What is Extracorporeal radiation and reimplantation(ECRT)
Extracorporeal radiation and reimplantation (ECRT) is a type of limb salvage surgery, performed in individuals suffering from bone sarcoma. ECRT is an established form of biological salvage method where the cancer-affected bone is sterilized with high-dose radiation, thereby effectively killing the cancer cells. This treated bone when reimplanted into the defect with plate and screws, will act like a bone graft (devoid of cancer cells) and is incorporated by the body gradually over time.
Indications for ECRT
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ECRT is indicated in the treatment of bone sarcomas such as Osteosarcoma, Ewing’s sarcoma, Chondrosarcoma, and Adamantinoma.
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Bone sarcomas involve the shaft(diaphysis) of the long bones, such as femur, tibia, humerus, radius, ulna, etc.
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Bone sarcomas involve flat bones, such as the pelvis, scapula, clavicle, etc.
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Pediatric and Young Adults age group
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As a component of Graft-Prosthesis-Composite Reconstruction
What are the tests done before ECRT?
Blood tests to assess hemoglobin levels, and blood group and rule out infection
Imaging tests in form of X-rays, CT scans, and MRIs of the involved limb. A PET CT scan will be done to stage the bone sarcoma
How is ECRT done?
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The tumour bone is dissected with a surrounding margin of healthy tissues
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The tumour bone is removed or cut based on preoperative calculations done with help of X-rays, CT scan, MRIs, and 3D models. Computer-assisted navigation is also utilised in complex situations.
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Samples are sent to assess response to chemotherapy and the tumour bone is subjected to high-dose radiation in a sterile environment.
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This “Cancer free” bone graft is treated with solvents and implanted into the bony defect with help of plates and screws.
Advantages of ECRT
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ECRT utilises the individual’s own bone stock to reconstruct the defect after the removal of tumour bone segment instead of tumour prosthesis. There is no risk of rejection.
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Benefits the paediatric age group where the growing ends of the bone need to be preserved to allow natural growth and increase in height.
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It does not need repeated or revision surgeries in the future, as is the case with tumour prostheses. It provides a future bone stock for the treatment of any complications.
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It is similar to the usage of massive bone allografts(when available), which is expensive and not easily available.
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It is an economically viable reconstructive option for limb salvage surgery.
What are the complications associated with the ECRT procedure?
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The complications associated with the ECRT procedure are similar to other biological limb salvage surgeries, as follows:
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Infection
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Delayed healing or incorporation of ECRT graft, Nonunion, and fracture of ECRT graft
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Local recurrence and tumour progression
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Clotting of blood in deep veins, Deep vein thrombosis
What is Aftercare?
Individuals after limb salvage surgery by ECRT can go home after a few days of hospital stay. Physiotherapy will commence from the next day of surgery, this improves confidence and increases compliance to further treatment. Due to the nature of biological reconstruction, the individual will not be allowed to place weight on the operated limb until signs of healing is seen on imaging tests such as X-ray and CT scan.