Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom; Leeds Cancer Centre, Leeds NHS Teaching Hospitals Trust, Leeds, Leeds, United Kingdom.
Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom; Leeds Cancer Centre, Leeds NHS Teaching Hospitals Trust, Leeds, Leeds, United Kingdom.
Int J Radiat Oncol Biol Phys. 2019 Nov 1;105(3):559-566. doi: 10.1016/j.ijrobp.2019.07.009. Epub 2019 Jul 22.
Pain response rates are equivalent after single 8 Gy and fractionated palliative radiation therapy for bone metastases. Reirradiation remains more frequent after a single fraction, although this does not simply reflect pain recurrence. Given the possible role of stereotactic radiation therapy in providing durable pain control, measures of durability are required. Net pain relief (NPR), the proportion of remaining life spent with pain response, may provide this. This study assesses the use of NPR as an outcome measure after palliative radiation therapy for bone metastases.
This is a secondary analysis of data collected in the Dutch Bone Metastasis Study, a randomized trial comparing palliative radiation therapy delivered as 8 Gy in a single fraction and 24 Gy in 6 fractions. NPR was assessed by survival cohorts, treatment regimen, and primary diagnoses. The consequences of missing data upon the use of NPR in future studies were considered within sensitivity analyses.
Patients whose pain improved after palliative radiation therapy experienced improvement for 56.6% of their remaining lives. Missing responses in questionnaires mean the range of uncertainty in NPR is 36.1% to 62.1%. When response beyond reirradiation was excluded, NPR after treatments of single-fraction 8 Gy and 24 Gy in 6 fractions was 49.0% and 56.5%, respectively (P = .004). Differential willingness to reirradiate may be influencing this outcome. When response beyond reirradiation was included, this difference was not seen (NPR of 55.4% vs 57.7%, respectively [P = .191]).
Patients who responded to conventional radiation therapy experienced improved pain control for approximately half of their remaining life. NPR may provide valuable information in assessing pain response durability. Missing data are, however, inevitable in this population. This must be minimized and the consequences recognized and reported. Additionally, reirradiation protocols and the frequency and duration of trial follow-up may have a significant impact upon this outcome, requiring careful consideration during trial design if NPR is to be used in future studies.
单次 8 Gy 和分次姑息性放疗治疗骨转移的疼痛缓解率相当。单次分割后再放疗更为频繁，尽管这并不简单地反映疼痛复发。鉴于立体定向放疗在提供持久疼痛控制方面的可能作用，需要评估其持久性。净疼痛缓解（NPR），即疼痛反应期内剩余生命的比例，可能提供这一指标。本研究评估 NPR 作为骨转移姑息性放疗后的一种结果测量指标。
这是对荷兰骨转移研究中收集的数据的二次分析，该研究是一项比较单次 8 Gy 和 24 Gy 分 6 次治疗的姑息性放疗的随机试验。通过生存队列、治疗方案和主要诊断来评估 NPR。在敏感性分析中考虑了未来研究中 NPR 缺失数据的后果。
疼痛在姑息性放疗后得到改善的患者，在其剩余生命中有 56.6%的时间经历了改善。问卷调查中的缺失反应意味着 NPR 的不确定性范围在 36.1%至 62.1%之间。当排除再放疗后的反应时，单次 8 Gy 分割和 24 Gy 分 6 次分割的 NPR 分别为 49.0%和 56.5%（P=0.004）。对再放疗的不同意愿可能影响这一结果。当包括再放疗后的反应时，这种差异就不存在了（NPR 分别为 55.4%和 57.7%，P=0.191）。
对常规放疗有反应的患者，疼痛控制改善的时间约为其剩余生命的一半。NPR 可能在评估疼痛反应持久性方面提供有价值的信息。然而，在这个人群中，缺失数据是不可避免的。这必须最小化，并认识到和报告其后果。此外，再放疗方案和试验随访的频率和持续时间可能对这一结果产生重大影响，如果要在未来的研究中使用 NPR，在试验设计时需要仔细考虑。
