The role of radiation therapy in the modern management of oligometastatic disease.

Multimodal treatment approaches are indispensable for patients with advanced-stage cancer, while radiation therapy has been established as essential part of therapeutic approaches and has been introduced as a better option to face challenges, such as, local relapse or oligometastatic disease. The mere insight of the concept of oligometastases, proposed for the first time in the middle 1990s, led to the hypothesis that this condition may be cured using local ablative weapons. This hypothesis has already been demonstrated by surgical ablative techniques. Even though been considered a gold-standard approach for ablation of metastatic lesions, surgery limitations, technical obstacles, or patients refusal, or advanced age, or associated comorbidities, or advancements in radiation delivery and imaging technology, all have allowed the progressive implementation of radiation therapy as an alternative local ablative weapon. The advanced technique of stereotactic body radiation therapy has been shown to be safe and effective, and achieved high local control rates, and long-term survival. Despite its good results, stereotactic radiotherapy still faces significant clinical challenges, including selection of candidate patients most likely to being in oligometastatic state and most likely to being in the therapeutic technique. In this article, we will make an overview of the oligometastatic disease and review the growing clinical literature of patients suffering from this condition and treated with radiation therapy.