BACKGROUND Postoperative chemoradiotherapy (CRT), using conventional radiotherapy (convRT), has a key role in the treatment of glioblastoma (GBM) supported by level 1A evidence. In the past decade, evidence supporting hypofractionated radiotherapy (HFRT) has emerged. However, GBM patients in clinical trials are highly selected. Consequently, real-world patients may not be able to undergo evidence-based treatments. The aim of this retrospective Danish cohort study was to evaluate the utilisation of and compliance with postoperative CRT in real-world GBM patients over time. MATERIAL AND METHODS All adults (≥18 years) with newly diagnosed GBM (histology confirmed) between 2011 and 2018 were identified via the Danish Neuro-Oncology Registry, which was furthermore used to extract all data. Radiotherapy (RT) was classified as convRT (≤2 Gy/fr, planned dose 44–66 Gy) or HFRT (>2 Gy/fr, planned dose 34 or 40 Gy). The utilisation of and compliance with CRT (only concomitant treatment assessed) was measured by intended and administered treatment, respectively. To assess trends, patients were grouped per year of diagnosis. Multivariable logistic regression was used to analyse the association of age (</≥70), sex, performance status (PS) before surgery and RT, tumour focality, extent of surgery, concomitant chemotherapy (CT), hospital (4 University Hospitals), and year of diagnosis, with convRT or HFRT. RESULTS The cohort consisted of 2153 patients. For the entire period, postoperative RT was planned in 1743 patients: utilisation of 81%, over time fluctuating between 77 and 84%. ConvRT was planned in 1428 patients (66%), with a steadily decreasing utilisation from 73% in 2011 to 52% in 2018. Of those, 1346 (94%) could complete RT as planned (over time fluctuating between 88–97%). In this group, the utilisation of and compliance with concomitant CT was 86% (fluctuating between 80–93%) and 73% (fluctuating between 47–84%), respectively. HFRT was planned in 315 patients (15%), with a utilisation of up to 26% in 2018, after a more pronounced increase since 2014. The compliance with HFRT was 93%, fluctuating between 85–100%. In this group, the utilisation of and compliance with concomitant CT was 33% (fluctuating between 0–47%) and 78% (fluctuating between 33–100%), respectively. The utilisation of HFRT compared to convRT was significantly associated with higher age, poorer PS before RT, multifocal tumour, less extensive surgery, less frequent concomitant CT, one hospital of RT treatment, and more recent diagnosis years. CONCLUSION The increased utilisation of HFRT is in line with emerging evidence during the cohort period. However, while HFRT was developed as a more convenient schedule for those with a poorer PS and older age, the overall utilisation of postoperative RT did not increase. Nor did the compliance with CRT increase in real-world Danish GBM patients.

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P14.69 胶质母细胞瘤患者术后放化疗的趋势：丹麦队列研究

背景 术后放化疗 (CRT)，使用常规放疗 (convRT)，在 1A 级证据支持的胶质母细胞瘤 (GBM) 治疗中具有关键作用。在过去十年中，出现了支持大分割放射治疗 (HFRT) 的证据。然而，临床试验中的GBM患者是高度选择的。因此，现实世界的患者可能无法接受循证治疗。这项回顾性丹麦队列研究的目的是评估真实世界 GBM 患者术后 CRT 的使用和依从性。材料和方法 2011 年至 2018 年间所有新诊断为 GBM（组织学证实）的成年人（≥18 岁）均通过丹麦神经肿瘤登记处确定，该登记处进一步用于提取所有数据。放疗 (RT) 被归类为 convRT (≤2 Gy/fr, 计划剂量 44-66 Gy）或 HFRT（>2 Gy/fr，计划剂量 34 或 40 Gy）。CRT 的使用和依从性（仅评估伴随治疗）分别通过预期和给予的治疗来衡量。为了评估趋势，患者在诊断后每年进行分组。使用多变量逻辑回归分析年龄（＜/≥70）、性别、术前和放疗前的体能状态（PS）、肿瘤病灶、手术范围、伴随化疗（CT）、医院（4所大学医院）的相关性和诊断年份，使用 convRT 或 HFRT。结果 该队列由 2153 名患者组成。在整个期间，1743 名患者计划进行术后放疗：利用率为 81%，随着时间的推移在 77% 和 84% 之间波动。计划在 1428 名患者（66%）中进行 ConvRT，利用率从 2011 年的 73% 稳步下降到 2018 年的 52%。其中 1346 人（94%）可以按计划完成 RT（随着时间的推移在 88-97% 之间波动）。在该组中，伴随 CT 的使用和依从性分别为 86%（在 80-93% 之间波动）和 73%（在 47-84% 之间波动）。HFRT 计划在 315 名患者（15%）中使用，2018 年使用率高达 26%，自 2014 年以来增加更为显着。HFRT 的依从性为 93%，在 85-100% 之间波动。在该组中，伴随 CT 的使用和依从性分别为 33%（在 0-47% 之间波动）和 78%（在 33-100% 之间波动）。与 convRT 相比，HFRT 的使用与更高的年龄、更差的放疗前 PS、多灶性肿瘤、更少的手术范围、更少的伴随 CT 频率显着相关，一家医院接受放疗治疗，最近诊断几年。结论 HFRT 的使用增加与队列期间新出现的证据一致。然而，虽然 HFRT 是为那些 PS 较差和年龄较大的人制定的更方便的时间表，但术后 RT 的总体利用率并没有增加。真实世界的丹麦 GBM 患者对 CRT 的依从性也没有增加。