Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Aug 10, 2015; 6(4): 30-34
Published online Aug 10, 2015. doi: 10.5306/wjco.v6.i4.30
Oligometastatic disease, the curative challenge in radiation oncology
Amalia Palacios-Eito, Sonia García-Cabezas
Amalia Palacios-Eito, Sonia García-Cabezas, Servicio de Oncología Radioterápica, Hospital Universitario Reina Sofía, 14004 Córdoba, Spain
Author contributions: Both authors contributed to this manuscript.
Conflict-of-interest statement: The authors have no conflict of interest related to the manuscript.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Amalia Palacios-Eito, PhD, Servicio de Oncología Radioterápica, Hospital Universitario Reina Sofía, Avda. Menéndez Pidal, s/n, 14004 Córdoba, Spain. amalia.palacios.sspa@juntadeandalucia.es
Telephone: +34-957-011415 Fax: +34-957-011414
Received: May 3, 2015
Peer-review started: May 3, 2015
First decision: June 3, 2015
Revised: June 17, 2015
Accepted: June 30, 2015
Article in press: July 2, 2015
Published online: August 10, 2015

The concept of oligometastatic disease was first described by Hellman and Weichselbaum in 1995. The mere insight of this concept led to the hypothesis that this disease may be cured using local ablative weapons. Surgery has already demonstrated this hypothesis. Surgery limitations, either technical or due to refusal or associated comorbidity, have led to implement alternative ablative options such as stereotactic body radiation therapy (SBRT). SBRT evolved from (stereotactic radiosurgery) because of the need to irradiate extracranial lesions and has been shown to be safe and effective. SBRT achieves local control rates ranging from 70%-90%, but highly variable survival rates depending on the group analyzed. Series with heterogeneous metastatic sites and tumor origin have reported 20% survival rates at 2-3 years, similar to those achieved with surgery. Despite its excellent results, SBRT still faces significant clinical challenges. Its optimal integration with systemic treatment is unknown, and response assessment is very difficult. However, the greatest challenge lies in selection of patients most likely to remain oligometastatic, those who will most benefit from the technique. Biomarkers, molecular signatures, that accurately predict the biological behavior of malignancy are needed. The expression profile of specific miRNAs has been shown to have a potential in this regard.

Keywords: Oligometastases, Radiotherapy, Stereotactic body radiotherapy, Stereotactic body radiation therapy, Stereotactic ablative body radiotherapy, Curative intent

Core tip: Surgery has been shown to be able to cure a proportion of oligometastatic patients. Surgery limitations, either technical or due to refusal, advanced age, or associated comorbidity, have led to progressive implementation of stereotactic body radiation therapy (SBRT) as an alternative local ablative weapon. SBRT has been shown to be safe and effective and to achieve local control rates around 80%, with a variable impact on survival depending on other associated prognostic factors. Despite its good results, SBRT still faces significant clinical challenges, including identification of optimal patients to be treated.