External Radiation Therapy

External radiation therapy uses high-intensity beams of radiation, directed at a very specific area of the body, to kill cancer cells and shrink tumors. We offer more than one type of external beam radiation therapy to treat cancer. The type that is used for each patient is dependent on the type of cancer and where it is located.

Types of External Radiation Therapy

Intensity Modulated Radiation Therapy

Intensity Modulated Radiation Therapy (IMRT) is an advanced form of radiation treatment that allows radiation oncologists to precisely target tumor cells. It is a noninvasive therapy that uses Computed Tomography (CT) or other imaging modalities to build three-dimensional diagnostic images and map treatment plans to deliver tightly focused radiation beams of varying intensity to cancerous tumors without needles, tubes or catheters. Varying the intensity of these beams enhances the ability of IMRT to maximize dosage and minimize the amount of radiation distributed to surrounding healthy tissue.

Stereotactic Radiosurgery

Stereotactic Radiosurgery (SRS) is an advanced type of radiation technology. Despite its name, SRS is a non-surgical procedure. It delivers precisely-targeted radiation at much higher doses than traditional radiation therapy – with minimal damage to surrounding tissue.

Stereotactic Radiosurgery is ideal for otherwise inoperable tumors, such as those in the brain that cannot be treated with traditional surgical methods.

Stereotactic Body Radiotherapy

Stereotactic Body Radiotherapy (SBRT) is an advanced type of radiation technology. It is used to treat malignant or benign small to medium size tumors in the body, including the lung, liver, abdomen, spine, prostate, head and neck.

Using detailed imaging, computerized three-dimensional treatment planning, and precise treatment coordination, the radiation dose is delivered with extreme accuracy to limit effects on nearby organs.

Image Guided Radiation Therapy

Image Guided Radiation Therapy (IGRT) is an advanced form of radiation treatment that combines imaging and treatment capabilities on a single machine. Because tumors can move, image-guided radiation therapy allows a radiation oncologist to see and track the tumor at the time of treatment, and to make very fine adjustments to a patient’s position so as to greatly increase the precision and accuracy of radiation therapy treatment. Knowing exactly where the tumor is allows clinicians to irradiate only the tumor, sparing the surrounding normal tissue. This accuracy results in higher radiation doses to the tumor and thereby increases the likelihood of controlling or eliminating the cancer.

Three-dimensional (3–D) Conformal Radiation Therapy

Three-dimensional (3-D) conformal radiation therapy utilizes a highly advanced technology that allows the radiation oncologist to more precisely target a tumor by conforming or shaping the radiation beams based on exact width, height, and depth measurements. A customized immobilization device is created for each patient that ensures consistent positioning of the patient during the planning/simulation phase and subsequent treatments. This precision delivery of radiation beams to the targeted areas helps minimize damage to nearby healthy tissue and organs. It is used to treat many types of cancer including, but not limited to those affecting the prostate, head and neck, lung and gastrointestinal tract.


New York Oncology Hematology is proud to offer the region’s only Varian TrueBeam Radiotherapy System. This exciting technology opens new treatment possibilities, while providing greater accuracy, speed and comfort for patients – especially for hard to reach cancers. TrueBeam creates new treatment options, allowing NYOH physicians to create a more customized cancer treatment plan for each patient.