TOTAL BODY IRRADIATION - THE ACUTE RADIOBIOLOGICAL RESPONSE TO DECREASING OF TRANSPLANTATION IMMUNITY

(TBI) has been used generally as a preparatory regime for patients undergoing bone marrow transplantation.

Our institute uses a 6MV photon beam delivered by a linear accelerator. The gantry with a large irradiating field is swinged above the patient in angle 120°. This method of irradiation is known as a method of sweeping beam. Patients are treated AP/PA to achieve dose uniformity (a deviation within 10 % of prescription dose) throughout the entire body during their laying in a special irradiation bed on the ground of an irradiation room. A 1 cm acrylic spoiler is placed to max. 20 cm from the surface of the patient to increase surface dose. Patient transmission lung shielding may be used to limit the dose to the lung. The machine dose rate is lowered to reduce the rate of dose delivery to the patient.

It is obligatory to make in vivo measurement for all patients undergoing TBI at many different body locations for each treatment. We exclusively use a measurement wireless kit of eight semiconductor diodes on account of mainly one fraction irradiated patients.

After each irradiation we subsequently monitor acute responses to a patient irradiated organism due to obtained measured doses and analyse causes of these changes, depend on delivered dose as a radiobiological response.

In this manner we have irradiated 172 patients over the past 6 years till the end of 2011.

e-mail: bartlova@mou.cz