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Radiation therapy is a key treatment to eradicate cancer and prevent it from returning.

As part of our Cancer Care Program, radiation oncology, which oversees radiation therapy, is one of our centers of excellence and is accredited by the American College of Radiology.

Radiation oncology is the use of radiation and radioactive materials to treat cancer and other diseases. The goal of radiation therapy is to target the cancer while limiting damage to normal tissue. Radiation therapy destroys cancer cells in the treated area by damaging their genetic material. This prevents the cells from multiplying, and keeps tumors from growing.

Half of all cancer patients are treated with radiation therapy. Depending on the type and extent of cancer, radiation therapy can be used alone or in combination with other treatments, such as surgery or chemotherapy.

Meet the Team

Health Quest radiation oncologists are board certified. Other team members include oncology-trained nurses and medical physicists who carefully calculate treatment plans and monitor equipment and procedures to ensure patient safety. Our medical physicists are certified by the American Board of Radiology or the American Board of Medical Physics and are licensed by New York State.

Dimitrios Papadopoulos, MD

Radiation Oncology
Dimitrios Papadopoulos, MD

Thomas Mazzilli, MD

Radiation Oncology
Thomas Mazzilli, MD

Radiation Oncology
Robert Smith, MD

Camilo Torres

Radiation Oncology
Camilo Torres, MD

Treatment Options

Using the most advanced equipment, the radiation oncologists can precisely target the cancerous area to increase the chances for success, which can lead to a speedier recovery. Radiation can take place before, during or after surgery and chemotherapy treatments. Your radiation oncologist will discuss the best course of treatment for your situation.

There are four common types of radiation therapy used to treat cancer:

  • External Beam Radiation Therapy directs a beam of radiation at the cancerous area to destroy the tumor and any nearby cancer cells. The team can control the size and shape of the beam, as well as how it is directed at the patient’s body. This treatment spares surrounding normal tissue.
  • Brachytherapy (or internal radiation therapy) involves placing a radioactive seed in or very close to the tumor, allowing the radiation oncologist to deliver a large dose of radiation directly to the cancerous cells with minimal impact on the surrounding tissue.
  • Intraoperative therapy is used in the operating room during surgery, especially for breast cancer. In this therapy, a small machine provides low-energy radiation to a specific target exposed during surgery.
  • Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy(SBRT) are two other highly sophisticated techniques of external beam radiation therapy. They are most commonly used to treat tumors of the brain, lung and liver.
  • TomoTherapyis a treatment system that uses a unique CT scanner to deliver radiation continuously from all angles around the patient. More angles and more precise modulation result in dose distributions that conform to tumors and minimize damage to surrounding healthy tissue.

The Process

Although each patient’s course of radiation therapy is different, here are the most common steps:

  • Consultation: A radiation oncologist reviews your medical tests, gives a complete physical examination and discusses the benefits and risks of radiation therapy. And a radiation oncology nurse explains the radiation oncology treatment process.
  • CT (Computed Tomography) Simulation: To help your team aim the treatment safely and exactly to the tumor each and every time, your anatomy is measured and skin marked to simulate treatment without administering actual radiation. During simulation, you are placed on the table in the exact position you will be in during the actual treatments. A simulation lasts about 60 minutes.
  • Treatment Planning: Special blocks or shields are made to shape the radiation to your tumor and keep the rays from hitting normal tissue. This planning process can be time consuming and may take up to two weeks to complete.
  • Verification Simulation: This procedure ensures that the plan that has been customized for your treatment lines up correctly on your body and covers the right areas. No treatment will be given at this time.
  • Daily Treatments: Treatment delivery from one or more directions may be used and the beam may be on for anywhere from ten seconds to several minutes for each field. A treatment visit can last 30 to 60 minutes.
  • Weekly Status Checks During Treatment: During radiation therapy, your radiation oncologist and nurse follow your progress, recommend treatments for any side effects (and address any concerns you may have). Verification films will be taken daily or after every 5 treatments. Your Health Quest treatment team reviews these films to be sure that the treatment beams remain precisely aimed at the proper target, ensuring treatment accuracy.
  • Follow-up Visits After Treatment: Follow-up appointments help your radiation oncologist make sure your recovery is proceeding normally. As time goes on, the frequency of your visits will decrease.

Medical Physicists/Residency Program

The radiation oncologists work with board certified medical physicists to ensure complex treatment plans are carefully calculated for each patient. They also monitor equipment and procedures to ensure patient safety.

Health Quest is one of the few institutions in New York State to operate a medical physics residency program. We feel that the presence of this teaching program helps to keep all of our staff performing at the highest professional level possible.

Safety First

Safety is a critical concern in an environment where radiation and potent chemicals are commonly used.

To best protect our patients and staff from unnecessary risk, we take every opportunity to ensure that staff is properly trained, our equipment is properly maintained and our procedures are flawless. This includes testing all of our equipment above and beyond what is recommended by the manufacturers. We also contract with independent organizations to do safety audits of our operations.

Committed to patient safety, many physicians and staff participate in the LifeWings team-training program to improve team communication skills and reduce errors. The LifeWings program brings together the best practices of high-reliability enterprises such as commercial aviation, U.S. Navy aircraft carriers, nuclear submarines and nuclear power plants and adapts them for use in healthcare organizations.


Dyson Center for Cancer Care
45 Reade Place
Poughkeepsie, NY 12601
(845) 431-5645
(800) 421-1220

Agarwal Radiation Oncology Center
670 Stoneleigh Avenue
Carmel, NY 10512
(845) 278-5641
(800) 421-1220

Ulster Radiation Oncology center
111 Mary's Avenue, Suite 1
Kingston, NY 12401
(845) 339-7700
(800) 421-1220

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