Application of Multi-point Real-time Dose Monitoring for Total Body Irradiation

  Objective  To explore the necessity of multi-point real-time dose monitoring for total body irradiation.

  Methods  Varian 2300 C/D accelerator 6 MV rays were applied on 25 cases ready for bone marrow transplant patients with total body irradiation. Treatment was conducted while using semiconductor dosimeters for multi-point real-time dose monitoring, and the results were monitored and recorded, during which the doses were adjusted to ensure that the radiation dose error was controlled within ±5%.

  Results  The measured dose and calculated dose showed large deviations in the first multi-point real-time dose monitoring of all these 25 patients. The median deviations of the head, chest, abdomen, pelvic, thigh, knee, and ankle were 6.10%, -1.30%, 5.90%, 5.05%, -4.00%, 3.05% and 3.30%, respectively. After timely bias adjustment based on the monitoring results, the dose deviations were within ±5% in all patients, and the median deviations of above mentioned points decreased to 0.35%, -1.05%, 0.60%, 0.20%, -2.55%, 1.20% and 0.85%, respectively.

  Conclusions  Multi-point real-time dose monitoring is necessary for the quality control of total body irradiation.