Feasibility of computed tomography-guided brachytherapy in childhood extremity soft-tissue nonrhabdomyosarcoma

Two children with grade II synovial sarcoma and one child with grade III leiomyosarcoma underwent external radiation and computed tomography(CT)- guided brachytherapy. They initially underwent multiple surgical resections and skin grafting. The CT-guided brachytherapy was performed in the CT scanning suite under general anesthesia. Accurate needle placement with uniform spacing was obtained in all three children. Iridium-192 sources were loaded the same day or the next day to deliver a total dose of 35 Gy, 30 Gy, and 30 Gy, respectively, at a dose rate of 0.4 to 0.6Gy/hr at a distance of 0.5 cm from the plane of implant. They received external radiation to doses of 23.4 Gy, 30.6 Gy, and 36 Gy, respectively. The total tumor dose in two children with negative margins were 58.4 and 60.6 Gy, respectively, and the child with positive margins received 66 Gy. All three children developed erythema and moist desquamation of skin that promptly healed within two to six weeks. CT-guided implantation is a safe and accurate means of obtaining ideal catheter placement and good dose distribution across the target volume. This technique has the potential for improving cure rates and limiting acute and long-term complications in the growing child.