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Ronald Ennis

  • ASSOCIATE PROFESSOR Radiation Oncology
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  • Radiation Oncology


  • MD, Yale University School of Medicine

  • MD, Yale University School of Medicine

  • Internship, Internal Medicine
    Long Island Jewish Medical Center

  • Residency, Therapeutic Radiolog
    Yale-New Haven Hospital


    Medical Training

    1993-1994 Chief Resident, Department of Therapeutic Radiology 
    Yale University School of Medicine, New Haven, CT


    1993-1994 Instructor, Department of Therapeutic Radiology 
    Yale University School of Medicine, New Haven, CT


    1991-1993 Resident, Department of Therapeutic Radiology 
    Yale University School of Medicine, New Haven, CT


    1990-1991 Intern, Department of Medicine, Long Island Jewish Medical Center, New Hyde Park, NY


    1990, M.D., Yale University School of Medicine, New Haven, CT

    1985, B.A., Columbia University, New York, NY


  • -
    New York Magazine's Top Doctors

  • 2005 - 2014
    America's Topd Doctors for Cancer

  • 2001 - 2015
    Castle Connelly America's Top Doctors



Prostate Cancer


Ennis, R.D., Peschel, R.E. Radiation Therapy for Prostate Cancer: Long-Term Results and Implications for Future Advances. Cancer 72: 2644-2650; 1993.;.

Ennis, R.D., Flynn, S.D., Fischer, D.B., Peschel, R.E. Preoperative Serum Prostate Specific Antigen (PSA) and Gleason Grade as Predictors of Pathologic Stage in Clinically Organ Confined Prostate Cancer: Implications for the Choice of Primary Treatment. Int J Radiat Oncol Biol Phys. 30:317-322; 1994..;.

Ennis, R.D., Fischer, D.B., Peschel, R.E. Early Prostate Specific Antigen (PSA) Response Predicts PSA Nadir in Patients with Prostate Cancer Treated with External Beam Radiation. Radiat Oncol Invest. 3:151-156; 1995.;.

Wilson, L.D., Ennis, R.D., Percarpio, B., Peschel, R.E. Location of the Prostatic Apex and its Relationship to the Ischial Tuberosities. Int J Radiat Oncol Biol Phys. 29:1133-1138; 1994.;.

Amols, H.I., Zaider, M., Weinberger, J., Ennis, R., Schiff, P.B., Reinstein, L.E. Dosimetric Considerations for Catheter Based Beta and Gamma Emitters in the Therapy of Neointimal Hyperplasia in Human Coronary Arteries. Int J Radiat Oncol Biol Phys. 36:913-921; 1996.;.

Weinberger, J., Amols, H., Ennis, R.D., Schwartz, A., Wiedermann, J.G., Marboe, C.. Intracoronary Irradiation: Dose Response for the Prevention of Restenosis in Swine. Int J Radiat Oncol Biol Phys. 36:767-775; 1996.;.

Neugut, A.I., Ahsan H., Robinson E., Ennis, R.D. Bladder Cancer and Other Second Malignancies Following Prostate Cancer Radiotherapy. Cancer. 79:1600-1604; 1997..;.

Ingenito, A.C., Ennis, R.D., Hsu, I.C., Begg, M.D., Benson, M.C., Schiff, P.B. Re-examining the Role of Prostate-Specific Antigen Density in Predicting Outcome for Clinically Localized Prostate Cancer. Urology. 50:7378; 1997.;.

Ennis, R.D., Katz, A.E., De Vries, G.M., Heitjan, D.F., O’Toole, K.M., Rubin, M., Buttyan, R., Benson, M.C., Schiff, P.B. Detection of Circulating Prostate Carcinoma Cells via an Enhanced Reverse Transcriptase-Polymerase Chain Reaction in Patients with Early Stage Prostate Carcinoma: Independence from other Pre-treatment Characteristics. Cancer. 79:2402-2408; 1997.;.

Ennis R.D., Malyszko, B., Rescigno, J., Whitman, A.E., Heitjan, D.F., O’Toole, K.M., Rubin, M., Schiff, P.B. Biologic Classification As an Alternative to Anatomic Staging for Clinically Localized Prostate Cancer: A Proposal Based on Patients Treated with External Beam Radiotherapy. Urology. 51:265-270; 1998.;.

Ennis, R.D., Malyszko, B.K., Heitjan, D.F., Rubin, M.A., O’Toole, K.M., Schiff, P.B. Changes in Biochemical Disease-Free Survival Rates as a Result of Adoption of the Consensus Conference Definition in Patients with Clinically Localized Prostate Cancer Treated with External-Beam Radiotherapy. Int J Radiat Oncol Biol Phys. 41:511-517; 1998.;.

Rubin, M.A., Buyyounouski, M., Bagiella, E., Sharir, S., Neugut, A., Benson, M., de la Taille, A., Katz, A.E., Olsson, C.A., Ennis, R.D. Microvessel Density in Prostate Cancer: Lack of Correlation with Tumor Grade, Pathologic Stage and Clinical Outcome. Urology. 53:542-547; 1999.;.

Lee, N., Newhouse, J.H., Olsson, C.A., Benson, M.C., Petrylak, D.P., Schiff, P.B., Bagiella, E., Malyszko, B., Ennis, R.D. Which Patients with Newly Diagnosed Prostate Cancer Need a Computed Tomography Scan of the Abdomen and Pelvis? An Analysis Based on 588 Patients. Urology. 54:490-494; 1999.;.

Peshel, R.E., Robnett, T.J., Hesse, D., King, C.R., Ennis, R.D., Schiff, P.B., Wilson, L.D. PSA Based Review of Adjuvant and Salvage Radiation Therapy Vs. Observation in Postoperative Prostate Cancer Patients. Int J Cancer (Radiat Oncol Invest). 90:29-36; 2000.;.

Ennis, R.D., Petrylak, D.P., Singh, P., Bagiella, E., O’Toole, K.M., Benson, M.C., Olsson, C.A. The Effect of Cystectomy and Peri-Operative Methotrexate, Vinblastine, Doxorubicin (Adriamycin), and Cisplatin (M-VAC) Chemotherapy on the Risk and Pattern of Relapse in Patients with Muscle Invasive Bladder Cancer. J. Urol. 163:1413-1418; 2000.;.

Wuu, C.S., Ennis, R.D., Schiff, P.B., Lee, E.K., Zaider, M. Dosimetric and Volumetric Criteria for Selecting a Source Activity and a Source Type (I-125 or Pd-103) in the Presence of Irregular Seed Placement in Permanent Prostate Implants. Int J Radiat Oncol Biol Phys. 47:815-820; 2000.;.

de la Taille, A., Katz, A.E., Bagiella, E., Buttyan, R., Sharir, S., Olsson, C.A., Burchardt, T., Ennis, R.D., Rubin, M.A. Microvessel Density as a Predictor of PSA recurrence after Radical Prostatectomy: A Comparison of CD-34 and CD-31. Am J Clin Pathol. 113:555-562; 2000.;.

Gewanter, R.M., Wuu, C.S., Laguna, J.L., Katz, A.E., Ennis, R.D. Intraoperative Preplanning for Transperineal Ultrasound-Guided Permanent Prostate Brachytherapy. Int J Radiat Oncol Biol Phys. 48:377-380; 2000.;.

Lee, N., Fawaz, R., Olsson, C.A., Benson, M.C., Petrylak, D.P., Schiff, P.B., Bagiella, E., Singh, A., Ennis, R.D. Which Patients with Newly Diagnosed Prostate Cancer Need a Radionuclide Bone Scan? An Analysis Based on 631 Patients. Int J Radiat Oncol Biol Phys. 48:1443-1446; 2000.;.

Lee, N., Wuu, C.S., Brody, R., Laguna, J.L., Katz, A.E., Bagiella, E., Ennis, R.D. Factors Predicting for Postimplantation Urinary Retention after Permanent Prostate Brachytherapy. Int J Radiat Oncol Bio Phys. 48:1457-1460; 2000.;.

Industry Relationships

Physicians and scientists on the faculty of the Icahn School of Medicine at Mount Sinai often interact with pharmaceutical, device and biotechnology companies to improve patient care, develop new therapies and achieve scientific breakthroughs. In order to promote an ethical and transparent environment for conducting research, providing clinical care and teaching, Mount Sinai requires that salaried faculty inform the School of their relationships with such companies.

Dr. Ennis did not report having any of the following types of financial relationships with industry during 2015 and/or 2016: consulting, scientific advisory board, industry-sponsored lectures, service on Board of Directors, participation on industry-sponsored committees, equity ownership valued at greater than 5% of a publicly traded company or any value in a privately held company. Please note that this information may differ from information posted on corporate sites due to timing or classification differences.

Mount Sinai's faculty policies relating to faculty collaboration with industry are posted on our website. Patients may wish to ask their physician about the activities they perform for companies.

Insurance Information

Physicians who provide services at hospitals and facilities in the Mount Sinai Health System might not participate in the same health plans as those Mount Sinai hospitals and facilities (even if the physicians are employed or contracted by those hospitals or facilities).

Information regarding insurance participation and billing by this physician may be found on this page, and can also be obtained by contacting this provider directly. Because physicians insurance participation can change, the insurance information on this page may not always be up-to-date. Please contact this physician directly to obtain the most up-to-date insurance information.

Insurance and health plan networks that the various Mount Sinai Health System hospitals and facilities participate in can be found on the Mount Sinai Health System website.

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