Eclipse(TM) Treatment Planning System with Proton Convolution Superposition algorithm license only The Eclipse Treatment Planning System (Eclipse TPS) is used to plan radiotherapy treatments for patients with malignant or benign diseases. Eclipse TPS is used to plan external beam irradiation with photon, elec- tron and proton beams, as well as for internal irradiation (brachytherapy) treatments. In addition, the Eclipse Proton Eye algorithm is specifically indicated for planning proton treatment of neoplasms of the eye.

There is an anomaly with the Eclipse(TM) Treatment Planning System [TPS] Proton Convolution Superposition [PCS] dose calculation algorithm. The PCS algo- rithm calculates the water equivalent range incorrectly for non-square 3D CT images (either different number of pixels in X and Y, or non-square pixels). Before the dose is calculated, Eclipse resamples the CT images to create a calculation image with a maximum resolution of 256 x 256. The PCS algorithm assumes uniform resolution in X and Y directions, or that X = Y for all images, and erroneously sets the Y = X for dose calcu- lation. For images that are not square, where either X<>Y, or the length of X does not equal the length of Y, the computed water equivalent range R is erroneous compared to the correct range R: 1) X=Y; R =R (R is correct); 2) XY R >R (R is too big).

The firm, Varian, disseminated the "URGENT MEDICAL DEVICE CORRECTION FIELD SAFETY NOTICE" dated 12/17/2018 to its customers on 12/26/2018. The letter explained the product, problem and a work around. The customers were instructed to do the following: Please retain a copy of this document along with your most current product labeling. complete the attached Recall Return Response form provided. Kindly return the completed form to [email protected] Advise the appropriate personnel working in your radiotherapy department of the content of this letter. For future reference, this document will be posted to the Varian Medical Systems customer support website: http://www.MyVarian.com. Varian Medical Systems has developed a technical correction for this issue. You will be contacted by a Customer Service representative to schedule its installation on your system. If you require further clarification, please feel free to contact your local Varian Medical Systems Customer Support District or Regional Manager or Varian Oncology Help Desk Contact Information at +1.888.827.4265 or Email: support @varian.com.