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Prakash Aryal, PhD

Academic Title:

Assistant Professor

Primary Appointment:

Radiation Oncology

Education and Training


1988                             B.Sc., Physics, Tribhuvan University, Nepal

1991                             M.Sc., Physics, Tribhvan University, Nepal 

1995                             Dip. R.P., Radiological Physics, Bombay University, India 

1999                              MSBS, Radiation Therapy, Medical College of Ohio, Toledo, OH 

2014                              Ph.D., Physics, University of Kentucky, Lexington, KY  

Dissertation title, “Reevaluation of the AAPM TG-43 Brachytherapy Dosimetry Parameters for an I-125 Seed, and the Influence of Eye Plaque Design on Dose Distributions and Dose-Volume Histograms”.  Advisors: Janelle A. Molloy, PhD, and Mark J. Rivard, PhD


2003                               Proxima Therapeutics GliaSite RTS training certificate

2004                               Novoste Beta-Cath vascular brachytherapy training certificate

2004                               American Board of Radiology (ABR), Therapeutic Radiological Physics


Dr. Prakash Aryal is an assistant professor in Radiation Oncology at University of Maryland. He obtained his master's degree in physics from Tribhuvan University, Nepal and post graduate degree in radiological physics from Bombay University, India. He came to United States in 1997 and obtained his master's degree in medical physics from Medical College of Ohio (now University of Toledo Medical Center) in 1999 and joined Baystate Medical Center in Springfield, MA as a medical physicist. His primary role was to supervise dosimetry section and guide dosimetrists for complex treatment plans. He moved to University of Kentucky in December 2000 as a staff physicist where he also obtained his PhD in physics. He  was a director of brachytherapy and faculty member before joining University of Maryland. His primary research interests are in brachytherapy, Monte Carlo simulation, electrons, motion management and image guided radiation therapy (IGRT). 

Research/Clinical Keywords

Brachytherapy, Monte Carlo Simulation, Motion Management, Image Guided Radiation Therapy (IGRT)

Highlighted Publications

  1. W. Luo, M. Young, P. Aryal, E J. Johnson, J A. Molloy, “Development of aQuantitative Target Localizing and Tracking Method for IGRT” Med. Phys. 37 , 3153 (2010)
  2. W. Luo, P. Aryal, and M. Randall. “Calculation of Prescribed Dose for Permanent Implant with Cs-131 Using LQ Equation including Resensitization”. Med. Phys. 39 , 3811 (2012)
  3. W. Luo, J. Molloy, P. Aryal, J. Feddock and M. Randall, “Determination of prescription dose for Cs-131 permanent implants using the BED formalism including resensitization correction,” Med. Phys. 41, 024101 (2014)
  4. P. Aryal, J. A. Molloy, and M. J. Rivard, “A modern Monte Carlo investigation of the TG-43 dosimetry parameters for an 125I seed already having AAPM consensus data,” Med. Phys. 41, 021702-(1-10) (2014)
  5. C. E. Wooten, M. E. Randall, J. Edwards, P. Aryal, W. Luo and J. Feddock “Implementation and early clinical results utilizing Cs-131 permanent interstitial implants for gynecologic malignancies.” Gynecol Oncol. 133(2):268-73, May (2014)
  6. P. Aryal, J. A. Molloy, and M. J. Rivard, “Independent dosimetric assessment of the model EP917 episcleral brachytherapy plaque,” Med. Phys. 41, 092102 (2014).
  7. P. Aryal, J. A. Molloy, and M. J. Rivard, “Erratum: Independent dosimetric assessment of  the model EP917 episcleral brachytherapy plaque” Med. Phys. 42, 3085 (2015)
  8.  J. Feddock, C.E. Wooten, P. Aryal, “Integrating Permanent InterstitialBrachytherapy Using Cesium-131 into the Primary Management of Gynecologic Malignancies: Bringing Back the Old School” Brachytherapy (Impact Factor: 2.76). 05/2015; 14:S60
  9. W. Luo, A. Meacham, X. Xie, J. Li, P. Aryal, R. McGarry and J. Molloy, “Monte Carlo dose verification for lung SBRT with CMS/XiO superposition algorithm" Biomedical Physics & Engineering Express, Volume 2, Number 1, February 2016.
  10.  Steber, C., DeMasi, J., Aryal, P., Randall, M.E. Feddock, J.M. "Initial Results of Outpatient Permanent Syed-Neblett Interstitial Implants Using Cesium-131 for Gynecologic Malignancies." International journal of radiation oncology, biology, physics 96, 2S (2016)

Clinical Specialty Details

1.        High and low dose rate brachytherapy (2000-present)

           Perform treatment planning- tandem and ovoids, cylinder, Wright applicators, Capri applicators

           Perform daily QA, quarterly HDR source exchange

           Perform annual HDR and LDR QA

           Perform interstitial gynecological Cs-131 implant, Syed implant with Ir-192

2.        Supervisor of brachytherapy (2011-present)

          Supervised of all the brachytherapy physics services in the department.

          Developed and implemented HDR brachytherapy planning and double check procedures.

          Provided safety training class for physicians, physicists, resident physician, nurses, and medical physics residents.

          Commissioned and implemented Cs-131 for permanent implant for gynecological malignant tumors.

          Commissioned VariSeed planning system with updated I-125 (model IAI-125A) dosimetry parameters.

          Revised and implemented HDR/LDR QA procedures.

          Commissioned prowess brachytherapy treatment planning system.

          Implemented Ra-223 calibration and its safety procedures.

          Performed several HDR/LDR plans.

3.       Prostate brachytherapy (1999-present)

          Perform treatment plans using Transrectal Ultra Sound Guided system.

          Perform source ordering, receiving, assay, source loading, CT based post plans.

4.       Machine QA (1999-present)

          Responsible to supervise for daily therapist QA record of Varian LINAC machines

          Responsible of monthly and annual QA of EX and Platinum Varian linear accelerators.

5.       Total Body Irradiation (2000-present)

          Commissioned Total Body Irradiation for EX and PLAT Varian machines

          Responsible for treatment planning, and dose calculation

          Responsible and supervise for compensator construction

6.       4D CT acquisition (2010-present)

          Perform QA for 4D CT acquisition

          Perform 4DCT acquisition for patient treatment

7.       Stereotactic body radiation therapy (SBRT) 2011-present

          Commissioned stereotactic body frame for Truebeam machine

         Perform QA for SBRT patients

          Supervise for daily CBCT acquisition and patient set up

8.       Routine physics duties (1999-present)

         Perform weekly charts check/review

         Supervise daily QA performed by therapists

         Perform monthly and annual QA

         Perform plan check

         Support dosimetry as needed

         Perform IMRT QA

         Construct custom compensator using bolus, lead, aquaplast etc.

Professional Activity

2005-2008                   Member, membership committee of American of Physicists in Medicine (AAPM)

2009-2014                    Member, AAPM Task Group 143

2010-present                Reviewer, Journal of brachytherapy (1 per year)

2014-present                Reviewer, Medical Physics

2014-present                Abstract reviewer, Medical Physics (25-30 per year)

2015-present                Oral Examiner, American Board of Radiology(ABR) for Therapeutic Radiological Physics