Extracorporeal radiation and reimplantation: a safe and viable option for reconstruction after sacral tumor resection?

Primary tumors of the sacrum are difficult to manage, as they often require morbid resections and complex reconstructions. In the case of tumors such as chordoma or chondrosarcoma, aggressive resections are often required to achieve appropriate margins (extending disease-free survival), followed by complex reconstructions. These reconstructions are aimed at restoring the pelvic ring and have traditionally resulted in a lumbosacral construct that utilizes structural allograft/autograft bone (fibula most commonly used) and more recently, reconstruction with 3D-printed custom sacral prostheses. While there are no reports of anatomical reconstruction using sacral allografts, extracorporeal radiation therapy (ECRT) and reimplantation provides a size and shape-matched irradiated autograft which avoids the cultural stigma, structural strength and graft-host concerns associated with allografts, as well as the high costs and time to production associated with custom 3D-printed implants. Here we present an illustrative case with technical notes, outlining the steps used at our center for ECRT. While early results with ECRT in the sacrum are promising, future larger studies should be carried out to help detect differences that may exist in long-term complications.