Centerpiece of New Mercy Proton Therapy Center Positioned into Place

The centerpiece of the new Mercy Proton Therapy Center, under construction at the David C. Pratt Cancer Center in Creve Coeur, Missouri — a gantry-mounted proton accelerator — was recently positioned into place by McCarthy Building Companies.

After a journey across seven states, the accelerator was placed through an opening in the vault’s 7-foot, 6-inch-thick concrete lid using a 350 ton capacity crane, the same day it arrived.

A small crowd of leaders and the project team took turns signing the equipment and then watched as the accelerator unit was placed. It was secured inside a three-story-high, 42-foot-by-47-foot “vault” treatment room, featuring concrete walls ranging from three to 7 ½ feet thick located within the new 17,000-square-foot, three-story addition to the David C. Pratt Cancer Center.

Because being as little as one inch off in thickness would result in less radiation shielding, the center was designed and built with extreme precision, with tolerances less than three quarters inch wall-to-wall and one inch floor-to-ceiling.

Construction began in July 2020; the center’s opening is planned for summer 2022.