Effectiveness of hypofractionated radiotherapy in painful bone metastases - Two prospective studies with 1 x 4 Gy and 4 x 4 Gy

Background: Although effectiveness of fractionated radiotherapy for painful bone metastases is well documented, there are unanswered questions regardi ng the adequacy of low-dose short radiation schedules for long-term pain co ntrol which give maximum benefit in patients with a short life expectancy. Patients and Methods: Two consecutive non-randomized prospective follow-up studies were performed at a single institution to analyze pain response and duration of response in patients with a variety of primary tumors. Include d were only patients with symptomatic nonvertebral bone metastases and with out impending pathologic fracture. Forty-five patients received 1 x 4 Gy to 50 different sites (group I) while 86 patients received 4 x 4 Gy to 96 sit es (group II). Pain relief to irradiation was evaluated according to patien t interviews using a 4-point categorical scale. Follow-up was performed 7 a nd 90 days after radiotherapy. Results: Pain relief after 4 x 4 Gy was significantly superior to 1 x 4 Gy with pain control rates being 86.5% vs 48% at day 7 (after end of treatment ) and 80% vs 55% at day 90, respectively. A subgroup analysis of patients t reated with 4 x 4 Gy demonstrated a more favorable outcome for breast cance r patients in comparison to patients with other primaries concerning pain r elief (96% vs 81%), pain control after 90 days (93% vs 72%), median time to pain progression (9 vs 3 months), and median overall survival (14 vs 5.5 m onths). Conclusions: In this study 4 x 4 Gy proved to be clearly superior to 1 x 4 Gy in relieving pain from symptomatic nonvertebral bone metastases without impending pathologic fracture. Even if radiotherapy with 1 single fraction seems to be applicable in specific cases doses higher than 4 Gy should be c hosen. In breast cancer patients pain control seems to be better compared t o other primaries.