P74. Bone scan imaging before and after intravenous bisphosphonate therapy for osseous metastases from breast cancer

Abstract

worsening of pain following radiotherapy (RT) for painful bone metastases in three outpatient palliative RT clinics in Canada. Materials and methods: Patients with bone metastases were eligible. The Brief Pain Inventory was employed. Worst pain scores and analgesic consumption were collected daily before, during and for 10 days after RT. Analgesic consumption was converted into total daily oral morphine equivalent. Pain flare was defined (a priori) as a two-point increase in the worst pain scale of 0–10 compared to baseline worst pain with no decrease in analgesic intake or a 25% increase in analgesic intake, employing daily oral morphine equivalent, with no decrease in worst pain score. To distinguish pain flare from progression of pain, the worst pain score and analgesic intake must return to baseline after the increase/flare. Results: A total of 111 patients were enrolled in the study. There were 55 males and 56 females with a median age of 64 years (range 40–89). Overall, 38% of evaluable participants experienced a pain flare during or in the ten days following RT for their painful bony metastases. Patients treated with a single 8 Gy demonstrated a pain flare incidence of 35% and those with multiple fractions 41%. Conclusion: Pain flare is a common event following palliative RT for patients with bone metastases. Therefore, identifying at-risk individuals and managing potential pain flares are crucial to achieve an optimal level of care.