New Strategies in Stereotactic Radiotherapy for Oligometastases

Abstract

Patients with metastatic solid tumors are usually treated with palliative intent. Systemic therapy and palliative radiation are often used, with the goals of prolonging survival or maintaining quality of life, but not of cure. In contrast to this paradigm, the theory of oligometastasis suggests that some patients who have a small number of metastases may be amenable to cure if all lesions can be eradicated. Aggressive treatment of patients with oligometastases, using either surgery or radiotherapy, has become more common in the past decade, yet in most situations, no randomized evidence is available to support such an approach. Stereotactic ablative radiotherapy (SABR) is a novel treatment for oligometastases, delivering large doses of radiotherapy in only a few treatments, with excellent rates of local control, and appears to be an excellent noninvasive alternative to surgical resection of metastases. This article reviews recent biologic and clinical data that support the existence of the oligometastatic state and discusses gaps in this evidence base. The emerging role for SABR in the management of this challenging patient population is discussed with a focus on ongoing clinical trials in an attempt to improve overall survival, delay progression, or induce immunologic anticancer effects through the abscopal effect.

Contribution of Serum Biomarkers to Prognostic Assessment in Patients With Oligometastatic Prostate Cancer

“…We limited this analysis to patients treated with first-line docetaxel rather than a variety of different approved options in order to eliminate bias arising from differences in first-line systemic treatment. As recently discussed by different groups, aggressive local treatment of oligometastatic cancer is expected to improve survival (2)(3)(4)18). Even in the absence of metastasis-directed local treatment, we found long-term survivors in the group with normal hemoglobin (and also LDH).…”

“…Increasing attention has recently been paid to patients with oligometastatic disease, i.e. a state between curable locoregional disease and incurable dissemination throughout large parts of the body (1)(2)(3)(4). If only few distant metastases are present, ablative local treatment or resection of all these lesions might result in longer survival than historically observed (5)(6)(7).…”

Rationale for the treatment of children with CCSK in the UMBRELLA SIOP–RTSG 2016 protocol

“…Regardless of response to preoperative chemotherapy or surgical treatment, radiotherapy to metastatic sites is indicated in patients with stage IV CCSK (TABLE 2). Based on extrapolating the results of prospective and review studies on adults and expert opinion, the use of highly conformal techniques can be considered in patients with metastatic CCSK, especially in instances of solitary metastasis or oligometastases, depending on the anatomical site 53,54 . Postoperative treatment is consistent with previous SIOP 93-01 and SIOP 2001 protocols, with the specific outlined differences, and consists of the five chemotherapeutic agents used for localized disease and abdominal radiotherapy (dose 10.8 Gy as in COG) for local stage II or III disease (TABLES 1,2).…”

Oligometastatic squamous cell carcinoma of the head and neck treated with stereotactic body ablative radiotherapy: Single‐institution outcomes

“…Since then, SABR has yielded encouraging outcomes in patients with oligometastases from various primary malignancies . As such, the use of metastases‐directed SABR continues to rise …”