ESTRO 2024 - Abstract Book

S1927

Clinical - Mixed sites, palliation

ESTRO 2024

Intracanal spinal cord metastases (ISCM), either intramedullary, leptomeningeal or epidural, are rare events and confer a poor prognosis. The optimal management of this entity remains largely unclear (1)(2). This study aimed to assess clinical and survival results.

Material/Methods:

We reviewed retrospectively Intracanal spinal cord metastases treated with conventional palliative radiotherapy in our institution between the 2012- 2023 period. The patients, tumour, and therapeutic strategy’s characteristics were collected from electronic records. We analysed clinical outcomes (ECOG, neurological and ambulatory status by modified McCormick Scale (3), pain, autonomic disorders), overall survival (OS) rate, and the potential related factors. In order to clarify prognostic factors and outcomes, we identify two categories: Intramedullary lesions (IL) and leptomeningeal-epidural lesions (LEL).

Exploratory analyses were conducted with Kaplan-Meier, log-rank and Cox proportional hazard models. The potential associations were performed with Pearson's chi-squared test.

Results:

A total of 37 cases of ISCM (in 35 patients) were reviewed. The median age was 59 years old. 59.4% female. The predominant primary cancer was lung and breast). Most ISCM were IL 23 (62%), LEL 14 (38%), and one of them had simultaneously both components. Median follow-up was 5.2 months (1.6 - 8.4, Q1-Q3). All of them received 3D conformal palliative radiotherapy, 27 (73%) with different multifractionated schemes (30Gy/10 fractions, 20 Gy/4-5 fractions) and 10 (37%) with 8 Gy in a single fraction. 86.5% of treatments were performed after 2017. Patients, tumour, and treatment characteristics are described in Figure 1.

After completion of radiotherapy, 2 cases of LEL received intrathecal therapy. 21 cases (56.8%) received systemic treatment, 14 (37.1%) did not receive it and 2 case were missing (5.4%).

Functional Analysis: A month after radiotherapy, 7 (18.9%) had improved ECOG and 16 cases (43.2%) maintained the same ECOG. The median ECOG after 1 month was 2, the same as baseline. From 18 cases with pain at baseline, 14 showed analgesic response. 23 (62.2%) preserved sphincters’ control, 3 (8.1%) incontinence, and 11 missing (29.7%). OS Analysis: The median OS rate was 6.6 months (3.38 - 9.89, Q1-Q3). In univariate analysis with Log Rank test, a worse OS was related to small cell lung cancer vs other (5.19 months vs. 8.08 months; p 0.017), LEL vs. IL (3.19 months vs. 8.21 months; p 0.011), baseline modified McCormick grades 3-5 vs. grades 1-2 (2.69 months vs. 8.21 months; p 0.004), Single vs. multiple fraction scheme (2.79 months vs. 6.70 months; p 0.025), ISCM as unique metastasis in baseline vs. multiple (31.84 months vs. 5.19 months; p 0.017).

Only small cell lung cancer (p 0.017), leptomeningeal-epidural metastases (p 0.037), and baseline modified McCormick grades 3-5 (p 0.016) remained as independent factors in multivariate analysis (Figure 2).