An
integral part of V.S. Hospital's comprehensive cancer center, the Department
of Radiation Oncology provides state-of-the-art cancer therapy and
compassionate patient care in close collaboration with oncologists, surgeons
and other cancer specialists. Our experts use the newest state-of-the-art
devices and procedures to provide patients with the best possible results.
Why are we the best? It's simple. The Department practices outstanding
patient care, produces and implements revolutionary research and technology
and relies on a talented pool of acclaimed faculty to train tomorrow's top
radiation oncologists and physicists. Our priority is to explore and apply
new ideas in the constantly changing field of therapeutic radiology.Radiation Therapy: Radiation therapy is the treatment of cancer using penetrating beams of high energy waves or streams of particles called radiation. Radiation therapy basically can be given in two different ways: teletherapy ("long distance therapy") and brachytherapy ("short distance therapy"). Teletherapy is the most common form of radiation treatment. A very high energy machine is used to generate different kinds of radiation that are aimed at a tumor from a distance
(i.e.,
the machine would not touch the tumor). The more capable the machine, the
more precisely a treatment plan can be tailored to your needs. The most
sophisticated teletherapy machine is a Linear Accelerator.Linear Accelerator: Our radiotherapy department currently houses one teletherapy unit - The Varian Clinac 2100 DMX High Energy Linear Accelerator with MLC. It is an extremely powerful, top-of-the-line, 23-million volt, computer controlled, ultra-precise linear accelerator. It can produce a spectrum of different energy x-rays and electrons (each type and energy penetrates tissues differently, allowing us to match each patient's needs with the right combination). The very high-energy beams of this machine are ideal for deeply situated tumors (for example, prostate cancers, rectal cancers, pancreatic cancers and uterine cancers).
HDR Brachytherapy: Internal radiation therapy or Brachytherapy is the placement of the radiation source as close as possible to the cancer cells. Instead of using a large radiation machine, the radioactive material, sealed in a thin wire, catheter, or tube (implant), is placed directly into the affected tissue. This method of treatment concentrates the radiation on the cancer cells and lessens radiation damage to some of the normal tissue near the cancer. Before actual treatment delivery, the treatment needs to be planned.
CT Simulator: This ability to localize structures in 3-dimensional space and plan the treatment portals in a virtual environment requires the use of imaging information that can be referenced to the treatment machine for precise alignment of the beams relative to the target. The Department of Radiation Oncology has a dedicated CT-simulator with patient setup indicators that relate the patient's position on the CT to the therapy unit. Our unit, a General Electric CT E Plus, is an advanced 3D spiral scanner. This allows us to acquire a full set of finely detailed images in a very short period of time and proceed to planning the patient's treatment in the absence of the patient. A computer-generated reconstruction of the patient with full anatomic information is used for the planning of optimal beam orientations.
Depending on the type of treatment the patient will be receiving, body moulds or other immobilization devices are made. They are used during each treatment to ensure that the patient is positioned correctly.
3D Treatment Planning: As treatment
plans have become more sophisticated, the ability of all radiology treatment
facilities to cure tumors without harming patients has improved. Much of
this success is directly attributable to the use of sophisticated computer
systems operated by highly trained, full-time dedicated medical physicists.
Typical planning systems depict for every patient both tumors and sensitive
normal tissues in 3-dimensional space. The radiation oncologist and the
medical physicist seek to include all of the tumor and as little normal
tissue as possible within the "envelope of irradiation." Such
plans are said to conform to the tumor and are often referred to as "conformal
irradiation."Beam Shaping: Radiation beams must be shaped to match their intended targets. Within virtually all treatment machines, soon after the beam is produced it is "collimated" into a useful shape by blocking unwanted parts of the beam. Depending on the desired shape, additional blocking of the beam is usually required. We custom build most of the blocks that our patients require and have a dedicated block-fabrication facility with a full-time block-cutting specialist. In addition, our linear accelerator has an 80-leaf collimator that is used to shape the beam further, under computer-controlled guidance, into complex geometric shapes for patients who require this technology. systems have the ability to create static field shapes or to dynamically collimate an active beam to alter the beam intensity as well as the beam shape.
Treatment Delivery: For most types of cancer, radiation therapy usually is given 5 days a week for 6 or 7 weeks. (When radiation is used for palliative care, the course of treatment is shorter, usually 2 to 3 weeks.) The total dose of radiation and the number of treatments patients need will depend on the size, location, and kind of cancer they have, the general health, and other medical treatments they may be receiving.
