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Sean Koerner

Sean Koerner, MD

4.924 ratings, 5 reviews

Radiation Oncology

Accepting New Patients

Highlights

Age Groups Seen

  • Adult 18-65
  • Older Adult >65

Languages

  • English

Gender

Male

Hospital Affiliations

  • Northwell Health - Vassar Brothers Medical Center
  • Northwell Health - Putnam Hospital
  • Northwell Health - Northern Dutchess Hospital

About Sean Koerner

Professional Statement

Dr. Koerner is a National Cancer Institute (NCI) trained radiation oncologist with experience treating an array of malignancies with advanced radiotherapy techniques. His practice includes stereotactic radiosurgery (SRS), stereotactic body radiation therapy (SBRT), and intensity modulated/image-guided radiotherapy (IMRT/IGRT), as well as the use of focused internal radiation (brachytherapy). He approaches each patient intending to provide the most appropriate, individualized treatment options and has extensive experience with the curative treatment of cancers with SBRT. Treatment of more advanced cancers, including cancers that have metastasized, is another of his areas of expertise.

Get To Know Me

Why should someone choose you to care for their health?
I treat all patients with the compassion, empathy, and individualized care that everyone deserves when facing a cancer diagnosis.

What is the most important thing your patients should expect from their professional relationship with you? What do you expect from them?
My patients should expect personal support, evidence-based care recommendations, and a commitment to seeing them through treatment. I expect patients to bring up their questions and concerns so that we can address them together.

How do you spend your valuable personal time when you’re not caring for patients?
I enjoy spending outdoor time with my family and friends, especially hiking in the Adirondacks, skiing, and experiencing new cultures.

Why did you choose your specialty and what is its greatest reward?
Radiation oncology provides an opportunity to help patients facing a multitude of challenges, and working with each patient to find the best treatment for them is a daily reward of this field.

Expertise

Education

  • Residency: UPMC Shadyside Hospital, 2024
  • Internship: Ascension St Francis, 2019
  • Medical School: New York Medical College, 2018

Locations

  1. Northwell Vassar Brothers Medical Center
  2. Northwell Vassar Brothers Medical Center The Dyson Center for Cancer Care
    • 45 Reade Pl Dyson Center Floor 1, Poughkeepsie, NY 12601
    • Get Directions
  3. Northwell Cancer Institute Radiation Oncology at Fishkill
    • 200 Westage Business Ctr Drive, Suite 130, Fishkill, NY 12524
    • Get Directions
  4. Northwell Cancer Institute Ulster Radiation Oncology Center at Kingston
  5. Northwell Putnam Hospital
  6. Northwell Putnam Hospital Argarwal Radiation Oncology Center

Insurance

Search plans
  • Aetna
  • Capital District Physicians' Health Plan
  • Centivo
  • Cigna
  • ConnectiCare
  • Coventry-Aetna
  • Elderplan
  • EmblemHealth
  • Empire BlueCross Blue Shield
  • Empire Plan
  • Fidelis Care
  • Hamaspik
  • Health Plus
  • MagnaCare
  • Medicaid New York
  • Medicare
  • Medicare Railroad
  • Multiplan Inc
  • MVP Health Care
  • Northwell Direct
  • Tricare Humana Military
  • United Healthcare
  • Wellcare

Ratings & Reviews

4.9 out of 5

24 ratings, 5 reviews

Provider star ratings are calculated using patient responses to the provider care questions in our patient experience survey. Below you can see the provider’s star rating and the number of his or her patients who have provided feedback. Ratings depicted represent those clinicians that have at least 30 completed surveys on a rolling 12 month basis.

    5 out of 5 stars
    Reviewed on 12/23/2025

    I think they are doing a great job

    5 out of 5 stars
    Reviewed on 12/11/2025

    Not at this time

    5 out of 5 stars
    Reviewed on 7/1/2025

    Very thorough!

    5 out of 5 stars
    Reviewed on 6/14/2025

    Speaks in a clear and concise manner tells you what he knows and what he’s thinking and what he is going to do about it

    5 out of 5 stars
    Reviewed on 3/1/2025

    He answered all the questions asked and was very concerned and understanding