Advanced ROS Treatment Techniques: External Radiation Therapy

External (or external beam) radiation therapy refers to any method of radiation therapy in which the radiation source is at a distance from the body. Advanced ROS offers the following state-of-the-art external beam treatment techniques and technologies:

3D Conformal Treatment Planning and Delivery

Traditionally, external beam radiation treatment planning has been based on two-dimensional images of the body. Advanced ROS uses the latest 3D conformal treatment planning systems to design radiation beams that conform to the exact shape and location of the tumor. A sophisticated computer system reconstructs CT images to create a 3D “virtual patient” on a computer screen which doctors then use to map out the exact location of the tumor and visualize the optimal path for the radiation beam. Many computational scenarios are tested in order to determine the best treatment strategy for each patient.

IMRT (Intensity Modulated Radiation Therapy)

IMRT is a treatment delivery method that uses 3D conformal principles and technology. IMRT allows us to target tissues with millimeter precision and vary (modulate) the strength (intensity) of the radiation beams during a treatment. Where older methods use a single radiation beam, IMRT breaks the beam into thousands of thin, tightly focused beams that enter the body from many angles to intersect on the cancer.

The linear accelerators at Advanced ROS are equipped with a multileaf collimator, a device that sculpts the beams to the shape of the tumor. As a result we can deliver a higher dosage of radiation to the tumor site and a lower dose to surrounding healthy tissue. IMRT produces the highest cancer control rate and the lowest rate of side effects of any generally available delivery method. Advanced ROS doctors are among the country’s most experienced practitioners of IMRT, having used it since the FDA approved it in 1996.


This new breakthrough technology combines in one system an advanced form of IMRT, CT scanning and advanced tools for planning and delivering radiation therapy. With TomoTherapy, Advanced ROS clinicians can now:

· Sculpt small, precise radiation beams to hit hard-to-reach tumors
· Deliver doses from all 360 degrees around the patient
· Target tumors using built-in CT scanning to confirm the shape and position of the tumor seconds before treatment begins
· Reduce radiation exposure to healthy surrounding tissue

TomoTherapy provides unprecedented accuracy in treatment planning and delivery. This allows for an increase in tumor dose, thereby increasing the likelihood of cancer cure and at the same time reducing side effects and complications. In June 2005, Advanced ROS will become the first radiation center in the Northeastern U.S. to offer TomoTherapy to our patients. To learn more about Tomotherapy, click here.

Stereotactic Radiosurgery and Radiotherapy

Stereotactic Radiosurgery (SRS) is not surgery in the conventional sense, but a treatment for brain tumors (both cancerous and non-cancerous) where the patient receives a single high dose of radiation. High-precision technology makes this possible, replacing the traditional 30 to 40 radiation treatments over six to eight weeks. All of the radiation is focused directly to the area of the abnormality with very little reaching normal brain structures or tissue. SRS is particularly useful for difficult to reach areas within the brain, and to treat tumors that used to be considered inoperable.

Many facilities use an SRS system that requires the patient to have screws drilled into the skull in order to attach a metal frame that allows reference points to be established. The frame has to be held in place all day while lengthy pre-treatment scans and procedures are performed. Advanced ROS offers patients the comfort and convenience of a frameless system. A few tiny gold markers are inserted into small incisions to help pinpoint the tumor.

Stereotactic Radiotherapy involves multiple daily treatments where in each session the patient receives a “fraction” of the total treatment dose. This is a non-invasive process suitable for patients with tumors near critical brain structures that cannot tolerate high single doses. Custom face masks along with precision lasers and x-ray verification are used to ensure that the treatment is reproducible and accurate over multiple sessions.


Conventional RT
vs. IMRT

IMRT Treatment Planning for Stereotactic Radiosurgery