We treated our first patient at the new Gordon Browne proton therapy center. This is the first time a proton therapy system (ProTom Radiance 330) was retrofitted in treatment rooms designed for conventional radiation treatments. The technical development at MGH was led by Ben Clasie, Ph.D., with substantial support from Greg Sharp, Ph.D., Drosoula Giantsoudi, Ph.D., Brian Winey, Ph.D., John Wolfgang, Ph.D., Ken Jee, Ph.D., Nick Depauw, Ph.D. and many others.