Comparison of total body irradiation before and after chemotherapy in pretreatment for hematopoietic stem cell transplantation.

OBJECTIVE

To explore the best time to carry out total body irradiation (TBI) in hematopoietic stem cell transplantation (HSCT) pretreatment.

METHODS

Retrospective analysis was applied in 88 cases of HSCT using TBI as pretreatment from March 2001 to June 2009 in our hospital. Using 8 MV X-ray, all the patients were irradiated by linear accelerator in 2 consecutive days, with a total dose of 7-11 Gy and an instantaneous dose rate ranging between 4.0 and 5.0 cGy/min. Of the 88 cases, 40 cases were given traditional high-dose chemotherapy before TBI (Group CT/TBI), and 48 cases were given TBI before chemotherapy (Group TBI/CT) instead.

RESULTS

Eighty-seven cases of transplantation were successful, with no serious complications, including radiation pneumonia. Compared with Group CT/TBI, Group TBI/CT showed similar incidence of complications (p=0.08), similar recent chemotherapy toxicity (p=0.833), and significantly lower recent radiation toxicity (p=0.000).

CONCLUSIONS

TBI in the pretreatment of HSCT is safe and effective. Using TBI before the high-dose chemotherapy can maintain the same pretreatment effect, effectively reduce apparent immediate reaction/discomfort during TBI, reduce preparation workload of radiotherapy, and lower radiation side-effects. Further research is needed to expand its clinical application.