The vertebral column is the main localization of bone metastases and is where they frequently indicate an advanced stage of a malignant primary disease [1, 2]. Two thirds of all patients with tumors are estimated to develop bone metastases in the course of their disease [3]. Spinal bone metastases are of central impact for patients in a palliative setting. The clinical symptoms include pain at rest and under exercise but also impaired activity of daily life, the risk of pathological fractures, and neurological deficits. Pain is the essential factor for decreased quality of life (QoL) of patients with bone metastases. In regard to pain therapy and re-calcification of former osteolytic lesions, palliative radiotherapy (RT) represents an effective treatment option [4]. The most common schedule was specified as 30 Gy in 10 fractions. The outcome showed a partial pain response in 50 % to 80 % of patients and a complete pain response in one third [5]. Stereotactic body radiation therapy (SBRT) using intensity-modulated radiotherapy (IMRT) can be a safe modality for treating spinal metastasis with enhanced targeting accuracy [6]. Secondly, IMRT to the spine was well tolerated (especially in the spinal cord), had no significant late toxicities, and spared other organs at risk simultaneously [7]. Pretreatment megavoltage computed tomography (CT) allows clinicians to position control and correction to determine the localization of the metastasis, and to hold a divergence of the dose of the local region most minimally [8]. Nguyen et al. [9] showed that SBRT with 24 Gy is a safe and effective treatment modality that can be used to achieve good tumor control and palliation of pain associated with spinal metastases. To the best of our knowledge, no comparable randomized study has been described in the literature so far.
The aims of this study were to apply a high biological dose in the tumor region and to achieve a comparable result related to pain relief and local control on the one hand and to reduce the overall treatment time for palliative patients with painful spinal bone metastases on the other hand. Secondly, the aim was to evaluate QoL, fatigue, and survival.