Re implantation of Sterilised tumour bone by Extra Corporeal Radiotherapy

Abstract

With the use of potent chemotherapeutic drugs, newer imaging modalities and improved surgical techniques limb preserving surgeries for malignant bone tumours have become the norm. Endoprosthesis still remains the commonest method of reconstruction after tumour resection. But when one is able to an oncologically safe intercalary resection for malignant bone tumours one method of reconstruction is reimplanting the resected tumour bone after sterilisation. Radiation given outside the body to sterilise the tumour bone is called Extra Corporeal Radiotherapy (ECRT). After resection the bone is cleaned of all its soft tissue and marrow contents and sent in a plastic container to the Radiotherapy department where it is subjected to 50 Gy of radiation which kills all cells including the tumour cells. The bone is brought back to the theatre and reimplanted after augmenting it with either bone cement or fibular grafts and stabilised by appropriate fixation devices. The advantage of reimplanting the same bone is that you get an exact match to the resected bone which is tumour free. Post operatively the joint is mobilised immediately and weight bearing started as appropriate to the fixation used. The diaphyseal end takes more time to unite than the metaphyseal end. In our series of 16 patients who had undergone ECRT and reimplantation for malignant bone tumours of the extremity and had completed two year follow up, the metaphyseal end took an average of 6.2 months (4 -12 months) for union while the diaphyseal end united in 10.6 months (5 -15 months). If the tumour has caused extensive destruction of the bone or has a pathological fracture, it may be mechanically not sound to reimplant it after ECRT. ECRT is an oncologically safe and mechanically stable procedure in biologically reconstructing bony defects after tumour resection.