Application of total body irradiation and real-time in vivo dosimetry with semiconductor dosimeter in hematogenous stem cell transplantation

Abstract

Objective To investigate the safety and clinical outcome of total body irradiation (TBI) and the real-time in vivo dosimetry with semiconductor dosimeter in hematogenous stem cell transplantation (HSCT). Methods Fifty-seven patients requiring HSCT were treated with TBI. The TBI was given with the semi-sitting or standing position or lateralcumbent posture, using 6 MV X-ray beams and opposed parallel fields technique (two or four fields, AP/PA fields) in a single fraction or multiple fractions. The real-time in vivo dosimetry was performed with six diodes positioned on the surface of patients to adjust the dose homo-geneity of the midplane using the different thickness lead sheets. Results Mild to moderate nausea, vomi-ting and swollen parotid occurred in 41 patients after TBI, which were relieved after allopathy therapy. No radiation-induced interstitial pneumonia was observed. All patients fulfilled the HSCT. The homogeneity of relative dose (normalize to umbilicus dose) in the different positions accorded with the requirement of the prescription dose. Conclusions The opposed parallel radiation, with the semi-sitting or standing positions or lateralcumbent posture, combined with the real-time in vivo dosimetry with semiconductor dosimeter is an effective and safe technique for TBI. Key words: Radiotherapy,total body; Dosimetry; Semiconductor detecting,real-time