SBRT for lung oligometastases: Who is the perfect candidate?

Abstract

Aim

To analyze the literature data about lung oligometastatic patients who underwent SBRT with regard to doses, fractionation, outcomes, response assessment and prognostic factors, trying to define “the right patient” for the local treatment.

Background

“Oligometastatic disease” is defined as a state in which metastases are limited in number and site and characterized by unusual cancer biology and behavior. In this setting local therapy could have a potential curative role. Recently, technological advances in Radiation Oncology permitted the introduction of Stereotactic Body Radiation Therapy (SBRT), a novel treatment modality that delivers ablative dose of radiation to the extra-cranial sites with high precision using single or a small number of fractions.

Materials and methods

We performed a literature search using Medical Subject Heading terms “stereotactic body radiation therapy” and “lung metastases”, considering a period of 10 years.

Results

Many non-randomized studies have shown that SBRT for lung oligometastases is safe and effective, with local control rates of about 80%. To date SBRT represents an alternative and competitive option in patients with lung oligometastatic disease who refuse surgical treatment or unsuitable for surgery. Based on published studies, SBRT might have major benefit for a patient with breast histology, disease-free interval ≥12 months, control of the primary tumor, small lesions, limited number of lesions and higher radiation dose delivered.

Conclusions

Well-designed collaborative trials are necessary to draw final conclusions. To date, the discussion within a multidisciplinary team becomes crucial to perform a careful patients’ selection in the setting of oligometastatic disease.