Beatriz E. Amendola MD, Presenter: Nothing to Disclose

Naipy Perez MS, Abstract Co-Author: Nothing to Disclose

Marco A. Amendola MD, Abstract Co-Author: Nothing to Disclose

Alejandro Iglesias ARRT, Abstract Co-Author: Nothing to Disclose

RapidArc is a new technology from Varian Medical system that is used to deliver highly focused intensity-modulated radiation therapy (IMRT) in shorter times than conventional IMRT. The linear accelerator rotates 360 degrees around the patient. The velocity of the gantry and the dose rate is modulated to deliver the desired dose from nearly any angle to the target volume by protecting surrounding structures. During delivery, the field shape, formed by a multileaf collimator (MLC), changes constantly. In addition, image guided radiation therapy with an on-board imager allows a more precise treatment delivery. RapidArc was incorporated in our center in October of 2008 in a Trilogy linear accelerator. Since then, 47 patients have been treated using this modality. The objective of this review is to describe our clinical experience with RapidArc including a comparison with conventional IMRT for various tumor sites in terms of dosimetry and treatment times.  

A group of 47 patients with various diagnoses are included in this report: prostate cancer 12, lung cancer 10, spine tumors 5, CNS and head and neck 8, pelvic tumors 5 and miscellaneous 4. We used RapidArc in three Stereotatic Radiosurgery (SRS) patients. Acute morbidity was assessed in all patients.

RapidArc plans were as good as or better than regular IMRT in terms of target coverage and reduction of dose in the surrounding healthy tissue. In addition, the average time a patient spent on the table for RapidArc treatments was significantly reduced. Acute morbidity was limited to one patient treated for prostate presenting increased urinary frequency and one patient with head and neck cancer developing xerostomy.

Our initial experience demonstrates the feasibility and accuracy of RapidArc for achieving highly conformal dose distributions for different sites. The efficient delivery, good tolerance and convenient reduction of treatment times make this technique an attractive choice for radiation therapy.

New developments in Radiation Oncology.

Amendola, B, Perez, N, Amendola, M, Iglesias, A, Clinical Applications of RapidArc: Initial Experience.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8013706.html