Radiation for bone metastases: Reconsidering the optimal timing.

Abstract

10122 Background: Bone metastases impair function and decrease quality of life due to acute or chronic pain. The standard approach for patients with multiple bone metastases is systemic therapy and palliative radiation therapy (RT) when the metastases become symptomatic. This study aims to understand the characteristics and outcomes for inpatients admitted for painful bone metastases. Methods: An inpatient radiation oncology consult registry was created in 2015 to evaluate patterns of care for patients receiving RT in the inpatient setting. Of the 1151 consults requested between 7/2015 and 6/2016, 28% (n = 323) were for evaluation of symptomatic bone metastases in patients who were hospitalized for acute or chronic pain. Among this cohort, 64% (n = 208) went on to receive RT for 225 bone metastases. Sixty percent of RT courses were initiated while the patient was hospitalized. Clinical characteristics correlated with overall survival (OS) were evaluated through Cox regression analysis. Results: The median follow up for the 208 patients who received RT was 4 months (0.1-9 months). Patient median age was 61 (10-92 years), and the median KPS was 70 (20-90). The most common sites treated were spine (50%), joints such as hip and shoulder (11%), long bones including femur and humerus (11%), and pelvis (10%). Sixty-one percent (n = 138) of the treated metastases were diagnosed ≥4 months prior to RT. The median survival after receiving palliative RT was 4 months (0-19 months). Among the 141 patients who had died at the time of analysis, 92 (65%) died within 2 months, and 128 (91%) within 6 months. Eighteen patients (9%) discontinued RT to transition to hospice care. OS after RT is significantly correlated with KPS (p < 0.0001) at the time of consult but not with patient age or site of treated disease. Conclusions: In this select group of inpatients who were evaluated for palliation of symptomatic bone metastases, we found a short OS after RT. The majority of metastases were present for ≥4 months prior to RT. This study suggests that earlier RT for high-risk metastases should be considered to prevent development of symptomatic disease that requires hospitalization. Risk factors for development of painful bone metastases are being studied prospectively at our institution.