Stereotactic radiation therapy (SRT) in the treatment of primary and metastatic bone lesions

Background. Еvaluation of stereotactic radiation therapy (SRT) in the treatment of primary and metastatic bone lesions.
Methods. We represent the results of bone treatment (both primary and metastatic bone tumors) in «Oncostop» clinic from 2013 up to 2015 – totally 74 cases, including 44 metastatic (61%) and 25 primary lesions (35%). all patients received Srt  using «Cyberknife-VSI».
Results. The median follow-up in metastatic and primary tumor groups was 14,5 and 15 months correspondingly. We found 9 cases of local recurrence, including 2 among 44 metastatic tumors (4,5%) and 7 – among 25 primary bone tumors (28%). Median recurrence-free interval in metastatic group was 4,5 months, in primary tumors group – 12 months. Among 9 recurrences, 8 patients received SRT after previous irradiation. The average irradiated volume among recurrences was 169,5 cc (max 410 cc). Three patients with recurrence received stereotactic reirradiation with good effect.
Conclusion. SRT is able to provide a long local disease and pain control among inoperable bone tumors (more than 12 months). The outcome of treatment depends on irradiated volume and sequence of methods. It is reasonable to use SRT in primary treatment of radioresistant disease, in case of recurrence repeated stereotactic irradiation is possible.