Re-irradiation of metastatic spinal cord compression: A feasibility study by volumetric-modulated arc radiotherapy for in-field recurrence creating a dosimetric hole on the central canal

When local recurrences arise within an irradiated region involving metastatic spinal cord compression,the dose limit to the spinal cord reduces the chance to re-treat the patient by 3D-conformational RT technique.The possibility of using volumetric modulated arc RT by RapidArc was evaluated for dose sparingat spinal cord level and preserving target coverage. A clinically satisfactory PTV coverage and dose sparingto the spinal cord were obtained. An upcoming trial on patients will provide clinical outcomes.