A RANDOMIZED TRIAL OF 3 SINGLE-DOSE RADIATION-THERAPY REGIMENS IN THETREATMENT OF METASTATIC BONE PAIN

Purpose: To investigate efficacy of three single dose radiation therap y (RT) regimens in the treatment of painful bone metastasis. Material and Methods: Patient self-assessment by using pain chart enabled evalu ation of response to treatment that consisted of either one of the thr ee single fractions of 4 Gy (group I; n = 109), 6 Gy (group II; n = 10 8), or 8 Gy (group III; n = 110). Results: Patients in groups II and I II had higher complete response rate than those in group I, but not si gnificantly, and with no difference between group IZ and III. However, both patients in group II (73%) and group III (78%) had significantly higher overall response rates when compared to those observed in grou p I (59%) (I vs II, p = 0.025; I vs III, p = 0.0019), and with no diff erence between groups II and III (p = 0.39). Patients in group III had shortest time to the occurrence of any pain relief which was signific antly better than those observed in group I (Welch's t-test, p = 0.012 ), with no difference between group I and II and group II and III, res pectively. There was no difference between the three treatment groups in duration of response and retreatment rate. No effect of histology o r metastatic site treated was found. No pathological fractures or spin al cord compressions were observed during the 8 weeks post-RT. Conclus ion: Results of this study seem to confirm that 8 Gy could be consider ed as probably ''lowest'' optimal single fraction RT in the treatment of painful bone metastasis, although single fraction RT of 4 Gy should not be easily discarded due to its applicability in specific cases. S ince single fraction RT of 6 Gy achieved results not different from th at obtained with 8 Gy, further studies are warranted in order to get m ore informations about ''lowest'' optimal single fraction RT in the tr eatment of painful bone metastasis. (C) 1998 Elsevier Science Inc.