3462 - Quality of Life Assessment of Palliative Radiotherapy for Patients with Low-Risk Asymptomatic Bone Metastasis: A Prospective Observational Study

Purpose/Objective(s):

The role of palliative radiotherapy for patients with low-risk asymptomatic bone metastases remains unclear. We evaluate short-term changes in quality of life (QoL) in these patients to identify specific patient subgroups and QoL outcomes that may benefit from palliative radiotherapy.

Materials/Methods:

This study is a secondary analysis of our prospective cohort (UMIN000044984, since August 2021), which enrolled patients who underwent palliative radiotherapy. Baseline and post-treatment follow-up for their symptoms, opioid dose, and QoL assessment (EORTC QLQ-C15-PAL and QLQ-BM22) were prospectively scheduled, including at 4 and 12 weeks after radiotherapy. The following were defined as eligibility criteria of the current secondary analysis: (1) a baseline Numerical Rating Scale (NRS) score of 0 or 1 without any opioids, (2) underwent palliative radiotherapy for uncomplicated bone metastasis, and (3) available baseline QoL and at least one-time follow-up within 12 weeks. Each scale of QoL changes was classified as "Improved," "Deteriorated," or "Stable" based on the Minimal Clinically Important Difference, with patients divided into two groups between Global Health Status/QOL (GHS/QoL) improved at least once vs. others and baseline characteristics were compared.

Results:

Of the registered 1,261 lesions from 717 patients, 53 lesions from 44 patients were eligible. The median age was 69 years, with 73% males and 53% spinal metastases, and baseline NRS 0 and 1 were 77% and 23%, respectively. The primary cancer sites were majored in the lung (32%), the prostate (23%), and the breast (13%). Standard-dose conventional radiotherapy (e.g., 8 Gy single fraction or 30 Gy/10 fractions) was used in 77% of cases, and 47% had continued systemic therapy before palliative radiotherapy. At 4 weeks, one patient (2%) experienced local pain progression. At 12 weeks, two patients (4%) died, and the other eight patients (15%) experienced pain progression (4 were local, and 4 were distant new lesions). GHS/QoL improvement was observed in 17 lesions (32%), with significantly higher scores increase at 4 weeks compared to the control group (+13 vs. -7, p <0.001). Significant baseline differences were found in several QoL scales between the improvement and control groups: GHS/QoL (38 vs. 75, p < 0.001), emotional functioning (70 vs. 89, p = 0.006), pain (18 vs. 7.9, p = 0.045), insomnia (16 vs. 5.6, p = 0.032), and appetite loss (25 vs. 3.7, p < 0.001), while no significant differences were observed in other clinical characteristics.

Conclusion:

The results of this study suggest that palliative radiotherapy when guided by baseline QoL stratification, may provide a QoL benefit for selected patients with low-risk asymptomatic bone metastases.