Dr. John E. Sylvester

  • MD
  • Radiation Oncologist
  • Spoken languages English


Special clinical interest in Prostate, Genitourinary, Bladder, Kidney, Penile, Testicular, Urethral, Ureter and Skin cancer

Dr. John Sylvester has performed over 6,000 prostate brachytherapy procedures. He has developed multiple technical improvements in the procedure, by improving visualization of the urethra during the procedure, optimally utilizing R.A.P.I.D. strand, and co-developed THINStrand. He has published numerous articles and medical textbook chapters on prostate brachytherapy and co-authored and edited The Prostate Cancer Treatment Book. He wrote the white paper on 4-D Calypso image guided IMRT and was first physician in USA to use SpaceOAR in prostate cancer IG-IMRT. Dr. Sylvester earned the “Innovation Research Award 2014” from the Manatee County Chamber of Commerce and was awarded Sarasota Magazine’s Top Doctors distinction from 2012-2016. He publishes Prostate cancer research papers every year and regularly lectures at the National Radiation Oncology Society Medical Conferences (ASTRO, ABS).

Career Positions

Current position(s)

  • GenesisCare - Radiation Oncologist, Lakewood Ranch, FL

Past position(s)

  • Lakewood Ranch Oncology Center - Director, Radiation Oncologist, Lakewood Ranch, FL
  • Prostate Cancer Treatment Center - Medical Director and Director of Research, Seattle, WA
  • Seattle Prostate Institute - Co-founder, Director of Education and Training, Institute Director, Seattle, WA



  • Undergrad - University of California Santa Barbara, BA, Biological Sciences, Santa Barbara, CA
  • Medical School - University of California Los Angeles School of Medicine, Los Angeles, CA


  • University of California Los Angeles Medical Center, Radiation Oncology, Chief Resident, Los Angeles, CA


  • University of Southern California, Huntington Memorial Hospital, Internal Medicine, Los Angeles, CA

Expertise And Interests


  • Prostate, Bladder and Testicular Cancer


Awards and honors

  • Lead Seattle investigator in a gene therapy protocol for salvage of external beam radiation therapy failures, lead investigator in a randomized trial evaluating the new Thin Strand™ versus standard size seeds, lead investigator in a multi-institutional pr


  • Continued Benefit to Rectal Separation for Prostate Radiation Therapy: Final Results of a Phase III Trial.
  • Sexual quality of life following prostate intensity modulated radiation therapy (IMRT) with a rectal/prostate spacer: Secondary analysis of a phase III trial.
  • Prospective, Randomized, Patient-Blinded, Multicenter Trial of Perirectal Spacer in Men Undergoing Prostate IG-IMRT: Dosimetry and Toxicity Evaluation
  • Defining and Treating Local Failure: Long-Term Brachytherapy Results
  • First Report on Seed Migration to the Lung with the Use of a Thinner I-125 Radioactive Seed Within 20 Gauge Needles for Permanent Seed Prostate Brachytherapy
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D. A. Hamstra, N. F. Mariados, D. K. Shah, S. M. Kurtzman, J. E. Sylvester, S. H. Zimberg, R. S. Hudes, L. Karsh, M. D. Logsdon, D. C. Beyer, M. Kos, R. A. Hsi, K. Forsythe, E. M. Soffen, P. M. Francke, H. Zhang, T. L. DeWeese, R. J. Ellis II, C. A. Mantz, W. R. Bosch, and J. M. Michalski;, 2016, ASTRO

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Daniel A. Hamstra, Dhiren Shah, Steven Kurtzman, John Sylvester, Shawn H. Zimberg, Richard S. Hudes, LawrenceIvan Karsh, Mark D. Logsdon, David Beyer, Michael Kos, R. Alex Hsi, Kevin Forsythe, Edward M Soffen, Patrick MFrancke, Hong Zhang, Theodore L. DeWeese, Rodney J. Ellis, Jeffrey Bogart, Constantine Mantz, Neil Mariados, 2017, Genitourinary Cancers Symposium

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John Sylvester's Reviews


based on 284 Ratings 63 Comments


I was impressed with the knowledge and professionalism of Dr Sylvester. He is a brilliant Dr.


Everything is good, no need to change.


Not a thing. Dr. Sylvester's treatments saved my life, and I'm very grateful. I trust and respect this doctor.


nothing missing

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