The Klarity PelvicFix™ Baseplate is a supine pelvic belly board that can be used with large, single thermoplastic sheets for immobilization of the entire abdominal and pelvic region. The baseplate includes a center cutout for easy treatment and an optional indexible thigh spacer. PelvicFix™ thermoplastic sheets attach to the sides and groin for indexible setup and can be adjusted to fit each patient. The baseplate can also be indexed to the treatment couch.