RapidArc®

Radiation therapy seeks to stop cancer cells from growing and dividing by damaging or killing them. The benefits of radiation therapy are enhanced the more closely the radiation beam conforms to the outlines of the tumor. With this kind of precise delivery of radiation to the targeted cancer tissue, the likelihood grows that treatment will kill all the cancer cells and shrink or eliminate the tumor, while protecting nearby healthy tissue and causing fewer side effects. Precisely targeted radiation that can detect and conform to the shape, size and location of the tumor, delivered swiftly and using higher doses, is the Holy Grail of radiation therapy.

Martin O’Neill Cancer Center offers the most precise, leading-edge radiation delivery technologies available, including Volumetric Arc Therapy (VMAT) or RapidArc® Radiotherapy Technology. An advanced form of IMRT, VMAT/RapidArc delivers a precisely-sculpted three-dimensional radiation dose while the radiation source rotates around your body. Like IMRT, VMAT/RapidArc uses 3-D scans of your body along with precision computer guidance to “paint” the radiation beams to exactly match the size, shape and location of the tumor. Small radiation beams are delivered from multiple directions, each customized in intensity and shape to conform exactly to the tumor. The responsive computer control adjusts the shape of the beam throughout treatment to ensure precision delivery of the radiation treatment with beams that can be as narrow as the width of a pencil tip. Because of this precision, higher doses of radiation can be used without increasing side effects. With less radiation spilled to nearby tissue, cancer cells receive a greater dose of radiation than with conventional therapies, while surrounding tissues receive less.

Like other treatments, VMAT/RapidArc therapy is delivered in a series of individual sessions. Using specialized software and an advanced Varian linear accelerator, VMAT/RapidArc delivers the radiation dose for each session from a number of different angles to the whole volume of the tumor in a 360-degree rotation, rather than in a slice-by-slice fashion. Unlike conventional IMRT treatments, where the machine must rotate several times around the patient or make repeated stops and starts to achieve different treatment angles, VMAT/RapidArc can deliver the dose to the entire tumor in a single rotation up to eight times as fast as conventional IMRT, typically in less than two minutes. With exposure times significantly reduced, healthy tissue receives even less damaging radiation while cancer cells receive the full therapeutic dose.

One key to our success with VMAT/RapidArc radiation therapy is the skill our radiation oncology team brings to treatment planning and delivery. Our radiation oncologists are leaders in their field, and every member of our team is a seasoned expert in radiation treatment. Using advanced scanning technologies, your radiation oncologist will map the exact location and shape of your tumor, and determine the total dose and number of treatments (fractions) your cancer will require, depending on the type, size, location, and density of your tumor. A radiation physicist and dosimetrist will program this information into the accelerator’s computer to set up your treatments. A radiation therapist will help you get into the correct position and ensure your comfort and monitor you throughout each treatment. Typically, treatment consists of five daily sessions each week for five to eight weeks.

VMAT/RapidArc can be used to non-invasively treat most solid tumors, cancerous and noncancerous, but is most commonly used to treat cancers of the prostate, head and neck, and central nervous system. It has also been used to treat breast, thyroid, lung, gastrointestinal and gynecological cancers and certain types of sarcomas.