Stereotactic radiotherapy of metastases Palliative effect and tumor control

In clinical practice metastases are being treated increasingly more with local definitive intent based on a prolonged course of the disease due to novel systemic therapies and the concept of oligometastasis. With stereotactic radiotherapy metastases can be treated with very high efficiency in only a few fractions. Identification of clinical studies investigating the use of stereotactic radiotherapy for treatment of oligometastases. Metastasis control rates and survival after stereotactic radiotherapy. Toxicity of the treatment. Differentiation from other local treatment approaches including surgery. Prognostic factors in patients with oligometastases. A literature search was carried out for prospective and retrospective studies on local stereotactic radiotherapy. The only proof that local treatment can prolong survival in patients with oligometastases comes from a randomized study that investigated the use of a radiosurgical boost after whole brain radiotherapy in patients with brain metastases. Various prospective phase II studies demonstrated excellent metastasis control rates and tolerability of extracranial stereotactic radiotherapy for treatment of lung, liver, spinal and oligometastases at multiple sites. Relevant prognostic factors for oligometastatic disease are histology, number and size of metastases and disease-free survival. Stereotactic radiotherapy has become a valid treatment option for patients with oligometastases and in clinical practice should also be considered as an alternative to surgical treatment of metastases.