radiation dose calculations,” *Health Physics, 109*(S1), p. S56, (2015).

[13] **T. Liu**, H. Lin, X. G. Xu, and M. Stabin, “Development of a nuclear medicine dosimetry module for the GPU-Based Monte Carlo code ARCHER,” *Medical Physics, 42*(6), p. 3661, (2015).

[14] **T. Liu**, L. Su, X. Du, H. Lin, K. Zieb, W. Ji, P. Caracappa, and X. G. Xu, “Parallel Monte Carlo methods for heterogeneous hardware computer systems using GPUs and coprocessors: recent development of ARCHER code (invited talk),” in *American Nuclear Society (ANS) Annual Meeting 2015*, San Antonio, TX, USA, (2015).

[15] **T. Liu**, N. Wolfe, C. D. Carothers, W. Ji, and X. G. Xu, “Status of ARCHER — A Monte Carlo Code for the High-Performance Heterogeneous Platforms Involving GPU and MIC,” in *Joint International Conference on Mathematics and Computation (M&C), Supercomputing in Nuclear Applications (SNA) and the Monte Carlo (MC) Method (M&C+SNA+MC 2015)*, Nashville, TN, USA, (2015).

[16] **T. Liu**, N. Wolfe, C. D. Carothers, W. Ji, and X. G. Xu, “Optimizing the Monte Carlo neutron cross-section construction code, XSBench, to MIC and GPU platforms,” in *Joint International Conference on Mathematics and Computation (M&C), Supercomputing in Nuclear Applications (SNA) and the Monte Carlo (MC) Method (M&C+SNA+MC 2015)*, Nashville, TN, USA, (2015).

[17] **T. Liu**, N. Wolfe, C. D. Carothers, and X. G. Xu, “Development of a medical physics Monte Carlo radiation transport code ARCHER,” in *GPU Technology Conference 2015*, San Jose, CA, USA, (2015).

[18] N. Wolfe, C. D. Carothers, **T. Liu**, and X. G. Xu, “Concurrent CPU, GPU and MIC execution algorithms for ARCHER Monte Carlo code involving photon and neutron radiation transport problems,” in *Joint International Conference on Mathematics and Computation (M&C), Supercomputing in Nuclear Applications (SNA) and the Monte Carlo (MC) Method (M&C+SNA+MC 2015)*, Nashville, TN, USA, (2015).

[19] X. Du, **T. Liu**, L. Su, P. F. Caracappa, and X. G. Xu, “Extension of ARCHER Monte Carlo code to health physics dosimetry and shielding design: preliminary results,” *Health Physics, 107*(S1), p. S38, (2014).

[20] X. Du, **T. Liu**, L. Su, W. Ji, P. F. Caracappa, and X. G. Xu, “Development of CSG-based radiation shielding module for ARCHER: preliminary results for photons,” in *Radiation Protection and Shielding Division of the American Nuclear Society 2014*, Knoxville, TN, USA, (2014).

[21] W. Huo, **T. Liu**, L. Su, X. Du, Z. Chen, and X. G. Xu, “Comparisons of dosimetric accuracy and calculation time of ARCHER and MCNP5 codes for the Ir-192 brachytherapy case,” in *Radiation Protection and Shielding Division of the American Nuclear Society 2014*, Knoxville, TN, USA, (2014).

[22] H. Lin, **T. Liu**, L. Su, X. Du, Y. Gao, P. F. Caracappa, and X. G. Xu, “Formation of computational phantoms from CT numbers for use in the ARCHER Monte Carlo code,” *Health Physics, 107*(S1), p. S98, (2014).

[23] **T. Liu**, X. Du, L. Su, Y. Gao, W. Ji, D. Zhang, J. Q. Shi, B. Liu, M. K. Kalra, and X. G. Xu, “Monte Carlo CT dose calculation: a comparison between experiment and simulation using ARCHER-CT,” *Medical Physics, 41*(6), p. 424, (2014).

[24] **T. Liu**, X. Du, L. Su, Y. Gao, W. Ji, D. Zhang, J. Q. Shi, B. Liu, M. K. Kalra, and X. G. Xu, “Testing of ARCHER-CT, a fast Monte Carlo Code for CT dose calculation: experiment versus simulation,” *Transactions of the American Nuclear Society, 110*, p. 481, (2014).

[25] **T. Liu**, X. Du, L. Su, W. Ji, and X. G. Xu, “Development of ARCHER-CT, a fast Monte Carlo code for patient-specific CT dose calculations using Nvidia GPU and Intel coprocessor technologies,” in *GPU Technology Conference 2014*, San Jose, CA, USA, (2014).

[26] **T. Liu**, L. Su, X. Du, P. F. Caracappa, and X. G. Xu, “Comparison of accuracy and speed of ARCHER with MCNP for organ dose calculations from external photon beams under standard irradiation geometries,” *Health Physics, 107*(S1), p. S114, (2014).

[27] **T. Liu**, L. Su, X. Du, H. Lin, K. Zieb, W. Ji, P. Caracappa, and X. G. Xu, “Parallel Monte Carlo methods for heterogeneous hardware computer systems using GPUs and coprocessors: recent development of ARCHER code,” in *Radiation Protection and Shielding Division of the American Nuclear Society 2014*, Knoxville, TN, USA, (2014).

[28] N. Wolfe, **T. Liu**, C. Carothers, and X. G. Xu, “Heterogeneous concurrent execution of Monte Carlo photon transport on CPU, GPU and MIC,” in *Proceedings of the 4th Workshop on Irregular Applications: Architectures and Algorithms*, (2014), pp. 49-52.

[29] X. Du, **T. Liu**, W. Ji, X. G. Xu, and F. B. Brown, “Evaluation of vectorized Monte Carlo algorithms on GPUs for a neutron eigenvalue problem,” in *Proceedings of International Conference on Mathematics and Computational Methods Applied to Nuclear Science & Engineering (M&C 2013)*, Sun Valley, Idaho, USA, (2013), pp. 2513-2522.

[30] X. Du, **T. Liu**, L. Su, M. Riblett, and X. G. Xu, “A hardware accelerator based fast Monte Carlo code for radiation dosimetry: software design and preliminary results,” *Medical Physics, 40*(6), p. 475, (2013).

[31] **T. Liu**, X. Du, W. Ji, X. G. Xu, and F. B. Brown, “A comparative study of history-based versus vectorized Monte Carlo methods in the GPU/CUDA environment for a simple neutron eigenvalue problem,” in *Joint International Conference on Supercomputing in Nuclear Applications and Monte Carlo (SNA & MC 2013)*, Paris, France, (2013).

[32] **T. Liu**, X. Du, and X. G. Xu, “Affordable supercomputer-based Monte Carlo CT dose calculations: a hardware comparison between Nvidia M2090 GPU and Intel Xeon Phi 5110p coprocessor,” *Medical Physics, 40*(6), p. 459, (2013).

[33] **T. Liu**, W. Ji, and X. G. Xu, “Development of GPU-based Monte Carlo code for fast CT imaging dose calculation on CUDA Fermi architecture,” in *International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 13)*, Sun Valley, ID, (2013).

[34] **T. Liu**, X. G. Xu, and C. D. Carothers, “Comparison of two accelerators for Monte Carlo radiation transport calculations, NVIDIA Tesla M2090 GPU and Intel Xeon Phi 5110p coprocessor: a case study for x-ray CT imaging dose calculation,” in *Joint International Conference on Supercomputing in Nuclear Applications and Monte Carlo (SNA & MC 2013)*, Paris, France, (2013).

[35] M. J. Riblett, **T. Liu**, W. Ji, and X. G. Xu, “Use of hardware accelerators for Monte Carlo-based neutron radiation transport: a preliminary study,” *Health Physics, 105*(S1), p. S99, (2013).

[36] L. Su, X. Du, **T. Liu**, and X. G. Xu, “GPU-accelerated Monte Carlo electron transport methods: development and application for radiation dose calculations using six GPU cards,” in *Joint International Conference on Supercomputing in Nuclear Applications and Monte Carlo (SNA & MC 2013)*, Paris, France, (2013).

[37] L. Su, X. Du, **T. Liu**, and X. G. Xu, “Fast Monte Carlo electron-photon transport code using hardware accelerators: preliminary results for brachytherapy and radionuclide therapy cases,” *Medical Physics, 40*(6), p. 397, (2013).

[38] L. Su, X. Du, **T. Liu**, and X. G. Xu, “A fast Monte Carlo electron transport code for dose calculations using the GPU accelerator,” *Health Physics, 105*(S1), p. S41, (2013).

[39] X. G. Xu, **T. Liu**, L. Su, X. Du, M. Riblett, W. Ji, and F. B. Brown, “An update of ARCHER, a Monte Carlo radiation transport software testbed for emerging hardware such as GPUs,” *Transactions of the American Nuclear Society, 108*, pp. 433-434, (2013).

[40] X. G. Xu, **T. Liu**, L. Su, X. Du, M. J. Riblett, W. Ji, D. Gu, C. D. Carothers, M. S. Shephard, F. B. Brown, M. K. Kalra, and B. Liu, “ARCHER, a new Monte Carlo software tool for emerging heterogeneous computing environments,” in

[41] D. Zhang, W. Cai, X. Li, **T. Liu**, and B. Liu, “A comparison of radiation dose to the colon between single-energy and dual-energy CT colonography,” in *Radiological Society of North America 2013, 99th Scientific Assembly and Annual Meeting*, Chicago, IL, USA, (2013).

[42] **T. Liu**, A. Ding, W. Ji, X. G. Xu, C. D. Carothers, and F. B. Brown, “A Monte Carlo neutron transport code for eigenvalue calculations on a dual-GPU system and CUDA environment,” in *International Topical Meeting on Advances in Reactor Physics (PHYSOR 2012)*, Knoxville, TN, USA, (2012).

[43] **T. Liu**, A. Ding, and X. G. Xu, “Accelerated Monte Carlo methods for photon dosimetry using a dual-GPU system and CUDA,” *Medical Physics, 39*(6), p. 3818, (2012).

[44] **T. Liu**, A. Ding, and X. G. Xu, “GPU-based Monte Carlo methods for accelerating radiographic and CT imaging dose calculations: feasibility and scalability,” *Medical Physics, 39*(6), p. 3876, (2012).

[45] **T. Liu**, L. Su, A. Ding, W. Ji, C. D. Carothers, and X. G. Xu, “GPU/CUDA-ready parallel Monte Carlo codes for reactor analysis and other applications,” *Transactions of the American Nuclear Society, 106*, pp. 378-379, (2012).

[46] L. Su, **T. Liu**, A. Ding, and X. G. Xu, “A GPU/CUDA based Monte Carlo code for proton transport: preliminary results of proton depth dose in water,” *Medical Physics, 39*(6), p. 3945, 2012 (2012).

[47] L. Su, **T. Liu**, A. Ding, and X. G. Xu, “GPU/CUDA-based Monte Carlo methods for radiation protection dose calculations involving X-ray and proton sources,” *Health Physics, 103*(S1), p. S78, (2012).

[48] X. G. Xu, L. Su, **T. Liu**, and A. Ding, “GPU-based Monte Carlo method for medical physics applications: preliminary results for x-ray and proton applications,” in *World Congress on Medical Physics and Biomedical Engineering (WC 2012)*, Beijing, China, (2012).

[49] A. Ding, **T. Liu**, C. Liang, W. Ji, M. S. Shepard, X. G. Xu, and F. B. Brown, “Evaluation of speedup of Monte Carlo calculations of simple reactor physics problems coded for the GPU/CUDA environment,” in *International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 11)*, Rio de Janeiro, Brazil, (2011).

[50] **T. Liu**, A. Ding, P. F. Caracappa, and X. G. Xu, “Modeling of obese individuals using automatic deformation of mesh-based computational phantoms,” *Health Physics, 101*(S1), p. S34, (2011).

[51] M. Mille, A. Ding, **T. Liu**, Y. Na, P. F. Caracappa, and X. G. Xu, “The effect of patient obesity on PET/CT imaging dose using a phantom with a body mass index of 45,” *Health Physics, 101 *(S1), p. S31, (2011).

[52] X. G. Xu and **T. Liu**, “Quantifying uncertainty in radiation protection dosimetry using statistical phantoms,” in *The 3rd International Workshop on Computational Phantoms for Radiation Protection, Imaging and Radiotherapy*, Beijing, China, (2011).

[53] **T. Liu**, M. Mille, P. F. Caracappa, X. G. Xu, S. Nour, and K. Inn, “A software solution to bioassay detector calibration using a library of virtual phantoms,” *Health Physics, 99*(S1), p. S78, (2010).