RAdiotherapy for Metastatic Spinal Cord Compression with Increased Radiation DosES

RAdiotherapy for Metastatic Spinal Cord Compression with Increased Radiation DosES

This clinical study aims to investigate whether high-precision radiotherapy, as supposed, leads to a better control of the irradiated spinal cord metastases when compared to conventional radiotherapy. This means that a progression or recurrence of motor deficits (weakness) of the legs following radiotherapy can be avoided more effectively. Furthermore, the high-precision radiotherapy will be compared to the conventional radiotherapy with respect to pain relief, motor function/ability to walk, quality of life, side effects and survival.

The aim of this single-arm study is to show that high-precision radiotherapy (RT) with 18x2.33 Gy in 3.5 weeks results in significantly better local progression free survival (LPFS) of metastatic spinal cord compression (MSCC) when compared to conventional RT with 10x3 Gy in 2 weeks. If such superiority could be shown, 18x2.33 Gy could be recommended, at least for those patients with favourable survival prognoses, since an in-field recurrence of MSCC in the irradiated part of the spine is generally very difficult to treat.

For this investigation the newly prospectively collected data will be compared with a historical cohort collected up to the time of data analysis.

The recruitment of all 65 patients (62 patients + 5% for potential drop-outs) is planned to be completed within 21 months. The follow-up period will be 12 months. This equals a total running time for the study of 33 months.

In accordance with a previous study assessing local control of MSCC, the following patient characteristics will be recorded to allow adequate comparison with the historical control group:

• Age
• Gender
• Type of primary tumor (breast cancer vs. prostate cancer vs. myeloma/ lymphoma vs. lung cancer vs. other tumors)
• Interval from tumor diagnosis to MSCC (≤15 months vs. >15 months)
• Number of involved vertebrae (1-2 vs. ≥3)
• Other bone metastases at the time of RT (no vs. yes)
• Visceral metastases at the time of RT (no vs. yes)
• Time developing motor deficits prior to RT (1-7 days vs. 8-14 days vs. >14 days)
• Ambulatory status prior to RT (no vs. yes)
• Eastern Cooperative Oncology Group (ECOG) performance score (0-2 vs- 3-4)
• Indication for decompressive surgery of affected spinal areas

The patients of this study who received high-precision RT with 18x2.33 Gy for MSCC will be compared to a historical control group of patients with a favorable survival prognosis who were treated with 10x3 Gy of conventional RT. The historical control group will include data from 235 patients qualifying for the comparison with the prospectively collected data.

Data for the historical control group will be collected from an already existing anonymized database with previous study data documented in the European Union.

To be eligible for control group, patients fulfilling the same inclusion criteria and exclusion criteria as defined in the prospective study are considered. Furthermore, to be consistent with efficacy analysis of the study, patients of the historical control group must have received at least 80% of the planned RT dose.

Propensity score techniques will be applied to reduce confounding due to differences between the historical control group and the prospective trial data.

Inclusion Criteria:

1. Motor deficits of the lower extremities resulting from MSCC, which have persisted for no longer than 30 days
2. Confirmation of diagnosis by MR-imaging (computed tomography [CT] allowed)
3. Age 18 years or older
4. Written informed consent
5. Favorable survival prognosis (defined as 36-45 points on the survival score)
6. Capacity of the patient to contract

Exclusion Criteria:

1. Previous RT or surgery of the spinal areas affected by MSCC
2. Symptomatic brain tumor or symptomatic brain metastases
3. Metastases of the cervical spine only
4. Other severe neurological disorders
5. Pregnancy, Lactation
6. Clear indication for spinal surgery