Intensity-modulated Radiotherapy With Integrated-boost in Patients With Spinal Bone Metastases

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. Local control is the essential factor for stability of the vertebral body of patients with spinal bone metastases. In regard to 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. Stereotactic body radiation therapy (SBRT) using intensity-modulated radiotherapy (IMRT) can be a safe modality for treating spinal metastasis with enhanced targeting accuracy [5]. 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 [6]. The main problem of the standard schedule is the limited dose application to the metastasis due to organ at risk myelon. Therefore, the aims of this study is to apply a high biological dose in the tumor region and to achieve an improved result related to local control for palliative patients with painful spinal bone metastases. Secondly, the aim is to evaluate QoL, fatigue, and survival of three different RT-techniques. To the best of our knowledge, no comparable randomized study has been described in the literature so far.