Treatment Options in Oligometastatic Disease: Stereotactic Body Radiation Therapy - Focus on Colorectal Cancer

Abstract

Background: Improvements in systemic therapy for metastatic colorectal cancer (CRC) have markedly extended survival, rendering local control of metastases to critical organs of increasing importance, especially in the oligometastatic setting where the disease may not yet have acquired the ability to widely disseminate. While surgical resection remains the gold standard for oligometastases in many organs, stereotactic body radiation therapy (SBRT) presents a non-invasive alternative for achieving local control. Methods: A literature review was performed to identify and summarize the findings of key prospective and retrospective studies that have shaped the field of SBRT for oligometastases to the lung, liver, and spine with a focus on oligometastases from CRC in particular. Results: Modern dose-escalated SBRT regimens can achieve 1-year local control rates of 77-100%, 90-100%, and 81-95% for oligometastases involving the lung, liver, and spine, respectively. Rates of grade 3 or greater toxicity with contemporary SBRT techniques are consistently low at <10% in the lung, <5% in the liver, and <2%/8% for neurologic/non-neurologic toxicity in the spine, respectively. Conclusion: SBRT appears safe and effective for treating oligometastases involving the lung, liver, and spine. Randomized trials comparing SBRT to surgical resection and other local therapeutic modalities for the treatment of CRC oligometastases bear consideration.

Multidisciplinary management of liver metastases in patients with colorectal cancer: a consensus of SEOM, AEC, SEOR, SERVEI, and SEMNIM

“…The common factor among ablation therapies is that they are less invasive than surgery, have a shorter recovery time and have fewer major complications [37]. RF, MW ablation, and more recently stereotactic body radiation therapy (SBRT) [38] are ablation therapies with minimal toxicity and good clinical results, providing an opportunity for curative intent to nonoperative patients. Currently, there are different ablation technologies available that can be applied percutaneously or intraoperatively that have demonstrated at least good local tumor control (LC) ( Tables 2 and 3).…”

Ablative dose stereotactic body radiation therapy for oligometastatic disease: a prospective single institution study

“…In addition to classical outcomes such as overall survival and local and distant control, we also focused on outcomes important for the patient's perception of the disease course -functional survival with Karnofsky performance status at least 70% (borderline where patients are able to care for themselves) and also the freedom from widespread distant metastasis (FFWD), mirrored by freedom from new treatment (FFNT) when the patient had adequate performance status for palliative treatment of widespread disease [29]. Since oligometastatic disease is treated by radical SBRT with curative potential [30][31][32], FFNT may be the most important outcome from patient view-point. To the best of our knowledge, this is the first report of FFNT of a large cohort of patients treated with high BED 10 ablative dose.…”

Efficacy and safety of percutaneous computed tomography-guided high-dose-rate interstitial brachytherapy in treatment of oligometastatic lymph node metastases of retroperitoneal space

“…In general, treatment of metastatic disease is challenging with an increasing tendency towards an individually tailored anticancer therapy to achieve the best possible outcomes. From an oncological perspective, the state of oligometastatic disease has been increasingly spotlighted in treatment strategies of metastatic disease, with the focus on colorectal cancer [32,33]. Therefore, one can argue that in an oligometastatic setting, the rationale for treating rLNM should be the same as for selected patients with liver or lung metastases, with the aim of complete ablation and therefore, the maximal possible reduction of the tumor cell biomass (i.e.…”